Distal Interphalangeal (DIP), Metacarpophalangeal (MCP) and Proximal Interphalangeal (PIP) Joint Implants

Number: 0798

Table Of Contents

Policy
Applicable CPT / HCPCS / ICD-10 Codes
Background
References

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Policy

Scope of Policy

This Clinical Policy Bulletin addresses distal interphalangeal (DIP), metacarpophalangeal (MCP), and proximal interphalangeal (PIP) joint implants.

1. Medical Necessity

   Aetna considers the following metacarpophalangeal (MCP) or proximal interphalangeal (PIP) joint implants medically necessary for members with symptomatic rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, or post-traumatic arthritis when conservative medical management fails to relieve pain or when digit deformity is interfering with hand function and activities of daily living:

   • Ascension MCP joint implants / Integra PyroCarbon MCP Total Joint of the index, long, ring, and small finger when soft tissue reconstruction can provide adequate stabilization; or
   • Ascension PIP joint implants when soft tissue and bone can provide adequate stabilization and fixation, and the member expects to place his/her hands under high-loading situations after reconstruction; or
   • Avanta MCP and PIP joint implants when soft tissue and bone can provide adequate stabilization and fixation, and the member expects to place his/her hands under high-loading situations after reconstruction; or
   • Silicone-elastomer MCP and PIP total joint implants.

   Aetna considers MCP and PIP joint implants for all other indications experimental and investigational because their value is unproven for all other indications.

2. Experimental and Investigational

   Aetna considers the following procedures experimental and investigational because the effectiveness of these approaches has not been established:

   1. CapFlex-PIP implant for PIP joint arthroplasty 
   2. Carpometacarpal (CMC) joint implants for members with symptomatic rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, or post-traumatic arthritis
   3. Distal interphalangeal (DIP) joint implants/splints for members with symptomatic rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, or post-traumatic arthritis
   4. ln2Bones Duafit interphalangeal implant for DIP joint with osteoarthritis 
   5. Resurfacing arthroplasty of the PIP joint in the treatment of osteoarthritis and all other indications
   6. Tactys prosthesis for PIP joint arthroplasty 
   7. Trapeziometacarpal (TMC) joint implants for members with symptomatic rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, or post-traumatic arthritis
   8. X-Fuse implant for DIP joint arthrodesis.

3. Related Policies

   • CPB 0708 - Metatarsal Phalangeal Joint Replacement

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Table:

CPT Codes / HCPCS Codes / ICD-10 Codes

Code	Code Description
CPT codes covered if selection criteria are met:
26531	Arthroplasty, metacarpophalangeal joint; with prosthetic implant
26536	Arthroplasty, interphalangeal joint; with prosthetic implant [covered for proximal interphalangeal (PIP) joint (see criteria) [not covered for distal interphalangeal (DIP)]
HCPCS codes covered if selection criteria are met:
L8630	Metacarpophalangeal joint implant
L8631	Metacarpal phalangeal joint replacement, two or more pieces, metal (e.g. stainless steel or cobalt chrome), ceramic-like material (e.g. pyrocarbon), for surgical implantation (all sizes, including entire system)
L8658	Interphalangeal joint spacer, silicone or equal
L8659	Interphalangeal finger joint replacement, 2 or more pieces, metal (e.g. stainless steel or cobalt chrome), ceramic-like (pyrocarbon) for surgical implantation, any size [Not covered for CapFlex-PIP implant and Tactys prosthesis]
ICD-10 codes covered if selection criteria are met [covered for metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joint, not distal interphalangeal joint (DIP)]:
M05.00 - M08.99	Rheumatoid arthritis
M12.541 - M12.549	Traumatic arthropathy, hand
M15.1 - M15.2, M18.0 - M18.12, M18.2, M18.30 - M18.31, M18.50 - M18.52, M18.9, M19.041 - M19.049, M19.141 - M19.149, M19.241 - M19.249	Osteoarthritis and allied disorders, hand
M32.0 - M32.9	Systemic lupus erythematosus
Resurfacing Arthroplasty of the proximal interphalangeal (PIP) joint:
ICD-10 codes not covered for indications listed in the CPB (not all inclusive):
M05.6 - M08.99	Rheumatoid arthritis
M15.1 - M15.2, M18.0 - M18.9 M19.041 - M19.049, M19.141 - M19.149 M19.241 - M19.249	Osteoarthritis and allied disorders, hand
Distal interphalangeal (DIP) joint implants:
Other CPT codes related to the CPB:
26860	Arthrodesis, interphalangeal joint, with or without internal fixation
26861	each additional interphalangeal joint (List separately in addition to code for primary procedure)
26862	with autograft (includes obtaining graft)
26863	with autograft (includes obtaining graft), each additional joint (List separately in addition to code for primary procedure)
HCPCS codes not covered if selection criteria are met:
ln2Bones Duafit implant, X-Fuse implant- no specific code
Other HCPCS codes related to the CPB:
C7506	Arthrodesis, interphalangeal joints, with or without internal fixation
ICD-10 codes not covered for indications listed in the CPB:
M15.1	Heberden's nodes (with arthropathy)
M15.2	Bouchard's nodes (with arthropathy)
M19.041 - M19.049	Primary osteoarthritis, hand
M19.141 - M19.149	Post-traumatic osteoarthritis, hand
M19.241 - M19.249	Secondary osteoarthritis, hand
Carpometacarpal (CMC) joint/trapeziometacarpal (TMC) joint implants:
HCPCS codes not covered for indications listed in the CPB:
C1776	Joint device (implantable) [carpometacarpal (CMC) joint/trapeziometacarpal (TMC)]
ICD-10 codes not covered for indications listed in the CPB:
M05.00 - M08.99	Rheumatoid arthritis
M12.541 - M12.549	Traumatic arthropathy, hand
M15.1 - M15.2, M18.0 - M18.12 M18.2, M18.30 - M18.31, M18.50 - M18.52, M18.9, M19.041 - M19.049, M19.141 - M19.149, M19.241 - M19.249	Osteoarthritis and allied disorders, hand
M32.0 - M32.9	Systemic lupus erythematosus

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Background

Arthritis of the hand joints is a common disorder that frequently deteriorates over time, although its severity of symptoms, rate of deterioration and functional effects vary.  When conservative medical management fails to relieve pain or when digit deformity is interfering with hand function and activities of daily living, surgical interventions are considered.  For individuals with metacarpophalangeal (MCP) deformities, surgical options include synovectomy, intrinsic release/transfer, extensor tendon relocation, arthrodesis, and implant arthroplasty.  Fewer surgical options exist for the arthritic interphalangeal (PIP) joint.  Currently, individuals with arthritis of the PIP joint have 2 surgical options: arthrodesis or implant arthroplasty.  Arthrodesis provides good pain relief and stability, however, finger function is lost in exchange for these benefits.

Proponents of artificial hand joints have suggested that these protheses reduce pain, increase mobility and improve function compared with alternative treatments.  Numerous total joint devices have been developed to reconstruct the MCP and PIP joints.  However, regardless of design, these devices usually fail due to difficulties in restoring the biomechanics of the joint.  In 1970, Swanson developed the silicone interpositional arthroplasty implant.  Although this device is a joint spacer and not a total joint replacement, it provides good pain relief.  Despite its numerous shortcomings (e.g., implant fracture, bone reaction adjacent to the implant, implant dislocation, silicone synovitis, and little active range of motion), the silicone spacer remains the preferred choice for the prosthetic reconstruction of the MCP and PIP joints (Hilker et al, 2007; Garcia-Moral, 2009).

Takigawa et al (2004) evaluated the Swanson silicone implant arthroplasty of the PIP joint, specifically evaluating clinical results with long-term assessment.  A retrospective review of 70 silicone implants of the PIP joint in 48 patients was performed with an average follow-up period of 6.5 years (range of 3 to 20 years).  Clinical assessment included motion, stability, and alignment.  Radiographic assessment included implant fracture, deformity, and cystic bone resorption.  The pathology consisted of degenerative joint disease in 14, post-traumatic arthritis in 11, rheumatoid arthritis in 13, and idiopathic arthritis associated with collagen disease in 12 patients.  Swan neck and boutonniere deformities were assessed separately.  Statistical analysis of pre-operative risk factors was compared with the post-operative assessment of pain, motion, and function (return to work).  There was no significant change in the active range-of-motion (ROM) before and after PIP arthroplasty (26 degrees versus 30 degrees).  Correction of swan neck and boutonniere deformities was difficult, usually leading to poor results.  There was improvement in maximum active extension before surgery lacking 32 degrees to after surgery lacking 18 degrees.  From a statistical standpoint rheumatoid joint involvement with PIP arthroplasty had poorer results than degenerative or post-traumatic arthritis with respect to pain relief and ROM.  Pain relief was present in 70 % of replaced PIP joints with residual pain and loss of strength in 30 %.  Radiographic analysis showed abnormal bone formation (cystic changes) in 45 %.  There were 11 implant fractures and 9 joints that required revision surgery.  The authors concluded that silicone replacement of the PIP joint is effective in providing pain relief from arthritis but does not provide improvement in motion or correction of deformity.  It provided a poorer outcome in rheumatoid disease in comparison with degenerative, post-traumatic, or idiopathic arthritis.

Individuals who are very active and use their hands for heavy labor may not be good candidates for the silicone rubber spacer.  Due to the shortcomings of the silicone implant, other materials have been investigated in the hopes of improving long-term outcomes of finger joint implants.  Pyrocarbon, a form of pyrolytic carbon, is a strong, durable, ceramic-like material that has proven its biocompatibility and durability in artificial heart valves and is being used in artificial hand joints as an alternative to silicone implants for end-stage arthritis.  

The Ascension MCP (Ascension Orthopedics, Inc., Austin, TX) received pre-market approval (PMA) from the U.S. Food and Drug Administration (FDA) in 2001.  It is indicated for use as a total joint replacement of the index, long, ring, and small finger MCP joints that exhibit symptoms of pain, limited motion, or inadequate body alignment (i.e., subluxation/dislocation) secondary to articular destruction or degenerative disease related to rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, or post-traumatic arthritis where soft tissue reconstruction can provide adequate stabilization.  In the approval letter, the FDA stated that Ascension Orthopedics, Inc. is required to conduct a post-approval study to obtain 12 months of post-operative data on each Ascension MCP device implanted in a minimum of 100 patients at 4 sites.

The Ascension PIP (Ascension Orthopedics, Inc., Austin, TX) pyrocarbon total joint is a bicondylar, anatomically shaped, articulating implant that allows joint flexion-extension, while providing some restriction of adduction-abduction motion.  The FDA granted a humanitarian use device approval for the Ascension PIP joint implant on March 22, 2002 for use in arthroplasty of the PIP joint when the patient has soft tissue and bone that can provide adequate stabilization and fixation under high-demand loading conditions after reconstruction and needs a revision of a failed PIP prosthesis, or has pain, limited motion, or joint subluxation/dislocation secondary to damage or destruction of the articular cartilage.  The FDA noted that compared to current treatment alternatives, such as arthrodesis or resection arthroplasty with a silicone spacer, the Ascension PIP may provide the potential benefits of increased motion and function, and may be used on patients whose strength and motion demands would exceed the capabilities of the currently available 1-piece silicone spacers.  The FDA concluded that pre-clinical testing of the Ascension PIP device demonstrated that the wear resistance, fracture strength, fatigue resistance, and resistance to articulating surface contact damage is acceptable for its intended use.

Based upon a systematic evidence review on artificial MCP and PIP joint replacement for end-stage arthritis, the National Institute for Health and Clinical Excellence (NICE, 2005) concluded that "[c]urrent evidence on the safety and efficacy of artificial MCP and interphalangeal (IP) joint replacement of the hand for end-stage arthritis appears adequate to support the use of this procedure provided that the normal arrangements are in place for consent, audit and clinical governance.  Most of the evidence was based on a single type of joint prosthesis.  The range of prostheses used is continually changing and clinicians are encouraged to submit their results to the appropriate joint-replacement registry for the evaluation of long-term outcomes of different types of prosthesis."  The specialist advisors to the Institute's Interventional Procedures Advisory Committee noted the following potential adverse effects: stiffness, loosening of the prosthesis, generation of wear debris, bone resorption, nerve injury, wound hematoma, silicone synovitis, infection and prosthesis fatigue.

Stutz et al (2005) evaluated the pyrolytic carbon Ascension PIP implant for replacing the PIP joint in 13 patients and reported that at 1 year the ROM of the PIP joint improved from 0-28-51 pre-operatively to 0-22-77 post-operatively (average value), pain relief was achieved at rest and in motion of 80 % on the visual analog scale (VAS) (0: no pain, 10: incapacitating pain) and on the verbal analog scale an improvement of 62 % was achieved.  The authors concluded that pyrolytic carbon implants reduce pain and are functionally superior to arthrodesis, however, a precise and individual post-operative protocol is necessary for beneficial results.

Schulz et al (2005) retrospectively reviewed the results of 20 out of 29 patients with idiopathic or post-traumatic arthritis who had been treated with the Ascension pyrolytic carbon PIP joint prosthesis from April 2002 to April 2004.  Clinical, subjective and radiologic parameters were studied.  On follow-up after 0.5 to 2.5 years the patients were satisfied with the pain relief; ROM varied.  However, with an average ROM of 50 degrees it was equivalent to the results in the literature.  Signs of periprosthetic cysts, osteophytes and loosening of the proximal as well as of the distal component could be seen in the radiograms of some patients.  There was no correlation between these radiologic observations and ROM, pain or grip strength.  In 3 cases the joint prosthesis had to be converted to an arthrodesis of the PIP joint.  Bearing in mind the correct indications (intact collateral ligaments, stable bone stock and sufficient extensor and flexor tendons), pyrocarbon prostheses are a treatment option for idiopathic and post-traumatic arthritis preserving motion and reducing pain.  Radiologic results seem to indicate an absence of osteointegration and tension forces at the prosthesis/bone interface.  Further investigation will be necessary to improve surface and design to increase radiologic results in long-term follow-up.  Additional surveys are required to improve indications, surgical approach and intra-operative control of correct component positioning.

Herren et al (2006) reported problematic bone fixation with the use of pyrocarbon implants in PIP joints.  Seventeen pyrocarbon PIP prostheses were implanted into 14 patients, followed prospectively and reviewed clinically.  The patients were assessed after a mean follow-up of 20.5 months subjectively by a VAS and radiographically.  Significant pain relief was noted in all patients from a mean of 7.6 pre-operatively to 1.3 at final follow-up.  Migration of one, or both, components was observed radiographically in 8 joints and radiolucent lines were evident in 3 more cases.  The clinical results of the implants that had migrated were less favorable for ROM and grip strength than the stable joints of this series, although statistically the results were not significant.  The number of possibly unstable prostheses in this series raises the question as to whether pyrocarbon is suitable for uncemented pressfit fixation in combination with early functional rehabilitation.

Nunley et al (2006) prospectively evaluated the subjective and objective functional outcome of patients treated with a pyrolytic carbon PIP joint arthroplasty for post-traumatic arthritis.  Five patients (7 joints) with traumatic injuries to the PIP joint were followed-up for more than 1 year after pyrolytic carbon arthroplasty.  All patients were treated with surgical reduction and stabilization at the time of the initial injury, but at a minimum of 6 months after the initial injury they had persistent pain, loss of motion, and functional limitations.  All patients had a stable PIP joint with a satisfactory extensor mechanism but had radiographic evidence of post-traumatic arthritis.  Patients were evaluated before and after arthroplasty with the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and VAS and by radiographic and physical examination.  At an average of 17 months, the mean DASH questionnaire score was unchanged.  The pain rating on the VAS was 6 out of 10 before surgery and 4 out of 10 after surgery; this change was not statistically significant.  The average ROM of the PIP joint decreased by 10 degrees at the last evaluation.  Grip strength improved from an average of 47 lb to 63 lb after surgery.  The authors concluded that the subjective and objective functional outcomes in 5 patients more than 1 year after pyrolytic carbon PIP joint arthroplasty for PIP joint trauma were disappointing and for post-traumatic patients, they no longer use pyrolytic carbon PIP joint arthroplasty.

In a prospective study, Hilker et al (2007) evaluated 28 Ascension pyrocarbon prostheses with a mean follow-up of 4 years and reported that stability was not a problem, subjective results were satisfactory, and the ROM remained unchanged; however 46 % of prosthesis stems exhibited radiolucent seams, 7 prostheses (25 %) were rated as loose and 5 of those had to be replaced by a silicone implant.  Use of the implant was abandoned as it was unreliable regarding bony fixation. 

Bravo et al (2007) retrospectively reviewed the surgical technique, post-operative therapy/splinting protocols, and clinical and radiographic outcomes of patients who had pyrolytic carbon PIP joint arthroplasty.  A total of 50 PIP joint replacements in 35 patients were performed with a minimum follow-up period of 27 months.  Indications for surgery included pain, decreased ROM, instability, and/or deformity.  The pre-operative diagnosis was osteoarthritis in 14, rheumatoid arthritis in 11, and post-traumatic arthritis in 10.  There were 20 women and 15 men affected.  The average age at the time of surgery was 53 years.  The fingers replaced included the index (n = 15), middle (n = 18), ring (n = 10), and small (n = 7).  The pre-operative arc of motion averaged 40 degrees (0 degrees to 60 degrees), and the pinch and grip measurements averaged 3 and 19 kg, respectively.  The pre-operative pain scores averaged 6 (scale 0 to 10) on a VAS.  The arc of motion was 47 degrees after surgery, and the average pinch and grip measurements were 4 and 25 kg, respectively.  Pain scores improved to 1.  At the final follow-up evaluation the overall patient satisfaction was nearly 80 %.  The results of index finger PIP replacements are compatible with other digits.  Fourteen joints (in 14 patients) to date have required additional procedures to improve or maintain joint motion/function or pain; 5 for minor reasons and 9 for major complications.  No infections were noted.  Although not medically necessary, 2 patients requested and had an amputation.  Radiographic subsidence and subsequent settling (in accordance with Wolff's law) without apparent loosening occurred in 20 joints.  Twenty-eight percent of patients required a second procedure and 8 % required a revision arthroplasty.  Radiographs showed gross changes in implant and eventual settling to a stable position in 40 % of the joints.  The authors concluded that the pyrolytic carbon implant arthroplasty showed improved pain relief and good overall patient satisfaction at the 2-year minimum follow-up evaluation, however, a longer follow-up period will help to better determine the efficacy of this implant.

Meier et al (2007) reported outcomes of PIP replacement with the pyrolytic carbon prostheses.  Indications included symptomatic arthritis of the proximal interphalangeal joint with preservation of the collateral ligaments, sufficient bone support, and intact or at least reconstructable extensor tendons.  Contraindications included: lack of stability (e.g., as a result of rheumatoid arthritis or destruction of the ligaments caused by an accident), non-reconstructable extensor tendons, florid or chronic infection, and lack of patient compliance.  Twenty patients were treated for post-traumatic or idiopathic arthritis with 24 pyrolytic carbon PIP prostheses, and a follow-up examination was carried out after an average of 15 months (6-30 months).  Surgical management was changed from arthroplasty to arthrodesis in 3 cases.  For the remaining prostheses, an average ROM of 50 degrees was achieved for the PIP joint.  On the VAS (0: no pain, 10: incapacitating pain), the patients suffered few symptoms (0 to 3).  Eighty percent of patients said they were satisfied with the outcome of the operation.  In 3 cases (1 infection, 2 dislocations) the prostheses had to be removed and arthrodesis performed.  Migration of the distal components was observed on the radiographs in 5 cases, and of the proximal components in 4 cases, although this did not have any effect on the functional parameters.  The development of a painless noise ("squeaking") was noticed in 9 out of 21 prostheses.  However, as with prosthetic migration, this did not cause any functional deficits.

Branam et al (2007) compared the outcomes of silicone PIP arthroplasties to pyrolytic carbon implants in patients with osteoarthritis in a retrospective review of 41 arthroplasties in 22 patients with severe PIP joint osteoarthritis performed by a single surgeon.  There were 13 patients and 22 joints in the silicone group with an average follow-up of 45 months.  There were 9 patients and 19 joints in the pyrolytic carbon group with an average follow-up of 19 months.  Clinical assessment included ROM, grip strength, and deformity.  Radiographs were evaluated for alignment, subsidence, and implant fracture.  Patients filled out a subjective questionnaire with respect to pain, appearance of the finger, and satisfaction.  Complications were recorded.  In the silicone group, the average pre-operative PIP joint ROM was 11 degrees/64 degrees (extension/flexion) and the average post-operative ROM was 13 degrees/62 degrees.  In the pyrolytic carbon group, the average pre-operative PIP joint ROM was 11 degrees/63 degrees and the average post-operative ROM was 13 degrees/66 degrees.  Eleven of 20 joints in the silicone group and 4 of 19 joints in the pyrolytic carbon group had a coronal plane deformity as defined by angulation of the PIP joint greater than or equal to10 degrees.  The average coronal plane deformity was 12 degrees in the silicone group and 2 degrees in the pyrolytic carbon group.  The difference was statistically significant.  In the silicone group, 3 of 22 joints required additional surgery.  Two implants in 1 patient were removed and the PIP joint fused, and 1 implant was permanently removed for sepsis.  In the pyrolytic carbon group, 8 of 19 joints squeaked, and there were 2 early post-operative dislocations and 2 implants with radiographic loosening.  To date, there has been no revision surgery.  Both groups had good pain relief.  Patients were generally satisfied with the appearance of their joints in the pyrolytic carbon arm; however, satisfaction with appearance was variable in the silicone group.  Nine of 13 patients in the silicone group and 6 of 7 patients in the pyrolytic carbon group would have the procedure again.  The authors reported that both implants provide excellent pain relief and comparable post-operative ROM.  Complications were implant specific.  The authors concluded that the results of this series show promise for the pyrolytic carbon PIP joint resurfacing arthroplasty but did not clearly demonstrate superiority compared with the silicone implant.

The Avanta MCP and PIP joint finger implants (Avanta Orthopaedics, Inc., San Diego, CA) received  humanitarian use device approval from the FDA for use in arthroplasty of the MCP or PIP joints when the patient is in need of a revision of failed MCP or PIP prosthesis(es); or the patient expects to place his/her hands under loading situations which preclude the use of an alternative implant in the painful osteo-arthritic and post-traumatic MCP or PIP joint.  The distal components are made of an ultra-high molecular weight polyethylene and the proximal components consists of a cobalt chromiun-molybdenum articulating surface.

Moller and colleagues (2005) compared the results of the Avanta versus Swanson silicone implants in the MCP joint in a prospective, randomized comparison of 30 patients (120 implants).  At 2-year follow-up, grip strength was measured, hand function was assessed with the Sollerman test and the subjective outcome was determined with VAS.  With both implants ulnar deviation and flexion deformities decreased, and there was no difference between the groups.  The increase in ROM was 7 degrees greater with Avanta implants than with Swanson implants.  Grip strength and hand function were unaltered but the VAS showed decreased pain levels and subjective improvements in hand function, grip strength and cosmesis.  Twenty-four of 30 patients were satisfied.  Fracture of the silicone spacer occurred with 12 Avanta (20 %) and 8 Swanson implants (13 %), with a higher fracture frequency in men.

In a randomized prospective trial, Escott et al (2010) compared post-operative ROM and function of Swanson and NeuFlex MCP joint implants.  A total of 33 patients who had rheumatoid arthritis underwent primary MCP arthroplasty of all 4 fingers in 40 hands; 20 received Swanson implants and 20 received NeuFlex implants.  Exclusion criteria included diagnosis of other connective tissue disorders and previous MCP joint surgery.  All participants followed the same post-operative rehabilitation protocol.  The primary outcome measure was active MCP flexion.  Secondary outcomes included active MCP extension, arc of motion, ulnar drift, function (Jamar grip strength and Sollerman hand function test), and the Michigan Hand Questionnaire.  Patients were assessed pre-operatively and 12 months post-operatively.  Patients' mean age was 62.5 years (Swanson) and 58.1 years (NeuFlex) (p = 0.03).  A total of 19 of 20 hands (Swanson) and 14 of 20 hands (NeuFlex) were from female patients.  Pre-operative active ROM was not significantly different.  At follow-up, both groups demonstrated increased active extension and arc of motion (p < 0.001), reduced active flexion and improved ulnar deviation (p < 0.001), increased mean Sollerman and Michigan Hand Questionnaire domain scores (p < 0.001), and improved grip strength (p = 0.03).  Active MCP flexion was significantly greater in all 4 digits of hands with NeuFlex implants compared with Swanson implants.  The NeuFlex group demonstrated a greater total arc of motion in the little finger.  Implant groups were not significantly different by individual digit for active MCP extension, ulnar drift, and composite flexion.  Functional outcomes did not differ between groups.  Patients with Swanson implants reported higher Michigan Hand Questionnaire scores in the function and aesthetics domains.  The authors concluded that both implant groups obtained satisfactory clinical improvement after MCP reconstruction of the hand.  The NeuFlex group demonstrated superior ROM, whereas the Swanson group had better self-reported function and aesthetics, but not objectively measured function.

Distal InterPhalangeal (DIP) Joint

Rehart and Kerschbaumer (2003) noted that finger joints were first replaced with endo-prostheses in 1940 by Burman.  Indications for the procedure are degenerative, post-traumatic or arthritis related destruction of the joints of the hand.  Nowadays, several more or less comparable prosthetic designs are available.  The replacement of single bones of the wrist has not been of lasting success.  Occasionally, an indication for arthroplasty of the trapezium-metacarpal joint of the thumb may exist.  The MCP joint of the thumb should, in the authors' experience, be fused when the need arises.  Up until the present, the silastic spacer of Swanson for the MCP and PIP joints has not shown any substantial development, although a variety of designs have been introduced.  Questions related to the complicated biomechanics of these articulations in combination with problems concerning the material to be used, intra-osseous fixation, the articulation of the prosthesis components and the design of the stems have not yet been solved convincingly.  The Swanson spacers in mid-term to long-term follow-ups show little active ROM, although the subjective patient satisfaction is very high and the potential for removal at its best.  The authors stated that they do not see an indication for arthroplasty in the distal interphalangeal (DIP) finger joints.

Drake and Segalman (2010) noted that arthritis in the small joints of the hand can be treated with arthrodesis or arthroplasty.  Arthrodesis has known risks of infection, pain, and nonunion.  Distal interphalangeal arthroplasty has been successful in preserving motion and alleviating pain for distal DIP, PIP, and MCP joints.  Unfortunately, complications arise that limit the success of surgery.  Silicone implants have been reliable for many years but still present with the risks of infection, implant breakage, stiffness, and pain.  Newer implant designs may limit some of these complications, but present with unique problems such as dislocations and loosening.  It is not yet clear as to which type of implant provides the most reliable results, although implant arthroplasty appears to give better function than arthrodesis.  Silicone arthroplasty does not lead to silicone synovitis and is a reliable procedure.  Pyrocarbon implants are showing some promise, particularly in the osteoarthritic patient.

Ikeda et al (2010) examined the usefulness of a custom-made splint for treatment of painful osteoarthritis of the DIP joints.  The splint was designed to be easily detachable so as not to diminish finger pad sensation or interfere with PIP joint motion.  These researchers enrolled 25 patients (24 women and 1 man, mean age of 58 years) with painful osteoarthritis of the DIP joints of the fingers and thumbs in this cohort study.  Nineteen patients had multiple affected digits in one or both hands.  Splints were applied to protect and immobilize the DIP joints.  These investigators assessed the outcome of this treatment using the VAS pain score and the Quick Disabilities of the Arm, Shoulder, and Hand score for subjective assessment of symptoms.  The mean follow-up period after wearing the splint until assessment was 6 months.  Subjects were assessed 6 months after they started wearing the splint.  Pain decreased from 100 % at pre-treatment to 34 % at final follow-up.  So, the average improvement ratio was 66 %.  The Quick Disabilities of the Arm, Shoulder, and Hand disability/symptom score changes were not statistically significant (28 points pre-treatment and 17 points at final follow-up).  The authors concluded that this splint reduced pain from DIP osteoarthritis according to the VAS; however, this does not enable the patient to obtain completely satisfactory function of the upper extremities.

Dickson and colleagues (2014) performed a systematic review of all studies on DIP joint arthrodesis published within the English literature to provide a comparison of the different techniques. The published studies were predominantly of Level IV evidence. The most commonly employed techniques were Kirschner wire, headless compression screw and cerclage wires. There was no difference in infection rates. Headless compression screws appeared to have increased union rates but are associated with complications not seen with other well-established and cheaper techniques. The screw diameter is often similar to or larger than the joint itself, which can result in penetration. Furthermore, they limit the available angle for achieving fusion. Other than in terms of union, there is insufficient evidence to show the headless compression screw is superior to other techniques.

In a prospective study, Jakubek and colleagues (2017) evaluated the nitinol (X-Fuse) implant in arthrodesis of the DIP and the thumb joints with respect to bone fusion and clinical efficiency.  This study included 24 consecutive patients (7 men, 17 women; mean age of 56.8 years; range of 27 to 79 years) with nitinol (X-Fuse) implants in their 41 joints.  All patients were followed-up clinically and radiographically with respect to fusion, complications and outcome at a minimum of 14 months post-operatively (mean of 28 ± 6 months).  X-rays, Disabilities of the Arm, Shoulder and Hand, and VAS scores were recorded pre-operatively and at post-operative 5th week, third month, 1st year, and subsequent visits.  The Disabilities of the Arm, Shoulder and Hand score improved significantly from pre-operative 37.7 points to post-operative 14.5 points at 1st year.  The VAS score improved significantly from pre-operative 5.5 to post-operative 0.85 points at 1st year.  Failure to fuse only occurred in 2 joints (5 %), resulting in fusion after re-operation.  No other severe complications such as deep infection, intra-operative fracture, wound healing problems or regional dystrophy were observed.  The authors concluded that the X-Fuse implant may be a reliable alternative method for finger joint arthrodesis.  Moreover, they stated that further multi-center clinical studies with a greater number of patients and longer follow-up periods are needed to establish a possible superiority of this system compared to other techniques of arthrodesis.

The authors noted that this study had several drawbacks: They primarily analyzed only a small number of patients (n = 24) at their institution within the short-term (mean of 28 months).  Furthermore, this study was an observational study.  Different methods of interphalangeal arthrodesis could be compared and contrasted within future efforts.

In a retrospective study, Runkel et al (2022) examined the risk factors for complications following different methods of DIP arthrodesis in the hand – 44 % were treated with K-wire/cerclage fixation, 46 % with X-fuse implants and 10 % with headless compression screws (HBS-screw).  The median follow-up was 16 weeks (range of 6 to 224).  The overall complication incidence was 44 % (minor complications = 29 % and major complications = 15 %).  The logistic regression showed that OA, revisional arthrodesis and smoking had a negative impact on the total complication incidence.  A Cox-regression analysis showed that HBS-screw arthrodesis was associated with a significantly lower incidence of major complications compared with K-wire/cerclage and X-Fuse-arthrodesis.  Revisional arthrodesis was 5 times more frequently connected with major complications than primary surgery.  Smokers were 3 times more likely to experience major complications than non-smokers.  The authors concluded that arthrodesis of the DIP joint often resulted in complications; risk factors must be kept in mind.  Level of Evidence = III.

Carpometacarpal (CMC) Joint / Trapeziometacarpal (TMC) Joint

Bozentka (2010) noted that resection arthroplasty with or without ligament reconstruction for thumb trapeziometacarpal (TMC) arthritis can be complicated by thumb shortening and pinch-strength weakness. Implant arthroplasties have been developed to limit loss of thumb length, improve strength, and limit post-operative convalescence. The ideal thumb carpometacarpal (CMC) implant should be strong and stable, provide full ROM, and prevent loosening. Unfortunately, no current prosthesis accomplishes all of these goals. The author concluded that until the ideal implant is developed, clinical acumen must be used to determine appropriate patients and implants.

Jager et al (2013) noted that trapeziectomy has been the basis of basal thumb arthritis surgical treatment since the 1950s. This resection arthroplasty has been continuously refined (soft-tissue interposition, ligament reconstruction, spacer implantation, etc.) without leading to a dramatic outcome improvement. Pain decrease is often satisfying in the long-term, but comfort during the early post-operative period may vary. Those disadvantages of trapeziectomy led to the emergence of total TMC prostheses in the 1970s, with a constant improvement of implant design. Few series have compared those 2 surgical techniques side-by-side, and prospective ones are even rarer. These investigators compared total TMC prosthesis and trapeziectomy-interposition in the very short-term in 2 similar groups of female patients, to determine whether prosthesis led to faster recovery or not. These researchers compared a total TMC prosthesis (MAIA) and trapeziectomy-interposition in the immediate and short-term (6 months), for objective, subjective, functional criteria, as well as short-term comfort or discomfort. They prospectively followed 2 comparable cohorts of 47 and 27 female patients above 50 years of age, treated for basal joint arthritis with a constrained TMC joint prosthesis or trapeziectomy-interposition, respectively. The patients were followed post-operatively for 6 months. Mobility, pain reduction, satisfaction, strength and functional scores were better in the prosthesis group. The pinch strength improved by 30 %, the length of the thumb column was maintained, and better correction of the subluxation was obtained in this group. There were 6 cases of De Quervain's tenosynovitis and 1 case of loosening due to trauma. The authors concluded that in the short-term, the MAIA TMC prosthesis gave better outcome than trapeziectomy with interposition. Moreover, they stated that this has to be confirmed in the long-term and after revision surgery that will be likely to occur.

Hentz (2014) stated that the TMC joint's unique anatomy and biomechanics render it susceptible to degeneration. For 60 years, treatment of the painful joint has been surgical when non-operative modalities have failed. Dozens of different operations have been proposed, including total or subtotal resection of the trapezium or resection and implant arthroplasty. Proponents initially reported high levels of patient satisfaction, but longer-term reports sometimes failed to support initial good results. To-date, no one procedure has been shown to be superior to another. The author identified factors responsible for the development of many different procedures to treat the same pathology and factors influencing whether procedures remained in the armamentarium or were abandoned. A non-systematic historical review of English-language surgical journals using the key words "carpometacarpal arthritis", or "trapeziometacarpal arthritis", and "surgery" in combination with "history" using the PubMed database was carried out. In addition, bibliographies of pertinent articles were reviewed. The factors that led to many surgical innovations appeared to be primarily theoretical concerns about the shortcomings of previously described procedures, especially about proximal migration of the thumb metacarpal after trapezial resection. Longevity of a particular procedure seems to be related to simplicity of design, especially for prosthetic arthroplasty. The evolution of surgery for TMC joint arthritis both paralleled and diverged from that in other joints. For example, for most degenerated joints (even many in the hand), treatment evolved from resection arthroplasty to implant arthroplasty. In contrast, for the TMC joint, the 60-yearold procedure of trapezial resection continues to be performed by a majority of surgeons; many modifications of that procedure have been offered, but none have shown better pain reduction or increased function over the original procedure. In parallel, many differently designed prosthetic total or hemi-joint arthroplasties have been proposed and performed, again with as yet unconvincing evidence that this technology improved results over those obtained by simple resection arthroplasty. The author concluded that many procedures have been described to treat TMC joint arthritis, from simple trapezial resection to complex soft tissue arthroplasty to prosthetic arthroplasty. In the absence of evidence for the superiority of any one procedure, surgeons should consider using established procedures rather than adopting novel ones, though novel procedures can and should be tested in properly designed clinical trials.

Huang et al (2015) stated that thumb CMC joint total arthroplasty has been undertaken for many years. The proponents believed the short-term outcomes are better than trapeziectomy and its variants, but the longer term complications are often higher. This systematic review of all peer-reviewed articles on thumb CMC joint total arthroplasty for osteoarthritis showed that there are reports of many implants. Some are no longer available. The reported outcomes are very variable: for some there are good long-term outcomes to beyond 10 years; for others there are unacceptably high early rates of failure. Overall, the published evidence does not show that total arthroplasty is better than trapeziectomy and its variants yet there is a higher complication rate and significant extra cost of using an implant. The authors concluded that future research needs to compare total arthroplasty with trapeziectomy to assess short-term results where the arthroplasties may be better, as well as the long-term outcomes and the healthcare and personal costs so that surgeons and patients can make fully informed choices about the treatment of symptomatic thumb CMC joint osteoarthritis.

Papalia et al (2015) performed an online search using Medline, Cochrane and Google scholar online databases, searching for studies on small joints replacement in hand surgery. Good functional and clinical outcomes can be achieved with silicone and pyrolitic carbon implants, either for TMC and MCP joints. In particular, the silicone spacer seems to be very effective for TMC osteoarthrosis, while the pyrolitic carbon total joint prosthesis produces excellent outcomes if used for MCP replacement. Major complications, such as persistent pain and implant loosening, have still a variable rate of occurrence. Heterogeneity in the methodology of the assessments in the studies reviewed and the implants and techniques involved made it difficult to carry out a complete and effective comparative analysis of the data collected. Larger cohorts treated with the same implant should be investigated in better designed trials, to draw more clinically relevant conclusions from the evidences presented. Better methodology is also a goal to achieve, since the average Coleman Methodology Score measured for the articles included was 54.9 out of 100. The authors concluded that more and better designed studies are needed to produce clear guidelines to define the better implant in terms of clinical outcomes, function and complications for TMC and MCP joints.

Semere and associates (2015) stated that the Roseland hydroxyapatite-coated (HAC) prosthesis is a total TMC joint prosthesis used for the surgical treatment of thumb basal joint arthritis. In a retrospective study, these researchers evaluated the long-term outcomes of the Roseland HAC prosthesis.  A total of 51 patients (64 thumbs) underwent TMC joint replacement with this prosthesis.  The mean follow-up was 12.5 years.  Survival rate of the prosthesis was 91 %.  There was either no pain or only occasional pain in 91 % of cases.  The mean quick disabilities of the arm, shoulder and hand (QuickDASH) score was 27.6.  Abnormal radiographic findings were present in 70 % of cases.  Since they were often asymptomatic, no further treatment was carried out.  Complications were common (25 %) and occurred early on but could often be treated without surgery.  The authors concluded that the long-term results with the Roseland HAC prosthesis were satisfactory in terms of pain relief and function.  However, the high complication rate was a major concern.

In a retrospective study, Zschock-Holle et al (2015) evaluated the clinical and radiological results after treatment of the first CMC joint by trapezium resection and implantation of a Swanson silicone prosthesis. The results of 100 trapezium resections in 72 patients with subsequent joint replacement by a Swanson silicone prosthesis have been followed-up over 8.6 years on average.  Besides the ROM, the strength in grip, tip pinch and key pinch were measured.  The quality of pain was determined using a VAS from 1 to 10.  The post-operative subjective satisfaction of patients was recorded as well as the DASH, Mayo, modified Wrist and Krimmer scores.  In follow-up X-ray controls, subluxations of the silicone implants as well as bony abnormalities were evaluated.  The post-operative ROM of the TMC joint in radial abduction was measured with 52^° and at palmar abduction with 39^°.  The average grip strength amounted to 16.5 kg.  This represented 80 % of the value of the contralateral side.  In tip pinch the force value was 3.3 kg, corresponding to 70 % of that of the opposite side and in key pinch, it was 3.5 kg, corresponding to 71 % of the healthy contralateral side.  The DASH score was recorded with 22.5 points.  Post-operative pain symptoms on the VAS were recorded at 2.4 points. The majority of the patients were satisfied or very satisfied after the surgical treatment. In X-ray controls, subluxations of the silicone implants could be detected in 54 cases (61.4%) as well as bony abnormalities in 41 cases (46.6 %).  However, there was no correlation between the radiological findings and patient satisfaction.  The authors concluded that trapezium resection and joint replacement with a silicone prosthesis achieved good results.  However, the high number of radiographic subluxations of the prosthesis and bone abnormalities as a cause of foreign body reactions limited these results.  These investigators noted that despite the good clinical findings, this method will not be used any more in their patient population.

Thillemann and colleagues (2016) retrospectively evaluated a consecutive series of 42 Motec thumb CMC total joint arthroplasties. The primary end-point was revision with implant removal and trapeziectomy.  At follow-up the DASH score, pain on numerical rating scale at rest and with activity and serum chrome and cobalt concentrations were assessed for both unrevised and revised patients.  At a mean follow-up of 26 months, 17 patients had been revised.  The 2-year cumulative revision rate was 42 % (95 % CI: 28 to 60 %).  The DASH score and pain scores at rest and with activity were comparable between the patients whose thumbs remained unrevised and those revised.  Patients with elevated serum chrome and cobalt levels had significantly higher DASH and pain scores, but elevated levels were not associated with revision.  The authors concluded that the revision rate in this study was unacceptably high.  However, pain and DASH scores after revision were acceptable and comparable with patients with non-revised implants.

Mattila and Waris (2016) noted that the bioabsorbable poly-L-D-lactide joint scaffold arthroplasty is a recent attempt in the reconstruction of small joints in rheumatoid patients. These researchers analyzed the 1-year clinical, functional and radiologic results of partial trapeziectomy with the poly-L-D-lactide (96/4) joint scaffold in 23 patients with isolated TMC osteoarthritis.  The results showed that the procedure provided pain relief and improvement in overall function according to the QuickDASH score in most patients.  However, radiographs demonstrated a high frequency of osteolysis around the implant; 7 patients developed clinically manifested foreign-body reactions 6 months to 1 year after surgery.  The reason for the unexpected tissue reactions may relate to excessive mechanical cyclic loading of the implant.  The authors concluded that the outcomes of this implant in their patients have not been sufficiently beneficial and they have discontinued use of this implant in isolated TMC osteoarthritis.

van Aaken et al (2016) stated that the PI2 spacer is designed for treatment of TMC osteoarthritis. However, the shape of this implant has raised concerns about its stability.  These investigators retrospectively investigated 45 implants in 41 patients (treated for TMC osteoarthritis between 2004 and 2009) who underwent trapeziectomy and insertion of a PI2 spacer.  Outcome parameters included revision rates and clinical outcomes correlated with implant position and scapho-metacarpal distance, assessed using standard radiographs.  A total of 12 implants (27 %) were removed at a median time of 10 months (interquartile range (IQR), 7 to 22).  These included 5 dislocations, 1 early infection, 6 patients underwent revision due to persistent pain, and 3 of these had scapho-trapezoid osteoarthritis, 2 had developed subluxation of the implant, and 1 did not show any radiographic abnormalities.  A review of patient records revealed that 33 implants remained in place at a median time of 29 months (IQR, 20 to 57).  However, of those, only 21 implants (64 %) in 17 patients were available for clinical evaluation at a median follow-up of 29 months (IQR, 19 to 62).  No significant differences in clinical outcomes including functional results were observed between in-place (n = 8) and subluxated (n = 13) implants.  The authors concluded that due to the high revision rate (12/45), consistent with other reports in the literature, they have abandoned the use of the PI2 spacer,; and have recommended the establishment of a registry for evaluation of future implants.

Kollig and colleagues (2016) stated that the role of joint replacement in the treatment of osteoarthritis of the thumb CMC joint is a subject of considerable controversy in the current literature.  In German-speaking countries this technique is used much less frequently than resection procedures.  Aseptic loosening of the prosthesis is believed to be the major cause of the high failure rates reported for cemented and un-cemented types of implants.  In this study the different implant designs were evaluated on the basis of the results reported in the international literature.  There were only a few studies that cover relatively long follow-up periods and provided convincing results for thumb CMC joint prostheses in terms of implant survival and function.  Aseptic loosening was reported to be the major cause with failure rates of 50 % or more.  Although a Norwegian study reported high 5-year and 10-year survival rates for various thumb CMC joint prostheses according to the Norwegian arthroplasty registry, it did not recommend the widespread use of thumb CMC joint replacement at the present time.  The authors concluded that joint replacement may be considered as a possible therapeutic option for advanced osteoarthritis of the thumb CMC joint, however, it should not always be recommended because long-term results are inconsistent and similar functional outcomes have been reported for alternative surgical techniques, such as resection arthroplasty.

Kollig and associates (2017) noted that thumb CMC joint replacement is associated with high rates of loosening and failure.  These researchers presented their findings for an un-cemented ceramic-ceramic total joint prosthesis with a reverse ball-and-socket design and bioactive coating.  Between 2008 and 2012, a total of 29 prostheses were inserted into 28 patients (mean age of 63 years) with advanced osteoarthritis.  After a mean period of 33 months (range of 9 to 62), 26 patients (27 implants) were available for follow-up.  Six months post-operatively, 50 % of the patients had radiological evidence of early loosening; 15 implants had been removed in 14 patients for aseptic loosening (n = 13) or trapezium fracture (n = 2).  The 12 patients whose prosthesis was still in place had a mean VAS pain score of 1.9 (range of 0 to 6) and a mean Disabilities of the Arm, Shoulder and Hand score of 23 (range of 0 to 73.3); 11 patients were satisfied with the procedure.  The rate of early aseptic failure was unacceptably high.  Level of evidence = IV.

In a retrospective, single-center study, Toffoli and Teissier (2017) evaluated the mid-term clinical and radiological results of the MAÏA TMC prosthesis.  This study involved 80 patients who underwent 96 MAÏA TMC prosthesis implantations from February 2006 to April 2009, and who had a minimum of 5 years' follow-up.  Indications for the procedure were painful TMC joint osteoarthritis affecting activities of daily living (ADL) and a failure of at least 6 months of non-surgical treatment.  Pre- and post-operative clinical and radiographic data were reviewed.  The mean age at surgery was 68 years (range of 53 to 84 years) and the median follow-up was 76 months (range of 60 to 102 months).  The mean Quick Disabilities of the Arm, Shoulder, and Hand score improved from 61.3 ± 17.1 to 17.5 ± 16.  The mobility of the thumb was restored to a ROM comparable with that of the contralateral thumb.  Opposition, defined by the Kapandji score, was almost normal (9.2 of 10; range of 6 to 10), as was the final mean key pinch and grip strength, which improved by 26 % and 43 %, respectively.  Among the 96 implants, 4 (4.2 %) were surgically revised for trapezium loosening; 1 dislocation was treated with closed reduction; 3 (3.1 %) post-traumatic trapezium fractures were immobilized for 8 weeks.  Among the 26 pre-operative reducible z-deformities, only 5 (19.2 %) were not totally corrected after surgery.  The procedure success, by survival analysis over 6 years, was 93 % (95 % CI: 87 to 98).  The authors concluded that MAÏA TMC total joint arthroplasty may be a reliable therapeutic option for TMC joint osteoarthritis, with very good results for pain relief, strength, mobility, and restoration of the thumb length, providing correction of most thumb z-deformities.  This study provided mid-term follow-up; and the level of evidence was IV.

Robles-Molina and co-workers (2017) stated that numerous surgical procedures have been described to treat TMC osteoarthritis, but no approach is currently considered superior.  Good long-term outcomes have been reported with multiple procedures.  No studies have been published comparing outcomes of the Arpe joint replacement (Biomet, Valence, France) with those of ligament reconstruction and tendon interposition (LRTI) using the Burton-Pellegrini technique.  In a retrospective, follow-up study, these researchers compared clinical outcomes between these techniques.  A total of 65 patients with Eaton stage III osteoarthritis of the thumb were included in this study.  Patients were assigned to LRTI (LRTI group) or total joint replacement (Arpe group) and were followed for a mean of 4.8 years.  The LRTI group included 34 patients and the Arpe group included 31.  Clinical outcome variables were determined pre-operatively and every 6 months post-operatively.  Pain relief and functional improvement were similar between groups.  Pinch strength and ROM were superior in the Arpe group.  Metacarpophalangeal hyper-extension appeared to be prevented in the Arpe group but increased over the follow-up period in the LRTI group.  However, the complication rate was higher in the Arpe group.  The authors concluded that arthroplasty with the Arpe prosthesis can be considered in selected patients who require greater strength and ROM, although it has been associated with a higher complications rate.  Moreover, they stated that prospective, multi-center studies with a longer follow-up are needed to ascertain the advantages of “ball and socket” prosthesis over trapeziectomy.

Drawbacks of this study included the retrospective design, the small sample size (n = 31 in the Arpe joint replacement group), the short follow-up period (mean of 4.8 years), and the absence of randomization (patients were allocated according to their preference), which implied a possible selection bias.

Smeraglia and colleagues (2018) noted that trapeziometacarpal arthritis is a common and disabling condition. There is no evidence in the literature of superiority of one surgical procedure over others.  Several prosthetic implants have been introduced to preserve joint mobility.  In a systematic review, these investigators searched Medline (PubMed), Web of Science and Scopus databases using the combined keywords “artelon”, “thumb”, “carpometacarpal”, “trapeziometacarpal” and “rhizoarthrosis”; 11 studies were identified.  The authors stated that the use of Artelon implant is not recommended because of its high revision rate and worse outcomes compared to conventional techniques.  They also noted that inert materials subjected to compressive and shearing forces could produce debris and subsequent inflammatory response.  There is debate in the published scientific literature regarding the role of pre-operative antibiotic prophylaxis and post-surgery inflammatory response.  These researchers stated that standard techniques (e.g., trapeziectomy alone or combined with interposition or suspensionplasty) offer effective treatment for thumb basal joint arthritis.  They also noted that several prosthetic implants showed promising results in terms of pain relief and functional request, but there is a need of long-term RCTs to demonstrate their equivalence, and eventually superiority, compared to standard techniques.

Mattila and associates (2018) stated that the poly-L/D-lactide joint scaffold (RegJoin) has recently been associated with adverse tissue reactions and osteolysis after partial trapeziectomy for trapeziometacarpal osteoarthritis; 22 of 23 patients previously operated on with this scaffold were re-examined at a mean follow-up of 3.3 years (range of 36 to 53 months).  Overall, the results showed an unacceptably high rate of adverse tissue reactions related to the degradation process of the implant, resulting in a revision procedure in 3 patients.  At final follow-up, at which point the implant had completely degraded, there were no signs of ongoing adverse tissue reactions.  The authors concluded that there was a significant decrease in pain, increase in strength and subjective improvement in function at final follow-up compared with the pre-operative results in patients who had not undergone revision surgery.  Moreover, they stated that due to the high incidence of adverse tissue reactions, the use of the implant has been discontinued in the treatment of trapeziometacarpal osteoarthritis.

Degeorge and associates (2018) stated that no surgical management is better than another regarding functional recovery for TMC joint osteoarthritis (OA).  Metacarpophalangeal (MCP) hyper-extension, directly due to the shortening of thumb height, appeared to be a factor of poor prognosis; MCP hyper-extension can be corrected by implantation of a trapeziometacarpal prosthesis (TMP), as opposed to trapeziectomy and ligamentoplasty (TL), and pinch strength is greater with TMP in this indication.  In a retrospective, observational case-control study, these researchers examined if TMP would provide better MCP stability than TL.  A total of 69 patients (41 TMP and 28 TL) were evaluated.   The following were evaluated: pain, mobility of the MCP joints, palmar grip and pinch strength.  Thumb height was measured on radiographs as a post-/pre-operative ratio.  The mean follow-up was 20 months (range of 6 to 38).  The TMP group showed greater reduction of the MCP hyper-extension in all hyper-extension groups, especially hyper-extension of greater than 30°, compared with TL.  The TMP group provided significant greater pinch strength in all the subgroups with pre-operative MCP hyper-extension.  Patient with post-operative MCP hyper-extension had a significant lower grip and pinch strength compared with patient without MCP hyperextension.  Radiographic analysis showed that thumb height changes were related to the degree of pre-operative hyper-extension.  Post-operatively, patients with post-operative MCP hyper-extension had a significant lower thumb height than patient without MCP hyperextension.  The authors concluded that MCP hyper-extension appeared to be a factor of poor prognosis for surgical treatment of TMC OA when it was not managed; and TMP provided better MCP stabilization by restoring thumb length and would avoid surgery on the MCP joint.  These investigators stated that TMP may be recommended in patients having symptomatic TMC joint OA and MCP joint hyper-extension.  The main drawback of this study were its relatively small sample size (n = 41 for TMP) and short-term follow-up (20 months).  Level of Evidence = III. 

Andrzejewski and Ledoux (2019) reported retrospectively the clinical and radiological outcomes and the survival of Maia TMC joint arthroplasty at a mean 5 years' follow-up.  These researchers examined the implant survival and the clinical outcomes of 93 patients (113 prostheses).  Patients were examined during a consultation and their mobility, key pinch strength and satisfaction were recorded.  Patients also completed a QuickDASH evaluation.  The 5-year survival rate was 92.2 %.  The mean QuickDASH Score was 26.7.  The complication rate was 31 % and the revision rate was 12.4 %.  The most common complication was dislocation and the most frequent cause of surgical revision was peri-prosthetic ossification; 2 cases of aseptic loosening were identified.  The authors concluded that the findings of this study showed that the Maia prosthesis provided satisfactory medium-term results and had an excellent 5-year survival; however, the high complication and revision rates were still a major concern.

In a systematic review, Ganhewa and colleagues (2019) estimated failure rates of TMC implants and compared against failure rates of non-implant techniques for surgical treatment of TMC joint (basal thumb joint) arthritis.  These researchers identified articles reporting on thumb implant arthroplasty and on non-implant arthroplasty techniques for treatment of base of thumb arthritis in the English literature.  Data were combined to calculate failure rates per 100 procedure-years.  Failure was defined by the requirement for a secondary salvage procedure.  The failure rates between different implant and non-implant arthroplasty groups were compared directly and implants with higher than anticipated failure rates were identified.  A total of 125 articles on implant arthroplasty and 33 articles on the outcome of non-implant surgical arthroplasty of the TMC joint were included.  The implant arthroplasty failure rates per 100 procedure-years were total joint replacement (2.4), hemiarthroplasty (2.5), interposition with partial trapezial resection (4.5), interposition with complete trapezial resection (1.7), and interposition with no trapezial resection (4.5).  The non-implant arthroplasty failure rates per 100 procedure-years were: trapeziectomy (0.49), joint fusion (0.52), and trapeziectomy with ligament reconstruction ± tendon interposition (0.23).  The authors concluded that several implant designs (arthroplasties) had high rates of failure due to aseptic loosening, dislocation, and persisting pain.  Furthermore, some implants had higher than anticipated failure rates than other implants within each class.  Overall, the failure rates of non-implant techniques were lower than those of implant arthroplasty.

In a prospective study, Vissera and co-workers (2019) examined long-term functional outcome after total TMC joint replacement with the Ivory arthroplasty for TMC joint OA.  Clinical outcome, overall function, pain, and radiologic outcome after a minimum of 10 years were evaluated for 26 Ivory arthroplasty in 24 patients; 2 patients had bilateral arthroplasties.  The female to male ratio was 22:2, and the mean age was 71 years (range of 57 to 83).  The mean follow-up period was 130 months (range of 120 to 142).  Overall functioning as defined by the QuickDASH score and VAS improved by 50 % and 81 %, respectively, when compared with the pre-operative status.  However, these outcomes deteriorated beyond 5 years after surgery.  Long-term results suggested the Ivory arthroplasty to be a reliable treatment for TMC OA since it improved overall function and reduced pain up to 10 years post-operatively.  However, revision within 10 years after surgery was needed in 4 of 26 cases.  Level of Evidence = II.

Verhulst et al (2020) noted that trapeziectomy with ligament reconstruction and tendon interposition as well as TMC prosthesis are 2 commonly used procedures for 1st CMC joint OA.  These investigators compared the short-term outcome of trapeziectomy with ligament reconstruction and tendon interposition to TMC prosthesis.  PubMed, Cochrane library and science direct data-base were searched with adequate search terms.  Used parameters were force, pain, mobility, functionality and complication.  All studies describing short-term outcome of ligament reconstruction and tendon interposition or TMC prosthesis were included in this review.  Trapeziometacarpal prostheses showed faster pain relief compared with trapeziectomy and ligament reconstruction and tendon interposition.  Overall, there was a better strength in the TMC prosthesis group.  A lack of information was found about the short- term functionality.  The mobility recovered faster in the prosthesis group, although different scoring scales were used for measurement.  The authors could confirm the faster pain relief in the prosthesis group and generally a faster recovery of strength and mobility; however, there were more short-term complications in the prosthesis group were.  These researchers stated that more studies are needed to examine the short-term recovery of strength, the mobility, functionality and satisfaction.

In a retrospective study, Smeraglia et al (2020) examined minimal 8-year outcomes of 46 TMC joints (46 patients) treated with pyrocarbon implant arthroplasty after partial trapeziectomy for TMC joint OA in 2 different hand surgery units.  The mean follow-up interval was 9.5 years (average of 113 months with a range 97 to 144 months).  The study showed that pyrocarbon interpositional arthroplasty provided pain relief and high patient satisfaction.  All patients experienced a reduction in the DASH score, with an average change of 30 points.  The VAS, the Kapandji score, and key pinch also showed remarkable improvement.  The PyroDisk implant exhibited good longevity, with good implant survival.  A review of the literature revealed that the functional outcomes after implant surgery were not superior to more common techniques, such as trapeziectomy with or without ligamentoplasty.  The authors concluded that this is a reliable surgery but may not have added benefits over simpler surgical treatments.  They stated that this implant could have a role, perhaps in a select group of young patients, as a time-procuring procedure.  Level of Evidence = IV.

Froschauer and colleagues (2020) compared 34 patients with thumb CMC OA (37 thumbs) treated with the Elektra prosthesis, with 18 patients (18 thumbs) treated with resection-suspension arthroplasty (RSA), with an overall mean follow-up period of 13.3 years.  Evaluation with disability of arm and shoulder scores, pain via VAS and ROM (radial and palmar abduction, and opposition) indicated no significant difference.  However, the cohort with a surviving prosthesis showed significantly better subjective grip strength (p = 0.04).  Complications occurred in 23 of the 37 thumbs in the prosthesis group compared with 2 in the RSA patients; and 17 prostheses required revision.  At revision operations, these researchers observed local signs of metallosis in 15 of 17 cases.  Patients receiving RSA were more satisfied with their treatment (p = 0.003).  Thus, the authors could not recommend the implantation of Elektra prosthesis and they speculated that the key problem of aseptic cup loosening was a result of the metal-on-metal bearing.  However, if a prosthesis system could overcome the hurdle of aseptic cup loosening, total thumb CMC arthroplasty could become a reasonable therapeutic option for thumb base surgery.  Therefore, randomized studies with a comparable long-term follow-up period are needed to verify the sustainability of such a CMC prosthesis.  Level of Evidence = III.

The authors stated that this study had several drawbacks.  First, these researchers included a number of subjective parameters in their assessment.  Owing to a lack of pre-operative data, they included subjective grip strength as a parameter, although it may be difficult to estimate present grip strength in comparison with that more than 12 years ago.  The small sample sizes (n = 34 for the Elektra prosthesis group), especially in the RSA cohort, and a lack of randomized sampling were the other drawbacks of the study.

In a retrospective study, Martins et al (2020) examined the outcomes of 46 TMC joint replacements with the Moovis prosthesis in 46 patients with painful OA.  The dual mobility design of this prosthesis aimed to reduce prosthetic dislocation and subsidence.  At follow-up 2 to 6 years (mean of 5 years) after operation, pain was reduced from 6 to 0 on a VAS from 0 to 10.  The scores of the QuickDASH questionnaire improved significantly.  Thumb motion and grip and pinch strength did not differ significantly from the contralateral hand.  There were no radiographical signs of implant subsidence or loosening; and no implant needed revision.  A total of 5 patients rated the result as excellent or good.  The authors concluded that the Moovis is a reliable and effective implant at short- to mid-term follow-up.  Level of Evidence = IV.

In a retrospective study, Dumartinet-Gibaud et al (2020) reported a series of 80 Arpe prostheses for TMC OA in 63 patients; 27 prostheses (20 patients) were lost to follow-up; 21 were revised, 8 of them during the 1st year following operation.  The calculated cumulated implant survival rate was 85 % at 10 years; but could be lower due to the lack of information on the patients lost to follow-up.  The number of complications due to technical errors was high; but after these researchers had performed 30 cases, the number of early revisions decreased markedly.  At follow-up, 23 of 32 thumbs were totally free of pain, and the patients were satisfied with 31 thumbs.  The authors concluded that the implant survival declined progressively in the long-term, with a survival rate of 80 % after 15 years of follow-up and a further decline thereafter.  These researchers also found that this surgery was difficult to master; they advised employing this implant for thumb TMC OA with caution.  Level of Evidence = IV.

Remy and associates (2020) noted that the TMC prosthesis is mostly used in Europe to treat OA of the basal joint of the thumb.  Its’ supposed benefits are that it restores the length of the thumb, improves strength, function and mobility while reducing recovery time compared to other surgical treatments.  However, previous reviews of the literature could not confirm these assumptions.  These researchers provided an updated systematic review to aid in addressing these questions via a methodical statistical analysis and to quantify the 2 main complications (failure and deep infection).  They carried out a selection of articles including implant case series in the Medline database based on specific criteria.  Data on pain, function, strength, infection, and failure were compiled and a statistical analysis was conducted.  Results showed a fast recovery in terms of pain and function but the positive effect on strength appeared to be limited.  The failure rate represented by the revision rate was high and the deep infection rate was fairly low.  The authors concluded that RCTs are needed to obtain reliable data to compare the prosthesis to other surgical treatments.

Vanmierlo et al (2022) stated that TMC arthroplasties were designed to restore an adequate level of mobility, stability, and grip strength.  These researchers examined pain as well as functional and radiographic outcome of Ivory arthroplasty in male patients,  Between 2005 and 2012, the Ivory arthroplasty was inserted in 21 male patients with degenerative TMC OA, of which 14 patients were found eligible for inclusion.  Mobility, grip strength, patient self-assessment (pain; QuickDASH), and radiographic outcome were measured; 22 female patients who received an Ivory arthroplasty between 2005 and 2007 were included and underwent the same evaluation.  Age at primary surgery, survival rate of the implant, and clinical outcome were compared between the 2 groups.  In both groups, QuickDASH score and mean pain sensation improved significantly.  The improvement in mobility obtained significance in the female group.  In the male group, 7 arthroplasties failed (mean follow-up of 65 months).  In the female group, 3 of the 24 arthroplasties failed (mean follow-up of 123 months).  Kaplan-Meier survival analysis demonstrated a significant lower implant survival in the male group.  The authors concluded  that decrease in muscle mass and decline in grip strength that post-menopausal women tend to experience might explain the significant difference in implant survival between sexes.  In 4 of the 7 failed arthroplasties in the male group, no surgical revision was needed.  These researchers stated that TMC arthroplasty, even after radiographic failure, still served as a spacer, avoiding collapse of the thumb base.  However, the failure rate of the Ivory arthroplasty in male patients was high, and an alternative treatment should be considered.

Hansen et al (2021) stated that for thumb CMC OA, trapeziectomy provides generally good results with reduction of pain and restoration of thumb mobility, however, shortening of the thumb may at least in theory lead to reduction in grip and pinch strength.  Furthermore, instability of the base of the 1st metacarpal and contact with the scaphoid may occur regardless of the several described techniques with ligament reconstruction and tendon interposition.  Therefore, for years alternatives to trapeziectomy have been explored and reported with disputable success.  Often the road from idea to implantation in patients appeared to have been short, and high complication rates and failure of new implant designs have been fairly common.  This has led to the general impression that the implants do not provide sufficient benefits compared with simple trapeziectomy.  More recent uncemented total joint replacement designs have shown rapid rehabilitation, reduction of pain, restoration of grip strength and movement, and much improved long-term implant survival.  These factors may make total joint replacement a realistic alternative to trapeziectomy. Still, patient selection has to be improved, as the benefits may be small in the low activity elderly patient.

In a prospective study, Dremstrup and associates (2021) analyzed the early results of 200 consecutive total TMC joint arthroplasties using the Moovis cup, a new generation, dual-mobility, uncemented conical cup, with special focus on early complications.  At the 24-month follow-up, these researchers found clinically relevant improvement of function and comfort.  Among intra-operative complications were 9 intra-operative trapezial fractures, which were treated by screw osteosynthesis; prolonged immobilization; and conversion to cemented cup fixation or primary or secondary trapeziectomy; 1 was left untreated as the loose cup did not cause notable symptoms.  There were 3 implants with polyethylene wear and 2 with liner dislocation.  The authors concluded that early outcomes of this new-generation implant were favorable, however, its surgery was challenging and associated with important intra-operative and early post-operative complications related to the learning curve.  Attentive reaming of the trapezium and careful cup impaction were crucial steps to avoid trapezial fracture and early cup failure.  Level of Evidence = II.

Holme and colleagues (2021) stated that thumb CMC joint (CMCJ) arthritis is a common and painful condition.  Thumb CMCJ prosthetic replacement aims to restore thumb biomechanics and improve pain and function.  Early reviews showed a lack of high-quality studies, but more recently a significant number of higher-quality studies have been published.  These researchers provided a concise and systematic overview of the evidence to-date.  They carried out a systematic review of several databases according to PRISMA guidelines.  Studies examining the outcomes of thumb CMCJ prosthetic total joint replacement were included.  Data extracted included patient-reported outcome measures (PROMs), pain scores, ROM, strength, survival rates and complications.  A total of 56 studies met all inclusion criteria and were analyzed.  There was 1 RCT, 3 prospective, comparative cohort studies, 5 retrospective, comparative cohort studies, and 47 descriptive cohort studies.  The reported studies included 2,731 patients with 3,048 thumb total CMCJ prosthetic joint replacements.  Follow-up ranged from 12 months to 13.1 years.  In general, good results were demonstrated, with improvements in PROMs, pain scores and strength.  Failure rates ranged from 2.6 % to 19.9 % depending upon implant studied.  Comparative studies demonstrated promising results for replacement when compared to resection arthroplasty, with modest improvements in PROMs but at a cost of increased rates of complications.  Studies reporting outcomes in thumb CMCJ prosthetic total joint replacement are increasing in both number and quality.  Failure, in terms of loosening and dislocation, remains a concern, although in the medium-term follow-up for modern implants this issue appeared to be lower when compared to their predecessors.  The authors also noted that functional outcomes look promising compared to resection arthroplasty, but further high-quality studies using a standardized resection arthroplasty technique and modern implants, together with standardized core outcome sets, will be of value.

The authors stated that this systematic review had several drawbacks.  The quality of evidence has improved since the last systematic review on this topic, with a further 7 comparative trials (including 1 RCT); however, the majority of studies were still of a moderate methodological quality, even among the comparative studies.  The quality of reporting did not allow for a meta-analysis due to the heterogeneous datasets; therefore, it was not possible to draw a definitive conclusion regarding the superiority of replacement versus resection arthroplasty.  The definitions of loosening were variable and thus difficult to accurately report between studies.  The inclusion of core outcome sets, standardizing reporting of outcomes, will aid in future meta-analyses of datasets to enable more definite conclusions to be reached.

Brinke et al (2021) examined long-term survival and clinical outcomes of the surface replacement TMC joint prosthesis (SR™TMC) and evaluated implant migration using RSA.  In this follow-up study, outcomes of 10 patients who received the SR™TMC joint prosthesis were assessed using DASH and Nelson scores, VAS of pain, and key pinch strength.  RSA-radiographs were obtained direct post-operatively and 6 months, 1, 5 and 10 years post-operatively and were analyzed using model-based RSA software.  During follow-up, 2 early revisions took place.  Mean pre-operative DASH and Nelson scores were 54 (SD 15) and 54 (SD 17), improved significantly after 6 months (DASH 25 (SD 20), Nelson 75 (SD 18)) and remained excellent during long-term follow-up in all patients with a stable implant.  At final follow-up, clinical scores deteriorated clearly in 2 patients with a loose implant in-situ.  The authors concluded that long-term survival of the SR™TMC joint prosthesis was relatively poor; however, clinical outcomes improved significantly in the short-term and remained excellent in the long-term in those patients with a stable implant, but deteriorated clearly in case of loosening.  These researchers stated that the role of RSA in TMC joint arthroplasty is potentially valuable but needs to be further investigated.

In a systematic review and meta-analysis, Raj and co-workers (2022) compared joint replacement (JR) and trapeziectomy techniques to provide an update as to which surgical intervention is superior for 1st CMC (CMC-1) joint OA.  In August 2020, Medline, Embase and Web of Science were searched for eligible studies that compared these 2 techniques for the treatment of CMC-1 joint OA.  Primary outcomes included the DASH, QuickDASH (QDASH) and pain VAS scores; secondary outcomes (e.g., total complication, dislocation and revision surgery rates) were also measured.  From 1,909 studies identified, 14 studies (1,005 patients) were eligible.  The meta-analysis found that post-operative QDASH scores were lower for patients in the JR group (5 studies, p = 0.0004).  Similarly, significantly better post-operative key pinch strength in favor of JR was observed (3 studies, p = 0.001).  However, pain (VAS) scores were similar between the 2 groups (5 studies, p = 0.21).  Moreover, JR techniques had significantly greater odds of overall complications (12 studies; odds ratio [OR] 2.12; 95 % CI: 1.13 to 3.96, p = 0.02) and significantly greater odds of revision surgery (9 studies; OR 5.14; 95 % CI: 2.06 to 12.81, p = 0.0004).  The authors concluded that based on very low- to moderate-quality evidence, JR treatments may result in better function with less disability with comparable pain (VAS) scores; however, JR had greater odds of complications and greater odds of requiring revision surgery.  These researchers stated that more robust RCTs that compare JR and TRAP with standardized outcome measures and long-term follow-up would strengthen the quality of evidence available.

The authors stated that this review had several drawbacks.  The majority of the included studies were non-randomized with either moderate (9 studies) or serious (2 studies) risk of bias.  The 1 RCT included also had “some concerns” based on its risk of bias assessment.  The GRADE rating of the studies that were included in the meta-analysis included 2 “very low” ratings, 2 “low” ratings and 1 “moderate” rating, partly due to the large number of observational studies, which were susceptible to selection bias.  Another drawback was the comparison of only 2 techniques, thus, excluding alternative treatments such as arthrodesis and spacers.  Furthermore, some of the studies included in this review employed older models of JRs, such as Elektra and De la Caffiniere, which were not reflective of the prostheses used currently.  For example, the Ivory, Elektra and ARPE prostheses have shown good promise in this review, and therefore, the possibility of improved outcomes with newer prostheses should be considered.  Moreover, no subgroup analysis of the JR arm of this review has been performed, which was due to the numerous types of JRs included as well as an insufficient number of studies of each type of JR, which were inadequate for the purposes of performing a meaningful subgroup analysis.  Finally, the meta-analyses are limited by the lack of robust RCTs that compare these 2 techniques, and thus, it is not currently possible to reach a definitive conclusion on which technique is superior overall.

The CapFlex-PIP Implant for Proximal Interphalangeal Joint Arthroplasty

In a prospective, case-series study, Schindele et al (2015) examined the 1-year post-operative clinical and patient-rated outcomes in patients receiving PIP joint arthroplasty with a modular surface gliding implant, CapFlex-PIP.  A total of 10 patients each with primary OA of a single PIP joint were assessed pre-operatively (baseline), at 6 weeks, and 3, 6, and 12 months after CapFlex-PIP arthroplasty for lateral stability and ROM of the affected digit.  Furthermore, patients rated their pain using a numeric rating scale (NRS) and function and overall assessment of their treatment and condition using the QuickDASH and Patient Evaluation Measure (PEM) questionnaires, respectively.  The mean baseline active mobility of the affected PIP joint increased from 42° to 51° by 1 year, although this change was not significant.  Patients reported reduced pain at 1 year, which was statistically significant.  There was also a significant improvement between baseline and 1-year QuickDASH (43 points versus 15 points, respectively) and PEM scores (51 points versus 25 points, respectively).  Absent or low lateral instability was observed in 9 joints at follow-up.  All implants remained intact over the 1-year post-operative period and there was no migration, osteolysis, or implant fracture.  After study completion, 2 patients underwent tenolysis.  The authors concluded that patients experienced a significant reduction in pain and a trend towards increased mobility.  All implants showed complete osteo-integration without evidence of radiological migration; and lateral stability improved.  Moreover, these researchers stated that this implant still requires careful systematic evaluation over years.  A special online registry has been created to monitor these patients on a regular basis.  Level of Evidence = IV.

The author stated that this study had several drawbacks.  First, the indication for this new prosthesis was restricted to patients with almost ideal joint conditions.  Little deviation of the joint axis, minimal lateral instability, sufficient ROM, intact extensor and flexor tendons, no cyst formation, and no protrusion of the affected joint were the prerequisites for implantation.  These investigators stated that these findings need to be confirmed in a larger study including less strict indication criteria.  Second, the surgeries were carried out by 2 experienced surgeons who were involved in the implant’s design.  However, all study evaluations were performed by independent observers.  Third, the small patient series (n = 10) limited the statistical power of this study.

Reischenboch et al (2021) examined the 5-year outcomes in patients after proximal interphalangeal joint arthroplasty using the surface replacing implant, CapFlex-PIP.  A total of 92 prosthesis were implanted and 65 patients with 68 implants were available for follow-up.  The brief Michigan Hand Outcomes Questionnaire (MHQ) score improved significantly from 45 (SD 15) before surgery to 71 (SD 17) at 5 years.  On the NRS, pain during activities decreased significantly from 6.4 (SD 1.9) to 1.8 (SD 1.9); ROM of the joints increased significantly from 45° (SD 21) to 54° (SD 24).  An axis deviation of more than 5° was found in 65 % of the joints before surgery, but only in 25 % at 5 years.  Soft tissue re-operations were carried out on 8 patients; 4 out of 92 implants underwent revision for stiffness or implant loosening.  In 3 implants, the distal component migrated without needing revision.  The authors concluded that the CapFlex-PIP implant showed favorable medium-term results in surface replacing arthroplasty of the proximal interphalangeal joint.  Moreover, these researchers stated that future prospective, long-term studies should be standardized regarding the surgical approach and examiner; and should include a control group to examine if the CapFlex-PIP surface replacing implant would yield superior outcomes over other implants.  Level of Evidence = IV.

The authors stated that this trial had several drawbacks.  First, these investigators analyzed data from a registry used for routine clinical documentation, a significant number of patients (23 patients, 26 %) were lost to follow-up and 8 patients had either missing clinical or questionnaire data at 5 years.  Second, no comparison group (e.g., patients with silicone arthroplasty) was available.  Third, the surgeries were carried out by 4 different surgeons and different approaches were used for implantation.  Assessments were also carried out by different surgeons; thus, variations in the surgical techniques or assessment could have potentially influenced the outcomes.  Fourth, the use of the brief MHQ, which evaluated the function of the entire hand.  Because patients often had more than 1 affected finger or joint, the score might be influenced by symptoms stemming from other parts of the hand.  Fifth, only 4 revisions were included in the estimation of the 5-year survival rate leading to a large confidence interval; thus, the revealed survival rate of 87 % could be unreliable and too low, since the Kaplan–Meier method is known to over-estimate the risk of implant revisions.

X Fuse Implant for Distal Interphalangeal Joint Arthrodesis

De Almeida et al (2019) reported the clinical and radiographic results of DIP joint arthrodesis using the X-Fuse implant with a mean follow-up of 24 months (6 to 54).  A total of 41 patients (33 women and 8 men) with a mean age of 65 years were operated on.  DIP joint arthrodesis was carried out on 54 fingers for advanced OA resistant to medical treatment.  Pain evaluated on a VAS was reduced significantly, going from 5 to 0.47.  Functional DASH and patient rated wrist evaluation (PRWE)-Hand scores were improved by 33 and 36 points, respectively; 4 fingers (7.4 %) were sensitive to cold.  No cases of nail dystrophy were reported.  The fusion rate was 89 %.  Of the 6 patients (11 %) who suffered a non-union, there was 1 case of asymptomatic fracture of the implant, without re-operation, and 1 case of infection, which required revision surgery.  The fusion position was stable at the review visit.  The repeat surgery rate was 3.7 %; both cases were for infection.  The authors concluded that the X-Fuse implant was a viable alternative to traditional arthrodesis techniques (compression screws and pins), with a similar fusion rate.  This implant appeared to be very well-tolerated by patients, with an absence of nail dystrophy and a reduction in the risk of infection.  Moreover, these researchers stated that in the future, a large, prospective study directly comparing compression screws and X-Fuse implants would be beneficial.  These investigators noted that the drawbacks of this trial were its retrospective design and the small number of cases in the non-union group, which did not allow for comparison with the successful group fusion.

McCarthy et al (2021) stated that arthrodesis of the distal interphalangeal joint of the fingers and interphalangeal joint of the thumb is a common procedure for multiple diagnoses.  These researchers examined the fusion rates and complications in patients who have been previously implanted with an X Fuse implant.  All patients who underwent distal interphalangeal and/or thumb interphalangeal joint fusion between June 2013 and May 2019 were included in this study.  A chart review was used to note demographics; hand dominance; and medical and surgical history, including complications, co-morbidities, clinical recovery, absence of pain, and functional use.  Pre- and post-operative radiographs were evaluated for angular deformity, post-operative correction of that deformity, boney consolidation, and tine cut-out.  A total of 53 patients (60 fingers; 43 women and 10 men) with a mean age of 62.6 years were included.  The surgical diagnoses included hereditary OA in 45 patients, rheumatoid arthritis (RA) in 4, psoriatic arthritis in 1, swan or mallet fingers in 5, ulnar motor loss instability in 2, and trauma or a fracture in 3.  For X Fuse, an implant angle of 0° was used in 51 cases, whereas 15° was used in 9 cases.  Bone consolidation was observed in all but 1 patient at an average time of 9.7 weeks (range of 4.1 to 17.6 weeks).  The X Fuse implant in small bones demonstrated minimal complications and a 98 % (59/60) fusion rate.  The authors concluded that the X Fuse implant produced a reliable fusion, with no implant prominence and a 1.7 % (1/60) rate of hardware removal.  Level of Evidence = IV.

The authors stated that a major drawback of this trial was the relatively short follow-up duration (average of 18.7 weeks (± 18.9 SD)).  The patients typically had their 1st post-operative visit 10 to 14 days after surgery, and then, they returned at 6 and 12 weeks.  Patients with functional use without pain were not followed-up beyond the 90-day period.  Those with problems returned as needed.  It was possible that a longer duration of follow-up would have resulted in additional long-term complication rates; however, these were rare once patients were doing well.  Another drawback of this series was the use of the temporary supplemental K-wire used in 50 of the 60 cases.  The technique manual stated that the use of any other implant with the X Fuse implant is contraindicated.  However, given the senior author’s experience, when the surface area for fusion was small and there was an intra-medullary device centrally, soft metaphyseal bone distally, and a pre-operative angular deformity, a bone graft and K-wire were added to ensure a high fusion rate.

The Tactys Prosthesis for Proximal Interphalangeal Joint Arthroplasty

Lozano et al (2022) stated that preliminary findings with the Tactys modular gliding prosthesis for PIPJ arthroplasty were encouraging, with notable improvement in clinical and functional scores at 1- and 2- year follow-up; however, a recent study found a trend for deterioration over time.  These researchers examined medium-term outcomes.  A total of 64 arthroplasties were carried out in 48 patients in a single center between January 2015 and January 2020.  Clinical, functional, and radiographic outcomes were analyzed at short- and medium-term follow-up for 15 of these arthroplasties.  Mean follow-up of the 48 patients was 3.1 years.  Pain significantly decreased on the NRS (p < 0.01) and the functional QuickDASH score improved from 67.3 to 55.9 (p < 0.01).  Grip and pinch strengths were lower in the operated than in the contralateral hand (p = 0.04 and p = 0.6, respectively).  PIP joint active ROM in flexion/extension improved from 44° to 49.4° (p = 0.17); 70 % of the 48 patients were satisfied; 15 arthroplasties were analyzed at 17- and 61-months follow-up; pain relief continued.  ROM decreased from 57° to 46° (p < 0.05) and the functional QuickDASH score deteriorated from 25.8 to 54.7 (p < 0.01).  Both grip and pinch strength increased, with a significant difference in pinch (p = 0.003).  The main complication was swan-neck deformity (46 %), with a mean 11 months' onset.  The authors concluded that these findings confirmed the deterioration trend observed over time in the functional results of the Tactys prosthesis despite good patient satisfaction.  Level of Evidence = 4.

Philips et al (2022) noted that degenerative arthritis of the PIP joint of the long fingers is a common disorder affecting mainly a female middle-aged population.  Conservative treatment is often effective; however, in some cases, pain can persist which can result in invalidating function.  Besides denervation and arthrodesis, arthroplasty is a valuable alternative treatment.  In a retrospective study, these researchers examined the clinical and radiological outcomes of the Tactys prosthesis with a mean follow-up of more than 5 years.  Between October 2005 and August 2019, a total of 10 joints in 9 patients, (1 patient had 2 prostheses in 2 separate fingers; 4 men and 6 women) were treated for painful degenerative arthritis of the long fingers with a Tactys prosthesis.  Power grip and pinch force were tested pre-operatively and post-operatively, and the functional outcome survey was carried out using the QuickDASH, recall QuickDASH, and PRWE standardized questionnaires score of 100 and the VAS from 0 to 10.  Mean follow-up was 65.7 months (range of 23 to 106).  Mean age was 71.5 years (range of 64 to 83).  QuickDASH score evolved from 68.43 to 41.92, ROM from 37.5° to 45.1°, VAS from 6.65 to 1.0.  Power grip and precision pinch evolved from 16.44 to 20.80 kg and 1.97 to 2.85 kg, respectively.  The authors concluded that Tactys arthroplasty can be proposed for individuals who have been unsuccessful treated with conservative treatment . Infection rate was still the highest complication, which could evolve in invalidating arthrodesis. These investigators stated that Tactys arthroplasty should be proposed exceptionally if the PIP joint arthritis causes invalidating functional pain.  This was a small study (n = 9 patients) with medium-term follow-up (mean of 65.7 months); these findings need to be validated by well-designed studies.

Unconstrained Pyrocarbon and Metal-on-Polyethylene Proximal Interphalangeal Joint Arthroplasty

Kulkarni et al (2022) stated that unconstrained pyrocarbon and metal-on-polyethylene (MoP) PIP joint arthroplasty is an increasingly popular alternative to silicone implants and arthrodesis.  In a systematic review, these investigators examined their outcomes.  A total of 30 studies comprising 1,324 joints (813 pyrocarbon, 511 MoP) were included.  Mean patient age was 59 years (38 to 78) and mean follow-up period was 54 months (12 to 118).  There were mean improvements of 4.5 points (2 to 6.9) in pain VAS, 10.5° (-26 to 58) in ROM, 3.1 kg (-4 to 7) in grip strength, 0.6 kg (-1.5 to 2) in pinch strength and 18 points (-3 to 29) in the DASH score, with no significant differences between implant types.  ROM gains deteriorated over time.  Clinical complications were frequent (23 %) and significantly more common with pyrocarbon, as were radiographic complications.  However, most were mild-to-moderate and did not necessarily correlate with negative outcomes or dissatisfaction.  Overall re-operation rate was 21 %, and revision rate 11 %, both more frequent with pyrocarbon.  Most revisions were within 24 months, beyond which survival was maintained up to 10 years.  The authors concluded that unconstrained PIP joint arthroplasty was effective in improving pain scores, active ROM, grip/pinch strength and PROMs, especially in patients with OA.  Results were generally maintained at least to the medium-term, although gains diminished in the longer term.  Complication and early revision rates were high, especially with pyrocarbon implants.  Most patients expressed positive attitudes to arthroplasty, with significant improvements in PROMs for both pyrocarbon and MoP implants.  Patients with post-traumatic and inflammatory arthropathy were generally less satisfied.  These researchers noted that there is currently insufficient data to recommend one implant type over another, although the early-to-medium term results of MoP implants are promising.  They stated that prospective surveillance via small joint registries is recommended.  Level of Evidence = III.

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References