Osteointegration of a modular metal-polyethylene surface gliding finger implant: a case report

Prosthetic arthroplasty of the proximal interphalangeal joint using a surface replacing implant (CapFlex-PIP): 3-year outcomes

Level of evidence: IV.

Novel approaches to fitting and implanting finger and nail prosthetics

PURPOSE

This work presents unique designs for prosthetic restoration of the distal finger. We first discuss fitting a prosthetic nail in order to restore the cosmetic deficit caused by partial or complete nail injury. This concept is inspired from snap fit and lanced sheet metal technology. We also discuss new approaches to designing and fitting a full fingertip prosthetic with a special suspension and a socket for more complete cosmetic fingertip restoration.

METHODS

The designs utilize the compliance and higher strain level of hinges to fit the prosthesis with either the residual nail or to the distal-most aspect of the amputated fingertip. These techniques require preparation of the residual nail to match the fabricated nails well as design of a snap fit nail prosthetic. The socket and suspension design of the full fingertip prosthetic is formed with a spring shape and has an open end to allow proper molding, fit, and suspension.

RESULTS

The introduced approaches simplify the assembly steps and propose unique, cosmetically appropriate, and potentially less irritating prosthetic options compared to what has been previously used. The socket of the finger has an ability to expand and can be worn on any stump size.

CONCLUSION

Low cost, fewer parts, ease of assembly and user friendly are the main attributes of the introduced designs. Future work to finalize these designs and trial them in humans is needed.

Surface replacing arthroplasty of the proximal interphalangeal joint using the CapFlex-PIP implant: a prospective study with 5-year outcomes

The purpose of this prospective study was to evaluate the 5-year outcomes in patients after proximal interphalangeal joint arthroplasty using the surface replacing implant, CapFlex-PIP. Ninety-two prosthesis were implanted and 65 patients with 68 implants were available for follow-up. The brief Michigan Hand Outcomes Questionnaire score improved significantly from 45 (SD 15) before surgery to 71 (SD 17) at 5 years. On the numeric rating scale, pain during activities decreased significantly from 6.4 (SD 1.9) to 1.8 (SD 1.9). Range of motion 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 reoperations were performed on eight patients. Four out of 92 implants underwent revision for stiffness or implant loosening. In three implants, the distal component migrated without needing revision. Overall, the CapFlex-PIP implant demonstrates favourable medium-term results in surface replacing arthroplasty of the proximal interphalangeal joint.Level of evidence: IV.

[Implant arthroplasty in the metacarpophalangeal and proximal interphalangeal finger joints]

BACKGROUND

 Osteoarthritic changes in the finger joints are common, especially in the elderly population. Without adequate treatment, these changes can lead to pain, joint deformity, instability or impaired motion. Operative treatment options can be divided into prosthetic joint replacement, joint fusion and denervation.

PATIENTS/MATERIAL AND METHOD

 During the last decades, various prosthetic implant designs have appeared on the market. This article provides an overview of implant evolution, current implants, clinical results and promising technical novelties.

RESULTS

 Due to favourable clinical long-term results, low revision rates and low costs, the proven silicone spacer has been the gold standard since the 1960 s. In the index and middle finger, lateral stability is crucial to providing a counter bearing to the thumb for a strong key pinch. Medullary-anchored prostheses and modular surface replacement designs have a higher intrinsic stability and may thus be advantageous in the index and middle finger. These implants show promising clinical medium-term results.

CONCLUSION

 In the past, technical novelties from big joint replacements could not automatically be translated to the finger joints and other parts of the hand. However, new trends such as customised or 3D-printed prosthetic implants are slowly beginning to gain importance in hand surgery.

Failure of Osseointegration of a Semiconstrained Finger Prosthesis in a Post-traumatic Metacarpophalangeal Joint Defect: A Case Report

CASE

Post-traumatic defects of the metacarpophalangeal joint (MCPj) remain challenging for hand surgeons. Restoration of stability and motion are difficult to achieve because of the complex anatomy and kinematics. The Robert Mathys (RM) semiconstrained prosthesis offers good intrinsic stability and mobility and therefore seems suitable. We report on a patient where the RM prosthesis was used for a traumatic destroyed ring finger MCPj reconstruction but failed because of aseptic loosening. We discuss possible reasons in light of the current literature on post-traumatic MCPj arthroplasties and the RM prosthesis in particular.

CONCLUSION

The RM proximal interphalangeal prosthesis does not seem suitable for post-traumatic replacement of the MCPj.

Non-vascularized partial joint transfer for Finger Proximal Interphalangeal joint reconstruction: a series of 9 patients

INTRODUCTION

Finger proximal interphalangeal joint (PIP) reconstruction after the destruction of parts of the joint remains challenging. Surgical techniques include implant arthroplasty, arthrodesis, free vascularized joint transfer, and non-vascularized bone and joint transfer. This study analyzes our experience after non-vascularized transfer in terms of range of motion, postoperative rehabilitation, and patient satisfaction.

MATERIALS AND METHODS

Between 2009 and 2014, ten patients underwent non-vascularized partial joint transfer for PIP joint reconstruction. One of them was lost to follow-up. Included patients had osteochondral partial joint transplants of 25-50% of the toes (n = 4) and the hand (n = 5). Range of motion (ROM), grip-, and pinch-strength were measured at the last follow-up control and compared to the healthy side. Patients were asked to score the pain at rest/ on load on a visual scale (VAS: 0 = no pain; 10 = excruciating pain). Satisfaction self-assessment was evaluated by asking the patients to grade their postoperative result as excellent, very good, good or poor.

RESULTS

Mean follow-up period was 4.0 years (range 1.2-7.9 years). Mean PIP joint flexion was 93 ± 26° at the last follow-up control. Mean grip- and pinch-strength of the operated side at the last control were, respectively, 43 ± 18 kg and 8 ± 5 kg, close to the healthy side values (45 ± 15 kg and 9 ± 4 kg). Mean pain at rest/on load measured on a visual scale was, respectively, 0.3 ± 1 and 1.8 ± 2. Eight patients (89%) rated their operation as excellent, and one as poor.

CONCLUSION

In this study, non-vascularized partial joint transfer provides a mobile and stable PIP joint 4 years after reconstruction. The surgical technique presented herein is complex depending on additional injuries but results in great patient satisfaction.

[Anatomy of the trapeziometacarpal joint in the context of arthroplasty]

The thumb has a crucial role in the hand due to its position with regard to the fingers. The CMC-1 joint enables an extraordinary range of motion, since its geometry allows for opposition. The former joint may often succumb to osteoarthritis because a great range of motion in combination with large forces, small contact areas, and thorough usage are always present. Joint replacement is challenged by the great range of motion based on the necessary joint stability and the demand for sufficient pain reduction. This review highlights the anatomy of the CMC-1 joint with regard to joint preplacement solutions.

[Anatomy of the metacarpophalangeal and proximal interphalangeal finger joint with respect to arthroplasty]

BACKGROUND

Precise knowledge of the anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joint is the basis for both indication and implantation of a finger joint prosthesis. Currently available finger joint prostheses inadequately take into account individual, ethnological, gender, age, and side differences. They can remain compromised despite the possible combination of their components.

OBJECTIVES

To elucidate which problems of finger joint arthroplasty exist due to the anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joints.

METHODS

The anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joint are described, and the problems and solutions of finger joint arthroplasty are presented.

RESULTS

Despite precise knowledge of the anatomy and biomechanics of the metacarpophalangeal and proximal interphalangeal joint, not all problems of finger joint arthroplasty have been solved. However, a modular surface replacement appears promising for the proximal interphalangeal joint.

CONCLUSIONS

Artificial joint replacement of the metacarpophalangeal and proximal interphalangeal joint is difficult with regard to morphology, small bone dimensions, complex biomechanics, and the strain of the hand. Further improvements, especially in design, should be achieved by exact anatomical imitation.

[Metacarpophalangeal joint replacement]

BACKGROUND

Arthroplasty of metacarpophalangeal (MCP) joints is crucial for patients with rheumatoid arthritis. Motion preserving therapies are mandatory for this joint, since loss of function of the MCP joint is detrimental. Many protheses or spacers have been introduced over the last 80 years, but most of them have been dismissed due to major complications.

CURRENT PROCEDURES

Since the 1960s the Swanson spacer has been established as the reference standard for motion preserving procedures of the finger MCP joints. High fracture rates of the spacer do not seem to limit function and patient satisfaction after all. Current long-term studies show at least promising results for pyrolytic carbon protheses with respect to range of motion, survival, and revision rates in comparison to the Swanson spacer.

[Open reduction and plate/screw osteosynthesis of proximal phalanx fractures]

OBJECTIVE

Anatomical open reduction and internal fixation using screw/plate osteosynthesis.

INDICATIONS

Extra-articular fractures with clinically evident malrotation of the finger, comminution fracture and/or loss of length, which cannot be treated non-operatively; fracture instability; intra-articular fracture with step off greater than 1 mm, which cannot be treated percutaneously but openly using plate/screw osteosythesis; failure of conservative treatment.

CONTRAINDICATIONS

General operative limitations.

SURGICAL TECHNIQUE

Dorsal, mediolateral, or palmar approach, temporary reduction using pincers or optional Kirschner wires; screw/plate osteosynthesis for internal fixation.

POSTOPERATIVE MANAGEMENT

Immediate mobilization facilitated by buddy loops for the first 4-6 weeks, prevention of edema using elastic dressing, physiotherapy.

RESULTS

Open reduction and internal fixation using screw/plate osteosynthesis provides good results in combination with immediate mobilization. Nevertheless, adhesion of tendons or capsule tissue with restriction of range of motion is observed.

Complications, reoperations and revisions after proximal interphalangeal joint arthroplasty: a systematic review and meta-analysis

This systematic review and meta-analysis investigates the prevalence of complications, reoperations (surgeries without implant modifications) and revisions (surgeries with implant modifications) after proximal interphalangeal joint arthroplasty with pyrocarbon, metal-polyethylene and silicone implants. Thirty-four articles investigating 1868 proximal interphalangeal joints were included. Implant-related complications were associated with 14%, 10% and 11% of the pyrocarbon, metal-polyethylene and silicone implants, respectively, yet these rates were not significantly different from one another. Silicone implants showed more finger deviations (3%) and instabilities (2%) compared with the other implants. Reoperations were fewer for silicone arthroplasties (1%) compared with pyrocarbon (7%) and metal-polyethylene implants (10%). The revision rates of 4%, 3% and 2% were similar for pyrocarbon, metal-polyethylene and silicone implants. Our results indicate that silicone implants remain a valuable option for the treatment of stable proximal interphalangeal joints. Surface replacing implants might be better to correct unstable or deviated proximal interphalangeal joints, although they are associated with a higher risk of reoperations.

Proximal interphalangeal joint arthroplasty with Tactys®: Clinical and radiographic results with a minimum follow-up of 12 months

The Tactys® implant is a total anatomic gliding and modular prosthesis for proximal interphalangeal (PIP) arthritis. We report the clinical and radiographic results of this implant with a minimum follow-up of 12 months. Thirty-three implants in 27 patients with a mean age of 67 years were reviewed. Surgical approach was mid-line dorsal and trans-tendinous. Postoperative active motion was performed with a protective splint for 4 weeks. All patients were evaluated (pain, range of motion, strength, function through QuickDASH and PRWE scores, X-rays) by an independent examiner. The mean follow-up was 21 months (range: 12-30). Pain decreased from 7.4 to 1.6 on a VAS scale (P<0.001). Flexion-extension range of motion increased from 32.1° to 59.2° (P<0.001). Functional QuickDASH and PRWE improved from 64.5 and 67.1 to 25.5 and 19.5, respectively (P<0.001). Grip and pinch strength increased from 15.1 and 1.8 to 24.2 and 2.4kg/F, respectively (P<0.001). At the last follow-up, a swan neck deformity was noticed in three patients, which was reducible in all cases. Four patients were reoperated: dorsal tenoarthrolysis in three cases and correction of swan neck deformity in one case. On X-rays, asymptomatic periprosthetic ossifications were noticed in 13 cases (39%). There were no signs of implant migration or loosening. Our results are comparable to those of other published studies of PIP arthroplasty. The modularity of the Tactys® implant allows the range of motion of the PIP joint to be maintained. It is a reliable alternative to other conventional PIP implants.

LEVEL OF EVIDENCE

Level 4, case series.

Robert Mathys Finger prosthesis of the proximal interphalangeal joint: a retrospective case series of 19 joints in 17 patients

INTRODUCTION

The Robert Mathys (RM) Finger is a hinged type of arthroplasty for the metacarpophalangeal and proximal interphalangeal (PIP) joint that compensates ligament instability. The aim of this study is to evaluate the outcomes and complications of RM Finger arthroplasty of the PIP joint.

MATERIALS AND METHODS

A retrospective case series of 19 RM Finger arthroplasties of the PIP joint in 17 patients was performed with a median follow-up of 36 months. The active range of motion (AROM) was measured pre-operatively, at the 6-week follow-up, at the termination of hand therapy, and at the final follow-up. Complications were recorded, as well as pain on a visual analog scale (VAS), stability, deformity, pinch strength, the Michigan Hand Outcomes Questionnaire (MHQ), and the Patient Global Index of Improvement Questionnaire.

RESULTS

One implant fracture occurred. Another patient had an amputation due to stiffness. For the remaining joints, AROM was 61°. One joint mobilization under local anesthesia, one arthrolysis and two extensor tendon reconstructions were also necessary. Pain at the follow-up was 1.2 on the VAS. Relative pinch strength was 69%. Joint stability was restored in all fingers, although one joint had an ulnar deviation of 15°. Eight fingers developed a snapping phenomenon, of which five had a swan neck deformity. One finger had an extension lag with a Boutonnière deformity. MHQ scores were less compared to the unaffected hand. Fifteen patients rated their outcome as improved compared to their pre-operative condition.

CONCLUSIONS

RM Finger arthroplasty of the PIP joint restores joint stability with AROM improvement, and with low pain, although it has a high rate of complications.

LEVEL OF EVIDENCE

IV.