Early results of a prospective study on the pyrolytic carbon (pyrocarbon) Amandys® for osteoarthritis of the wrist

Arthroscopic proximal carpal row replacement by semitendinosus and gracilis graft (CArpus Row Plasty Using the Semitendinosus: CARPUS procedure). An anatomical study of 16 cases

INTRODUCTION

Post-traumatic lesions of the carpus (scapholunate rupture, scaphoid non-union) frequently evolve into disabling osteoarthritis (scapholunate advanced collapse or scaphoid non-union advanced collapse: SLAC or SNAC wrist). Proximal row carpectomy (PRC) is a reliable option but with poorer prognosis in case of osteoarthritis of the distal radius or capitate head. In such situations, radiocarpal arthrodesis may be necessary, sacrificing wrist motion. To circumvent this limitation, we propose a new procedure consisting in arthroscopic PRC and replacing the proximal row by tendon graft.

METHODS

This was a study on 16 cadaver specimens. A scapholunate pin was introduced via an approach into the anatomical snuffbox and used as a guide for a cannulated drill bit (9mm) to create a tunnel through the proximal row. The arthroscope and a reamer were introduced into the tunnel via its radial and ulnar ends. PRC was performed under arthroscopic control. The gracilis and semitendinosus tendons were harvested and folded so as to obtain a graft with the same length and diameter as the proximal row. The graft was threaded through the radial approach and fixed to the capsule.

RESULTS

Mean procedure time was 68min. There was no pre- to postoperative difference in joint motion or carpal height. On radiocinematography, the graft was stable between the radius and the second row of the carpus. The radial and ulnar sensory branches, median nerve and radial artery were intact at end of procedure.

DISCUSSION

This technique could be a solution in SLAC or SNAC wrist with osteoarthritis of the capitate head or radial glenoid. It also conserves carpal height. Being arthroscopic, the procedure avoids the major edema observed after a dorsal approach of the carpus, and also ensures graft stability, since the radiocarpal ligaments are conserved. Harvesting from a second anatomical site and the in vivo fate of the transplant are two issues that need to be discussed.

CONCLUSION

This anatomical study paves the way for clinical experimentation.

LEVEL OF EVIDENCE

IV.

Medium-Term Outcomes for Amandys Implant: A 5-Year Minimum Follow-Up of 63 Cases

Background  Amandys is a pyrocarbon interposition implant used as a therapeutic alternative to total wrist fusion (TWF) or total wrist arthroplasty (TWA) in painful and disabling extensive destruction of the wrist. Objective  To review mid-term outcomes in a continuous prospective series of patients who underwent wrist arthroplasty Amandys with a minimum follow-up of 5 years. Methods  Clinical evaluation included a satisfaction survey, pain, two functional scores, the short version of the Disabilities of the Arm, Shoulder, and Hand (QuickDASH) and the Patient-Rated Wrist Evaluation (PRWE), active wrist mobility, and grip strength compared with the contralateral side. Radiological evaluation was used to detect implant subsidence, carpal migration, bone lysis, or implant malposition. All per- and postoperative complications were collected. Results  Fifty-nine patients (63 procedures) were evaluated with a mean follow-up of 7 years; 57% of the patients were males, and the mean age was 58 years. Among the patients, 90% were satisfied or very satisfied. Pain was significantly improved, with a gain of 4/10 ( p  < 0.001). Functional outcomes also improved between the second and fifth year of follow-up. Active mobility was preserved and grip strength was significantly improved by 7 kg ( p  < 0.001). No implant subsidence or carpal migration was observed. Ten patients (11.9%) underwent revision surgery for conflict (1%), rotation (6%), or implant dislocation (5%). All complications and revisions occurred early with no new events after 1 year of follow-up. Discussion  Mid-term clinical and radiological outcomes were stable with improvement of functional scores. The survival rate was comparable to that reported for TWF with conserved mobility. We report fewer complications compared with those reported for TWA or TWF. Early instability of the implant was the main etiology of the revisions. Repositioning of the implant was successful. No conversion to TWA or TWF was necessary. Conclusions  Mid-term outcomes of the Amandys implants were encouraging. Patients conserved good wrist motion with improved strength and functional scores. The implant was well tolerated. Functional outcomes continue to improve with the follow-up. The survival rate remains stable after 2 years. The level of evidence of this study is IV (therapeutic case series).

Ulnar nerve compression secondary to migration of pyrocarbon implant following right wrist arthroplasty

A 50-year-old, right-hand dominant woman presented with a seven-month history of stiffness, pain and swelling on the ulnar side of her right wrist. She had undergone right wrist arthroplasty with a Pyrocarbon Amandys implant seven months previously for post-traumatic degenerative arthritis. She had an uneventful initial recovery until developing carpal tunnel syndrome, for which she underwent carpal tunnel release 5 months after her arthroplasty.

Examination revealed a painful and limited range of movement in the affected wrist, with weakness of the first dorsal interosseous muscle and altered sensation in the ring finger. A hard swelling was visible and palpable on the palmar-ulnar aspect of the wrist. X-rays showed that the swelling was due to the dislocated Amandys implant (which was thought to be causing compression neuropathy of the ulnar nerve). The patient underwent removal of the pyrocarbon implant (through a palmar approach) and total wrist fusion one month later, following which the wrist successfully united and all symptoms of ulnar nerve compression resolved.

Although some studies have reported migration of pyrocarbon implant following total wrist arthroplasty, to our knowledge, this is the first reported case of ulnar compression neuropathy from a migrated pyrocarbon wrist implant.

Promising results after hemi-shoulder arthroplasty using pyrolytic carbon heads in young and middle-aged patients

INTRODUCTION

The objective of this prospective cohort study was the assessment of short-term outcome results of shoulder hemiarthroplasty (HA) using pyrolytic carbon (PC) heads. PC has been introduced as a new material to avoid surgical revision due to glenoid erosion after HA. Glenoid erosion due to the use of metallic heads is known to reduce durability.

HYPOTHESIS

HA using PC heads shows comparable or better radiographic and clinical outcome compared to the conventional HA using metallic heads in the short-term.

PATIENTS AND METHODS

This study was conducted as a single center prospective cohort follow-up study including a total number of 16 consecutive HA with PC heads. Inclusion criteria were indication for HA, an intact rotator cuff, no proximal humeral fractures in patient's history and age>18years. Mean age at the time of arthroplasty was 52.8±10.8years. The mean follow-up was 24.3±8.1months. Baseline and follow-up Numeric Rating Scale (NRS), Constant Scores (CS), Range of Motion (ROM) and radiographs were assessed.

RESULTS

At a mean follow-up of 24.3months the mean CS (p<0.001), mean NRS (p<0.001) and mean ROM (p<0.05) improved statistically significant. Subgroup analysis revealed no differences between subgroups (sex, age, diagnosis, and handedness). Survival rate was high (94.1%). One periprosthetic fracture occurred as the only complication during follow-up. Radiographs showed glenoid erosion in one case and subacromial space reduction in two cases.

DISCUSSION

PC heads in HA show satisfying short-term results at a mean follow-up of two years, which are comparable to those of conventional HA. The clinical improvements were highly significant with good implant survival. However, long-term follow-up results are necessary, especially compared to conventional HA.

LEVEL OF EVIDENCE

IV; observational therapeutic cohort study.

Results of interposition arthroplasty with the Amandys® pyrocarbon implant in rheumatoid wrist at a mean 5 years' follow-up

Management of severe joint involvement in rheumatoid wrist is controversial. The gold-standard is total wrist fusion, but total wrist replacement offers a motion-conserving alternative. The purpose of this study was to present the results of interposition arthroplasty with the Amandys® pyrocarbon implant in rheumatoid wrist. We performed a retrospective review of 28 arthroplasties for rheumatoid wrist arthritis. Eighteen females and 5 males were included, with a mean age of 55.7 years. Mean follow-up was 64 months. We measured range of motion, grip strength, and pain (on VAS). Function was evaluated preoperatively and at last follow-up with the DASH and PRWE scores. Mean range of motion in flexion-extension was maintained while mean inclination and rotational range of motion showed significant improvement. Mean grip strength increased from 10 kg to 17 kg. Mean pain score decreased from 6/10 to 2/10. Mean PRWE and QuickDASH scores decreased from 62/100 to 25/100 and from 62/100 to 36/100, respectively. Three patients underwent early reoperation to reposition a dislocated implant. No implants had to be removed. Amandys® pyrocarbon arthroplasty is a reliable alternative to total fusion or total replacement in rheumatoid wrist. Indications must be limited to well-aligned wrists with competent capsule-ligament structures.

Clinical, functional, and radiological results of the Amandys® interposition arthroplasty in 13 cases of wrist osteoarthritis

Amandys® pyrocarbon interposition arthroplasty is intended for widespread arthritis of the wrist. The aim of this study was to assess the clinical, functional, and radiological results of this arthroplasty with a minimum follow-up of 12 months. This retrospective single-center study brought together all osteoarthritis indications that can benefit from an Amandys® arthroplasty. Twenty-one implants were used between January 2011 and October 2018. There were seven cases of distal radius malunion, eight SLAC wrists, two SNAC wrists, two cases of Kienböck's disease at Lichtman's stage 4, and two aftermaths of inflammatory arthritis. Twenty-four percent of patients had previously undergone another type of surgery for this wrist arthritis. Six implants were removed, five early for dislocation and one after 6 years for chronic pain. Thirteen patients were reviewed with an average follow-up of 40.7 months (21-90). The average pain level on a visual analog scale was 3.1/10 (0-7). The mean range motion was 36° flexion (10-60) and 33° extension (15-50). The mean grip strength at the last follow-up was 14.8 kg (2-30) (43% of contralateral). The average QuickDASH and PRWE functional scores were 37.9/100 (0-80) and 29.6/100 (0-83.5), respectively. Amandys® interposition arthroplasty is an interesting alternative to total wrist fusion or total wrist prosthesis for widespread arthritis of the wrist. For the implant to be stable, the capsulo-ligamentous systems must be intact.

Dynamic assessment of the wrist after total wrist arthroplasty

Our aim was to assess the outcome in patients with total wrist arthroplasty performed for end stage wrist osteoarthritis. We analysed the ranges of motion of operated and un-operated wrists using a flexible electrogoniometer during the Sollerman hand function test. We assessed grip strength with a digital dynamometer and completed patient reported outcome scores more than one year post-operatively. We reviewed 12 patients with a mean age of 64 (range 48-82) years. The flexion-extension arc was 72% and radioulnar deviation arc was 53% of the un-operated side but the total range of motion (area of circumduction) was 43% of the un-operated side and only 20% of the circumduction in age and gender-matched normal volunteers. Peak grip strength was 68% of the un-operated side. The patients reported good outcome with mean Michigan Hand Questionnaire (MHQ) scores of 56 (range 25-84) and mean Patient Evaluation Measure (PEM) scores of 39 (range 20-68). Patients completed the activities of Sollerman hand function test in twice the time (6 min) as required for a normal volunteer (2.8 min). The circumduction ellipses were narrow and central with limited radio-ulnar deviation and small mean areas of motion during activities of daily living.