Tenosynovial chondromatosis of the wrist: A case report.

We report the case of an 80-year-old woman who presented with an asymptomatic slowly growing mass in the dorsal aspect of her right wrist. Radiographs revealed a snail-shaped radiopaque structure. Surgical exploration and excision revealed a calcified lesion over the extensor digitorum communis. Histopathological analysis confirmed the diagnosis of tenosynovial chondromatosis. At the last follow-up, four years after surgery, the patient was asymptomatic and free of recurrence. Practitioners and hand surgeons should be aware of the dorsal involvement and evocative radiological calcifications of tenosynovial chondromatosis, which is a rare benign soft tissue neoplasm that affects all tendon sheaths of the hand.

Pyrocarbon interposition implant after lunate resection in Kienböck's disease: A case series.

In advanced stages of Kienböck's disease, the lunate is no longer conservable. One of the surgical options is to resect the lunate and replace it with a prosthesis. The procedure consisted in lunate resection and interposition of a free APSI® or Pi2® pyrocarbon implant through a dorsal approach. Follow-up was clinical and radiological on QuickDASH and PRWE scores. At a median follow-up of 3 years, 12 patients were reviewed, with a median age of 56 years. Flexion significantly decreased from 42° to 28° (p < 0.01). Extension and pronation-supination were conserved. Strength was 94% compared to the opposite side, with no significant difference from the preoperative measurement. Median QuickDASH and PRWE scores were 15.9 and 23.5 respectively and had significantly improved. One patient underwent scaphocapitate fusion because she was still in pain; the other patients were pain-free. No patients had to change jobs because of their wrist. Radiographically, there was no carpal collapse and carpal height was conserved. Radioscaphoid angle and ulnar translation were stable. There was 1 case of asymptomatic implant dislocation. Interposition of a pyrocarbon implant after lunate resection in advanced Kienböck's disease is a motion-conserving procedure that provides pain relief and functional recovery in the short and medium term. LEVEL OF EVIDENCE: IV.

Arthroplasty for destroyed proximal interphalangeal joint in hand trauma surgery: Silicone hinged NeuFlex® or gliding Tactys®?

The treatment of proximal interphalangeal joints (PIP) after a traumatic injury has produced disappointing outcomes. The objective of this study was to evaluate the functional results of emergency hinged or gliding arthroplasty for destroyed PIP joints. A two-center retrospective study was carried out in 24 patients with open and closed trauma of the PIP joint of the fingers from 2007 to 2019. Fifteen hinged silicone implants (NeuFlex®) and nine gliding implants (Tactys®) were used. Pain on a visual analog scale (VAS), stability and total active motion (TAM), grip and pinch strength (Jamar®), QuickDASH and PRWE and satisfaction were assessed, and X-rays were performed. With a mean follow-up of 48 months, 24 patients aged 58 years on average were reviewed. Pain on VAS was 0.2/10, the TAM was 72% of the contralateral side, the QuickDASH was 15.6/100 and the PRWE was 24.5/100. PIP flexion was ≥50% of the contralateral side in 75% of patients. PIP and DIP extensor lag of 9° was significantly larger with the Tactys® than with the NeuFlex®, with no significant difference in the TAM. Three clinodactylies in fingers with the NeuFlex® and three reducible swanneck deformities in fingers with the Tactys® were noted. Three-quarters of patients were very satisfied or satisfied with the outcome. Emergency PIP arthroplasty with Tactys® seems to provide functional results that are as good as with NeuFlex®. Clinodactyly was found with NeuFlex® use. A significant PIP and IPD extensor lag of 9° and swan-neck deformities were found with Tactys® without significant functional impairment.

Radiological and functional correlation following "SLIC" scapholunate-intercarpal ligamentoplasty at minimum 12 months' follow-up.

We report outcomes for scapholunate-intercarpal ligamentoplasty ("SLIC procedure"), performed in 22 patients (mean age at surgery, 39.7 years), for reducible static scapholunate (SL) instability without repairable stump. Patients were evaluated for pain and active wrist range of motion, grip strength, functional scores (QuickDASH and PRWE) and radiological appearance (SL gap, SL angle, radiolunate angle, capitolunate angle), preoperatively and at a mean 28.3 months' follow-up (range 12-65). A CT scan without injection was performed at follow-up to measure the posterior radioscaphoid angle (PRSA). The objective was to assess radiological-functional correlations after SLIC ligamentoplasty and to analyze postoperative PRSA correction. The hypothesis was that correcting the PRSA improves clinical and functional outcomes. Pain on a visual analog scale improved significantly, from 2.7 to 0.7 at rest and from 7 to 3.2 during hand use. Mean wrist flexion was 46.4° and extension 59.1°. Grip strength reached 82.8% of the contralateral value. Functional scores improved significantly. Mean SL angle decreased significantly from 81.1° to 73.5°, and static scapholunate gap from 4.7 mm to 3.6 mm. Scaphoid subluxation was fully corrected in 15 cases (68%). PRSA angle was significantly corrected, from a mean 112.7° to 104.2°. Patients in whom PRSA was corrected showed a tendency for better clinical and subjective outcomes. There was 1 case of scaphoid necrosis, 7 of recurrent static instability, including 3 early at 4 months, 3 of scaphocapitate osteoarthritis, and 5 of carpal collapse with SLAC wrist. There were no significant correlations between clinical and radiological results in the medium term after SL ligamentoplasty by the SLIC procedure. The results were quite good in the medium term and pointed to the importance of correcting rotatory subluxation of the scaphoid, revealed by the PRSA, more than correcting the scapholunate gap.

Tendon transfer surgery for radial nerve palsy.

Palliative tendon transfer is an integral part of radial nerve palsy treatment. It can be considered in the first weeks when the possibility of nerve repair by direct suture or nerve grafting is not feasible or reasonable. Mostly, it is discussed secondarily when it is too late for nerve surgery and motor recovery cannot be expected, or after failure or incomplete recovery after nerve repair. The goal of tendon transfers is to restore wrist, finger and thumb extension. For wrist extension, the use of pronator teres is well accepted. The best tendon transfer for finger extension is debated. This can be restored doing a flexor carpi ulnaris (FCU), flexor carpi radialis or flexor digitorum superficialis (FDS) to extensor digitorum communis transfer. Regarding thumb extension and abduction, a palmaris longus (PL) or one FDS tendon to the rerouted extensor pollicis longus (EPL) transfer can be performed. If a transfer is done on the EPL without rerouting it, abduction can be restored by doing a tendon transfer to the abductor pollicis longus (APL) or an APL tenodesis. The different tendon transfer options are selected based on the surgeon's preference, and most importantly, discussed with the patients to define the objectives together. The transfer is chosen based on the clinical examination (high or low radial nerve palsy, tendon available for transfer like PL, wrist mobility) and based on the patient's needs and expectations (activities requiring the FCU, finger independence, independence of thumb extension or abduction). If the surgical rules and the postoperative instructions for rehabilitation are followed, tendon transfers for radial nerve palsy regularly produce very satisfactory results.

Restoration of thumb opposition (opponensplasty).

The authors review the therapeutic principles that must be applied when restoring the thumb opposition surgically. Among the many surgical techniques, five are featured: transfer of the flexor digitorum superficialis of the third or fourth finger, transfer of the extensor indicis proprius, transfer of the palmaris longus, translocation of the flexor palmaris longus tendon, transfer of the extensor pollicis longus. After summarizing the procedures, they emphasize the practical points that must be respected. This surgery, which cannot restore sensitivity, requires a precise assessment of the patient's wishes and information on what can be really expected.

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.

Pyrocarbon implants for the basal thumb arthritis.

Silicone implants for the treatment of basal thumb arthritis were first proposed in the 1970's by Swanson. They became extremely popular and despite good functional results, the high rate of complications such as instability, material breakage and foreign body reactions led to them being progressively abandoned by most surgeons. Pyrocarbon implants were introduced at the beginning of the 2000's. A large range of different implant models that can be used for either hemiarthroplasty or interposition arthroplasty. For some implants, a supplemental ligamentoplasty procedure is required to avoid instability. Miniaturization of some implants provides new options for minimally invasive surgery, which is relevant in low and medium grades of osteoarthritis, especially for young, active patients. Medium- and long-term follow-up have now been reached by some pyrocarbon interpositions. Their results confirm that these implants are a reliable alternative to other techniques. This paper focuses on the surgical techniques and outcomes of pyrocarbon implants for the treatment of basal thumb arthritis. It is based on published data and the author's experience.

Pyrocardan® implant after failed trapeziectomy.

The aim of this retrospective study was to analyze the medium-term results of patients treated with a pyrocarbon interposition implant (Pyrocardan®, Wright Medical™) after failed trapeziectomy. Eight female patients with an average age of 63 years were included in this single-center study. The average follow-up was 54 months (28-85 months). The average time elapsed between the trapeziectomy and the revision surgery was 116 months. Trapeziectomy failures were due to a painful scaphometacarpal and/or metacarpotrapezoid impingement. Patients were assessed radiologically and clinically for range of motion, strength (pinch and grip), pain (visual analog scale - VAS) and function (QuickDASH and PRWE scores). We found pain reduction with the mean VAS decreasing from 6.3 preoperatively to 2.5 postoperatively. Function improved with the QuickDASH and PRWE scores going from 52.9 and 49.1 preoperatively to 30.7 and 31.0 at the last follow-up, respectively. Strength and range of motion did not change significantly. Seven patients were satisfied or very satisfied with the surgery, while one patient did not experience any improvement after surgery. There was no radiological evidence of dislocation or bone reaction around the implant. Revision of failed trapeziectomy with the Pyrocardan® implant in cases of severe and painful first metacarpal subsidence is an effective solution that improves pain and function in the medium term.

Effect of cryotherapy on pain and analgesic consumption after wrist or thumb surgery.

Cryotherapy has demonstrated its efficacy in post-traumatic soft tissue pain, through its anti-inflammatory action. Its postoperative use has also been the topic of many studies and has now proved its efficacy in indications such as ligament or knee arthroplasty surgery. The aim of this study was to analyze the effect of cryotherapy on pain and analgesic consumption after wrist or base of the thumb surgery. We prospectively included 60 patients from March 2017 to May 2018. All these patients had undergone wrist or base of the thumb surgery involving a bone procedure. Thirty patients were managed with cryotherapy (the Handfreez® splint), 30 patients were included in the control group with conventional immobilization. The data collected included a visual analogue scale (VAS), and analgesic and non-steroidal anti-inflammatory drug (NSAID) consumption, both during the hospital stay and then at home for one week. The results from the two groups were compared. During the hospital stay, morphine consumption was significantly lower in the cryotherapy group (p = 0.04). At home, NSAID consumption was significantly lower in the cryotherapy group (p = 0.009). The VAS score was not significantly different between the two groups. In our study, we demonstrated the benefits of cryotherapy on consumption of analgesics and NSAIDs after bone surgery of the wrist or the base of the thumb.

Pyrocardan® implant arthroplasty for trapeziometacarpal osteoarthritis with a minimum follow-up of 5 years.

Many surgical procedures are available for treating trapeziometacarpal (TMC) osteoarthritis (OA). The aim of this study was to analyze the mid- to long-term outcomes of 103 pyrocarbon interposition arthroplasties in the TMC joint with Pyrocardan® implant performed prospectively in a single center to treat painful early stage OA. There were 96 patients with a median age of 59 years. Twenty-eight percent of patients were manual workers and 39% had a fixed dislocation of the first metacarpal. Fifteen percent of patients were 50 years old or more. After a minimum follow-up of 5 years, there was a marked improvement in the pain level (0.6/10), QuickDASH (9/100) and PRWHE (4/100) scores and strength (key pinch 8kg, grip strength 27kg). There were no differences in strength or range of motion compared to the opposite side. Four patients underwent revision surgeries. Two of them were converted to trapeziectomy. The 5-year implant survival rate was 96.2%. Dislocation of the first metacarpal was completely corrected in 80% of cases. Younger patients (≤50 years old) had slightly better outcomes than older ones. Overall satisfaction rate was 96%. Pyrocardan® interposition implant arthroplasty is a reliable alternative to trapeziectomy, total arthroplasty or fusion of the TMC joint especially for young, active patients.

Hand injuries treated at a hand emergency center during the COVID-19 lockdown.

The recent coronavirus outbreak has tested the adaptability, cooperation and organizational capabilities of our healthcare systems. Restrictions were implemented in several countries to reduce virus transmission whilst emergency departments (ED) were overwhelmed and there was shortage of healthcare providers. Given this situation and the consequences of hand injuries, we studied the epidemiology of hand injuries in an accredited FESSH emergency center during the lockdown in France (March 17 to May 10, 2020) due to the coronavirus outbreak. During this period, 1947 patients consulted for a hand injury. We found high percentages of men (63%), open wounds (70%), domestic accidents (88%) and surgical treatment being required (76%). There was a significant decrease in admissions and consultations relative to the same period in 2019. This reference data can help healthcare systems prepare for future outbreaks and similar restrictions.

Scapholunate, lunotriquetral and TFCC ligament injuries associated with intraarticular distal radius fractures: Arthroscopic assessment and correlation with fracture types.

The aim of this study was to evaluate the prevalence of arthroscopic scapholunate (SL) and/or lunotriquetral (LQ) laxity and triangular fibrocartilaginous complex (TFCC) injuries in patients who have an intraarticular fracture of the distal radius and to correlate these lesions with fracture type. Fifty-seven intraarticular radius fractures, whether or not they were associated with an ulnar styloid fracture, were evaluated and treated by arthroscopy. Scapholunate and lunotriquetral ligament injuries were classified according to the EWAS classification. TFCC lesions were assessed according to Palmer's classification. Each injury was documented through preoperative X-rays and a CT scan. Fracture type and soft tissue injury were not significantly associated one to another. Arthroscopic examination revealed at least one soft tissue injury in 39 intraarticular fractures of the distal radius (68.4%). Twenty-five percent of arthroscopic SL laxities (including severe EWAS 3 injuries) were not detected on standard radiographs. Arthroscopic SL laxity was present in 8 of 11 cases (72.7%) of radial styloid fracture and in 15 of 25 cases (60%) of fractures with at least one radial styloid component. There was no association between LQ integrity and fracture type. Ulnar styloid fractures (base or tip) and TFCC lesions were significantly correlated (P<0.0001). The prevalence of soft tissue lesions secondary to intraarticular fractures of the distal radius was 68.4%. However, there was no statistically significant relationship between the different types of radius fractures and soft tissue injuries. On the other hand, ulnar styloid fracture was predictive of TFCC injury.

Arthroplasty of the proximal interphalangeal joint with the Tactys® modular prosthesis: Results in case of index finger and clinodactyly.

There are various surgical solutions for arthrosis of the proximal interphalangeal (PIP) joint: arthrodesis or denervation. Clinodactyly that is major and the index fingers are traditional contraindications for PIP arthroplasty prostheses. The recurrence of clinodactyly with ligament imbalance and mechanical complications are known complications. The purpose of our study was to evaluate the objective and subjective clinical results and radiological complications of Tactys® prostheses on the PIP joint of the index fingers or with clinodactyly of more than 5° in the other fingers. Two surgeons have implanted 35 total gliding modular Tactys® prostheses in 29 women and 3 men since 2010. The indications for surgery were arthrotic and painful PIP joints. Average pre-op clinodactyly was 7.03° (5-30°) with ulnar deviation (29 cases). Eleven index fingers presented with average clinodactyly of 14.2° (10-20°). The digits operated on were as follows: 13 index fingers, 14 middle fingers, 5 ring fingers and 3 little fingers. Arthrosis was primitive in 23 cases, post-traumatic in 6 cases and rheumatoid in 6 cases. The average age of patients undergoing surgery was 63.7 years (40-85). Objective (mobility, strength, index finger exclusion, scores, clinodactyly) and subjective (patient satisfaction, pain) functional results were collected by a neutral and independent observer, as were radiological complications. With an average follow-up of 2.6 years (1-6.3), the range of motion in all digits improved by 5.4° on average (55.5-60.8). The improvement in range of motion in the index fingers was 4.5° (57-61.5). Clinodactyly in all fingers was corrected by 1.36° (0-20). In the index fingers, average clinodactyly was 1.3° (0-10). The pinch strength in all PIP joints improved significantly from 2.3 kg (0.5-5) to 3.7 kg (1-8). On the PIP of the index fingers, the pinch strength had increased significantly from 2.5 kg (1-4) before surgery to 3.8 kg (1-7.5) post-op. Functional scores improved: PRWE (from 55.36 to 26.7/100), Quick DASH (from 54.6 to 30.5/100). Patient satisfaction was excellent in 15 cases, good in 8 cases, average in 10 cases, poor in 2 cases. The average VAS Pain Score improved from 5.6 to 1.45. We found 3 major complications requiring surgery: 2 stiffening and 1 mechanical loosening with secondary arthrodesis. Five patients presented with non-troublesome, reducible swan neck deformity and one algodystrophy. A gliding, fixed Tactys® prosthesis allowed us to restore ligament balance and to optimally rebalance the periarticular structures. The improvement in range of motion and the correction of clinodactyly was maintained over time. Total arthroplasty of the PIP with a Tactys® is no longer a formal contraindication for the index fingers and in cases of clinodactyly of more than 5°.

Evaluation of a shape memory staple (Qual®) in radial shortening osteotomy in Kienböck's disease: A retrospective study of 30 cases.

The QUAL® (Memometal, Stryker) device is a shape memory staple used for bone fixation during distal radius shortening osteotomy in the context of Kienböck's disease. The present study is a retrospective, single-center and multisurgeon study of 30 patients with a mean follow-up of 8 years. Clinical criteria (range of motion (ROM), strength, pain and functional score) and radiographic data (ulnar variance, distal radius articular surface inclination, Lichtman stage, carpal height and bone healing) were evaluated pre- and post-operatively. We found satisfactory results with the mean grip strength of 22 kg/F before surgery and 24 kg/F after surgery. The mean ROM was 88° preoperatively and 82° postoperatively and the mean ulnar deviation was 23° preoperatively and 21° post-operatively. There was no change in radial deviation and pronation-supination after surgery. The average ulnar variance was 1 mm before surgery and 0.2 mm after surgery. The inclination of the distal radius articular surface on lateral and anteroposterior views and the mean carpal height were similar to the pre-operative ones. There was no delay in bone healing. The mean pain score was 2 at rest on a visual analogue scale after surgery. Seven patients experienced an increase in their Lichtman stage at the follow-up, and two patients were waiting for conversion to a non-conservative surgical treatment. Seven staples were removed postoperatively. Seventy-eight percent of patients returned to work after 3 months on average. Seventy-five percent of patients were at least satisfied with the outcome of their surgery. The QUAL® staple is a reliable option for fixation during shortening osteotomy of the radius in Kienböck's disease.

Adaptive Proximal Scaphoid Implant (APSI): 10-year outcomes in patients with SNAC wrists.

Radioscaphoid arthroplasty with the Adaptive Proximal Scaphoid Implant (APSI®) is an attractive treatment alternative in the short and medium term for patients with early scaphoid non-union advanced collapse (SNAC) wrist. The purpose of our study was to determine the long-term outcomes of this implant in SNAC wrists. All patients who received the implant from October 2002 to October 2010 were included. A clinical and radiographic study was performed. Our case series included 39 patients, of which 33 were contacted, with a mean follow-up of 10 years (5.8-13.4). Most of the patients had stage-1 SNAC wrist (95%). There were nine complications (27%), seven of which required reoperation: implant dislocation (44%) or progression of the carpal degeneration (33%). Ninety-six percent of patients contacted were satisfied or very satisfied with their surgery (although 21% needed a second surgery) with a Mayo Wrist Score of 80/100 and a Patient-Rated Wrist Evaluation of 17.5/100. Wrist strength was 86% of the contralateral side. Flexion-extension range was 101° and pain assessed using a visual analog scale was at 1.2 (0-6). We report satisfactory and lasting results with the APSI®, similar to those of scaphoid excision with four-corner fusion and proximal row carpectomy. Hence, the APSI® is a reliable alternative for treating osteoarthritis in SNAC wrists.

Pyrocarbon implants for the hand and wrist.

Thanks to its remarkable mechanical properties and excellent biocompatibility, pyrocarbon is an ideal material for articular use. Various pyrocarbon implants for the hand and wrist have been developed over the past 25 years, with about 15 currently available for hemi-, total and interposition arthroplasty. This article describes the production methods and mechanical properties of pyrocarbon. The author summarizes the various implants available for each type of joint, their reported results in the literature, as well as his team's experience.

The radial approach to the wrist with styloidectomy: A cadaver study.

The radial approach to the wrist is already used in several surgical techniques such as radial styloidectomy and Zaidemberg's vascularized radial graft. The aim of our work was to describe the surgical anatomy of that approach and to determine the acceptable limits of radial oblique styloidectomy that does not damage the anterior and posterior radiocarpal ligaments. This radial approach was performed on 11 cadaver specimens. The superficial branches of the radial nerve and the antebrachial cephalic vein were carefully located in the superficial plane. The radiocarpal articular capsule was opened longitudinally between the first and second compartments of the extensor tendons. We drew the oblique radial styloidectomy line at 3, 6 and 9mm from the apex of radial styloid process on the articular surface and then measured the width of ligaments theoretically taken away by the styloidectomy. An oblique radial styloidectomy of less than 6mm preserved the anterior and posterior radiocarpal ligaments. There was one case of radial artery damage while opening the joint capsule. The radial approach to the wrist as described in this work provided good access to the radial styloid process, the radioscaphoid joint and the proximal pole of the scaphoid, if the approach is done carefully to preserve the superficial branches of the radial nerve, the antebrachial cephalic vein and the radial artery. Radial styloidectomy can be performed up to 6mm from the apex without significantly damaging the radiocarpal ligaments, particularly the volar ones.

Treatment of scaphotrapeziotrapezoid osteoarthritis with the Pyrocardan® implant: Results with a minimum follow-up of 2 years.

The aim of this study was to report the results of arthroplasty using a mobile pyrocarbon implant (Pyrocardan®) for isolated scaphotrapeziotrapezoid (STT) osteoarthritis. The hypothesis was that this arthroplasty leads to functional improvement without carpal instability. Twenty patients (22 implants) were included with a minimum follow-up of 2 years and an average age of 59.6 years. Outcome criteria were pain (VAS scale), QuickDASH and PRWE scores, strength (grip and pinch), wrist mobility, the Kapandji index, carpal height and the capitolunar angle measured on X-rays. The preoperative data was compared to the postoperative data. The average follow-up was 3.8 years. There was a significant improvement in pain, clinical scores and pinch strength. In terms of range of motion, we found that amplitudes were maintained except for a significant decrease in wrist extension. X-rays did not show any carpal instability; carpal height was maintained and the capitolunar angle was significantly improved. No implant dislocation was reported. The good functional and radiographic outcomes, and the absence of surgical complications are evidence that the Pyrocardan® resurfacing implant is a valid option for treating STT osteoarthritis. If this arthroplasty procedure fails, another procedure can still be done. However, a long-term assessment of this technique is still needed.

Rotational stability test for the diagnosis of radial collateral ligament rupture in the fingers: Anatomical study.

Diagnosing rupture of the radial collateral ligament (RCL) of the finger metacarpophalangeal (MCP) joints is difficult. The aim of this cadaver study was to validate a rotational test for the MCP after RCL transection. With the MCP and proximal interphalangeal joints in flexion, rotation along the axis of the proximal phalanx was applied through an extended distal interphalangeal joint to 36 cadaver fingers. Each finger's pulp described an arc of pronation and supination that was noted on the palm. The test was repeated three times: before transection, after transection of the proper collateral ligament (CL) and after transection of both the proper and accessory CLs. Rotational arcs were measured in pronation and supination. Mean length of the pronation arc after transection of the main RCL was 17.53mm, while it was only 12.41mm before transection for the supination arc. Mean length of the pronation arc after transection of both CLs was 22.83mm compared to only 11.93mm before transection. Our results show a significant difference in pronation stability of the MCP joint after transection of the RCL proper. We can conclude that this rotational stability test is a valid test for diagnosing RCL rupture in MCP joints.