Thumb metacarpophalangeal sprains are one of the most common hand injuries+as others joint trauma, arthroscopic management may enhance results while decreasing morbidity. The aim of this work was to improve surgical recovery and outcomes in thumb metacarpophalangeal collateral ligament ruptures using a new and simple arthroscopic repair. We experimented first the procedure on 8 cadaveric thumbs then we initiate a prospective series including all surgical acute (<3weeks) ligament ruptures without avulsion fractures. Over a period of 2years, 17 patients [14 ulnar collateral ligament (UCL) and 3 radial collateral ligament (RCL) injuries] were included. Diagnosis was obtained using a bilateral examination, X rays and ultrasound. We used a 1.9mm arthroscope with only two 2mm-long portals - one optical portal (dorsolateral for UCL injuries, dorsomedial for RCL injuries) and one instrumental portal near of the collateral ligament rupture. Through this instrumental portal, we were able to reduce the Stener lesion and repair ligaments using a 2mm titanium suture screw anchor. A splint was kept for 3weeks followed by physiotherapy. A postoperative X ray was performed to confirm the anchor position then physical examination after 3, 6 and 12weeks.

Analysis criteria were:

– preoperative - demographic data, diagnosis conditions;

– perioperative - duration of the surgery, all ligament lesions observed at 360°;

– postoperative - MP range of motion and KeyPinch strength, pain, stability testing, time off work, potential complications (scare, nerve damage).

All patients were reviewed three times.

Preoperative criteria - all preoperative radiographic volar subluxations were associated with the arthroscopic report of a complete rupture of at least one part (accessory or proper part) of the collateral ligament.

Peroperative criteria - duration of surgery was 24minutes (15–32).

Ligament assessment - all UCL ruptures were distal (n=14), all RCL ruptures were proximal (n=3), 5 accessory collateral ligament damages were contralateral to the main ligament rupture.

Postoperative criteria - in UCL ruptures (n=14), postoperative X rays demonstrated that all anchors were localized in the palmar half of the phalanx, 12 in the palmar third. About strength and motion - at 3weeks - ROM - 50%, KeyPinch - 35%+6weeks - ROM - 85%, KeyPinch - 68%+12weeks - ROM - 90%, KeyPinch 87%.

None chronic instability and none dorsal sensitive nerve damage were noticed.

Arthroscopic repair of thumb metacarpophalangeal injuries enables a precise ligamentous diagnosis. This is a safe procedure to perform an accurate repair and achieve a quick recovery with excellent outcomes.