Double-row repair of the distal attachment of the superficial medial collateral ligament: a basic science pilot study

To describe a novel repair for tibial-sided superficial medial collateral ligament (sMCL) lesions and determine whether it restores medial joint opening to uninjured state. Agreement among experienced knee surgeons when evaluating medial joint laxity was also explored.

On a series of eight human cadaveric knees, surgical elevation of the distal insertion of the sMCL was performed to replicate injury. The cut ligament was repaired using a novel double-row 'suture-bridge' technique. Valgus stress fluoroscopic images were taken with the ligament in three states: (I)ntact, (C)ut and (R)epaired, in two positions: 0 and 20° flexion. Joint opening was measured on calibrated fluoroscopic images (in mm) based on methods described by LaPrade. Joint space opening was also estimated by three experienced knee surgeons without fluoroscopy.

On fluoroscopy, no significant differences in mean joint opening were observed between an intact versus repaired ligament in 0 and 20° flexion [0.5 mm (95 % CI -1.6, 0.73; n.s.) and 0.3 mm (95 % CI -1.17, 1.71; n.s.)], respectively. Agreement among surgeons was substantial (ICC = 0.622, 95 % CI 0.52, 0.73).

The surgical technique adequately restored joint opening to an intact state with response to valgus stress. Agreement among surgeons when quantifying joint opening in mm was substantial. This paper addresses a technically difficult problem and provides pragmatic and practical information for surgeons who manage complicated multi-ligament knee injuries.