Arthroscopic Scapholunate Posterior Capsulodesis

Abstract

Objective/Hypothesis: Arthroscopic capsuloligamentous dorsal repair in chronic scapholunate (SL) tear (Mathoulin) has become a common surgical option. Questions remain about this technique: Are there always strong enough remaining parts of the ligaments? Is the 3/0 absorbable stitch strong enough to stabilize SL complex in any cases? We propose 2 modified procedures: one using transosseous fixation and another one using suture anchors. The aim of this study is to assess and compare the primary stabilization of the SL complex. Materials and Methods: Ten fresh cadaveric wrists were used. One wrist was excluded because of severe radius malunion and arthritis. SL instability was created by cutting scapholunate interosseous (SLIO) ligament, dorsal radio carpal (DRC), and dorsal inter carpal (DIC) carpal insertions under arthroscopic control. The dorsal capsule in front of SL area was carefully spared. A synovectomy was performed. A 3-4 enlarged extra capsular approach was used: through a 10 mm transverse incision, the third and fourth compartments were opened, leaving the dorsal capsule unharmed. SL stabilization was performed using suture anchors for 5 wrists (group 1). Through the 3-4 enlarged extra capsular approach, the dorsal capsule was pierced with 2 Micro CorkScrew (Arthrex, Napples, Florida, USA), one was fixed in scaphoid proximal pole and the other one in posterior horn of lunate. Each strands of the lunate anchor were firmly knotted with each strands of the scaphoid anchor. SL stabilization was performed using transosseous sutures for 4 wrists (group 2). Through the 3-4 enlarged extra capsular approach, 2 tunnels were drilled through the proximal pole of scaphoid and the posterior horn of lunate. A fiberwire (Arthrex, Napples, Florida, USA) was passed through the dorsal capsule and through the tunnels passing by the mid carpal joint. A U-shaped self locking knot was performed. SL instability was evaluated before and after surgical procedures using European Wrist Arthroscopy Society (EWAS) arthroscopic classification and fluoroscopic measures of SL angles and SL diastasis. At the end of the procedures, large longitudinal dorsal approaches were performed. Lesions of the tendons, nerves, and cartilage were reported. Results: Fluoroscopic initial evaluation shows normal SL angles and no SL diastasis, except for one wrist of group 2 which already had SL instability. Arthroscopic initial evaluation found EWAS stage 3C to 5 instability. In group 1, stabilization was obtained for 3 wrists (EWAS stages 1, 1, and 2). One wrist was not stabilized (EWAS 4). There was 1 anchor loosening. In group 2, procedure could not be achieved because of fracture of the scaphoid tunnel in 2 cases. The wrist with static instability was fairly stabilized: diastasis 7 to 1 mm, SL angle from 15° to 70°, and EWAS stage from 5 to 1. One wrist was only partially stabilized (EWAS stage from 4 to 3C). Except for the osteochondral lesions of scaphoid in group 2, no iatrogenic lesions were observed. Conclusions: Transosseous tunnels are a difficult procedure and can lead to osteochondral lesions. Anchors seemed to be easier and to provide fair primary stabilization. Secondary stabilization should be evaluated in a clinical study.