Capsulodèse scapho-lunaire sous arthroscopie, étude cadavérique préliminaire comparant 2 techniques de fixation : suture trans-osseuse et ancres

Arthroscopic capsuloligamentous dorsal repair in chronic scapholunate tear (Mathoulin) has become a common surgical option. Questions remain about this technique particularly for the avulsions of the ligament on scaphoid or lunate. We propose modified procedures with 2 types of bone anchorage: trans-osseous suture and suture anchors. The aim of this study is to assess and compare the primary stabilization. Ten fresh cadaveric forearms were used. One wrist was excluded because of severe radius malunion with osteochondral lesions. Scapholunate instability was obtained by cutting scapholunate inter-osseous ligament and carpal insertions of DRC and DIC ligaments through MC portal. Bony abrasion of dorsal areas of scaphoid proximal pole and lunate dorsal horn was performed trough 6R and 1–2 portals. A 1 cm enlarged 3–4 portal was used to drill the tunnels or fix the anchors: the 3rd and 4th compartments were opened leaving the dorsal capsule unharmed. In group 1 (5 wrists), the dorsal capsule was fixed with 2 anchors (mini Pushlock, Arthrex, Napples, USA) on the abraded areas of scapoid and lunate. Each strands of the lunate anchor were knotted with each strands of the scaphoid anchor. In group 2 (4 wrists), dorsal capsule was fixed with a U-shaped Fiber wire (Arthrex, Napples, USA) trans-osseous self locking stitch. Trans-osseous tunnels were drilled on scaphoid and lunate from mid carpal to radio carpal joint under arthroscopic and fluoroscopic control. Scapholunate stability was evaluated before and after the procedures using EWAS arthroscopic classification and fluoroscopic measures of scapholunate angle and diastasis. One wrist of group 2 had static instability before ligaments cutting. Except for this wrist, no static instability was found after ligaments cutting. EWAS stages were 3C to 5. In group 1, stabilization was obtained for 3 wrists. Two wrists were not stabilized (stage 3A and 4). There was an anchor loosening for one of this wrist. 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 (no static instability, stage 1). One wrist was only partially stabilized (stage 3C). Except for the osteochondral lesion of scaphoid in group 2, no iatrogenic lesions were observed. Trans-osseous suture is a difficult procedure and can lead to osteo chondral lesions. Anchors seemed to be easier and provide sufficient primary stabilization. Secondary stabilization should be evaluated in a clinical study.