Arthroscopic-assisted scapholunate ligament reconstruction for chronic SL instability
Epublication WebSurg.com, Sep 2011;11(09). URL: http://websurg.com/doi/lt03enho001
Both the dorsal and the volar portion of the scapholunate interosseous ligaments are the major stabilizers of the scapholunate joint. Most conventional methods to restore scapholunate stability do not address the volar constraints and frequently fail to reduce the SL gapping. Wrist arthroscopy allows for a complete evaluation of the SL interval, accompanying ligament status and associated SLAC wrist changes. It enables simultaneous reconstruction of the dorsal and palmar scapholunate ligaments anatomically with the use of the palmaris longus tendon as a tendon graft in a box-like structure. With the assistance of arthroscopy, a combined limited dorsal and volar incision can expose the dorsal and palmar scapholunate interval, where bone tunnels can be made by a cannulated drill under image control on the proximal scaphoid and lunate. The palmaris longus tendon graft is then used to reduce and connect the two bones in a box-like fashion. Once joint diastasis has been reduced and DISI malrotation has been corrected, the tendon graft can be knotted under maximal tension on the dorsal surface of the scapholunate joint in a shoe-lacing manner. Correction and control of the DISI deformity can be achieved by placing drill holes at different levels, more proximally over the lunate and distally over the scaphoid to counter-rotate the deformity. Either the scapholunate or the scaphocapitate joint is then transfixed using K-wires for temporary protection of the reconstruction. From October 2002 to June 2009, the treatment method was applied in 8 patients suffering from chronic SL instability with an average duration of 7.4 months (3-9 months). There were 6 male and 2 female patients. The average age for this group was 45.4 years (34-60 years). Six of the injured wrists were right wrist injuries. There were two Geissler grade 3 and six grade 4 instability cases. The average pre-operative SL interval was 4.7mm (3-9mm). Concomitant procedures were performed in 4 patients. The average follow-up was 34.9 months (10-66 months). Symptoms in all patients —except in one— either improved or completely disappeared. The functional wrist score improved from 23.1 to 34.4 on a 40-point scale. Pain score decreased from 12 to 4.4 on a 20-point scale. There was no pain in 5 patients and exertion pain in 3. The injured/uninjured grip power ratio improved from 73.9% to 89%. The average SL interval at final follow-up was 3.6mm (2-7mm). An ischemic change of the proximal scaphoid was noted in one case without symptoms or progression. There were no major complications. All patients —except one— were satisfied with the procedure and the treatment outcome.