gms | German Medical Science

Objectives/Interrogation: Lunocapitate fusion (LCF) with scaphoid excision is an alternative method of four-corner fusion to treat advanced osteoarthritis of scapholunate advanced collapse (SLAC) or scaphoid nonunion advanced collapse (SNAC) wrists with an advantage of less dissection of carpal ligaments and joint capsule. As a minimally invasive procedure, arthroscopic LCF is expected to have same benefits of open LCF as well as additional merits of fast recovery and cosmetic satisfaction to the patients. We retrospectively reviewed 8 cases of arthroscopic LCF for evaluating clinical and radiological outcomes of this procedure.

Methods: From Jan 2013 to Dec 2016, all patients with SLAC (stage II or III) or SNAC (stage II or III) wrist, who underwent arthroscopic LCF with scaphoidectomy were enrolled in this retrospective study. Union was determined by CT taken 8 to 10 weeks after operation with bridging trabecular at arthrodesis site. These clinical outcomes were assessed preoperatively and last follow-up: visual analogue scale (VAS) pain score, grip strength, active range of motion (ROM), Mayo wrist score (MWS), and Disabilities of Arm, Shoulder and Hand (DASH) score. For radiologic outcomes, carpal height ratio (CHR), lunate coverage index (LCI), and radiocarpal joint narrowing were measured. Any operation-related complications were also evaluated.

Results and Conclusions: The mean follow-up period was 24.9 (12 to 36) months. The union rate was 75% (6 of 8), but it was increased to 100% (4 of 4) when considering cases using 2 screws for fixation. The 2 cases of nonunion had underwent revisional four-corner fusion 8 and 10 months after operation respectively. VAS pain score was improved from 7.0 ± 1.8 to 1.7 ± 0.8, and grip strength from 70.4% ± 11.7% to 85.4% ± 8.6%. Flexion-extension arc was increased from 52.0° ± 14.4° to 65.8° ± 15.6°, and radial-ulnar deviation arc from 27.5° ± 4.2° to 35.0° ± 11.8°. MWS was improved from 40.8 ± 10.7 to 72.5 ± 8.2, and DASH score from 41.3 ± 11.3 to 15.3 ± 7.9. One case with asymptomatic loosening of screw was observed, and one case with irritation of radiocarpal joint due to screw had an operation of arthroscopic change of problematic screw 2 months after operation.

Arthroscopic LCF with scaphoid excision can be alternative treatment of patients with SLAC or SNAC wrists with its advantage of minimal invasiveness. However, the high rate of nonunion is main concern of this procedure, we recommend arthrodesis using 2 screws rather than 1 screw for increasing rate of union.