Decreased Complication Rate Using Partially Threaded Compared With Fully Threaded Compression Screws in 4 Corner Arthrodesis: A Retrospective Study.

Background: Scapho-lunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) of the wrist are the most common types of wrist arthritis. We compared the union rate and complication profile of patients with SLAC and SNAC wrist undergoing 4 corner arthrodesis with partially threaded or fully threaded headless compression screws.

Methods: A single-center retrospective review was conducted to identify all patients treated for SLAC and SNAC with 4 corner fusion using headless compression screws from 2016 to 2021. A total of 33 patients undergoing surgery on 35 wrists were identified and included in the study. Demographics, comorbidities, complication profile, and radiographs were collected and compared between groups.

Results: One hundred percent (16/16) of partially threaded and 84.2% (16/19) of fully threaded screws demonstrated union by minimum 10-week follow-up. The total complication rate (avascular necrosis of lunate, screw loosening, etc.) was 31.4%; 52.6% of wrists implanted with fully threaded screws experienced complications compared with a 6.3% complication rate with partially threaded screws. The difference was statistically significant between the 2 groups (P = .004).

Conclusions: Four corner arthrodesis using antegrade compression screws is an effective, reproducible method to achieve fusion in the wrist. The use of fully threaded screws was associated with more complications than with partially threaded screws, although union rate was not significantly different. Future studies with larger sample sizes would be useful to fully elucidate differences between these 2 constructs.