Abstract
Purpose: To evaluate the functional and radiographic results of a scaphoid excision and four-corner fusion using headless compression screws on scapholunate advanced collapse (SLAC) wrist and scaphoid nonunion advanced collapse (SNAC) wrist.
Subjects and Methods: Three patients, with a mean age of 53.7 (range, 43-62) years, were treated for SLAC wrist (2 cases), SNAC wrist (1 cases). Four-corner fusion was achieved with an Acutrak® screw (one wrist) and a Twinfix® screw (2 wrists). The average follow-up time was 6.7 (range, 5-10) months. We evaluated the wrist range of motion (ROM), grip strength, visual analog scale (VAS), and modified Mayo wrist score. Radiographs were evaluated for union, carpal hight ratio (CHR) and radio-lunate angle (RLA).
Results: Average wrist ROM flexion/extension was 38°/40°after surgery and 48°/30° before surgery. The mean postoperative grip strength improved to 25.2kg, compared with 14.1kg before surgery. The average postoperative VAS was 5mm, an improvement over the preoperative average of 78mm. The postoperative mean modified Mayo wrist score was 57, which was better than the preoperative score of 22. Union had occurred in all wrists by an average 10 weeks. The postoperative mean CHR averaged 0.52, compared with the preoperative values of 0.50. Average RLA was -10° postoperatively, compared to -17° preoperatively.
Conclusion: Four-corner fusion using headless compression screws is an effective method allowing early ROM exercise and improvement of VAS, grip strength, and modified Mayo wrist score.
