HOW DOES THE DEGREE OF WRIST OSTEOARTHRITIS AFFECT THE OUTCOMES OF SURGICAL TREATMENT OF SCAPHOID NONUNION?

Abstract

Objective. To evaluate the effectiveness of surgical treatment of scaphoid nonunion using screw fixation with bone grafting in patients with different stages of wrist osteoarthritis. Methods. This single-center study included 81 adult patients with nonunion located in the middle third of the scaphoid. All patients underwent surgical treatment consisting of nonunion resection via a volar approach, iliac crest bone grafting, and fixation with a specialized compression screw. Exclusion criteria were nonunion of the proximal or distal third of the scaphoid, signs of avascular necrosis of bone fragments, and bilateral wrist involvement. Patients were divided into four subgroups: without osteoarthritis and with stage I, II, and III osteoarthritis according to the SNAC classification (SNAC 0, I, II, III), comprising 34, 21, 19, and 7 patients, respectively. Outcomes were assessed at 1 year or longer postoperatively, including union rate, cylindrical grip strength (as a percentage of the contralateral side), DASH score, and wrist flexion–extension range of motion. Results. Bone union was achieved in 88 % of cases overall. The rate of nonunion increased significantly with advancing osteoarthritis stage: 3, 10, 21 and 42 % for SNAC 0, I, II, and III, respectively (p = 0.0021). Most postoperative functional outcomes (range of motion, grip strength, and qDASH scores) demonstrated clinical and subjective improvement in patients with achieved union; however, the magnitude of improvement decreased with increasing osteoarthritis severity, particularly in SNAC III. Among patients who achieved scaphoid union, no statistically significant differences were found in the improvement of strength, range of motion, or disability scores depending on the stage of wrist osteoarthritis.