Distal Ulna Hook Locking Plate Fixation for Unstable Distal Ulna Fractures: A Prospective Clinical Study

BACKGROUND: Distal ulna fractures, particularly when displaced or unstable, play a critical role in the stability and function of the distal radioulnar joint. Inadequate treatment may result in persistent pain, instability, and impaired wrist function. Recent advances in angular stable fixation have led to the development of anatomically contoured distal ulna hook locking plates; however, clinical data regarding their outcomes remain limited. OBJECTIVE: To evaluate the radiological and functional outcomes of distal ulna fractures treated with open reduction and internal fixation using a distal ulna hook locking compression plate. METHODS: This prospective study included 30 patients with displaced or unstable distal ulna fractures treated with a distal ulna hook locking plate. Patients were followed for a minimum of 6 months. Clinical assessment included wrist range of motion, grip strength, and functional evaluation using the Modified Mayo Wrist Score. RESULTS: Radiological union was achieved in all patients, with a mean time to union of 12.7 ± 3.4 weeks (range, 8-24 weeks). Three patients (10%) demonstrated delayed union, and no cases of nonunion were recorded. At final follow-up, mean wrist flexion and extension were 70° and 71°, respectively, while mean pronation and supination were 73.2° and 73°. Mean grip strength was 89% of the contralateral side. The mean Modified Mayo Wrist Score was 82.4 ± 9.1, with excellent results in 19 patients (63.3%), good results in 8 patients (26.7%), and satisfactory results in 3 patients (10%); no patient had a poor outcome. CONCLUSION: Distal ulna hook locking plate fixation provides reliable fracture union, satisfactory functional outcomes, and a low complication rate in the treatment of displaced and unstable distal ulna fractures.