HERBERT SCREW FIXATION FOR SCAPHOID NONUNIONS - AN ANALYSIS OF FACTORS INFLUENCING OUTCOME

A retrospective review of 160 cases of scaphoid nonunion treated by in ternal fixation using a Herbert screw with bone grafting was conducted at an average followup of 24 months, Definite radiographic union was achieved in 90% of cases, Based on Cooney's clinical scoring system, 8 0 cases had an excellent result, 37 had a good result, 33 had a fair r esult, and 10 had a poor result, Failure of union was related to the e xistence of avascular changes of the proximal fragment, instability of the fracture fragment, the prolonged delay in surgery, and the locati on of the fracture site, In-the united scaphoids, the lengthy period o f postoperative immobilization, the existence of osteoarthritis, and t he prolonged delay in surgery were significant factors in the patient' s functional outcome, Overall, the results do not support the view tha t a residual flexion deformity of the scaphoid is less likely to yield a satisfactory outcome, although it seems worthwhile to correct exces sive angulation at the time of repair to promote an anatomic union, th ereby preventing early arthritis, A bone graft with internal fixation using a Herbert screw and a shorter period of immobilization may give a satisfactory functional result when the nonunion is treated before t he onset of arthritic changes in the wrist.