gms | German Medical Science

Objectives/Interrogation: Fixation of chronic unstable scaphoid nonunion with a volar angular stable mini-plate and cancellous bone grafting has shown to be a successful technique in small series. No mid or long term follow-up has been documented ever since. Our objective was to evaluate the midterm follow-up of plate fixation for scaphoid nonunion and to evaluate the necessity for hardware removal in these patients.

Methods: Patients with a chronic unstable scaphoid nonunion were prospectively enrolled and treated with open reduction of the scaphoid fracture using a volar approach and internal fixation using an angular stable miniplate fixation and cancellous bone grafting from the ipsilateral iliac crest. Follow-up included physical examination, functional assessment using the PRWHE questionnaire and multiplanar reformation computed tomography at a three month interval until union was confirmed. For the midterm follow up, (median 31 months after surgery) physical examination and functional assessment will be re-evaluated.

Results and Conclusions: Forty-eight patients with a mean age of 30 years with a mean duration of nonunion of 45 months were included. Eleven patients had previous surgery of the scaphoid fracture, 26 patients had a dorsal intercalated segment instability and 13 patients had a scaphoid nonunion advanced collapse of the affected wrist. Post-operative, 93% of patients showed radiological confirmed healing of nonunion. Average time to union was 4 months. Due to impingement of the plate on the volar rim, 17 patients had the hardware removed during follow up. No significant changes in range of motion and grip strength were found postoperative after 3 months compared to pre-operative function. Functional outcome improved significant after 3 months (PRWHE from 50 to 25 points). Midterm functional outcome after 1-3 years will be evaluated but is expected to improve further, especially after plate removal.

In conclusion, angular stable plate fixation supplemented with autologous cancellous bone grafting is a successful technique for treatment of chronic unstable scaphoid nonunion, resulting in union in the majority of patients within half a year in this large cohort. Impingement of the plate against the volar rim may necessitate a second operation for hardware removal and should be discussed pre-operatively with the patient. Midterm results will determine if functional outcome will further improve.