Double screw versus angular stable plate fixation of scaphoid waist nonunions in combination with intraoperative extracorporeal shockwave therapy (ESWT).

INTRODUCTION

Over the past years, different fixation techniques focused on rotational stability in order to increase stability and stimulate union rates. Additionally, extracorporeal shockwave therapy (ESWT) has gained importance in the treatment of delayed and nonunions. Purpose of this study was to compare the radiological and clinical outcome of two headless compression screws (HCS) and plate fixation in scaphoid nonunions, in combination with intraoperative high energy ESWT.

MATERIALS AND

METHODS

Thirty-eight patients with scaphoid nonunions were treated by using a nonvascularized bone graft from the iliac crest and stabilization with either two HCS or a volar angular stable scaphoid plate. All patients received one ESWT session with 3000 impulses and energy flux per pulse of 0.41 mJ/mm2 intraoperatively. Clinical assessment included range of motion (ROM), pain according to the Visual Analog Scale (VAS), grip strength, disability of the Arm Shoulder and Hand Score, Patient-Rated Wrist Evaluation Score, Michigan Hand Outcomes Questionnaire and modified Green O'Brien (Mayo) Wrist Score. To confirm union, a CT scan of the wrist was performed.

RESULTS

Thirty-two patients returned for clinical and radiological examination. Out of these, 29 (91%) showed bony union. All patients treated with two HCS compared to 16 out of 19 (84%) patients treated by plate showed bony union on the CT scans. The difference was not statistically significant. However, at a mean follow-up interval of 34 months, no significant differences could be found in ROM, pain, grip strength and patient-reported outcome measurements between the two HCS and plate group. Height-to-length ratio and capitolunate angle improved significantly in both groups compared to preoperative.

CONCLUSIONS

Scaphoid nonunion stabilization by using two HCS or angular stable volar plate fixation and intraoperative ESWT results in comparable high union rates and good functional outcome. Due to the higher rate for a secondary intervention (plate removal), HCS might be preferable as first choice, whereas the scaphoid plate fixation should be reserved for recalcitrant (substantial bone loss, humpback deformity or failed prior surgical intervention) scaphoid nonunions.