Complex proximal humeral fractures: a prospective study of 22 cases treated using the "Bilboquet" device.

ABSTRACT

INTRODUCTION: Despite recent improvements in surgical devices, complex proximal humerus fractures internal fixation still encounters frequent mechanical failures. HYPOTHESIS: The aim of this study was to confirm that the Bilboquet device (a design mimicking the cup-and-ball game) helps solving mechanical difficulties associated with these fractures internal fixation and to present a simplified version of the original surgical procedure. PATIENTS AND METHOD: This non-randomised prospective study included 22 fractures in 22 patients, mean age 70 years. According to the Neer classification there were three-part fractures in seven cases and four-part fractures in 15 cases. Fractures were all reduced and treated by internal fixation in a simplified surgical procedure using the Bilboquet device. RESULTS: Mean postoperative follow-up was 34 months. The mean Constant score was 66 and the weighted Constant score was 86. Mean active forward elevation was 108° and mean active external rotation was 28°. No per- or postoperative complications occurred. Initial reduction of the tuberosity was incomplete in four cases. Union was obtained in all fractures. There was no secondary tilting of the head, and no migration or pseudarthrosis of the tuberosities. Five patients developed postoperative avascular necrosis of the humeral head. DISCUSSION: The Bilboquet staple component provides a supporting platform for the entire humeral head area. This peripheral stabilization associated with tension band wiring explains the lack of secondary displacement in these cases. Although the Bilboquet device provides a solution to the mechanical problems of complex fractures of the proximal humerus, it does not solve the problem of secondary avascular necrosis of the humeral head, which occurred in 23% of the patients in this series and in 33% of patients in the four-part fractures subgroup. LEVEL OF EVIDENCE IV (non-randomised prospective study).