Correlation of radiological parameters to functional outcome in complex proximal humerus fracture fixation: A study of 127 cases.

Abstract

The purpose of this study is to analyze the radiological and functional outcome of complex proximal humerus fractures treated by open reduction and plate fixation, and how radiological parameters correlate with functional outcome. Retrospective study. Level-1 trauma center. One hundred twenty-seven patients were analyzed, with a mean follow-up of 5 (3-7) years. Radiological parameters studied were neck-shaft angle (NSA), greater tuberosity (GT) to articular surface (AS) distance, medial hinge reduction, and presence (or absence) of calcar screw. Functional outcome evaluated by DASH and Constant-Murley (C-M) score. The mean age is 53.8 years. All patients had a union in 14 (12-18) weeks. The mean NSA is 135° (112-155°). One hundred and thirteen patients with an NSA of >120° had a good functional outcome. Fourteen patients with NSA ≤120° had shoulder abduction <90°. The mean GT to AS distance is 7.2 mm (-2 to 16). The superior displacement of GT above AS is associated with abduction of <90° (16 patients). The mean medial gap is 3 mm (0-17). In 14 patients with a medial gap of >4 mm and without calcar screw, varus collapse is observed. All patients had a good outcome on DASH score and 122 patients had good to excellent outcome on C-M score. Five patients with poor outcome on C-M score had NSA <120° and displacement of GT above AS. Radiographic indicators for poor outcome are varus angulation with NSA <120°, superior displacement of GT above AS, the presence of medial gap >4 mm, and absence of calcar specific screw. This "terrible triad" of proximal humerus fracture should be avoided during operative fixation.