Functional and radiographic medium-term outcome evaluation of the Humerus Block, a minimally invasive operative technique for proximal humeral fractures

Abstract

Conservative treatment of severe displacement of proximal humeral fracture fragments yields bad functional results, but open operative techniques have a high risk of avascular necrosis of the humeral head. We performed a medium-term outcome evaluation of the Humerus Block (Synthes, Oberdorf, Switzerland), a minimally invasive technique used in selected patients with proximal humeral fractures, to investigate the functional and radiographic outcome. Of 47 patients operated on with the Humerus Block, 34 with a minimum follow-up of 30 months and a mean follow-up of 4 years and 4 months, were invited for interview, radiographic evaluation, and functional analysis by the Constant, Disabilities of Arm, Shoulder and Hand (DASH) and the University of California, Los Angeles (UCLA) scorings. Paired t test was used to investigate equivalence of the geometric mean scores of the trauma and control arm, for the scores of the functional analyses, and for the scores for mobility of the shoulder. Scorings and clinical examination showed that 85% of shoulder function and motion were preserved compared with the control arm. Radiographic evaluation showed very good healing and positioning of the fracture fragments, and only 10% developed avascular necrosis of the humeral head. With very satisfied patients; good clinical, functional, and radiographic outcomes; a short hospital stay; few complications; a reduced cost of implant; and a low incidence of avascular necrosis, this technique is a valuable alternative for operative treatment of proximal humeral fractures.