Hemiarthroplasty for proximal humerus fracture and consequences of a comminuted greater tubercle fragment.

Abstract

A prerequisite for a satisfying functional result in the treatment of comminuted fractures of the proximal humerus with hemiarthroplasty is anatomical reduction, fixation and healing of the tuberculi around the prosthetic neck in order to restore normal function of the rotator cuff. This was a retrospective study to examine the outcome after hemiarthroplasty using a prosthetic stem designed to optimise re-attachment and healing of the tuberculi (Aequalis; Tornier and Global Fx, DePuy). A special emphasis was on the effect on outcome a comminuted greater tubercle might have. At follow-up, clinical results were evaluated using the Constant score and WOOS index. All patients had radiographs taken of the injured shoulder. Quality of tubercle healing and prosthetic height were estimated; acromiohumeral distance was registered as well as greater tubercle comminution and resorption. Thirty-four patients with 35 hemiarthroplasties were included. Mean age was 71 years (range 47-88) at the time of injury. At follow-up (mean 38 months, range 23-67), the mean Constant score was 44 points (range 18-87). The mean WOOS index was 58 (range 15-96). A comminuted tubercle was associated with tubercle resorption and superior migration of the arthroplasty. Also, there was a correlation for the functional Constant score, but for the WOOS index, there was none. Like several other studies, we generally saw a group of patients with limited pain but poor range of movement in the shoulder. Our hypothesis was that comminution of the greater tubercle would correlate with both rotator cuff arthropathic radiographical features and more detrimental functional scores than average. Thus, a subtype of fracture could be identified at the time of injury and perhaps be allocated to a different treatment than hemiarthroplasty. Due to a limited number of patients in this study, we are unable to make any strong statistically supported conclusions regarding this hypothesis. Level 4 evidence.