A Prospective Clinical Study of Proximal Humerus Fractures Treated With a Locking Proximal Humerus Plate

OBJECTIVES:The purpose of this prospective study was to evaluate the safety, efficacy, and functional outcome of the locked proximal humerus plate (LPHP) to treat proximal humerus fractures. DESIGN:Prospective clinical trial. SETTING:University orthopedic center. PATIENTS:Over a 25-month period, 64 consecutive patients were treated with a LPHP for an unstable or displaced proximal humerus fracture. INTERVENTION:Demographic data, trauma mechanisms, surgical approaches, and postoperative complications were collected from medical records. Fracture classification according to the Neer classification, radiographic head-shaft angle, and screw tip-articular surface distance in true anteroposterior and axillary lateral radiographs of the shoulder were measured postoperatively. MAIN OUTCOME MEASUREMENTS:The functional outcome was evaluated with a Constant-Murley (CM) evaluation. The CM score is a validated shoulder-specific scoring system in which patients report subjective findings. The physician reported the objective measurements of the shoulder. RESULTS:Follow-ups were completed for all of the patients. The overall complication rate was 35.9%, with screw penetration into the glenohumeral joint as the most frequent problem (7.6%). Deep wound infections were observed in 3.1% (n = 2) of the cases and avascular necrosis in 3.1% (n = 2). All complications occurred in 4-part fractures. Subacromial impingement, frozen shoulder, rotator cuff rupture, and wound dehiscence were observed in 3.1% (n = 2), 3.1% (n = 2), 1.6% (n = 1), and 1.6% (n = 1) of the cases, respectively. Multivariate linear regression analysis revealed that the fracture pattern and the presence or absence of medial support were significant predictors of functional outcome (P = 0.026 and P = 0.003, respectively). Patient age (P = 0.581), sex (P = 0.325), and initial tuberosity displacement (varus/extension or valgus/impaction; P = 0.059) were not significantly associated with the CM score. CONCLUSIONS:The LPHP seems to be a promising implant for the fixation of proximal humerus fractures. However, there are certain limitations that should be mentioned. The number of cases in our study was small, and no safe conclusions can be extracted regarding the rate of avascular necrosis. Additional studies with larger cohorts and longer follow-ups are necessary to better define the appropriate indications for and expected outcomes of this technology.