Inferior Subluxation Of Humeral Head Research Articles

Inferior subluxation of humeral head after osteosynthesis for greater tuberosity fracture

BackgroundInferior subluxation of the humeral head is frequently observed immediately after surgery for proximal humerus fractures; however, the incidence and risk factors of inferior subluxation after osteosynthesis for isolated greater tuberosity fractures remain unsolved. Additionally, the postoperative course of inferior subluxation has not been elucidated. The purpose of the present study is to identify the predictors for the occurrence of postoperative inferior subluxation by multivariate analysis and investigate the postoperative shift of inferior subluxation and its effect on surgical outcomes.MethodsWe retrospectively identified 68 patients who underwent surgery for isolated greater tuberosity fractures. The dependent variable was the inferior subluxation at 1 week postoperatively. The explanatory variables were age, sex, affected side of the shoulder, body mass index, history of smoking, local osteoporosis, time period to surgery, axillary nerve injury, inferior subluxation before surgery, fracture dislocation, surgical approach, surgical method, operative time, amount of blood loss, and postoperative drainage. Baseline variables that were statistically significant in the univariate analyses were included in the logistic regression analysis. The patients were further categorized into two groups according to the presence of inferior shoulder subluxation exhibited 1 week postoperatively: patients with inferior subluxation (+ IS group) and patients without inferior subluxation (− IS group). We compared the incidence of postoperative complications between the two groups.ResultsOf 68 patients, 17 (25.0%) had inferior shoulder subluxation observed 1 week postoperatively. Multivariate analysis showed that long operative time was a risk factor for postoperative subluxation (odds ratio = 1.03; P = 0.030). In all cases, inferior subluxation disappeared within 3 months of surgery. No significant difference in complication rate was observed between the + IS and − IS groups.ConclusionsThe present study provides novel information regarding postoperative inferior subluxation of fractures of the greater tuberosity. Inferior subluxation occurred in 25% of patients immediately after surgery. Long operative time contributes to the onset of postoperative inferior subluxation; however, this was temporary in all cases and had no significant effect on the surgical outcomes.Level of Evidence: Level III.

Humeral head inferior subluxation in proximal humerus fractures.

The objectives of this study are to propose a reliable radiologic method for detecting static inferior subluxation of humeral head, to calculate the relative intra- and inter-observer reliability, and to evaluate its presence pre- and post-surgery. This is a retrospective observational study of patients surgically treated for a fracture of the proximal humerus. Fractures were classified using Codman-Lego criteria (radiographic, CT images), osteoporosis was assessed. To identify inferior subluxation, an original method is proposed. This measurement was done pre-operatively, at three and 12 month post-operatively. Clinical evaluation was recorded at final follow-up using Constant Score. One hundred fifty fractures surgically treated were studied. Intra- and inter-observer reliabilities were excellent and high, respectively. In pre-operative x-rays, a significant inferior subluxation was noted in 17/150 cases (11.3%), with significant correlation with fracture pattern (p=0.045), female sex (p=0.038), age older than 70 (p=0.003), obesity (BMI>30, p=0.03), and local osteoporosis (p=0.002). At three month of follow-up, 22 cases (14.6%) had inferior subluxation, with significant correlation with female sex (p=0.04), age older than 70 (p=0.002), obesity (p=0.02), pin or screw articular surface perforation (p<0.001). At 12 month of follow-up, seven cases showed persistent inferior subluxation, with significant correlation with age older than 70 (p=0.032), obesity (p=0.041), screw joint perforation and lower Constant Score (p<0.001). Inferior subluxation was mostly found in osteoporotic fractures of the elderly, obese, and of female sex both pre- and post-operatively. The intra- and inter-observer reliabilities of proposed radiographic measurement were high and excellent, respectively. In the early postoperative months, we found a high correlation between inferior subluxation and articular surface perforation; when persisting at later follow-ups, we might speculate that it could represent an early phase of avascular necrosis of the humeral head. Level III, observational study.