Predicting reoperation after operative treatment of proximal humerus fractures.

Purpose The current understanding of the factors associated with a second surgery or loss of alignment after operative treatment of a proximal humerus fracture has relied on small sample studies with stepwise regression analysis. In this study, we used a powerful regression analysis over a large sample and with many variables to test the null hypothesis that there are no factors associated with a revision surgery or loss of alignment after operative treatment of proximal humerus fractures. Methods A retrospective review of all surgically treated proximal humerus fractures from January 1, 2000, to December 31, 2015, was performed at a tertiary level hospital. We extracted longitudinal medical records for all patients, and the data were organized into two categories of predictors: fracture/operative characteristics and patient characteristics. Results During the study period, 423 patients met the inclusion criteria. Three hundred and fourteen of the fractures underwent Open Reduction Internal Fixation (ORIF) and 109 underwent Hemiarthroplasty. Thirty-three patients underwent revision surgery (8%). Seventy-nine patients treated with ORIF had loss of alignment (25%). Across the entire cohort, the least absolute shrinkage selection operator (LASSO) analysis found that patients between 40 and 60 years of age had a higher odds of revision surgery (OR = 1.6). In patients treated with ORIF, the LASSO regression found an unreduced calcar to be the strongest predictor of loss of alignment (OR = 5.5), followed by osteoporosis (OR = 1.3), prior radiation treatment (OR = 1.3), unreduced greater tuberosity (OR = 1.2) and age over 80 years (OR = 1.2). Conclusion Reoperation after proximal humerus surgery is infrequent even though loss of alignment is common. In our cohort, not all patients who had a loss of alignment underwent revision surgery; consequently, obtaining the best possible reduction at the index surgery is paramount.