Factors predicting complication rates after primary shoulder arthroplasty

Hypothesis: Shoulder arthroplasty is an effective treatment for arthritic conditions and intraarticular fractures of the proximal humerus. Treatment options include total and hemiarthroplasty of the shoulder. They hypothesis of this study was that a mandatory statewide discharge database could identify the epidemiology of primary shoulder arthroplasty, 90 day complication rates, implant survival rates, and patient and hospital characteristics associated with complications. Materials and methods: We identified patients undergoing primary total shoulder replacement and hemiarthroplasty between 1995 and 2005. We report rates of complications within 90 days of surgery and performed survival analysis using revision surgery as the endpoint. Logistic and proportional hazard regression models were used to estimate the effect of patient and provider factors in predicting the rates of adverse outcomes. Results: During the study period, 15,288 patients underwent shoulder arthroplasty. Patients undergoing total shoulder arthroplasty and hemiarthroplasty had no statistically significant difference in the aggregate risk of 90-day complications or the risk of implant failure within the study period. Fracture patients were shown to have a higher risk of short-term complications (odds ratio, 3.2; P < .001). Implant failure rates were lower in patients with fracture, rheumatoid arthritis, increased comorbidity, and advanced age. Conclusion: This study reports similar rates of short-term complications and implant failure in patients undergoing total or hemiarthroplasty, an overall mortality rate of 1.3%, and a pulmonary embolism rate of 0.6%. The findings of our study indicate that the risk of short-term complications is highest in patients undergoing total or hemiarthroplasty for a fracture compared with nonfracture indications. Our results also indicate that longer-term, implant survival is largely driven by factors associated with increased activity, such as age. In patients undergoing surgery for arthritis of the shoulder, we found no difference in implant survival rates between total and hemiarthroplasty of the shoulder. Level of evidence: Level II, Retrospective Design, Prognostic Study. (C) 2011 Journal of Shoulder and Elbow Surgery Board of Trustees.