Predictors for nonunion, reoperation and infection after surgical fixation of patellar fracture

Introduction: The most common major complications following surgical fixation of patellar fractures are infection, nonunion and reoperation. In this study, we sought to define the predisposing factors to the development of these complications.

Methods: Open reduction and internal fixation surgeries for patellar fractures that were performed in a single institution between 2006 and 2011 were retrospectively reviewed. Patients' demographic data (age, gender, comorbidities), injury and fracture data (associated injuries, type of fracture, open or closed fracture), surgical data (type of surgery and interval between fracture occurrence and surgery) and major postoperative complications (infection, nonunion, symptomatic hardware and revision surgery) were collected from the medical records and verified by a telephone survey. Correlation analysis identified the major variables influencing the development of these complications.

Results: The cohort of 188 patients had an average follow-up of 908 days. Thirteen (6.9 %) patients developed infection, 3 (1.6 %) had fracture nonunion and 42 (22.3 %) required a second operation. A history of cerebrovascular accident (CVA) correlated significantly with the development of infection (OR 6.18, CI 1.1–35.6, p = 0.041) and nonunion (OR 14.9, CI 1.2–188.1; p = 0.037). A history of diabetes significantly increased the risk of a second operation (OR 8.69, CI 95 % 1.8–41.9, p = 0.007). Open fracture did not increase the risk of any of these complications.

Conclusions: A history of CVA and diabetes mellitus significantly increased the risk of complications following patellar fracture fixation. Patients with these comorbidities should be informed of their increased risk of these complications and be followed up more rigorously.