BACKGROUND: The subcutaneous location of the patella and the demand for early knee motion contribute to the difficulty in treating patients with patella fractures. The reported rates in the literature for hardware removal after patella open reduction and internal fixation range from 0% to 60%. The wide variability of these reports leaves the true frequency of re-operation and complications after patella open reduction and internal fixation in question. Furthermore, gaining a better understanding of the factors that contribute to re-operation and complications will help to generate hypotheses and research agendas to address these difficult problems. METHODS: We performed a systematic review to identify publications in which adult patients with patella fractures were surgically treated with a minimum of 6-month follow-up. The surgical technique (tension band or other), infection rate, nonunion rate, and re-operation rate (including removal of hardware) were recorded. Meta-regression analysis was used to describe the potential contributory factors for re-operation, nonunion, and infection while controlling for age, gender, open fracture, surgical technique, and date of publication. Separate regression models were constructed for each outcome depending on the number of studies available for inclusion. RESULTS: The frequency of re-operation was 33.6% in a meta-analysis of 24 studies (737 patella fractures). The frequency of infection was 3.2% in a meta-analysis of 18 studies (522 patella fractures). The frequency of nonunion was 1.3% in a meta-analysis of 15 studies (464 patella fractures). There were no significant predictors for re-operation, nonunion, or infection in any of the regression analyses. CONCLUSION: Although the frequencies of nonunion and infection are relatively low after surgical treatment of patella fractures, the modern rate of re-operation is substantial. LEVEL OF EVIDENCE: Meta-analysis, level III+.
- systematic review