Factors affecting the rate of surgical site infection in patients after hemiarthroplasty of the hip following a fracture of the neck of the femur

Aims

Surgical site infection can be a devastating complication of hemiarthroplasty of the hip, when performed in elderly patients with a displaced fracture of the femoral neck. It results in a prolonged stay in hospital, a poor outcome and increased costs. Many studies have identified risk and prognostic factors for deep infection. However, most have combined the rates of infection following total hip arthroplasty and internal fixation as well as hemiarthroplasty, despite the fact that they are different entities. The aim of this study was to clarify the risk and prognostic factors causing deep infection after hemiarthroplasty alone.

Patients and Methods

Data were extracted from a prospective hip fracture database and completed by retrospective review of the hospital records. A total of 916 patients undergoing a hemiarthroplasty in two level II trauma teaching hospitals between 01 January 2011 and 01 May 2016 were included. We analysed the potential peri-operative risk factors with univariable and multivariable logistic regression analysis.

Results

A total of 92 patients (10%) had a surgical site infection, and 44 (4.9%) developed a deep infection. After univariable analyses, the multivariable model showed that the level of experience of the surgeon measured by the number of hemiarthroplasties performed per year was a significant prognostic factor (odds ratio (OR) 0.93, p = 0.042) for the development of an infection. Secondly, the development of a haematoma (OR 9.6, p < 0.001), a re-operation (OR 4.7, p = 0.004) and an operating time of < 45 mins (OR 5.1, p = 0.002) or > 90 mins (OR 2.7, p = 0.034) were also significant factors.

Conclusion

There was a significant association between the experience of the surgeon and the rate of deep infection. Secondly, a haematoma, a re-operation and both shorter and longer operating times were associated with an increased risk of deep infection after hemiarthroplasty. No association was found between deep infection and the anatomical approach, the time when surgery was undertaken and the use of a drain.