Abstract
BACKGROUND: Radiographically measured subcutaneous peri-incisional tissue depth has been correlated with post-operative surgical site infection after cardiac, cervical spine, and total knee surgery. Its impact following primary total hip arthroplasty (THA) has not been studied. We compare the interobserver reliability of measuring peritrochanteric fat thickness on pre-operative radiographs and hypothesize that these measurements are a reproducible way to predict acute post-operative wound complications and infection in patients undergoing THA. METHODS: A retrospective case-control analysis was performed at a single institution. Patients taken to the operating room within 90 days of their primary THA for a wound complication or deep infection between 2008 and 2016 were identified. Patients <18 years old, those with history of open surgery on the affected hip, or with inadequate radiographs were excluded. Patients were matched 1:1 for gender, age, BMI, and ASA score to THA patients without early wound complications. RESULTS: All radiographic measurements performed were found to have excellent inter-rater reliabilities (range 0.96-0.98). There was no difference in peritrochanteric fat thickness measurements between the two groups including the sourcil to skin surface (89.5 mm vs. 91.9 mm, p = 0.5), tip of greater trochanter to skin surface (52.9 mm vs. 53.7 mm, p = 0.8), and lateral greater trochanter to skin surface (36.0 mm vs. 37.8 mm, p = 0.6) measurements. CONCLUSION: Contrary to other previously reported surgical procedures, radiographic measurement of subcutaneous depth is not a valid tool for predicting a return to the OR for wound complications in the early post-operative period following primary total hip arthroplasty.