Abstract
Introduction
Previous research has demonstrated increased early complication rates following total hip arthroplasty in obese patients, as defined by body mass index (BMI). Subcutaneous fat depth has been shown to be an independent risk factor for wound infection in cervical and lumbar spine surgery as well as after abdominal laparotomy. The aim of this study was to investigate whether increased peri-trochanteric fat depth was associated with increased risk of early complication following total hip arthroplasty.
Methods
We analysed prospectively collected data on a consecutive series of 1220 patients undergoing primary total hip arthroplasty from June 2013 until May 2018. The vertical soft tissue depth from the most prominent part of the greater trochanter to the skin was measured using a sterile ruler and recorded to the nearest millimetre. BMI was calculated at the patient's pre-operative assessment review. All complications (infection, dislocation and peri-prosthetic fracture) occuring within the initial 12 month follow-up were identified.
Results
Females had a significantly greater fat depth at the greater trochanter in comparison to males (median 3.0cm (IQR 2.3–4.0) versus 2.0cm (IQR 1.7–3.0), p<0.001) despite equivalent BMI between genders (males median BMI 30.0 (IQR 27.0–33.0); female median 29.0 (IQR 25.0–33.0). Fat depth had a weak correlation with BMI (R2 0.41 males and R2 0.43 females). Patients with the greatest fat depth (upper quartile) were at no greater risk of developing a complication compared to patients with the lowest fat depth (lower quartile); 2% vs 1.8%, p=0.829.
Conclusions
Peri-trochanteric fat depth is only weakly correlated with BMI. We found no correlation between increased fat depth and risk of early complication following primary total hip arthroplasty.
