Urinary catheterisation may be associated with a risk of infection in hip and knee arthroplasty, however post-operative urinary retention can be distressing for the patient. This study investigates the factors that might predict the need for post-operative catheterisation.

A prospective blinded study of 128 consecutive patients undergoing lower limb arthroplasty was carried out. Data obtained included sex, age, joint (hip or knee), prostate score (IPSS), previous urinary retention, co-morbidities and residual bladder volume after attempted complete voiding measured using an ultrasound bladder scanner. Anaesthetic type and requirement for urinary catheterisation postoperatively were recorded. Predictive risk factors were identified using binary logistic regression, and expressed as odds ratios (OR) and 95% confidence intervals (CI).

The mean age was 69.5 years. There were 56 males and 72 females. 38 patients (30%) required post-operative catheterisation. Logistic regression identified the following predictive risk factors: bladder scan volume per ml increase (OR 1.006; CI 1.000–1.012); male sex (OR 5.51; CI 2.01–15.16); previous catheter (OR 4.26; CI 1.53–11.82); spinal/epidural/combined spinal epidural anaesthesia (OR 6.78; CI 1.75–26.32); moderate IPSS score (OR 5.15; CI 1.73–15.37); severe IPSS score (OR 3.53; CI 0.605–20.54). Our model specificity is 91%, positive predictor value 71% and negative predictor value 82%.

Introduction

Urinary catheterisation can cause bacteraemia and therefore may be associated with a risk of infection in hip and knee arthroplasty. However postoperative urinary retention can be distressing for the patient. This study investigates the factors that might predict the need for postoperative catheterisation in order to help develop a protocol to decide who should be electively catheterised.