Short-Term Indwelling Foley Catheters Do Not Reduce the Risk of Postoperative Urinary Retention in Uncomplicated Primary THA and TKA

Abstract

Background: The purpose of this randomized controlled trial was to determine whether a short-term Foley catheter (inserted in the operating room and removed upon arrival to the orthopaedic floor) would reduce the risk of postoperative urinary retention (POUR) in patients undergoing primary total hip (THA) and total knee arthroplasty (TKA).Methods: Three hundred and eighty-eight patients undergoing inpatient primary TKA (n = 228) or THA (n = 160) with spinal anesthesia were randomized to receive a short-term Foley catheter (n = 194) or no Foley (n = 194). There were 143 male and 245 female patients. The primary outcome was POUR, defined as requiring ‡2 straight catheterizations or the placement of an indwelling urinary catheter when indicated by retention of ‡450 mL on bladder scans. Secondary outcomes included urinary tract infections (UTIs) within 3 weeks and the need for ‡1 straight catheterization. A power analysis determined that 194 patients per group were required to detect a 7% minimal clinically important difference in POUR rates at 80% power and alpha of 0.05. Intention-to-treat and as-treated analyses were performed (2 patients received the non-allocated treatment). Outcomes were compared between the groups using univariate and multivariate analyses, with alpha < 0.05.Results: Nine patients developed POUR: 4 in the short-term Foley group and 5 in the control group (2.1% versus 2.6%; p = 1.00). Of those who developed POUR, 8 were male and 1 was female (88.9% versus 11.1%; p = 0.002). Twenty-four patients required ‡1 straight catheterization: 10 in the Foley group and 14 in the control group (5.2% versus 7.2%; p = 0.40). Four patients developed UTIs: 3 in the Foley group and 1 in the control group (1.5% versus 0.5%; p = 0.62) on intention-to-treat analysis, and 4 in the Foley group and none in the control group (2.1% versus 0.0%; p = 0.12) on as-treated analysis. Conclusions:The use of a short-term Foley catheter inserted in the operating room and removed on arrival to the orthopaedic floor does not decrease the rate of POUR.