Incidence of and risk factors for postoperative urinary retention in fast-track hip and knee arthroplasty

Background and purpose - Postoperative urinary retention (POUR) is a clinical challenge, but there is no scientific evidence for treatment principles. We describe the incidence of and predictive factors for POUR in fast-track total hip (THA) and knee arthroplasty (TKA). Patients and methods - This was a prospective observational study involving 1,062 elective fast-track THAs or TKAs, which were performed in 4 orthopedics departments between April and November 2013. Primary outcome was the incidence of POUR, defined by postoperative catheterization. Age, sex, anesthetic technique, type of arthroplasty, and preoperative international prostate symptom score (IPSS) were compared between catheterized and non-catheterized patients. Results - The incidence of POUR was 40% (range between departments: 30-55%). Median bladder volume evacuated by catheterization was 0.6 (0.1-1.9) L. Spinal anesthesia increased the risk of POUR (OR = 1.5, 95% CI: 1.02-2.3; p = 0.04) whereas age, sex, and type of arthroplasty did not. Median IPSS was 6 in non-catheterized males and 8 in catheterized males (p = 0.02), but it was 6 in the females in both groups (p = 0.4). Interpretation - The incidence of POUR in fast-track THA and TKA was 40%, with spinal anesthesia and increased IPSS in males as predictive factors. The large variation in perioperative bladder management and in bladder volumes evacuated by catheterization calls for randomized studies to define evidence-based principles for treatment of POUR in the future.