Urinary Retention After Arthroplasty

This study is looking at urinary retention — difficulty urinating — that can occur after knee replacement (arthroplasty) surgery. After surgery, some patients find it hard to empty their bladder fully, which can be uncomfortable and may require medical intervention. This study aims to better understand how common this problem is and what factors might make it more or less likely to happen. Participants are adults scheduled for a planned total knee arthroplasty (knee replacement) under spinal anesthesia. The study does not change the surgery itself — it observes patients after surgery to track any urinary issues and assess outcomes. You may be eligible if... - You are 18 years of age or older - You are having an elective (planned) total knee arthroplasty - Your surgery will be done under spinal anesthesia You may NOT be eligible if... - You have had previous surgery for urologic cancer - Your surgery is for a fracture (rather than planned replacement) - You already have untreated urinary retention - You have a nephrostomy (a tube in your kidney) - You are having general anesthesia Talk to your doctor to see if this trial is right for you.