Post-Operative Urinary Retention on Revision Knee Arthroplasty: the Role of Intrathecal Morphine

Launched by UNIVERSITY OF TORONTO · Jun 25, 2025

Keywords

ClinConnect Summary

This clinical trial is looking at how a specific pain medicine called intrathecal morphine (given through spinal anesthesia) affects the chances of having trouble urinating after revision knee replacement surgery. Revision knee replacement is a common surgery to fix or replace a previous knee implant. Managing pain well after surgery is very important, and this study compares two groups of patients: one group receives intrathecal morphine during spinal anesthesia, and the other group does not. Both groups will get other types of nerve blocks around the knee to help control pain. The researchers want to see if avoiding intrathecal morphine reduces the risk of urinary problems after surgery while still keeping pain under control.

People who might join this study are adults over 21 years old who are having a single, non-infected revision knee replacement and are generally in good health (not severely ill or dependent on alcohol or drugs). They should not have allergies to the medicines used in the study or be using strong opioids recently. Participants should also be able to understand and follow instructions about managing pain with special catheters placed near the nerves. If you join, you can expect to receive spinal anesthesia with or without intrathecal morphine, along with other nerve blocks to help with pain after surgery. The study will closely monitor your ability to urinate and your pain levels after the operation. This research could help improve pain relief methods while reducing certain side effects for future patients having knee replacement surgery.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • Non pregnant patients undergoing unilateral non infected rTKA surgery;
• • Older than 21 years of age, with American Society of Anesthesiologists (ASA) physical status I-III;
• • With no alcohol or drug dependency history;
• • With sufficient understanding and co-operation about the usage of a perineural catheter for pain management; body mass index (BMI) under 45;
• • With no allergy to medications used in the study protocol (bupivacaine, lidocaine, ropivacaine, midazolam, propofol, ketamine, morphine, hydromorphone, fentanyl, acetaminophen, celecoxib, ondansetron, dexamethasone, tranexamic acid);
• • No current or recent use of opioids (within the last 2 weeks) in an average oral morphine equivalent (OME) of 20 mg/day or higher;
• • With no contra-indications for neuraxial anesthesia, IPACK block, ACB and adductor canal catheter insertion;
• • Who speak and understand the English language;
• • Who agrees to participate on this study through the signature of the consent form.
• Exclusion Criteria:
• • Patients will be excluded of the study if they have a failed spinal anesthesia and needs for a conversion to general anesthesia;
• • If peripheral nerve blocks are not possible to be performed due to technical difficulties;
• • If during patient's care a deviation of the protocol occurs;
• • If CACB catheter has issues on its function, disconnects or exteriorizes within the first 48 hours of infusion;
• • Or if patient decides to withdraw from the study.