Clinical Practice of Hydromorphone in Multimodal Analgesia for Enhanced Recovery After Surgery (ERAS) in Knee Arthroplasty

This study proposes a multimodal analgesia regimen comprising preoperative non-steroidal anti-inflammatory drugs (NSAIDs) for preemptive analgesia, intra-articular injection at the end of surgery, and postoperative adductor canal block. The objective is to observe the analgesic efficacy and duration of hydromorphone combined with ropivacaine in the adductor canal block on resting and movement-related pain in patients following total knee arthroplasty, as well as the time to recovery from motor blockade and the incidence of drug-related adverse events.

Inclusion Criteria: 1. ASA physical status I-III; 2. Undergoing elective unilateral primary total knee arthroplasty (TKA); 3. Implementing the ERAS protocol 4. Body-mass index (BMI) of 18.5-32.0 kg/m²; 5. Provided written informed consent. Exclusion Criteria: 1. Allergy to amide local anaesthetics or opioids; 2. Chronico or disorder opioid use; 3. Pre-existing central and peripheral nerve injuries； 4. Lower limb muscle weakness 5. Unable to cooperate with VAS pain assessment 6. Contraindications for nerve block include infection at the puncture site.