Intra-articular patient-controlled analgesia improves early rehabilitation after knee surgery

The influence of patient-controlled intra-articular analgesia with ropivacaine, morphine and ketorolac (RMK) on postoperative pain relief and early rehabilitation after anterior cruciate ligament reconstruction was studied. Twenty six patients, randomized into two groups, were enrolled in a placebo-controlled, double-blind study. At the end of surgery a catheter was placed intra-articularly and connected to a patient-controlled pump, programmed to deliver 10 mL bolus and 60 min lockout interval. RMK group received 0.25% ropivacaine, morphine 0.2 mg/mL and ketorolac 1 mg/mL; P group saline. Pain was measured with 10 cm visual analog scale. At pain scores > 3 cm, all patients were instructed to self-administer morphine intravenously using a patient-controlled pump. Daily rescue morphine consumption was noted and 48 h rehabilitation programme was evaluated. Daily morphine consumption was significantly lower in the RMK group (p < 0.001). At 24h after surgery, the patients in the RMK group experienced significantly less pain (p < 0.05). The patients in the RMK group achieved higher maximum degree of knee flexion in supine (p < 0.001) and in prone position (p < 0.05) compared to placebo group and better pain free flexion with assistance on day 1 (p < 0.05) and 2 (p > 0.05). The results show that patient-controlled intra-articular analgesia with RMK combination provides effective pain relief following anterior cruciate ligament reconstruction and improves early physical rehabilitation.