Comparison of Continuous Epidural Analgesia and Intravenous Patient-Controlled Analgesia with Opioids in Terms of Postoperative Pain and Their Complications in Mega-Prosthesis Total Knee Arthroplasty for Bone Cancers

Total knee arthroplasty with mega-prosthesis in oncologic patients is a painful surgery and may be associated with nerve injury. Epidural analgesia (EA) with local anaesthetics (LA) is routinely used for pain relief in these patients. At our institute, we came across a high incidence of motor weakness in these patients compelling to shift to patient-controlled analgesia (PCA) with intravenous opioids. We retrospectively analysed our data to find the incidence and reasons for motor weakness and also to compare the efficacy of EA and PCA as analgesics. Over a period of 15 months, 68 patients were operated; out of these, 41 were in EA and 27 in PCA. Demographic details, level of epidural placement, drug used, pain scores, degree of motor weakness, measures taken to relieve the motor weakness and the improvement in symptoms after treatment were recorded. In the IV PCA group, details of drug used, dose of bolus, pain and sedation scores were analysed. Groups were comparable demographically. Motor weaknesses were present in 9 (22%) and 0 patients in EA and IV PCA groups respectively (p = 0.009). Average and maximum pain scores were significantly higher on day 1 in the IV PCA group (p of 0.00 and 0.001 respectively). Maximum pain scores were also significantly higher in the IV PCA group on day 2 (p = 0.010). Two patients out of 27 in IV PCA were found drowsy. Motor weakness is known with EA but can be managed effectively using a lower concentration of LA or by stopping the infusion of LA.