Total hip replacement (THR) and total knee replacement (TKR) surgery have evolved into reliable and suitable surgical procedures to relieve pain and restore function among patients with damaged or degenerated hip or knee joints and chronic pain.
Fast-track surgery, which evolved as a coordinated multimodal effort combining modern concepts of patient education with multimodal anesthetic and analgesic methods has been introduced to improve rehabilitation after surgery.
The aims of this PhD thesis were in randomized controlled designs to evaluate the efficacy of a peri and intra-articular analgesic technique for postoperative pain after THR and TKR in terms of: I) evaluating whether local infiltration analgesia (LIA) could enhance postoperative pain relief after THA, II) evaluating the efficacy of LIA on postoperative pain relief after TKA, III) evaluating the external validity of study II.
In study I, we evaluated 80 prospectively randomized patients undergoing elective primary THA. One group received continuous epidural infusion (Group EPI); another group received the LIA technique consisting of an infiltration around the hip joint with a solution of 100 ml ropivacaine 2 mg/ml, 1 ml ketorolac 30 mg/ml, and 1 ml epinephrine 0.5 mg/ml at the conclusion of surgery combined with one postoperative intra-articular injection of the same substances through an intra-articular catheter (Group ART). Outcomes were; analgesic requirements, pain assessments measured on the 0-100 mm visual analog scale (VAS), side effects and length of stay (LOS). Narcotic consumption was significantly reduced in Group ART compared to Group EPI (P = 0.004). Pain levels at rest and during mobilization were similar in both groups but significantly reduced in Group ART after cessation of treatment. LOS was reduced by 2 days in Group ART compared with Group EPI (P < 0.001)
In study II, we evaluated the efficacy of two different analgesic regimes after TKA on analgesic requirements and postoperative pain in 40 prospectively randomized patients after elective, unilateral, primary TKA. One group received the LIA technique consisting of infiltration combined with continuous intra-articular infusion of ropivacaine 2 mg/mL plus ketorolac 30 mg/mL (group A); another group received continuous epidural infusion of ropivacaine 2 mg/mL combined with intravenous (IV) ketorolac 30 mg/mL (group E). The median cumulated narcotic consumption was significantly reduced in group A compared with group E (P = 0.01). Pain scores at rest and during mobilization were significantly lower in group A than in group E. Time spent in the post anesthesia care unit was significantly reduced by 70 min in group A (P <0.001), and corrected length of stay (the day patients fulfilled discharge criteria) was reduced by 25% compared with group E (P < 0.01).
In study III, we studied the distribution of preoperative characteristics and postoperative clinical variables among participants and non-participants in study II. In the randomized controlled trial (RCT), 157 patients were identified as potential participants, 99 were excluded (non-participants), 9 enrolled participants declined to participate (non-consenters). Significant differences were found in both preoperative characteristics and clinical outcome variables. The non-participants were older, less healthy, and needed more help from home care system. Furthermore, they were hospitalized longer and were more often transferred to a rehabilitation ward.