RESUMEN
PURPOSE: In recent years, there has been an increasing interest in peri-articular injections (PAI) to control post-operative pain after total knee arthroplasty (TKA). Previous studies have evaluated the effect of PAI using multimodal analgaesic protocols, but the concomitant use of patient-controlled analgesia (PCA) may has masked the genuine effects of PAI. We investigated the efficacy of PAI compared with PCA and determined whether conventional PCA can be effectively replaced with PAI after TKA. METHODS: Eighty patients undergoing unilateral TKA were randomised into two groups. The PCA group consisted of patients who used PCA after surgery, while the PAI group included patients who did not use PCA post-operatively but were given PAI during surgery. We measured changes in visual analogue scale (VAS) scores, straight leg raising (SLR), range of motion (ROM) and consumption of antiemetics or analgaesics. RESULTS: Pain levels in the PAI group were significantly lower than in the PCA group during two weeks post-operatively (p < 0.05).; functional recovery in the SLR test showed no difference between groups (p > 0.05).; mean ROM showed no difference; (p > 0.05) and there was no difference in the number of patients who needed additional analgaesics. However, antiemetic use was significantly lower for the PAI group (p < 0.05). CONCLUSIONS: PAI offered improved pain control and minimal side effects compared with PCA. Thus, PAI can replace conventional PCA for controlling post-operative pain after TKA.