Local infiltration of analgesia and sciatic nerve block provide similar pain relief after total knee arthroplasty

BACKGROUND: Although femoral nerve block provides satisfactory analgesia after total knee arthroplasty (TKA), residual posterior knee pain may decrease patient satisfaction. We conducted a randomized controlled trial to clarify the efficacy of the sciatic nerve block (SNB) and local infiltration of analgesia with steroid (LIA) regarding postoperative analgesia after TKA, when administrated in addition to femoral nerve block (FNB). METHODS: Seventy-eight patients were randomly allocated to the two groups: concomitant administration of FNB and SNB or FNB and LIA. The outcome measures included post-operative pain, passive knee motion, C-reactive protein level, time to achieve rehabilitation goals, the Knee Society Score at the time of discharge, patient satisfaction level with anesthesia, length of hospital stay, surgical time, and complications related to local anesthesia. RESULTS: The patients in group SNB showed less pain than group LIA only on postoperative hours 0 and 3. Satisfactory postoperative analgesia after TKA was also achieved with LIA combined with FNB, while averting the risks associated with SNB. The influence on progress of rehabilitation and length of hospital stay was similar for both anesthesia techniques. CONCLUSIONS: The LIA offers a potentially safer alternative to SNB as an adjunct to FNB, particularly for patients who have risk factors for sciatic nerve injury.