BACKGROUND: We compared the effects of continuous femoral nerve block (CFNB) and continuous intraarticular block (CIAB) on pain, functional recovery and adverse effects after total knee arthroplasty (TKA).

MATERIAL AND METHODS: We prospectively randomized 54 patients undergoing TKA into 2 groups: CFNB (Group F) and CIAB (Group I). Surgery was performed under spinal anesthesia. All patients received patient-controlled analgesia (PCA) with morphine, diclofenac, and acetaminophen for the first 72 h postoperatively. Pain was assessed with a visual analog scale (VAS), 48-h morphine consumption and 72-h local anesthetic dosage were recorded, motor blockade was assessed, maximum range of motion (ROM) was measured, and adverse effect profiles were recorded.

RESULTS: There was no significant difference in postoperative pain at rest, in passive motion, active motion, or active movement (2-min walk test (2MWT)) between study groups. Group I had less opioid usage in the first 24 h postoperatively (p<0.05). No significant difference was found between the groups in the postoperative local anesthetic dosage (p>0.05). Significantly lower scores of Bromage scale in Group I in 72 h after surgery (p<0.05) were found. Group I had superior passive maximum ROM in 1 month after surgery and superior active maximum ROM on day 7 and at 1 month after surgery (p<0.05).

CONCLUSIONS: Both CFNB and CIAB are effective postoperative analgesia methods after TKA. CIAB leads to lower postoperative opioid usage in the first 24 h, lower motor blockade in the first 72 h, and better knee function on day 7 and at 1 month after surgery.

Keywords: Arthroplasty, Replacement, Knee, Injections, Intra-Articular, Nerve Block, Pain, Postoperative