To investigate the effect of femoropopliteal combined nerve block and local periarticular infiltration anesthesia on pain control after total knee arthroplasty.

A total of 102 patients who underwent unilateral total knee arthroplasty in Jianyang People’s Hospital from June 2020 to August 2022 were selected; patients with severe osteoporosis, coagulation disorders, reumatoids, malignant tumors, chronic pain and patients on long-term analgesic therapy were excluded. They were divided into the observation group (given combined femoral-popliteal nerve block) and the control group (given local periarticular infiltration anesthesia) according to the random number table method, with 51 cases in each group. Repeated measures analysis of variance was used to compare the visual analogue scale (VAS) scores for pain, adrenocorticotropic hormone (ACTH), cortisol (COR), and the number of compressions for patient-controlled intravenous analgesia (PCIA) at different time points between the two groups in the resting state and the passive movement state. Independent sample t tests were used to compare the time of the first compression between the two groups.

The differences in VAS score, ACTH, COR, postoperative PCIA compression times were statistically significant between the two groups ( inter-group F=150.034, 150.539, 121.930, 157.205, time F=564.883, 19.802, 1554.104, 1586、661, interaction F=10.579, 29.889, 154.069, 201.473, all P<0.001). VAS scores at rest and passive exercise at six, 12, 24, 48 h and 72 h in observation group were lower than those in control group (t=4.029, 5.222, 8.886, 6.232, 7.172, 7.737, 8.198, 8.818, 10.752, 11.799, all P<0.05). At one and three days after operation, ACTH and COR in observation group were lower than those in control group (t=9.713, 14.607, 15.099, 12.394, all P<0.05). The number of PCIA compressions six, 12 h and 24 h after operation in the observation group was lower than that in the control group, and the first PCIA compression time was longer than that in the control group (t=12.541, 15.290, 14.761, 5.650, all P<0.05).

Femoropopliteal nerve block has an ideal analgesic effect in total knee arthroplasty, which is conducive to reducing stress response and PCIA compression times.