[Effect of continuous femoral nerve block combined with periarticular local infiltration analgesia on early operative functional recovery after total knee arthroplasty: a randomized double-blind controlled study].

OBJECTIVE: To investigate the effects of early rehabilitation training after total knee arthroplasty surgery by continuous femoral nerve block (CFNB) with or without periarticular local infiltration analgesia (PLIA).

METHODS: In this randomized, double-blind, controlled study, 100 patients under-going primary unilateral total knee arthroplasty in patients with knee osteoarthritis were enrolled. All the patients received CFNB for postoperative analgesia before combined spinal epidural anesthesia. They were randomly divided into 2 groups (n=50 each): CFNB group, CFNB combined with PLIA group (PLIA group). Group PLIA received periarticular local infiltration analgesia with 20 mL ropivacaine (5 g/L), while the equal volume of normal saline was used instead of ropivacaine in group CFNB. Postoperative pain during rest and passive exercises including front and rear portions of knees, the time of ability to perform an active straight leg raise, the time of ability to reach 90° knee flexion, and preoperative and postoperative hospital for special surgery knee score (HSS) were evaluated.

RESULTS: Compared with group CFNB, the visual analogue scores (VAS) of front of knees at rest time in group PLIA had no significant difference (P>0.05); there were significant differences at 4, 8, 12, 24 h postoperation in portions of knees at rest time (P<0.05); the VAS had significant differences at 24 h in passive exercises of knees (P<0.05); the VAS had significant differences at 12, 24 h in portions of knees at passive exercises of the knees (P<0.05); the time of ability to perform an active straight leg raise had significant differences in the two groups (P<0.05).

CONCLUSION: Compared with CFNB postoperative analgesia alone, CFNB with PLIA could relieve rest pain and pain during passive movement after total knee arthroplasty. CFNB with PLIA could shorten the time to perform an active straight leg raise and the time of ability to reach 90° knee flexion. And so some patients could improve postoperative rehabilitation training.