Influences of continuous femoral nerve block on knee function and quality of life in patients following total knee arthroplasty.

OBJECTIVE Continuous femoral nerve block (CFNB), guided by ultrasound combined nerve stimulations, offers advantages for both sides and provides effective postoperative analgesia after total knee arthroplasty (TKA). The objective of this study was to evaluate the medium-term impact of continuous femoral nerve block on knee function and quality of life in patients following TKA. METHODS This was a follow-up study. Total 168 adult patients scheduled for elective TKA were randomly allocated to receive postoperative continuous femoral nerve block guided by ultrasound combined nerve stimulator (group CFNB, n = 82) or patient-controlled epidural analgesia (group PCEA, n = 86). Quality of life, knee function, patient satisfaction, pain medication and associated adverse effects were compared at 1, 3, 6, and 12 months postoperatively. Quality of life was assessed using the Medical Outcomes Study Short Form-36 Health Survey (MOS SF-36), and clinical results were assessed using the Hospital for Special Surgery (HSS) Knee Scoring System. Patient satisfaction scores were divided into four categories. RESULTS A total of 162 patients completed the 12-month follow-up. The CFNB group patients had significantly improved SF-36 scores and physical function at 1 month postoperatively (P < 0.05); the remaining seven dimensions were similar between the two groups. No differences were observed at 3, 6 or 12 months. HSS scores for the four observational time points were comparable. The CFNB group patients reported less pain; improved knee function, maximum flexion and strength; less celecoxib consumption and fewer side effects at 1 month than the PCEA group patients. The satisfaction score at 12 months decreased significantly, compared with that at 1 month in both groups (3.6 to 2.95 and 3.4 to 2.45, respectively). No difference in satisfaction score was observed between the two groups. CONCLUSIONS Continuous femoral nerve block not only could provide effective postoperative analgesia but also could improve joint function and quality of life in patients at one month postoperatively. Continuous femoral nerve block is a good choice for postoperative analgesia after TKA.