Can multimodal periarticular injection plus continuous femoral nerve block provide better pain control after total knee arthroplasty? A prospective, crossover, randomised clinical trial

Abstract

INTRODUCTION: Postoperative pain control after total knee arthroplasty (TKA) is a major concern of patients and affects rehabilitation. This study compares the efficacy of pain control using multimodal periarticular injection plus continuous femoral nerve block (Method A) and multimodal periarticular injection alone (Method B). MATERIALS AND METHODS: This was a randomised, crossover, clinical trial. Patients having scheduled for staged TKA were randomised to receive either Method A or Method B in the first stage. In the second stage, they received opposite treatment. The primary objective outcome measure was morphine consumption by patient-controlled analgesia in the first 72 hours postoperatively. Visual analogue scale (VAS) of pain at rest and that of during movement was compared. RESULTS: Cumulative morphine consumption was lower in Method A (mean ± standard deviation, 16 ± 14 mg) than Method B (28 ± 4.9 mg) in the first 72 hours (p=0.16). The VAS rest pain score using Method A (day 1, 2; day 2, 1.8; day 3, 1.2) were similar as Method B (day 1, 2.1; day 2, 1.6; day 3, 0.6) [p>0.05]. The VAS motion pain score using Method A (day 1, 4.3; day 2, 5.2; day 3, 4.1) were also similar as Method B (day 1, 5.1; day 2, 4.2; day 3, 3.5) [p>0.05]. DISCUSSION AND CONCLUSION: Multimodal pain control using periarticular injection plus continuous femoral nerve block provides better objective pain control than periarticular injection alone. Subjective pain control did not differ in these 2 methods.