A comparison of peri-articular injection and femoral block for pain management after total knee arthroplasty: A prospective cohort study

Abstract

Aim: Though Total knee arthroplasty (TKA) is an effective treatment method for osteoarthritis, insufficient postoperative pain control negatively affects patients’ satisfaction and functional results. The aim of this study is to compare the effects of intraoperative peri-articular injection and postoperative single-dose femoral nerve block on functional results, the need for analgesia, and pain in the short-term following total knee arthroplasty (TKA).Methods: Thirty-one patients who received peri-articular injection (PAI) during TKA and 38 who were administered a single dose of femoral nerve block (FNB) postoperatively were evaluated. In both groups, an intravenous patient-controlled analgesia (PCA) device was utilized for postoperative analgesia. Analgesia demand and the amount administered from the PCA in the first 24 hours were recorded. For the evaluation of the level of postoperative pain, a visual analog scale (VAS) was used at rest at 2nd, 4th, 8th, 12th, and 24th hours, and dynamic VAS was used at the 24th hour to assess pain with mobilization. Range of movement (ROM) was recorded with the measurements of active flexion and extension angles at the first, second and third postoperative days.Results: The resting VAS scores at the 2nd, 4th, 8th, and 24th hours were significantly lower in the PAI group than in the FNB group (P=0.032, P=0.037, P=0.014, P=0.004, respectively). The number of patients’ demands on the PCA for pain relief and the number of doses administered were higher in the FNB group. The ROM values measured on postoperative days 1, 2, and 3 were insignificantly greater in the PAI patients (P=0.956, P=0.103, P=0.162, respectively).Conclusion: The peri-articular injection technique, when used appropriately, is easy to apply with a low-side effect profile. Therefore, it can be considered a safe and effective analgesia method providing a higher level of patient comfort and greater range of movement.