Efficiency of Femoral Nerve Block for Recovery after Primary Total Knee
Purpose The aim of our study is to evaluate the efficiency of femoral
nerve block on recovery after primary total knee arthroplasty. Our
primary goal is to provide adequate analgesia with a lower concentration
of bupivacaine (0.125%) as well as the usual concentration (0.25%).
Comparing the degree of motor block, side effects, postoperative pain
scores, opioid consumption, and ambulation and discharge times are our
secondary goals. Methods The study was conducted as randomized,
controlled and double blind. Sixty three patients were randomised into
three groups: G125(n:21) received FNB with 20ml of 0,125% bupivacaine,
G25(n:21) received 10ml of 0,25% bupivacaine and GCont(n:21) received
no block. FNB was applied with ultrasound guidance after the operation.
Pain scores(NRS) at certain time intervals, total opioid consumption,
motor block, knee flexion and discharge times were recorded. Results For
GCont, pain scores were significantly higher at 2nd, 6th, 12th and 24th
hour postoperatively, total opioid consumption was higher(G125:75mg,
G25:0mg, GCont:280mg) and first opioid demand time was earlier(G125:12th
hour, G25:21st hour GCont:2nd hour). First knee flexion time and
mobilization time were also delayed for GCont. G25 had lower scores for
quadriceps muscle strength(G25:3/5, G125:4/5, GCont:5/5, Manual Test at
6th Hour), but this did not affect mobilization compared to G125.
Conclusion G125 had lower quadriceps muscle strength loss compared to
the G25 and earlier mobilization and flexion times, low opioid
consumption and low pain scores compared to the control group. In this
respect, we believe the femoral nerve block with 0,125% bupivacaine
proves to be a suitable option for analgesia with the potential of
maintaining enough movement for recovery after TKA.