A prospective double blinded randomized study of anterior cruciate ligament reconstruction with hamstrings tendon and spinal anesthesia with or without femoral nerve block

Abstract

Background: Current literature supports the thought that anesthesia and analgesia administered perioperatively for an anterior cruciate ligament (ACL) reconstruction have a great influence on time to effective rehabilitation during the first week after hospital discharge.

Purpose: The aim of this study is to answer the research question is there a difference in clinical outcomes between the use of a femoral nerve block with spinal anesthesia versus spinal analgesia alone for people undergoing ACL reconstruction?

Methods: ACL reconstruction with spinal anesthesia and patient sedation (Group one); and spinal anesthesia with patient sedation and an additional femoral nerve block (Group two). Patients were re-evaluated for pain, range of motion (ROM), active contraction of the quadriceps, and a Functional Independence Measure (FIM) scoring scale.

Results: Spinal anesthesia with a femoral nerve block demonstrates pain relief 6h after surgery (VAS 0.37; p=0.007). From the third (VAS=4.56; p=0.028) to the seventh (VAS=2.87; p=0.05) days after surgery, this same nerve blockage delivered higher pain scores. Patients had a similar progressive improvement on knee joint range of motion with or without femoral nerve block (p<0.002). Group one and two had 23.75 and 24.29° 6h after surgery and 87.81 and 85.36° of knee flexion after 48h post op.

Conclusion: Spinal anesthesia associated with a femoral nerve block had no additional benefits on pain control after the third postoperative day. There were no differences between groups concerning ability for knee flexion and to complete daily activities during postoperative period.

Level of evidence: Randomized Clinical Trial Level I.

Keywords: ACL reconstruction; Anesthesia; Femoral nerve block; Knee; Randomized clinical trial.