Comparison of combined adductor canal block with peri-hamstring infiltration versus adductor canal block for postoperative analgesia in arthroscopic anterior cruciate ligament reconstruction surgery

Background

Pain after anterior cruciate ligament reconstruction (ACLR) can be attributed to both arthroscopic surgery and graft - donor site. Conventionally used techniques of peripheral nerve blockade may not provide complete analgesia to graft - donor site. Moreover, femoral nerve blockade is known to cause quadriceps strength deficit. The purpose of this study was to evaluate whether addition of peri-hamstring infiltration to adductor canal block can lead to better analgesia after surgery than block alone.

Methods

60 ASA grade I & II patients scheduled for anterior cruciate ligament reconstruction surgery using ipsilateral hamstring autograft under subarachnoid block were randomly distributed into 2 groups to receive postoperatively either adductor canal block alone (group A) or peri-hamstring infiltration along with adductor canal block (group AH). Adductor canal block was given in both the groups using 15 ml of 0.5% ropivacaine with 1:200000 adrenaline. Patients in Group AH received additional 20 ml 0.5% ropivacaine with 1:200000 adrenaline at hamstring donor site. Postoperative pain on Visual Analogue Score (VAS) at various time intervals, time to first rescue analgesic requirement, cumulative analgesic requirement over 24 h, quadriceps strength, adverse effects and patient satisfaction were recorded.

Results

Statistically significant difference in mean VAS score (resting & dynamic) was observed in both the groups at 8 and 12 h (p value < 0.001). Time to first rescue analgesic was longer in group AH (11.47 ± 2.92hrs) compared to group A (8.13 ± 1.28hrs). Cumulative ketorolac requirement was lower in group AH (34 ± 18.86 mg) in contrast to group A (49 ± 20.06 mg). Quadriceps strength was comparable in both the groups and no major complications were observed in either group. However, patient satisfaction measured by Numeric Rating Scale (NRS) was much better in group AH.

Conclusion

Peri-Hamstring infiltration of local anaesthetic along with adductor canal block is better than adductor canal block alone at allaying postoperative pain due to hamstring autograft.