Comparison between Ultrasound Guided Femoral Nerve Block versus IPACK Block in Patients Undergoing Total Knee Replacement on Postoperative Ambulation and Pain: A randomised controlled clinical trial

Background: Total knee replacement (TKR) is a widely used surgical technique for knee disorders. The study is aimed to assess the interspace between the popliteal artery and capsule of the posterior knee (IPACK) block concerning postoperative ambulation as a primary outcome and analgesic efficacy as a secondary outcome when compared to the femoral nerve block (FNB) following TKR.
Methods: Under spinal anaesthesia, forty patients undergoing elective unilateral TKR were divided into two groups: FNB, receiving ultrasound-guided FNB, and IPACK Block, receiving ultrasound-guided IPACK block. Ambulation was assessed with the timed up-and-go (TUG) and 10-meter walk tests. Post-surgery, pethidine consumption in 24 hours and VAS scores were recorded.
Results: After 24 hours postoperative, TUG showed a mean value of 4.8±1.2 seconds in the IPACK group compared with 8.7±2.1 seconds in the FNB group (p < 0.001). The time needed for a 10-meter walk test was significantly longer in the FNB group (12.1±2.1 seconds) than in the IPACK group (8.3±1.2 seconds) in the first 12 hours postoperative. Similarly, 24 hours postoperatively, values were 6.4±1.2 seconds Vs 10.4±2.1 seconds respectively (p < 0.001). Using the VAS score, the FNB group demonstrated a greater analgesic effect than the IPACK group, while taking less total pethidine (73.8±17.2 mg) compared to 110.0±29.7 mg in the IBACK group.
Conclusion: There was delayed ambulation in FNB than in IPACK. The FNB has a better analgesic profile compared to the IPACK block with less total analgesics consumption over 24 hours post-operatively.