# Analgesic and Functional Outcomes of Ultrasound-Guided Pericapsular Nerve Group (PENG), Fascia Iliaca, and Femoral Nerve Blocks in Hip Fracture Surgery: A Randomized Controlled Trial

## TL;DR

A new nerve block technique called PENG provides better pain relief and less muscle weakness than traditional methods after hip fracture surgery.

## Contribution

This study is the first to compare PENG + LFCN block with FICB and FNB + LFCN in hip fracture surgery using a randomized controlled trial.

## Key findings

- PENG + LFCN block resulted in the greatest pain reduction 30 minutes post-block.
- PENG group had longer time to first rescue analgesia and lower opioid use.
- PENG preserved quadriceps strength and improved patient satisfaction compared to other techniques.

## Abstract

Background and aim

Hip fractures are associated with significant pain and functional limitations in the perioperative period. Conventional regional anesthesia techniques, such as femoral nerve block (FNB) and fascia iliaca compartment block (FICB), provide analgesia but may cause quadriceps weakness. The pericapsular nerve group (PENG) block, a newer motor-sparing technique, may offer improved outcomes. This study aimed to compare the analgesic efficacy and functional outcomes of PENG + lateral femoral cutaneous nerve (LFCN) block with FICB and FNB + LFCN in patients undergoing hip fracture surgery.

Methods

In this randomized, assessor-blinded clinical trial, 180 patients with proximal femur fractures were assigned to PENG + LFCN, supra-inguinal FICB, or FNB + LFCN (n = 60 each). Blocks were performed under ultrasound guidance using standardized doses of ropivacaine and dexamethasone. The primary outcome was the median reduction in Visual Analog Scale (VAS) score during movement at 30 minutes post-block. Secondary outcomes included ease of spinal positioning, postoperative VAS scores, time to first rescue analgesia, 24-hour opioid consumption, quadriceps strength, patient satisfaction, and complications. Data were analyzed using the Kruskal-Wallis test, with post hoc pairwise comparisons performed using the Dwass-Steel-Critchlow-Fligner procedure.

Results

The median reduction in post-block VAS at 30 minutes was greatest in the PENG group (7.0 points), followed by the FICB group (5.0 points) and the FNB group (3.0 points) (p < 0.001). Post hoc analysis showed that PENG provided superior analgesia compared with both FICB and FNB (p < 0.0001), and FICB was also superior to FNB (p < 0.0001). The PENG group also had a longer median time to first rescue analgesia (24 hours; IQR: 12-24) and lower 24-hour median opioid consumption (5 mg morphine equivalent; IQR: 0-5) compared with the FICB and FNB groups (p < 0.001 for both). Patients in the PENG group demonstrated minimal quadriceps weakness and higher satisfaction (p < 0.001 for both). No major complications occurred.

Conclusions

The PENG + LFCN block provided superior analgesia, facilitated spinal anesthesia positioning, reduced opioid requirements, and better preserved quadriceps strength compared with FICB and FNB + LFCN. These findings support the PENG block as an effective motor-sparing alternative for perioperative analgesia in hip fracture surgery.