Pericapsular Nerve Group (PENG) Block Versus Femoral Nerve Block: Impact on Quadriceps Muscle Strength in Patients with Hip Fracture — A Prospective Randomized Controlled Trial

Background: Hip fractures are among the most prevalent orthopedic complications in elderly individuals. Objectives: This study aimed to compare the effects of pericapsular nerve group (PENG) block and femoral nerve (FN) block on quadriceps muscle strength in patients with hip fractures. Methods: This study included 100 patients with hip fractures scheduled for hip surgery under spinal anesthesia. Patients were randomly assigned to either the PENG block group or the FN block group, with 50 subjects in each. The PENG block group received 20 mL of 0.25% bupivacaine via ultrasound-guided PENG block. The FN block group received the same medication and dosage using an ultrasound-guided FN block. The primary outcome was quadriceps muscle strength after the resolution of spinal anesthesia. Secondary outcomes included perioperative pain intensity [Visual Analog Scale (VAS) at rest and during movement], patient acceptance and quality of positioning for spinal anesthesia, 24-hour post-operative tramadol consumption, and the incidence of adverse events. Results: Quadriceps muscle strength after the effects of spinal anesthesia had worn off (intact/reduced/absent) was significantly higher in the PENG block group (32/14/4) compared to the FN block group (0/24/26). In addition, the PENG block group demonstrated superior quality of patient positioning during spinal anesthesia (2.24 ± 0.52) compared to the FN block group (2.00 ± 0.54). Conclusions: The PENG block demonstrated superior preservation of quadriceps muscle strength, a significantly longer duration of analgesia, and improved quality of patient positioning for spinal anesthesia compared to the FN block.