Effects of Fascia Iliaca Compartment Block and Femoral Nerve Block on Pain, Inflammation, and Stress Response in Hip Fracture Surgery

Abstract

BACKGROUND: Hip fracture is a common and serious injury in the elderly population, with postoperative pain management directly impacting rehabilitation quality and functional recovery. While peripheral nerve blocks have become an integral component of multimodal analgesia, systematic comparison of different blocking techniques across various types of hip fractures remains limited. OBJECTIVE: To compare the analgesic effects, safety profiles, and postoperative recovery impacts of fascia iliaca compartment block and femoral nerve block in different types of hip fracture surgeries. METHODS: A total of 180 patients scheduled for hip fracture surgery between January 2022 and June 2024 were enrolled and divided according to fracture type into femoral neck fracture group (n=60), intertrochanteric fracture group (n=60), and subtrochanteric fracture group (n=60). Patients in each group were randomly assigned to either fascia iliaca compartment block group or femoral nerve block group using a random number table, with 30 patients in each subgroup. Corresponding nerve blocks were performed preoperatively. Numeric pain scores were recorded immediately and at 6, 12, and 24 hours postoperatively; 24-hour morphine consumption, time to first ambulation, hospital stay, inflammatory markers (interleukin-6, tumor necrosis factor-α), stress response markers (cortisol, glucose), and adverse events were also assessed. Multivariate regression analysis identified factors influencing analgesic effect, and a nomogram prediction model was constructed. RESULTS AND CONCLUSION: In femoral neck and intertrochanteric fracture groups, the fascia iliaca compartment block subgroup had significantly lower numeric pain scores immediately and at 6 and 12 hours postoperatively compared with the femoral nerve block subgroup (P < 0.01). In the femoral neck fracture group, mean differences in pain scores were 0.86 (95%CI: 0.47-1.25), 0.90 (95%CI: 0.45-1.35), and 0.79 (95%CI: 0.30-1.28) at immediate, 6, and 12 hours, respectively; in the intertrochanteric fracture group, differences were 0.83 (95%CI: 0.43-1.23), 0.87 (95%CI: 0.44-1.30), and 0.70 (95%CI: 0.31-1.09). In these two groups, fascia iliaca compartment block significantly reduced 24-hour morphine consumption (P < 0.001), shortened time to first ambulation (P < 0.05), and reduced hospital stay (P < 0.05). In the subtrochanteric fracture group, no significant differences were observed between the two block techniques for any outcome (P > 0.05). Fascia iliaca compartment block significantly lowered inflammatory markers (interleukin-6, tumor necrosis factor-α) and stress markers (cortisol, glucose) compared with femoral nerve block (P < 0.001). Adverse event rates were comparable (P=0.825). Multivariate regression identified block type (β=-3.76, P < 0.001), fracture type (subtrochanteric β=5.47, P < 0.001), age ≥75 years (β=-1.75, P=0.022), and ASA grade III (β=2.32, P=0.016) as independent predictors of analgesic effect. The nomogram showed good calibration. Interleukin-6 levels positively correlated with hospital stay (r=0.42, P < 0.001) and time to first ambulation (r=0.38, P < 0.001). In conclusion, compared with femoral nerve block, fascia iliaca compartment block provides superior postoperative analgesia for femoral neck and intertrochanteric fractures, reduces inflammation and stress responses, and promotes early recovery; however, in subtrochanteric fractures, the two techniques are equivalent. Block type, fracture type, age, and ASA grade are independent factors influencing analgesic effect. The nomogram may guide individualized analgesic strategies.

1. Introduction

Hip fracture is one of the most common orthopedic injuries in the elderly population, causing severe pain and leading to long-term functional impairment and increased mortality, posing a major global public health challenge [1-3]. Perioperative pain management is a critical factor in improving outcomes for hip fracture patients. Evidence-based medicine shows that effective pain control facilitates early functional exercise, significantly reduces complications such as postoperative pulmonary infection, deep vein thrombosis, and delirium, shortens hospital stay, lowers 30-day readmission rates, and reduces healthcare resource consumption [4-5]. Currently, multimodal analgesia has become the standard perioperative pain management strategy for hip fractures, with regional nerve block techniques gaining attention due to their ability to reduce opioid use and related adverse effects [6-7].

Fascia iliaca compartment block and femoral nerve block are two commonly used regional block techniques for hip surgery. Anatomically, fascia iliaca compartment block involves injecting local anesthetic into the potential space between the fascia iliaca and the iliacus muscle, simultaneously blocking the femoral nerve, lateral femoral cutaneous nerve, and part of the obturator nerve, theoretically providing broader analgesic coverage [8]. In contrast, femoral nerve block directly targets the femoral nerve, primarily affecting pain transmission from the anterior and medial thigh, with relatively simpler operation [9]. The application of ultrasound guidance has significantly improved the success rate and safety of both techniques, but the choice between them remains controversial in clinical practice. Specifically, fascia iliaca compartment block, despite its broader coverage, requires more technical expertise and a longer learning curve; femoral nerve block is simpler but may risk incomplete analgesia. Additionally, differences in local anesthetic dosage, procedure time, and cost influence clinical decision-making, yet high-level evidence is lacking [10].