Microanatomy of the lateral femoral cutaneous nerve in relation to inguinal ligament and its clinical importance

Abstract

BACKGROUND: A better knowledge of the composition and properties of connective tissue related to the Lateral Femoral Cutaneous Nerve (LFCN) and to the Inguinal Ligament may be important to understand the diagnosis and treatment applicable to injuries such as meralgia paresthetica. OBJECTIVE: To determine the relative amounts of the non-fascicular components in the following areas: (i) proximal to the inguinal ligament [LFCN-1], (ii) deep to the inguinal ligament [LFCN-2], or (iii) distal to LFCN-2 [LFCN-3]. These amounts were discriminated as adipose [FAT] and non-adipose (connective) [NON-FAT] tissues. METHOD: Samples of LFCN-1, LFCN-2 and LFCN-3 from 21 human cadaveric samples were used. Paraffin sections of these structures were processed by Masson's trichrome stain for connective tissue. The number of fascicles was counted in each of these structures; FAT and NON-FAT areas were determined in the non-fascicular areas of the structures. RESULTS: There were more fascicles in LFCN-3 vs. LFCN-1 or LFCN-2; there was more NON-FAT vs. FAT in LFCN-2 vs. LFCN-1 and LFCN-3; inversely, there was more FAT vs. NON-FAT in LFCN-3 vs. LFCN-1 and LFCN-2. All of these comparisons were statistically significant. CONCLUSION: The presence of a higher content of NON-FAT in LFCN-2 and FAT in LFCN-3 may help to explain meralgia paresthetica resulting from compression or focal entrapment of the Lateral Femoral Cutaneous Nerve as it passes deep relative to the inguinal ligament.

A case of meralgia paresthetica caused by prone positioning in a COVID-19 patient with acute respiratory distress syndrome

“…Its anterior branch provides sensory innervation of the thigh (Figure 1). 4 If the LFCN is compressed along the nerve trace due to any cause, MP which is characterized by sensory complaints such as dysesthesia, tingling, numbness, and burning sensation at varying degrees at the anterolateral aspect of the thigh or, rarely, pain may occur. 5 MP can usually be corrected non-surgically, such as removal of compressive agents, use of nonsteroidal anti-inflammatory drugs, or local injections of corticosteroids.…”