Ultrasound of the Lateral Femoral Cutaneous Nerve in Asymptomatic Adults

Jiaan Zhu; Yiwen Zhao; Fang liu; Yunxia Huang; Junjie Shao; Bing Hu

Disclosures

BMC Musculoskelet Disord. 2012;13(227) 

In This Article

Results

All 120 subjects were Chinese (72 (60%) were male) with a mean age of 41.4 ± 21.3 years (range 18–76), a mean height of 173 cm, a mean weight of 71.1 kg, and a mean BMI of 24.9 ±4.1.

Each nerve was identified using ultrasound in all participants. In the intermuscular space between the tensor fasciae latae muscle and the sartorius, which presented a hypoechoic structure, the transverse sonogram of the LFCN usually showed an ovoid hypoechoic structure with hyperechoic dots within it (Figure 2).

No significant differences were observed between the right and the left sides with respect to the CSA, the distance between LFCN and the ASIS, the numerical and categorical variables of the LFCN, or the relationship between the nerve and the IL. Therefore, the parameters from the bilateral sides were combined for the final analysis. The CSA of the LFCN was 1.04±0.44 mm2. The mean distance between the LFCN and the ASIS was 15.6 ± 4.2 mm (range 2.2–38.7). The nerve passed under the IL in 198 cases (82.5%), whereas in 44 cases (17.5%), it passed through the IL (Figures 3, 4). The LFCN consisted of 1–4 branches just after its passage under or through the IL. The nerve was represented by a single structure in 174 cases (72.5%) and consisted of 2, 3 and 4 branches in 36 (15%), 27 (11.3%) and 3 cases (1.2%), respectively. No statistically significant differences were observed between the ultrasound findings and age, sex, height, weight, or BMI.

Figure 3.

Transverse ultrasound image shows the nerve passing under the inguinal ligament. ASIS: anterior superior iliac spine; LFCN: lateral femoral cutaneous nerve; IL: inguinal ligament.

Figure 4.

Transverse ultrasound image shows the nerve passing through the inguinal ligament. ASIS: anterior superior iliac spine; LFCN: lateral femoral cutaneous nerve; IL: inguinal ligament.

Two neuromas were identified in 2 volunteers, all which were located close to the ASIS (Figure 5).

Figure 5.

Transverse ultrasound image shows a neuroma (arrow) of the LFCN. ASIS: anterior superior iliac spine.

The mean time required for identifying the nerve (the duration from placement of the ultrasound transducer on the skin to visual identification of the unilateral LFCN) was 7s. In the same 30 cases, the mean time was 9s (F.) and 10s (Y.X.). The intraobserver variability correlation coefficient was 0.912.

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