Femoral nerve entrapment: a new insight

Area of Science:

• Anatomy
• Neurology
• Surgical Anatomy

Background:

• Femoral nerve compression in the iliac fossa is typically linked to pathologies.
• Muscular variations, specifically aberrant slips of the iliacus muscle, have been anecdotally suggested as a cause.
• No comprehensive studies have systematically investigated these muscular variations as a cause of femoral nerve compression.

Purpose of the Study:

• To investigate the prevalence and characteristics of aberrant muscular slips of the iliacus and psoas muscles related to the femoral nerve.
• To determine if these muscular variations represent a potential risk factor for femoral nerve entrapment.

Main Methods:

• Dissection of 121 embalmed cadavers (242 specimens) to identify muscular variations affecting the femoral nerve.
• Detailed documentation of the relationship between muscular slips and the femoral nerve.
• Statistical analysis using the chi-squared test to compare findings by sex and side.

Main Results:

• Aberrant muscular slips from the iliacus and psoas muscles were identified in 19 specimens (7.9%).
• The most common variation was muscular slips piercing the femoral nerve (17 specimens, 7.0%), altering its structure before entering the thigh.
• A muscular slip or sheet covering the femoral nerve was less common (2 specimens, 0.8%).
• No significant differences in the occurrence of these variations were observed between sexes or sides.

Conclusions:

• Aberrant muscular slips of the iliacus and psoas muscles are a notable anatomical variation in the iliac fossa.
• These muscular variations, particularly those piercing the femoral nerve, are potential anatomical risk factors for femoral nerve entrapment.
• Further clinical correlation is warranted to confirm the direct link between these findings and symptomatic femoral nerve compression.