Anatomical variations of the lumbar plexus: a descriptive anatomy study with proposed clinical implications.

This study used dissection of 34 lumbar plexes to look at the prevalence of anatomical variations in the lumbar plexus and the six peripheral branches from the origin at the ventral roots of (T12) L1-L4 to the exit from the pelvic cavity. Prevalence of anatomical variation in the individual nerves ranged from 8.8-47.1% with a mean prevalence of 20.1%. Anatomical variations included absence of the iliohypogastric nerve, an early split of the genitofemoral nerve into genital and femoral branches, an aberrant segmental origin for the lateral femoral cutaneous nerve, bifurcation of the lateral femoral nerve prior to exiting the pelvic cavity, bifurcation of the femoral nerve into two to three slips separated by psoas major muscle fibers, the presence of a single anterior femoral cutaneous nerve rather than the normal presentation of two separate anterior femoral cutaneous branches, and the presence of an accessory obturator nerve. Comparison with relevant research literature showed a wide variation in reported prevalence of the anatomical variations noted in this study. Clinical implications and directions for future research are proposed.