A Cadaveric Study of Rare Presence of Psoas Minor Muscle Pierced by Genitofemoral Nerve

Background. The psoas minor muscle is an inconstant muscle found only in 65% of the population. It is a slender muscle with long tendon lies on the anterior surface of the psoas major muscle. The aim of the present study was to determine the parameters like the occurrence of psoas minor muscle with its position related to psoas major muscle, present whether unilateral or bilateral and its relation to genitofemoral nerve. Methods. The study was conducted in 10 cadavers in the Department of Anatomy at Panimalar Medical College Hospital and Research Institute. The presence of psoas minor muscle was observed during routine dissection of posterior abdominal wall by the undergraduate medical students. The parameters included are presence, position, unilateral or bilateral and relation to genitofemoral nerve of the muscle was evaluated on both sides (right and left) of 10 cadavers. Results. The psoas minor muscle was found in 20% (2/10) cadavers. The muscle was found on the anterior surface of psoas major in 20% (2/10), bilateral in 10% (1/10) cases, unilateral in 10% (1/10) cases and in one cadaver (unilateral) the genitofemoral nerve pierced the psoas minor muscle which was a rare finding reported in the present study. Conclusions. The psoas minor is not frequently found muscle in humans. But the knowledge about its presence in some cases may avoid confusion during surgical or radiological procedures. Therefore, it’s the responsibility of anatomist to report its presence and variations which will be useful for the surgeons as a reference guide.