Meralgia paresthetica secondary to limb length discrepancy: case report.

Meralgia paresthetica consists of pain and dysthesia in the lateral thigh caused by entrapment of the lateral femoral cutaneous nerve (L2-L3) underneath the inguinal ligament. Abdominal distension, tight clothing, and hip hyperextension are all described causes of this condition. To our knowledge this has never been attributed to a limb length discrepancy. We present a 51-year-old man with a long-standing history of right sided meralgia paresthetica. History and physical and radiological examination were unrewarding except that his left leg was shorter than the right by 2 cm. Nerve conduction studies of the lateral femoral cutaneous nerve on the left had a normal latency and amplitude but were absent on the right. To prove the hpothesis that the limb length discrepancy was responsible for the condition, a single subject study was performed. The presence or absence of pain and dysesthesia in the right thigh was the observed behavior. Intervention consisted of wearing a 1.5-cm lift in the left or right shoe for 2 weeks each with an intervening 2-week lift-free period. Pain was recorded on a numeric scale and numbness as being present or absent. There was continuing pain without and with the lift in the right shoe but no pain or numbness with the lift in left shoe. It was concluded that the limb length discrepancy was responsible for the meralgia paresthetica. Pertinent literature and possible pathomechanics are discussed.