Saphenous neuropathy in a patient with low back pain.

Saphenous nerve, a pure sensory nerve, may compromise as a result or complication of a surgical procedure or secondary to trauma or insidiously. We present a male patient with low back pain concomitant with pain in medial portion of left thigh in addition to pain and numbness in medial part of leg and inferior part of patella after a strenuous activity. Preliminary diagnosis suggested that the patient had radiculopathy but electrodiagnostic tests revealed the absence of left saphenous response both in medial leg and infrapatellar region, while normal findings were recorded from right side. Needle electromyography in L4 innervated muscles were normal. The patient had saphenous nerve entrapment in left thigh. Two months later symptoms relieved with conservative therapy.