Review Question - QID 214663

The patient is presenting with a left-sided far lateral disc herniation at the L3-L4 level. This pathology impinges on the exiting L3 nerve root, and more specifically the dorsal root ganglion, leading to severe pain in the groin and anteromedial thigh. L3 nerve root compression would be most associated with hip adduction weakness.

Examination of the hip can be useful for differentiating hip versus spine pathology and involvement of different nerve roots. Typically hip flexion is mediated by the L2 nerve root, hip adduction by L3, hip abduction by L5, and hip extension by S1. Provocative maneuvers of the hip, including flexion adduction internal rotation (FADIR) and flexion abduction external rotation (FABER) testing, as well hip internal and external rotation testing should be performed to evaluate the hip joint as a cause of pain. When the source of pain is still indeterminate, diagnostic injections should be attempted.

Chang et al. retrospectively evaluated risk factors for failure of decompression of foraminal and far lateral lumbar disc herniations. They report overall good results for far-lateral herniations treated with a lateral intermuscular microdecompression but poor outcomes in patients with double herniations (disc herniation in extraforaminal location and intra-canal location). In the subset of patients with double herniations, they recommend total facetectomy to address the pathology.

Shawky Abdelgawaad et al. report results of a minimally invasive transtubular technique for extraforaminal disc herniations. They report good results with recurrence of symptoms in only 2 of 76 patients.

Figure A is an axial T2 MRI image showing a left-sided far lateral (extraforaminal) disc herniation, which would impinge on the exiting L3 nerve root.

Incorrect Answers:
Answer 1: Sensation on the lateral aspect of the foot is supplied by S1.
Answer 2: The gluteus maximus is innervated by the L5-S2 nerve roots.
Answer 4: Extensor hallucis longus is supplied by L5.
Answer 5: Leg heaviness after ambulation is typical of lumbar spinal stenosis. Spinal stenosis typically has non-dermatomal symptoms but may have concomitant components of radiculopathy. This patient does not have MRI findings suggestive of spinal stenosis.