Review Question - QID 214609

The patient is presenting with a left L5-S1 far lateral disc herniation resulting in left L5 radiculopathy. This would cause left hip abduction weakness.

Lumbar disc herniation is the result of recurrent torsional strain on the disc complex leading to annular tear and expulsion of disc material into the spinal canal or neuroforamen. Far lateral disc herniations cause mechanical compression on the exiting nerve root leading to radiculopathy. Classic symptoms include dermatomal neuropathic pain described as burning and tingling with possible motor weakness in the innervated muscles. The L5 nerve root has contributions to the extensor hallicus longus, tibialis anterior, gluteus medius, and gluteus minimus.

Atlas et al. performed a 10-year prospective study of 10-year outcomes lumbar disc herniation in 507 patients treated surgically and nonsurgically. They reported that 56% of surgically treated patients reported their back and leg pain to be much better or completely resolved compared to 40% treated conservatively and 71% of surgically treated patients being satisfied with their current status compared to 56% in nonsurgically treated. They concluded that surgical treatment of disc herniation provided more complete relief and greater patient satisfaction at 1-years than nonsurgical treatment.

Overdevest et al. performed a subgroup analysis of a randomized control trial to assess motor deficit recovery of lumbar radiculopathy following surgical decompression in 150 patients. They reported there was a significantly faster motor recovery in patients that underwent early surgical decompression, but there were similar improvements in motor recovery at 26 and 52 weeks in the early and late surgery groups. The authors concluded that early surgical intervention for lumbar disc herniation can promote more rapid motor recovery.

Figures A, B, and C are the axial T2, parasagittal T2, and coronal T2 MRI of the lumbar spine demonstrating a left far lateral L5-S1 herniated nucleus pulposus impinging on the left L5 nerve root. Illustration A is a chart depicting the major nerve root innervations of the lower extremity muscles and their corresponding actions.

Incorrect answers:
Answer 1: The patient has a left L5-S1 far lateral disc herniation, which could result in extensor hallicus longus weakness, tibialis anterior weakness, or gluteus medius and minimus weakness.
Answer 2: Right hip flexion is initiated by the iliopsoas, which is innervated by the L2 and L3 nerve root.
Answer 3: Left knee extension is initiated by the quadriceps, which is innervated by the L3 and L4 nerve root.
Answer 5: Right foot plantarflexion is initiated by the gastrocnemius and soleus muscles, which are innervated by the S1 and S2 nerve roots.