Review Question - QID 4642

The clinical presentation is consistent with a degenerative anterior spondylolisthesis at L4/L5 which has failed conservative management. The most appropriate treatment is a posterior laminectomy and instrumented fusion.

Degenerative spondylolisthesis occurs when one vertebral body is subluxated forward on it's inferior vertebrae, most commonly at the L4/5 level. Symptoms typically involve mechanical back pain and neurogenic claudication/leg pain, which may be unilateral or bilateral. Patients may also have L4 or L5 nerve root symptoms. Radiographs and MRI are important for evaluation and pre-operative planning. Decompression and instrumented fusion is indicated after conservative management has failed (physiotherapy, NSAIDs, epidural steroid injections).

Weinstein et al. performed a combined randomized and observational cohort study evaluating surgical and nonsurgical management for lumbar degenerative spondylolisthesis. They showed that surgery led to greater improvements in pain and function compared to non-surgical management.

Pearson et al. compared patients with degenerative spondylolisthesis and spinal stenosis. They found that patients with degenerative spondylolisthesis had greater improvements than spinal stenosis patients following surgery in all primary outcome measures (physical function, bodily pain, and Oswestry Disability Index).

Sengupta and Herkowitz performed a literature review on the management of degenerative spondylolisthesis. They concluded that fusion provides a better outcome than decompression alone.

Illustration A shows a lateral x-ray of a lumbar spine following posterior decompression and instrumented fusion of a L4/L5 degenerative spondylolisthesis.

Incorrect Answers:
Answer 1: The clinical picture is consistent with neurogenic claudication. The diagnosis may be confused with vascular claudication, which would warrant a vascular surgery consultation
Answer 2: While some surgeons report good results with ALIF for lumbar spondylolisthesis, fusion rates are suboptimal and cage extrusion has been observed with stand-alone anterior constructs. Anterior lumbar interbody fusion is typically reserved for patients who have failed a previous posterior instrumented fusion.
Answer 3: Laminectomy only would not address the instability from the spondylolisthesis
Answer 5: Uninstrumented fusion has been shown to be inferior to instrumented fusion for degenerative spondylolisthesis