Review Question - QID 4746

The patient has a degenerative spondylolisthesis with associated spinal stenosis at L4-5. The appropriate surgical treatment would involve L4-5 decompression and fusion. A decompression (laminectomy) adjacent to a fusion increases the risk of developing adjacent segment disease.

The patient has a degenerative spondylolisthesis with associated spinal stenosis at L4-5. When spinal stenosis is associated with any type of instability, such as spondylolisthesis, long-term results are improved if the patient undergoes a fusion. While a decompression and posterior fusion is an excellent option for this patient, patients who undergo a lumbar fusion with decompression are at risk of developing spinal stenosis at levels adjacent to the fusion.

Sears et al. reported risk factors for adjacent segment disease in over 900 patients. Risk factors identified were multi-level surgery, age > 60, and an adjacent-level laminectomy. The average incidence of adjacent segment disease requiring surgery was 2.5% annually.

Cheh et al. reported on the incidence of adjacent segment disease after 188 lumbar fusion procedures, and they found similar risk factors, such as age > 50 and multi-level surgery. They also reported that patients who required surgery ending at L1, L2, or L3 had an increased risk compared to fusions ending at L4 or L5.

Figure A is the lateral radiographs demonstrating an L4-5 degenerative spondylolisthesis. Figures C and D are the sagittal and axial MRI demonstrating left lateral recess stenosis from a synovial facet cyst.

Incorrect Answers:
Answer 2: A one-level fusion has a lower risk of adjacent segment disease than a multi-level fusion
Answer 3 and 4: Neither a degenerative spondylolisthesis nor obesity has been shown to increase the risk of adjacent segment disease.
Answer 5: Cheh et al. found circumferential fusion was not a risk factor for ASD.