Do Curve Characteristics Influence Stenosis Location and Occurrence of Radicular Pain in Adult Degenerative Scoliosis?

Abstract

Study design: Retrospective cohort.

Objective: The aim of this study was to describe the various locations of spinal stenosis (LSS) in lumbar scoliosis and its related clinical symptoms.

Introduction: Adults with lumbar scoliosis often present with pain and disability. Association of scoliosis and stenosis is not rare, but remains sparsely explored. Consequences of scoliosis on stenosis location and treatment remain debatable.

Methods: Patients operated for symptomatic LSS with lumbar scoliosis (Cobb angle >20°) from 2015 to 2016 were included. All patients completed preoperative clinical and neurologic examination. Coronal and sagittal radiographic parameters, rotatory subluxation (RS), and spondylolisthesis were analyzed on full spine radiographs. Computed tomographic scan multiplanar reconstructions were performed to measure central, foraminal, and lateral recess stenosis, from T10 to the sacrum.

Results: A total of 76 patients were included (69 ± 9 years old, 77% female). Sixty percent had neurogenic claudication, and L5 was the most common radicular pain (41%). The mean Cobb angle was 33° ± 16°. Overall, 35 (46%) patients had coronal malalignment; in 69%, side of the coronal tilt corresponded to side of the concavity of the lumbosacral curve. Sixty patients had RS (most frequent level L3-L4). In 50% of the cohort, RS was located at the junction between the lumbar and lumbosacral curves. In 70% (n = 53) of the patients, central stenosis occurred at the junction between the lumbar and lumbosacral curves. Foraminal and lateral stenosis were most frequently observed in the concavity of the distal lumbosacral curve. L5 radicular pain was significantly more frequent in case of lumbosacral contra-curve and right coronal malalignment.

Conclusion: LSS is frequent in lumbar scoliosis. Relationships exist between curve characteristics and symptomatic LSS in lumbar scoliosis; especially, concavity of the lumbosacral contra-curve and the junctional level between the lumbar curve and the lumbosacral contra-curve. Therefore, accurate analysis of stenosis in ASD seems mandatory, to at least perform decompression because perfect planned treatment for stenosis and scoliosis correction might not always be possible because of the patient's general health status.

Level of evidence: Level 4.

Keywords: Coronal tilt; Lumbar scoliosis; Lumbar spinal stenosis; Lumboscral contra-curve; Rotatory subluxation.