Key points

Introduction

Adult spinal deformity is a common and important pathologic condition affecting the spinal column. The impact of spinal deformity on the health status of affected patients is significant, It affects domains of health, including pain, function, mental health, and self-image. The burden of disease that is encompassed by spinal deformity may be measured by both the prevalence of the disorder, and the impact of the disorder on affected patients. The prevalence of deformity in the aging spine is common, and spinal deformity contributes to the clinical presentation of back pain in most women older than age 60 years. The impact of deformity on health-related quality of life is significant. Patients presenting with symptomatic spinal deformity self-report their health status preference as significantly worse than other common medical conditions, including cardiopulmonary disease, mental health disorders, and other musculoskeletal disorders. An evidence-based approach to the appropriate management of deformity is important because of the prevalence, impact, and burden of adult deformity. The management of patients with radiculopathy and adult deformity is characterized by significant variability, with options encompassing decompression alone, decompression with a limited fusion, and decompression with a multilevel fusion for realignment of the spine. This article reviews the spectrum of surgical approaches for the management of symptomatic lumbar deformity with radiculopathy and provides guidance for an evidence-based approach to when less invasive procedures may be appropriate and when more invasive procedures, including deformity correction, are appropriate.

Introduction

Adult spinal deformity is a common and important pathologic condition affecting the spinal column. The impact of spinal deformity on the health status of affected patients is significant, It affects domains of health, including pain, function, mental health, and self-image. The burden of disease that is encompassed by spinal deformity may be measured by both the prevalence of the disorder, and the impact of the disorder on affected patients. The prevalence of deformity in the aging spine is common, and spinal deformity contributes to the clinical presentation of back pain in most women older than age 60 years. The impact of deformity on health-related quality of life is significant. Patients presenting with symptomatic spinal deformity self-report their health status preference as significantly worse than other common medical conditions, including cardiopulmonary disease, mental health disorders, and other musculoskeletal disorders. An evidence-based approach to the appropriate management of deformity is important because of the prevalence, impact, and burden of adult deformity. The management of patients with radiculopathy and adult deformity is characterized by significant variability, with options encompassing decompression alone, decompression with a limited fusion, and decompression with a multilevel fusion for realignment of the spine. This article reviews the spectrum of surgical approaches for the management of symptomatic lumbar deformity with radiculopathy and provides guidance for an evidence-based approach to when less invasive procedures may be appropriate and when more invasive procedures, including deformity correction, are appropriate.

Variability in approaches to care

The management of lumbar radiculopathy in the setting of spinal deformity is characterized by significant variability. The presence of variability is clear evidence of the absence of an evidence-based approach to care. The appropriate management of adult degenerative scoliosis is the treatment that leads to the most reliable improvement of health-related quality of life while limiting the risks of complications and harm. In a value-based health care economy, the cost of care is also an important consideration. Appropriate care is the strategy that optimizes the clinical outcome while minimizing both risk and costs of care. An evidence-based approach to the management of symptomatic radiculopathy with spinal deformity may include decompression alone, decompression with limited fusion, or decompression with extensive realignment of the spine. The most appropriate treatment requires an understanding of the type of deformity, curve characteristics, and alignment of the spine.

Decompression alone

Decompression procedures have relatively low costs and complication rates. When performed in a patient with a stable spine, a simple decompression has been shown to be cost-effective. However, the removal of bony elements and soft tissue disruption required for decompressive procedures have the potential to exacerbate existing deformity. A classic study by Herkowitz and colleagues demonstrates significantly improved outcomes in patients with spondylolisthesis treated with posterolateral fusion compared with decompression alone. More recently, Houten and Nasser reported rapid progression of deformity with limited decompression in the setting of scoliosis. Several investigators have reported high rates of progressive deformity and failure of surgery in patients with deformity and symptomatic stenosis.

The presence of pre-existing instability increases the chances that a decompression will fail, whereas a stable deformity indicates a decompression alone may be appropriate. The stable spine is the spine that can withstand physiologic loads without risk of progressive deformity, segmental translation, or compromise of the neural elements. Stability can be determined by dynamic radiographs, including flexion and extension views, and radiographic assessments, including the presence of bridging osteophytes.

The effect of decompression alone on the spine with segmental olisthesis, rotatory subluxation, or scoliosis is to further compromise segmental stability without improving segmental alignment of the spine. A recent randomized trial by Forsth and colleagues showed equivocal outcomes and reoperation rates in subjects treated with simple decompression versus decompression and fusion for lumbar stenosis with spondylolisthesis. However, they did not evaluate stability in their trial. A series by Modhia and colleagues showed that revision surgery rates were similar in subjects undergoing decompression versus decompression with fusion. Cases involving instability were excluded and preoperative deformity was not recorded.

A series by Katz and colleagues retrospectively reviewed 7-year to 10-year follow-up data for spinal stenosis treated with decompression. They found that 23% of subjects required a revision. However, they did not measure preoperative deformity parameters or identify risk factors for reoperation. At final follow-up, 33% of subjects continued to have severe back pain and 76% were satisfied with their outcome.

A retrospective study by Hosogane and colleagues reviewed 50 subjects who had a coronal deformity 1 year after decompression surgery. Ten percent of subjects required revision surgery at 33-month follow-up but none of the indications were related to deformity progression. Of the parameters to predict curve progression, they found that osteophyte formation on the curve concavity was the only factor that was protective. Hansraj and colleagues reviewed 50 elderly subjects with deformity and symptomatic stenosis who were treated with decompression alone. Their cohort had a Cobb angle less than 20° and no segmental translation or instability, with only 5% undergoing revision over 5 years. Decompression alone may be appropriate for the group of patients who have smaller curves (<20°); segmental stability, including bridging osteophytes; and radiculopathy that does not require realignment of the spine for adequate decompression.