Radiculopathy in degenerative lumbar scoliosis: correlation of stenosis with relief from selective nerve root steroid injections.

OBJECTIVE

The purpose is to define the origin of radiculopathy of patients with degenerative lumbar scoliosis-stenosis and to assess the correlation between percentage of initial radicular leg pain relief with selective nerve root injections and lateral canal dimensions.

DESIGN

Retrospective clinical study.

SETTING AND PATIENTS

Thirty-six consecutive patients (average age 72) from Twin Cities Spine Center with degenerative lumbar scoliosis (average major curve 25°) and radicular symptoms were studied.

INTERVENTIONS

Patients underwent 46 selective steroid injections of nerve roots concordant with clinical symptomatology.

OUTCOME MEASURES

Radiographic measurements included major and lumbosacral curve Cobb angle. Computerized measurements of magnetic resonance imaging (MRI) included minimum subarticular height and foramen cross-sectional area of the nerve roots that were injected. Initial response from the nerve root injections was also rated.

RESULTS

Twenty-five percent of nerve root symptoms were coming from the major curve, 72.2% from the lumbosacral hemicurve and 2.8% from both (P<0.001). The affected nerve roots were more frequently the L4 (34.8%) and L5 (28.3%) nerve roots. A total of 71.7% of radicular symptoms were originating from the concavity of the curve and 28.7% from the convexity (P<0.001). The relief from injections was more than 50% in 75% of the patients at 15 days postinjection. There was no statistical significant correlation (P>0.05) between the lateral canal dimensions and the initial response to injection of anesthetic plus steroid injection.

CONCLUSIONS

In degenerative lumbar scoliotic curves, radicular symptoms are attributed mainly to nerve roots exiting from the concavity of the lumbosacral hemicurve. No evidence was found that the rate of initial relief from selective nerve root injections correlates with the degree of stenosis noted in the MRI.