Etiologies of recurrent low back pain after laminectomy with emphasis on segmental instability

Abstract

Laminectomy is a surgical treatment for lumbar stenosis. In some patients, however, back pain may recur after this operation. This study was performed to determine underlying causes of recurrent back pain after laminectomy and examine the possibility of an association between axial rotation and segmental instability after laminectomy. A total of 35 patients with previous laminectomy with and without discectomy and recurrent back pain were recruited. Etiologies of recurrent back pain were investigated. An axially rotated lumbar vertebra was reported, when at extreme parasagittal sections the posterior borders of two successive vertebral bodies were not aligned. The frequency of this image finding was compared before and after laminectomy. An axially rotated lumbar vertebra was present in two patients before operation and in four patients after it. Only two new cases with axial vertebral rotation were identified after laminectomy (p = 0.50). The underlying causes of recurrent low back pain after laminectomy were disc reherniation (57.1%), spondylolisthesis (20%), scarring (8.6%), new axial rotation (5.7%), ligamentum flavum hypertrophy (5.7%) and diastematomyelia (2.9%). According to these findings, recurrent disc herniation and spondylolisthesis are two major causes of recurrent back pain after laminectomy. Axial lumbar vertebral rotation is not associated with instability.