Histochemistry and Morphology of Erector Spinae Muscle in Lumbar Disc Herniation

Abstract

The purpose of this study was to detect any changes in the erector spinae muscles In patients undergoing surgery for lumbar disc herniation (LDH) and to analyze which factors (sex, age, the level and site of disc protrusion, and duration of symptoms) would be related to these changes. The percentage of mean area of the type I fibers was significantly larger in males and in the older age group (P < 0.05), due to the decreasing size of type lla and llb fibers. Patients with LDH have: 1) angulated and selective atrophy of type II fibers with a higher type llb/lla ratio; 2) with increasing age and duration of symptoms, more marked atrophy of type II fibers; and 3) other unspeciflc pathologic changes.