CORRELATIVE MEASUREMENT OF ANTERIOR MARGIN OF THE ANULUS FOR SURGICALPLANNING

Study Design. This study was a retrospective anatomic correlation of i ntervertebral disc dimensions with current surgical guidelines. Object ives. To develop safer guidelines for disc instrumentation. Summary of Background Data. Anterior perforation of the anulus fibrosus and inju ry to intra-abdominal structures is a known complication of lumbar dis cectomy. Coplanar magnetic resonance imaging of the lumbar interverteb ral discs could decrease the rate of complication using axial T1-weigh ted scans. Methods. Three measurements through the intervertebral disc s of the lumbar spine were taken in 50 patients. These were correlated with current surgical guidelines for lumbar instrumentation. Results. Most of the measurements exceeded the current suggested guidelines fo r instrumentation at 3 cm. Conclusions. Current guidelines for introdu ction of instruments into the lumbar disc spaces should be reevaluated . Appropriate measurements should be made on an individual basis.