Foraminal and far lateral lumbar disc herniations: surgical alternatives and outcome measures

Far lateral disc herniations constitute 7 - 12% of all disc herniations. They may be purely far lateral or extraforaminal in location, located beyond the pedicles, or may include intraforaminal and even intracanalicular components. Occurring predominantly at the L4-L5 and L3-L4 levels in almost equal numbers, they are occasionally noted at L5-S1. Clinical syndromes reflect compression of the superiorly exiting nerve root and ganglion; ie an L4-L5 far lateral disc produces a L4 root syndrome. Clinical complaints often include severe radicular pain accompanied by very positive mechanical signs; Lasegue and reverse Lasegue (femoral stretch test) maneuvers. Neurological deficits, including motor, reflex, and sensory findings, are seen over 75% of the time. Although conservative management is occasionally successful (10%), surgery is usually required. The extent of stenosis and attendant degenerative changes dictate whether laminectomy, hemilaminectomy or laminotomy are required along with one of several facet resection options; full facetectomy, the intertransverse approach, medial facetectomy, or an extreme lateral procedure. Postoperatively, patients' neurological outcomes based on both surgeon and patient based outcome measures (SF-36), were comparable for the different surgical procedures which had been based on the individual patient's pathology.