The Intertransverse Approach to Extraforaminal Disc Protrusion in the Lumbar Spine

Study Design This retrospective study describes the typical clinical presentation of the extraforaminal disc herniation in the authors' experience, and the surgical management of this via the intertransverse approach. Objectives To establish an accurate preoperative diagnosis that enables the surgeon to plan an operative approach for preserving the apophysial joint. Summary of Background Data In the past, failure to recognize the extraforaminal disc herniation (clinically and via investigations) resulted in inadequate management, often with destructive surgical approaches to the pathology. This need not be so. Methods The records of 40 patients who underwent surgery for extraforaminal disc herniation were analyzed and long-term follow-up was conducted by telephone. Also, the extraforaminal areas of the lumbar spine in cadavers were dissected and examined. Results Examination of the cadaver specimens confirmed the presence of a fibrous band (always seen at surgery) lateral to the nerve root. The results of surgical decompression of the nerve root via the intertransverse approach were at least comparable with other approaches. There was complete resolution of presenting leg pain in 85% of the patients, 7.5% were left with minimal residual discomfort, and 7.5% derived little or no benefit from surgery. Conclusions The extraforaminal disc herniation is a distinct clinical entity that, with a high index of suspicion and the aid of magnetic resonance imaging, can be identified preoperatively. This provides the basis for a planned surgical approach in which destruction of the apophysial joint can be avoided.