MICROSURGICAL MANAGEMENT OF LATERAL LUMBAR DISC HERNIATIONS - COMBINED LATERAL AND INTERLAMINAR APPROACH

Seventy-three patients presenting either with biradicular symptoms cau sed by involvement of the upper and lower root or with monoradicular s ymptoms caused by affection of the upper root were treated between Jan uary 1993 and July 1995 in our department. An interlaminar and lateral access was used to decompress both the upper and lower root by combin ing the conventional interlaminar approach and a lateral partial facet ectomy. With this technique, satisfactory to excellent results were ob tained in 92% of the patients. The advantages of the combined approach are (i) optimized visualization of the disc and surrounding anatomica l structures, (ii) improved exposure of the lateral foramen and thorou gh removal of disc material, (iii) minimal risk of root injury by impr oved visualization, (iv) preservation of a functional facet joint and thereby reduction of postoperative instability with persistent back pa in. Since occasionally lateral disc herniations are poorly visualized by computed tomography or magnetic resonance imaging, the decision to use the combined approach should be guided by the patient's clinical p resentation rather than by radiological findings.