The translaminar approach to lumbar disc herniations impinging the exiting root.

OBJECTIVE: We undertook a prospective, non-randomized study on the translaminar approach for the treatment of cephalad extruded disc fragments impinging the exiting root.

METHODS: Between May 2000 and July 2004, 104 patients (59 men)-presenting with upper lumbar root compression in 74% of the cases -underwent a translaminar approach. The mean age was 57 years (range, 27-80 yr). The lamina was approached either through the conventional subperiosteal route or via a muscle splitting access. Mostly intraforaminal disc fragments were removed through a translaminar hole 10 mm in diameter, and the disc space was cleared in cases of evident perforation of the annulus. Follow-up examinations were performed by an independent observer at 1 and 6 weeks; 3, 6, and 12 months; and once yearly thereafter (mean follow-up period, 32 mo).

RESULTS: Extruded (61%) or subligamentous (39%) disc fragments were found intra-operatively. Laminae L4 (44%) and L5 (26%) were mostly involved. In eight cases, the translaminar hole was enlarged to a conventional laminotomy. In 13 patients, the disc space was cleared. The outcomes according to the Macnab criteria were excellent (67%), good (27%), fair (5%), and poor (1%). The incidence of recurrent disc herniations was 7%. Functional radiography performed in the first 20 patients 6 months after surgery and an additional 12 patients complaining of postsurgical back pain excluded any instability.

CONCLUSION: The translaminar approach is recommended in disc herniations encroaching the exiting root, as an alternative to the conventional interlaminar route.