The translaminar approach to lumbar disc herniations impinging the exiting root

We undertook a prospective, non-randomized study on the translaminar approach for the treatment of cephalad extruded disc fragments impinging the exiting root. 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). 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. The translaminar approach is recommended in disc herniations encroaching the exiting root, as an alternative to the conventional interlaminar route.