[Keel-based lumbar total disk replacement: Prodisc-L and Prodisc-O].

OBJECTIVE: Improvement of chronic low back pain caused by degenerative disc disease. Maintenance of motion in the treated segment. Reduction of possible adjacent-segment degeneration. INDICATIONS: Chronic low back pain, resistant to conservative therapy due to painful degeneration of the intervertebral disks ("degenerative disk disease"). CONTRAINDICATIONS: Spondylolisthesis, scoliosis, osteoporosis, infection, spinal stenosis, degeneration of the vertebral articulations, (pathologic) fractures. SURGICAL TECHNIQUE: The intervertebral disk is removed via an anterior (Prodisc- L) or anterolateral (Prodisc-O) approach. The segment is sufficiently mobilized, if necessary, by release of the posterior longitudinal ligament. After end-plate preparation, a groove for the keel is chiseled, the end plates are inserted, and the inlay is securely locked in place. POSTOPERATIVE MANAGEMENT: Careful beginning of food intake for prophylaxis of ileus. Early mobilization starting on the 1st day after surgery.
RESULTS: From April 2002 to February 2008, 87 Prodisc-L intervertebral disk prostheses were implanted in 71 patients (43 women, 28 men, average age 45 years). Clinical evaluation was based on the visual analog scale (VAS), the Oswestry Disability Index (ODI), and the SF-36 questionnaire. Follow-up assessment also included radiographic views of the lumbar spine in two planes in flexion and extension and standing. The follow-up interval for all patients was at least 1 year and 2 years for 62 patients. After 2 years, 42 patients were very satisfied with the operation, 13 patients were satisfied, and seven patients were less satisfied. The clinical parameters recorded on the VAS, ODI, and SF-36 improved from 7.5 to 3.5 (VAS), 46.0 to 22.9 (ODI), and 30.5 to 44.8 (SF-36, Physical Component Summary Score) from the time of preoperative assessment to the 2-year follow-up.