342 Lumbar Total Disc Replacement by the Lateral Approach Up to 10-Year Follow-up.

INTRODUCTION: The XL-TDR artificial disc is placed by the lateral approach with maintenance of the anterior longitudinal ligament. The purpose of this study was to analyze results of XL-TDR for the treatment of symptomatic degenerative disc disease.

METHODS: This is a prospective nonrandomized single-center study. Sixty cases were enrolled (31 males; 66 levels; average age 42.8 years). Eleven of 60 patients (18%) had not completed at least a 5-year follow-up (FUP), and 49 were enrolled (53 levels) in the analysis. Mean FUP = 93 months (60-122). End points included visual analog scale (VAS) and Oswestry Disability Index (ODI) questionnaires, radiographic outcomes (radiographs and CT) such as heterotopic ossification (HO) and maintenance of disc motion, complications, reoperation, and heterotopic ossification grades.

RESULTS: The mean surgical duration was 122 minutes with mean 58 mL of expected blood loss. All but 3 patients stood up/walked at the same day. Five levels (10%; 5/53) required fusion. Both removal of the prostheses and interbody fusion were performed by the lateral transpsoas approach. One case due to CrCo allergy (at 2 months); 4 due to persistent pain from different causes. Two cases (4%; 2/49) evolved with adjacent level disease that required surgery. One case required sacroiliac fusion. One partial disc migration was identified. Flex/ext films from 38 levels were available at least at a 5-year FUP. HO grade 0 = 13%; grade I = 18%; grade II = 32%; grade III = 16%; grade IV = 21% (8 cases). Most heterotopic ossification cases (85%) occurred in the lateral aspect of the disc space. Patient-reported outcomes showed significant improvement (P < .01) maintained up to a minimum of 5 years. VAS back pain: preoperative 8.5, postoperative early 2.5, and last FUP 3.0. ODI: preoperative 54%, postoperative early 31%, and last FUP 21%.

CONCLUSION: The benefits of this option include minimal fast mobilization and a lower rate of adjacent level disease. The data show satisfactory sustained pain relief and improved physical function for patient with the disc. Lumbar artificial disc replacement done by the lateral approach seems to be a feasible effective treatment for mild degenerative disc disease.