Abstract
Study Design: Prospective Cohort study.
Objective: To prospectively evaluate the Maverick Lumbar Disc Prosthesis (Medtronic, USA) at one year follow-up.
Methods: Prospective analysis of the Maverick Lumbar Disc Prosthesis implanted in the first 30 consecutive patients for the treatment of single-level degenerative disc disease of the lumbar spine resistant to conservative treatment for more than one year.
Subjects: Sixteen females and 14 males with an average age of 44 years and minimum follow-up of 1 year. The prosthesis was implanted at L4-L5 in 18 patients and at L5-S1 in 12.
Outcome Measures: Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS) preoperatively and at routine scheduled follow-ups. Radiographic analysis included sagittal balance parameters on standing full length lateral radiographs of the spine and range of motion on flexion/extension dynamic radiographs.
Results: Clinical success (ODI improvement > 15), was 82% and 86%, at 6 months and one year follow-up respectively. The VAS showed an improvement in back pain from 7.1 (+/− 2) pre-operatively to 3.0 (+/− 1.8) post-operatively. At one year there were no device related complications. The measured range of motion in flexion-extension ranged from 3 to 12 degrees (mean range of motion, 6 +/− 4 degrees). There was no significant change in sacral tilt, pelvic tilt, or overall lordosis after disc replacement. In one case the ureter was injured during the approach.
Conclusions: The results of total disc arthroplasty presented here compare favourably with results reported in the literature following ALIF. It appears that the disc prosthesis has enough freedom of motion to allow the patient to maintain normal sagittal and spino-pelvic balance with radiographic evidence of normal range of motion. These early favourable clinical results and the influence on adjacent motion segments can be assessed only after long term follow-up.
These abstracts were prepared by Mr. Brian J C Freeman FRCS (Tr & Orth). Correspondence should be addressed to him at The Centre for Spinal Studies and Surgery, University Hospital, Queens Medical Centre, Nottingham NG7 2UH.
