Early Experience with a PDN (Prosthetic Disc Nucleus) Combined with A Coflex Device for treating Two.level Lumbar Degenerative Disease

Son, Seong; Kim, Woo Kyung; Lee, Sang Gu; Yoo, Chan Jong; Park, Chan Woo

Abstract

OBJECTIVE
Discectomy and/or spinal fusion have been the standard treatment options with proven effectiveness to treat degenerative spinal disease. To treat patients with more physiologic effective methods, there have been many efforts to develop various kinds of devices such as posterior dynamic stabilization and disc replacement. We reviewed our early experiences with the combined use of a partial disc replacement device, PDN-Solo(R) (Raymedica, Minneapolis, MN, USA) and an interspinous device, Coflex(R) (Fixanos, Pefonnas, France) in two.level lumbar degenerative disease.
METHODS
A total of 13 patients with two.level lumbar degenerative disease underwent an operation from June 2003 to September 2004. A retrospective review of the clinical and radiological data was conducted for all the cases. The intervertebral disc height, the segmental lordotic angle and the total lumbar lordosis were measured. The clinical outcomes were evaluated by using the visual analogue scale (VAS), the Oswestry disability index (ODI) and MacNab's criteria.
RESULTS
There were nine men and four women (mean age 34.4 years, range 21-64 years). The mean follow up period was 36.6 months (range 36-43 months). The average segmental lordotic angle of the PDN level was changed from 8.96degrees to 8.41degrees and that of the Coflex level was changed from 5.49degrees to 2.95degrees. The total lumbar lordotic angle was decreased from 33.74degrees to 32.40degrees. The intervertebral disc height of the PDN level was changed from 7.56 mm to 8.41 mm and that of the Coflex level was changed from 9.33 mm to 9.89 mm. The average degree of recovery from back pain was 5.6 points (from 8.9 to 3.3) and the average degree of recovery from leg pain was 4.4 points (from 7.5 to 3.1). The average degree of ODI recovery was 41.7 points (from 67.1 to 25.4). According to MacNab's criteria, the results were excellent in 4 patients (30.8%) and good in 7 patients (53.8%).
CONCLUSION
Using the PDN with the Coflex may avoid rigid fixation in specially selected cases with two.level disease, i.e., those patients with spinal stenosis and a herniated lumbar disc. But further biomechanical tests and more longterm follow.up are needed.