Lumbar spine arthroplasty using the ProDisc II

The ProDisc was developed by Thierry Marnay, a French orthopedic surgeon, in the late 1980s. Marnay and his associate implanted ProDiscs into 64 patients from 1990 to 1993. Demonstrating remarkable intellectual restraint, he let this cohort of patients "incubate" so he could see their progress before performing any additional implantations. In 1998, 61 of these patients were still alive, and 58 (95%) of them were available for a thorough follow-up evaluation. No device-related safety issues were identified during this review, and 93% of these patients were satisfied with their implants. This unique and strong data set led to an unusually rapid Food and Drug Administration (FDA) approval for an Investigational Device Exemption study in the United States, prospectively comparing implantation of a ProDisc with a 360-degree fusion, with both single- and double-level study arms. This article represents data on the first 78 patients with at least 6-month follow-up, with 54 of these patients also having 1-year follow-up, enrolled in a prospective randomized FDA study evaluating the safety and efficacy of ProDisc II versus control, a 360-degree lumbar spinal fusion. Data were collected preoperatively at 6 weeks, 3 months, 6 months and 1 year postoperatively. Visual analog scale (VAS), Oswestry Low Back Pain Disability Questionnaire (ODQ) and patient satisfaction rates were evaluated at these intervals, as well as range of motion, return to work, recreational status and ambulatory status. At 6-month follow-up, there were there were 55 ProDisc patients and 23 who underwent fusion. Twenty-five of these patients had two-level surgery. Estimated blood loss (ProDisc, 103 cc, vs fusion, 213 cc) and operative time (ProDisc, 90 minutes, vs fusion, 232 minutes) were significantly different (p< .01). Hospital stays were shorter (ProDisc, 2.24 days, vs fusion, 3.26 days [p< .01]) for ProDisc patients. There was a significant reduction in the ODQ scores from preoperative values in both ProDisc and fusion groups. Similarly, there was a significant reduction for both groups in VAS scores from before to after surgery. A trend was identified at 6 months in patient satisfaction rates favoring ProDisc versus fusion (p= .08), which became more pronounced (although still not statistically significant) at 1 year. Flexion and lateral bend range of motion was significantly improved in ProDisc patients compared with the fusion group (p= .02). Ambulatory status as well as recreational activity improved faster in the ProDisc group. The data suggest that total disc arthroplasty may be an attractive option to lumbar fusion for the surgical treatment of disabling mechanical low back pain secondary to lumbar disc disease.