SEATTLE, Sept. 29 /PRNewswire/ -- Data presented today at the 21st annual meeting of the North American Spine Society (NASS) indicate that patients undergoing disc arthroplasty with PRODISC(R)-L Total Disc Replacement (PRODISC-L) experienced post- and peri-operative outcomes that were better than those of patients undergoing circumferential spinal fusion. According to the study, PRODISC-L patients had significantly higher overall success compared to fusion patients (P=0.005), as defined by a composite of primary measures including pain, patient satisfaction and overall radiographic success.
“This is the first randomized investigational device exemption study to show statistical superiority of an artificial disc compared to fusion,” said Rick Delamarter, MD, associate clinical professor in the Department of Surgery at University of California, Los Angeles, School of Medicine and co-lead investigator. “These data underscore the potential efficacy and safety of disc arthroplasty for people looking for a surgical treatment for debilitating lower back pain which can help them maintain movement throughout their spine.”
Patients undergoing disc arthroplasty with PRODISC-L experienced significantly greater success regarding pain outcomes and neurologic function than patients undergoing fusion. Sixty-eight percent of PRODISC-L patients achieved a measure of pain success compared with 55 percent of patients undergoing fusion, as assessed by a 15-point decrease in the Oswestry Low Back Pain Disability Questionnaire (ODI), a measure of the extent to which low back pain affects a person’s ability to carry out everyday tasks. Neurologic success, improvement or maintenance of neurologic function, also was significantly greater in patients receiving PRODISC-L, with 91 of PRODISC-L patients achieving the measure compared with 81 percent of fusion patients (P < 0.03).
Additionally, patients receiving PRODISC-L experienced significant improvement in pain and patient satisfaction following surgery (67 percent) compared with fusion patients (61 percent), based on a score of less than -20 mm on the Visual Analog Scale (VAS). PRODISC-L patients also reported significantly greater satisfaction than fusion patients, an indication of whether they would have the surgery again (77 mm PRODISC-L versus 67 mm fusion, P < 0.01).
In the study, PRODISC-L patients also maintained spinal movement through two years after surgery. Significantly, X-rays at 24 months indicated that 97 percent of patients undergoing fusion had fused vertebrae at the surgery site, while patients receiving PRODISC-L maintained an average movement of nearly eight degrees.
“Because PRODISC-L has motion similar to that of the normal disc, it may allow the spine to remain healthier longer,” said Jack Zigler, MD, a spine surgeon at Texas Back Institute in Plano, Texas, and co-lead investigator. “As a surgeon, it is gratifying to see patients recover function more quickly than after fusion and return to their normal activities more easily.”
In addition to the post-operative improvements, patients receiving PRODISC-L experienced shorter hospital stays, required less time for surgery and lost less blood during surgery than did fusion patients. The average length of hospitalization was 3.5 +/- 1.29 days for PRODISC-L patients compared with 4.4 +/- 1.54 days for fusion patients, and PRODISC-L patients spent an average of more than 100 fewer minutes in surgery than did fusion patients (121 +/- 59.2 minutes for PRODISC-L patients versus 229 +/- 75.9 for fusion patients) (P < 0.0001, for surgery time). Additionally, patients receiving fusion lost 465 +/- 440 cc of blood, which was significantly more than the 204 +/-231.3 lost by PRODISC-L patients (P < 0.0001).
About the Study
This multi-center, prospective, randomized investigational device exemption study was designed to assess the safety and efficacy of PRODISC-L, comparing clinical outcomes, radiographic motion and patient satisfaction in patients treated with PRODISC-L versus those treated with circumferential spinal fusion. A total of 236 patients at 17 centers across the United States were randomized at a 2:1 ratio of disc replacement with PRODISC-L (n=161) to circumferential fusion (n=75). Patients were assessed pre-operatively and post-operatively at six weeks and three, six, 12, 18 and 24 months. Outcome measures included ODI, VAS, radiographs, physical exam and the Short Form 36 (SF-36), a measurement tool used to assess the physical and mental health status of a patient.
Overall complications were similar in the two treatment groups. Four percent of PRODISC-L patients (n=6) required reoperations compared with five percent of fusion patients (n=4). No post-operative infections occurred in the PRODISC-L group versus three percent in the fusion group (n=2). One percent of PRODISC-L patients (n=2) experienced deep vein thrombosis compared with one percent of fusion patients (n=1).
About Synthes Training Program
In order to further maximize positive clinical outcomes and ensure proper physician technique with PRODISC-L during the disc arthroplasty surgery, Synthes, the disc’s manufacturers, will launch an intensive, three-phase training and education program in October 2006. The program includes information regarding use of PRODISC-L as indicated by the U.S. Food and Drug Administration (FDA) and criteria for patient selection as well as case reviews and hands-on experience with the device. Developed by some of the most experienced arthroplasty faculty in the world, with more than 2000 total disc replacement procedures among them, the program is designed to provide surgeons with the highest level of familiarity and direct experience with PRODISC-L through careful, personalized training that reinforces safe, reproducible surgical techniques.
About Synthes
Synthes is a leading global medical device company. We develop, produce and market instruments, implants and biomaterials for the surgical fixation, correction and regeneration of the human skeleton and its soft tissues.
Synthes Spine
CONTACT: Laura Longwell, Dorland, cell: +1-917-751-8079, for Synthes Spine
