A prospective randomized multi-center study for the treatment of lumbar spinal stenosis with the X STOP interspinous implant: 1-year results

Abstract

Patients suffering from neurogenic intermittent claudication secondary to lumbar spinal stenosis have historically been limited to a choice between a decompressive laminectomy with or without fusion or a regimen of non-operative therapies. The X STOP Interspinous Process Distraction System (St. Francis Medical Technologies, Concord, Calif.), a new interspinous implant for patients whose symptoms are exacerbated in extension and relieved in flexion, has been available in Europe since June 2002. This study reports the results from a prospective, randomized trial of the X STOP conducted at nine centers in the U.S. Two hundred patients were enrolled in the study and 191 were treated; 100 received the X STOP and 91 received non-operative therapy (NON OP) as a control. The Zurich Claudication Questionnaire (ZCQ) was the primary outcomes measurement. Validated for lumbar spinal stenosis patients, the ZCQ measures physical function, symptom severity, and patient satisfaction. Patients completed the ZCQ upon enrollment and at follow-up periods of 6 weeks, 6 months, and 1 year. Using the ZCQ criteria, at 6 weeks the success rate was 52% for X STOP patients and 10% for NON OP patients. At 6 months, the success rates were 52 and 9%, respectively, and at 1 year, 59 and 12%. The results of this prospective study indicate that the X STOP offers a significant improvement over non-operative therapies at 1 year with a success rate comparable to published reports for decompressive laminectomy, but with considerably lower morbidity.

Market approval processes for new types of spinal devices: challenges and recommendations for improvement

“…The authors concluded that the X-Stop Ò offers a significant improvement in The Zurich Claudication Questionnaire over non-operative treatment after 1-year and 2-year follow-up [13,21] and in improving quality of life [20]. Furthermore, the authors stated that, at 1-year and 2-year follow-up, results were similar to published reports on decompressive laminectomy, with considerably lower morbidity [13,21].…”

“…Prior to its PMA, only five studies on the X-Stop Ò were published. These included a prospective randomized multi-center study (191 patients) [13], a study on preliminary experiences in ten patients only [14] and three in vitro studies [15][16][17]. Up to now a total of ten RCTs [13,[18][19][20][21][22][23][24][25] and three cost-effectiveness studies [26][27][28] were published.…”

“…The first study by Zucherman et al was a multi-center RCT in which the X-Stop Ò (100 patients) was compared with non-operative treatment (91 patients) for lumbar spinal stenosis [13,21]. The authors concluded that the X-Stop Ò offers a significant improvement in The Zurich Claudication Questionnaire over non-operative treatment after 1-year and 2-year follow-up [13,21] and in improving quality of life [20].…”

Minimally invasive surgery for lumbar spinal stenosis

“…While the research group was planning to perform a randomized controlled trial (RCT), such a prospective comparative study of this implant is not available in Pubmed. After the introduction of this implant by Senegas, the development of other IPDs followed, such as Minns, X-stop and Coflex [13][14][15][16]. Cadaveric studies did not show any biomechanical difference between the various IPDs, and they were therefore considered as interchangeable, although differences in clinical effectiveness were not investigated [15].…”

British spine surgery

“…We have a strong evidence-based specialty. This has been helped by the randomised controlled studies in the new techniques of spinal arthroplasty, vertebroplasty, interspinous spacers and re-evaluation of conventional techniques with the Sciatica study from Holland and the controversial and expensive SPORT studies form North America [1][2][3][4][5]. Not all of these have provided the results we were expecting, particularly the Vertebroplasty studies Buchbinder and Kallmes [6,7].…”