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Five-Year Results of the Prodisc-C Multicenter Randomized Clinical Trial
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Proceedings of the NASS 26th Annual Meeting / The Spine Journal 11 (2011) 1S–173S
87. Five-Year Results of the Prodisc-C Multicenter Randomized Clinical Trial Sean Kearns, PhD1, Michael Janssen, DO2, Daniel Murrey, MD3, Rick Delamarter, MD4; 1Spine Education and Research Institute, Denver, CO, USA; 2Center for Spinal Disorders, Denver, CO, USA; 3 OrthoCarolina, Charlotte, NC, USA; 4Los Angeles, CA, USA BACKGROUND CONTEXT: Cervical total disc replacement (TDR) is intended to treat symptomatic cervical disc disease (SCDD), as an alternative to cervical fusion. TDR maintains motion at the vertebral segment, while allowing for decompression and relief of radicular symptoms. PURPOSE: The purpose of this trial is to compare the safety and efficacy of cervical TDR, ProDisc-C (Synthes Spine Company, L.P., West Chester, PA), to anterior cervical discectomy and fusion (ACDF) surgery for the treatment of one-level SCDD between C3 and C7. STUDY DESIGN/SETTING: The study was conducted at 13 sites. A noninferiority design with a 1:1 randomization was used. PATIENT SAMPLE: Two hundred nine patients were randomized and treated (106 ACDF; 103 ProDisc-C). OUTCOME MEASURES: Visual analog scale (VAS) pain and intensity (neck and arm), VAS satisfaction, neck disability index (NDI), neurological exam, device success, adverse event occurrence, and short form-36 (SF-36) standardized questionnaires. METHODS: A prospective, randomized, controlled clinical trial was performed. Patients were enrolled and treated in accordance with the US Food and Drug Administration (FDA)-approved protocol. 5 year follow up data is presented. RESULTS: Demographics were similar between the two patient groups (ProDisc-C: 42.168.4 years, 44.7% males; Fusion: 43.567.1 years, 46.2% males). The most commonly treated level was C5-C6 (ProDisc-C: 56.3%; Fusion557.5%). For all variables, except secondary surgery, there was significant improvement from baseline values, but no significant difference between the treatment groups. NDI at five years was significantly improved from baseline in both treatment groups (p!.0001) Prodisc-C: 20.3620.3 (61.1638.4% mean improvement) ACDF: 23.0619.4 (54.7638.6% mean improvement). VAS satisfaction scores (0 5 no satisfaction; 100 5 completely satisfied) were similar at 5 years (p5.3212) Prodisc-C: 86.6623.0 ACDF: 82.1626.0. Secondary surgery rates did show a difference with 5 of 103 Prodisc-C patients (4.9%) and 16 of 106 ACDF patients (15.1%) requiring an additional operation at the index or adjacent level within 5 years. There was no significant difference in other adverse events. CONCLUSIONS: 5 year data from the Prodisc-C clinical trial shows that total disc arthroplasty is a safe and effective treatment for single level cervical degenerative disc disease. Non-inferiority studies show it is as effective as ACDF in the treatment of cervical degenerative disc disease. Additionally total disc arthroplasty appears to have a lower incidence of secondary surgery at the index or adjacent levels, and maintains a more physiological range of motion. FDA DEVICE/DRUG STATUS: Prodisc-C: Approved for this indication.
PURPOSE: This study was designed to investigate the transitional appearance of heterotopic ossification from the mid-term observational study of heterotopic ossification and to understand natural course of heterotopic ossification. STUDY DESIGN/SETTING: Retrospective clinical study. PATIENT SAMPLE: The total of 67 patients undergoing cervical arthroplasty surgery. OUTCOME MEASURES: Determination of heterotopic ossification using postoperative cervical lateral radiographs and computed tomography. METHODS: The total of 67 patients undergoing cervical arthroplasty with the Bryan Cervical Disc Prosthesis (Medtronic Sofamor Danek, Memphis, TN, USA), Mobi-C disc prosthesis (LDR medical, Troyes, France) and ProDisc-C (Synthes, Inc., West Chester, PA, USA) were included. The investigation of heterotopic ossification was already made in the mid-term observational study at 19.9 months after operation. Cervical lateral radiographs and computed tomography obtained after the last observation were used to identify the change in the heterotopic ossification. The change in the grade of heterotopic ossification and the characteristics were investigated according to the preexisting ossification and different prosthesis. RESULTS: Each prosthesis group included patients as follows; Bryan disc 21 patients, Mobi-C 29 patients, and ProDisc-C 17 patients. Overall heterotopic ossification rate was 46.3% (31 of 67 patients; Bryan disc 28.6%, Mobi-C 45.2%, ProDisc-C 64.7%) at 18.6 months follow up period in the midterm observation and final heterotopic ossification rate was 64.2% (43 of 67 patients; Bryan disc 28.6%, Mobi-C 83.9%, ProDisc-C 76.5%) at 36.9 months in the present study. The time interval of observation was 18.3 months in average and increased heterotopic ossification rate was 17.9%. The rate of relative increase was overall 39.4% compared with preexisting status. Each preexisting heterotopic ossification showed the different rate of relative increase as below; grade 1 (33.3%), grade 2 (66.7%), grade 3 (47.4%) and grade 4 (0.0%, no change possible by definition). The rates of relative increase by the prosthesis were the Bryan disc group 5.0%, Mobi-C group 58.6%and the ProDisc-C group 47.1%. The overall new occurrence rate of heterotopic ossification was 33.3%; by prosthesis were the Bryan disc group 0.0%, Mobi-C group 70.6% and the ProDisc-C group 33.3%. CONCLUSIONS: Occurrence of heterotopic ossification is inevitable postoperative complication after cervical artificial disc replacement. The occurrence rate of heterotopic ossification was higher than our expectation. Moreover, the progressive ossification pattern after initial occurrence was revealed in this study. But the lower grade of preexisting heterotopic ossification showed the slow or no progression in the ossification and advanced preexisting heterotopic ossification showed more progression. FDA DEVICE/DRUG STATUS: Bryan Cervical Disc Prosthesis: Approved for this indication; Mobi-C disc prosthesis: Approved for this indication; ProDisc-C: Approved for this indication. doi: 10.1016/j.spinee.2011.08.121
doi: 10.1016/j.spinee.2011.08.120
89. Cost-Effectiveness of Single-Level Cervical Disc Arthroplasty Compared to Single-Level Anterior Cervical Discectomy and Fusion Sheeraz Qureshi, MD, MBA1, Andrew Hecht, MD2; 1Mount Sinai School of Medicine, New York, NY, USA; 2New York, NY, USA
88. Transitional Appearance of Advanced Heterotopic Ossification in Cervical Artificial Disc Replacement Seong Yi, MD, PhD1, Jae Keun Oh, MD1, Yoon Ha, MD2, Keungnyun Kim, MD3, Do-Heum Yoon, MD3; 1Yonsei University College of Medicine, Seoul, South Korea; 2Department of Neurosurgery, Seoul, South Korea; 3Yonsei University Hospital, Seoul, South Korea
BACKGROUND CONTEXT: In recent years, there has been increased interest in the use of cervical disc replacement (CDR) as an alternative to anterior cervical discectomy and fusion (ACDF). While ACDF is a proven intervention for patients with myelopathy or radiculopathy, there are inherent limitations specific to the procedure. CDR was designed to preserve motion, avoid the limitations of fusion, and theoretically allow for a quicker return to activity. A number of recent systematic reviews and randomaized controlled trials have been published demonstrating positive clinical results for CDR, but there are no studies demonstrating which strategy is more cost-effective.
BACKGROUND CONTEXT: Reported heterotopic ossification occurrence rate in cervical artificial disc replacement was unexpectedly high and varied.
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.
Proceedings of the NASS 26th Annual Meeting / The Spine Journal 11 (2011) 1S–173S
87. Five-Year Results of the Prodisc-C Multicenter Randomized Clinical Trial Sean Kearns, PhD1, Michael Janssen, DO2, Daniel Murrey, MD3, Rick Delamarter, MD4; 1Spine Education and Research Institute, Denver, CO, USA; 2Center for Spinal Disorders, Denver, CO, USA; 3 OrthoCarolina, Charlotte, NC, USA; 4Los Angeles, CA, USA BACKGROUND CONTEXT: Cervical total disc replacement (TDR) is intended to treat symptomatic cervical disc disease (SCDD), as an alternative to cervical fusion. TDR maintains motion at the vertebral segment, while allowing for decompression and relief of radicular symptoms. PURPOSE: The purpose of this trial is to compare the safety and efficacy of cervical TDR, ProDisc-C (Synthes Spine Company, L.P., West Chester, PA), to anterior cervical discectomy and fusion (ACDF) surgery for the treatment of one-level SCDD between C3 and C7. STUDY DESIGN/SETTING: The study was conducted at 13 sites. A noninferiority design with a 1:1 randomization was used. PATIENT SAMPLE: Two hundred nine patients were randomized and treated (106 ACDF; 103 ProDisc-C). OUTCOME MEASURES: Visual analog scale (VAS) pain and intensity (neck and arm), VAS satisfaction, neck disability index (NDI), neurological exam, device success, adverse event occurrence, and short form-36 (SF-36) standardized questionnaires. METHODS: A prospective, randomized, controlled clinical trial was performed. Patients were enrolled and treated in accordance with the US Food and Drug Administration (FDA)-approved protocol. 5 year follow up data is presented. RESULTS: Demographics were similar between the two patient groups (ProDisc-C: 42.168.4 years, 44.7% males; Fusion: 43.567.1 years, 46.2% males). The most commonly treated level was C5-C6 (ProDisc-C: 56.3%; Fusion557.5%). For all variables, except secondary surgery, there was significant improvement from baseline values, but no significant difference between the treatment groups. NDI at five years was significantly improved from baseline in both treatment groups (p!.0001) Prodisc-C: 20.3620.3 (61.1638.4% mean improvement) ACDF: 23.0619.4 (54.7638.6% mean improvement). VAS satisfaction scores (0 5 no satisfaction; 100 5 completely satisfied) were similar at 5 years (p5.3212) Prodisc-C: 86.6623.0 ACDF: 82.1626.0. Secondary surgery rates did show a difference with 5 of 103 Prodisc-C patients (4.9%) and 16 of 106 ACDF patients (15.1%) requiring an additional operation at the index or adjacent level within 5 years. There was no significant difference in other adverse events. CONCLUSIONS: 5 year data from the Prodisc-C clinical trial shows that total disc arthroplasty is a safe and effective treatment for single level cervical degenerative disc disease. Non-inferiority studies show it is as effective as ACDF in the treatment of cervical degenerative disc disease. Additionally total disc arthroplasty appears to have a lower incidence of secondary surgery at the index or adjacent levels, and maintains a more physiological range of motion. FDA DEVICE/DRUG STATUS: Prodisc-C: Approved for this indication.
PURPOSE: This study was designed to investigate the transitional appearance of heterotopic ossification from the mid-term observational study of heterotopic ossification and to understand natural course of heterotopic ossification. STUDY DESIGN/SETTING: Retrospective clinical study. PATIENT SAMPLE: The total of 67 patients undergoing cervical arthroplasty surgery. OUTCOME MEASURES: Determination of heterotopic ossification using postoperative cervical lateral radiographs and computed tomography. METHODS: The total of 67 patients undergoing cervical arthroplasty with the Bryan Cervical Disc Prosthesis (Medtronic Sofamor Danek, Memphis, TN, USA), Mobi-C disc prosthesis (LDR medical, Troyes, France) and ProDisc-C (Synthes, Inc., West Chester, PA, USA) were included. The investigation of heterotopic ossification was already made in the mid-term observational study at 19.9 months after operation. Cervical lateral radiographs and computed tomography obtained after the last observation were used to identify the change in the heterotopic ossification. The change in the grade of heterotopic ossification and the characteristics were investigated according to the preexisting ossification and different prosthesis. RESULTS: Each prosthesis group included patients as follows; Bryan disc 21 patients, Mobi-C 29 patients, and ProDisc-C 17 patients. Overall heterotopic ossification rate was 46.3% (31 of 67 patients; Bryan disc 28.6%, Mobi-C 45.2%, ProDisc-C 64.7%) at 18.6 months follow up period in the midterm observation and final heterotopic ossification rate was 64.2% (43 of 67 patients; Bryan disc 28.6%, Mobi-C 83.9%, ProDisc-C 76.5%) at 36.9 months in the present study. The time interval of observation was 18.3 months in average and increased heterotopic ossification rate was 17.9%. The rate of relative increase was overall 39.4% compared with preexisting status. Each preexisting heterotopic ossification showed the different rate of relative increase as below; grade 1 (33.3%), grade 2 (66.7%), grade 3 (47.4%) and grade 4 (0.0%, no change possible by definition). The rates of relative increase by the prosthesis were the Bryan disc group 5.0%, Mobi-C group 58.6%and the ProDisc-C group 47.1%. The overall new occurrence rate of heterotopic ossification was 33.3%; by prosthesis were the Bryan disc group 0.0%, Mobi-C group 70.6% and the ProDisc-C group 33.3%. CONCLUSIONS: Occurrence of heterotopic ossification is inevitable postoperative complication after cervical artificial disc replacement. The occurrence rate of heterotopic ossification was higher than our expectation. Moreover, the progressive ossification pattern after initial occurrence was revealed in this study. But the lower grade of preexisting heterotopic ossification showed the slow or no progression in the ossification and advanced preexisting heterotopic ossification showed more progression. FDA DEVICE/DRUG STATUS: Bryan Cervical Disc Prosthesis: Approved for this indication; Mobi-C disc prosthesis: Approved for this indication; ProDisc-C: Approved for this indication. doi: 10.1016/j.spinee.2011.08.121
doi: 10.1016/j.spinee.2011.08.120
89. Cost-Effectiveness of Single-Level Cervical Disc Arthroplasty Compared to Single-Level Anterior Cervical Discectomy and Fusion Sheeraz Qureshi, MD, MBA1, Andrew Hecht, MD2; 1Mount Sinai School of Medicine, New York, NY, USA; 2New York, NY, USA
88. Transitional Appearance of Advanced Heterotopic Ossification in Cervical Artificial Disc Replacement Seong Yi, MD, PhD1, Jae Keun Oh, MD1, Yoon Ha, MD2, Keungnyun Kim, MD3, Do-Heum Yoon, MD3; 1Yonsei University College of Medicine, Seoul, South Korea; 2Department of Neurosurgery, Seoul, South Korea; 3Yonsei University Hospital, Seoul, South Korea
BACKGROUND CONTEXT: In recent years, there has been increased interest in the use of cervical disc replacement (CDR) as an alternative to anterior cervical discectomy and fusion (ACDF). While ACDF is a proven intervention for patients with myelopathy or radiculopathy, there are inherent limitations specific to the procedure. CDR was designed to preserve motion, avoid the limitations of fusion, and theoretically allow for a quicker return to activity. A number of recent systematic reviews and randomaized controlled trials have been published demonstrating positive clinical results for CDR, but there are no studies demonstrating which strategy is more cost-effective.
BACKGROUND CONTEXT: Reported heterotopic ossification occurrence rate in cervical artificial disc replacement was unexpectedly high and varied.
All referenced figures and tables will be available at the Annual Meeting and will be included with the post-meeting online content.