Prospective, randomized, multicenter study of cervical arthroplasty: 269 patients from the Kineflex|C artificial disc investigational device exemption study with a minimum 2-year follow-up

2011 ◽  
Vol 15 (4) ◽  
pp. 348-358 ◽  
Author(s):  
Domagoj Coric ◽  
Pierce D. Nunley ◽  
Richard D. Guyer ◽  
David Musante ◽  
Cameron N. Carmody ◽  
...  

Object Cervical total disc replacement (CTDR) represents a relatively novel procedure intended to address some of the shortcomings associated with anterior cervical discectomy and fusion (ACDF) by preserving motion at the treated level. This prospective, randomized, multicenter study evaluates the safety and efficacy of a new metal-on-metal CTDR implant (Kineflex|C) by comparing it with ACDF in the treatment of single-level spondylosis with radiculopathy. Methods The study was a prospective, randomized US FDA Investigational Device Exemption (IDE) pivotal trial conducted at 21 centers across the US. The primary clinical outcome measures included the Neck Disability Index (NDI), visual analog scale (VAS) scores, and a composite measure of clinical success. Patients were randomized to CTDR using the Kineflex|C (SpinalMotion, Inc.) cervical artificial disc or ACDF using structural allograft and an anterior plate. Results A total of 269 patients were enrolled and randomly assigned to either CTDR (136 patients) or to ACDF (133 patients). There were no significant differences between the CTDR and ACDF groups when comparing operative time, blood loss, length of hospital stay, or the reoperation rate at the index level. The overall success rate was significantly greater in the CTDR group (85%) compared with the ACDF group (71%) (p = 0.05). In both groups, the mean NDI scores improved significantly by 6 weeks after surgery and remained significantly improved throughout the 24-month follow-up (p < 0.0001). Similarly, the VAS pain scores improved significantly by 6 weeks and remained significantly improved through the 24-month follow-up (p < 0.0001). The range of motion (ROM) in the CTDR group decreased at 3 months but was significantly greater than the preoperative mean at 12- and 24-month follow-up. The ROM in the ACDF group was significantly reduced by 3 months and remained so throughout the follow-up. Adjacent-level degeneration was also evaluated in both groups from preoperatively to 2-year follow-up and was classified as none, mild, moderate, or severe. Preoperatively, there were no significant differences between groups when evaluating the different levels of adjacent-level degeneration. At the 2-year follow-up, there were significantly more patients in the ACDF group with severe adjacent-level radiographic changes (p < 0.0001). However, there were no significant differences between groups in adjacent-level reoperation rate (7.6% for the Kineflex|C group and 6.1% for the ACDF group). Conclusions Cervical total disc replacement allows for neural decompression and clinical results comparable to ACDF. Kineflex|C was associated with a significantly greater overall success rate than fusion while maintaining motion at the index level. Furthermore, there were significantly fewer Kineflex|C patients showing severe adjacent-level radiographic changes at the 2-year follow-up. These results from a prospective, randomized study support that Kineflex|C CTDR is a viable alternative to ACDF in select patients with cervical radiculopathy.

2015 ◽  
Vol 15 (10) ◽  
pp. S129
Author(s):  
Jeffrey M. Spivak ◽  
Jack E. Zigler ◽  
Michael E. Janssen ◽  
Bruce V. Darden ◽  
Kris E. Radcliff

2010 ◽  
Vol 13 (6) ◽  
pp. 715-721 ◽  
Author(s):  
Domagoj Coric ◽  
Joseph Cassis ◽  
John D. Carew ◽  
Margaret O. Boltes

Object Cervical total disc replacement (TDR) was developed to address some of the shortcomings associated with anterior cervical discectomy and fusion (ACDF) by preserving motion at the treated level. To establish an evidence-based rationale for cervical TDR to serve as a viable alternative to ACDF, cervical arthroplasty must establish equivalent or superior clinical outcomes while maintaining motion. The authors report on 98 patients from a single investigational site involved in 3 separate prospective, randomized, controlled investigational device exemption multicenter trials comparing cervical arthroplasty to ACDF with a 2–6-year follow-up. Methods Patients with 1- and 2-level cervical disc disease producing radiculopathy and/or myelopathy were randomized prospectively under 3 separate investigational device exemption pivotal trials to undergo ACDF with plate or artificial disc placement. The 3 arthroplasty systems evaluated were the Bryan cervical disc, Kineflex/C disc, and Discover cervical disc. The patients were evaluated with pre- and postoperative serial neurological examinations, radiographs, and clinical outcome indices at 1, 3, 6, 12, 24, 36, 48, and 60 months. Results Ninety-eight patients were treated at the authors' single investigational site. Fifty-seven of these patients underwent cervical arthroplasty and 41 underwent ACDF. A minimum 24-month follow-up was available for 90 patients (92%; 53 in the combined arthroplasty group and 37 in the combined ACDF group) with a follow-up duration ranging from 24 to 67 months (mean 38 months). Clinical success, defined as a composite measure consisting of 5 separate components, was significantly higher in the combined arthroplasty group (85%) compared with the combined ACDF group (70%; p = 0.035). The Neck Disability Index and visual analog scale patient self-report measures were evaluated at 3–24-months follow-up, and all groups showed excellent clinical outcomes. All groups (Bryan, Kineflex/C, Discover, and ACDF) showed statistically significant improvement from the preoperative period to a minimum 2-year follow-up (p < 0.0001). Overall, angular motion was improved by 0.91° in the combined arthroplasty group and reduced by 7.8° in the combined ACDF group (p < 0.0001). In the ACDF group there was a fusion rate of 97% (36 of 37 cases). In the arthroplasty group there was a 5.6% incidence of bridging heterotopic ossification (3 cases). There were a total of 4 reoperations (7.5%) in the combined arthroplasty group with 1 (1.9%) at the adjacent level. There were 3 reoperations (8.1%) in the ACDF group, all at the adjacent level. Conclusions The prospective, intermediate-term (average follow-up > 3 years) results of cervical TDR at the authors' site are encouraging. Patients treated with the artificial discs showed significantly better clinical results, maintained motion at the treated level, and trended toward less adjacent-level disease.


2017 ◽  
Vol 42 (videosuppl1) ◽  
pp. V6
Author(s):  
Domagoj Coric ◽  
John Parish ◽  
Margaret O. Boltes

There has been a steady evolution of cervical total disc replacement (TDR) devices over the last decade resulting in surgical technique that closely mimics anterior cervical discectomy and fusion as well as disc design that emphasizes quality of motion. The M6-C TDR device is a modern-generation artificial disc composed of titanium endplates with tri-keel fixation as well as a polyethylene weave with a polyurethane core. Although not yet approved by the FDA, M6-C has finished a pilot and pivotal US Investigational Device Exemption (IDE) study. The authors present the surgical technique for implantation of a 2-level M6-C cervical TDR device.The video can be found here: https://youtu.be/rFEAqINLRCo.


2012 ◽  
Vol 12 (9) ◽  
pp. S97 ◽  
Author(s):  
Jean-Paul Steib ◽  
Jean Huppert ◽  
Thierry Dufour ◽  
Pierre Bernard ◽  
Jacques Beaurain ◽  
...  

2012 ◽  
Vol 16 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Soo Eon Lee ◽  
Chun Kee Chung ◽  
Tae Ahn Jahng

Object The purpose of cervical total disc replacement (TDR) is to decrease the incidence of adjacent segment disease through motion preservation. Heterotopic ossification (HO) is a well-known complication after hip and knee arthroplasties. There are few reports regarding HO in patients undergoing cervical TDR, however; and the occurrence of HO and its effects on cervical motion have rarely been reported. Moreover, temporal progression of HO has not been fully addressed. One goal of this study involved determining the incidence of HO following cervical TDR, as identified from plain radiographs, and demonstrating the progression of HO during the follow-up period. A second goal consisted of determining whether segmental motion could be preserved and identifying the relationship between HO and clinical outcomes. Methods The authors conducted a retrospective clinical and radiological study of 28 consecutive patients who underwent cervical TDR with Mobi-C prostheses (LDR Medical) between September 2006 and October 2008. Radiological outcomes were evaluated using lateral dynamic radiographs obtained preoperatively and at 1, 3, 6, 12, and 24 months postoperatively. The occurrence of HO was interpreted on lateral radiographs using the McAfee classification. Cervical range of motion (ROM) was also measured. The visual analog scale (VAS) and Neck Disability Index (NDI) were used to evaluate clinical outcome. Results The mean follow-up period was 21.6 ± 7.0 months, and the mean occurrence of HO was at 8.0 ± 6.6 months postoperatively. At the last follow-up, 18 (64.3%) of 28 patients had HO: Grade I, 6 patients; Grade II, 8 patients; Grade III, 3 patients; and Grade IV, 1 patient. Heterotopic ossification progression was proportional to the duration of follow-up; HO was present in 3 (10.7%) of 28 patients at 1 month; 7 (25.0%) of 28 patients at 3 months; 11 (42.3%) of 26 patients at 6 months; 15 (62.5%) of 24 patients at 12 months; and 17 (77.3%) of 22 patients at 24 months. Cervical ROM was preserved in Grades I and II HO but was restricted in Grades III and IV HO. Clinical improvement according to the VAS and NDI was not significantly correlated with the occurrence of HO. Conclusions The overall incidence of HO after cervical TDR was relatively high. Moreover, HO began unexpectedly to appear early after surgery. Heterotopic ossification progression was proportional to the time that had elapsed postoperatively. Grade III or IV HO can restrict the cervical ROM and may lead to spontaneous fusion; however, the occurrence of HO did not affect clinical outcome. The results of this study indicate that a high incidence of HO with the possibility of spontaneous fusion is to be expected during long-term follow-up and should be considered before performing cervical TDR.


2012 ◽  
Vol 16 (3) ◽  
pp. 231-235 ◽  
Author(s):  
Tsung-Hsi Tu ◽  
Jau-Ching Wu ◽  
Li-Yu Fay ◽  
Chin-Chu Ko ◽  
Wen-Cheng Huang ◽  
...  

Cervical total disc replacement (TDR) is a viable option for the surgical treatment of degenerative disc disease. This 67-year-old nonsmoking male patient underwent single-level ProDisc-C cervical TDR at C5–6 without any intraoperative problem. His radicular pain improved and he had no neck pain immediately after the operation. However, on postoperative Day 3, a radiograph demonstrated a vertical split fracture of the C-5 vertebra. This fracture was managed conservatively, and 2 years postoperatively a follow-up CT scan demonstrated stable device position and fusion of the fracture. Although the linear fracture caused no neurological symptoms or device migration, the authors advocate prudence in selection and installation of keel-design prostheses, even in a single-level cervical TDR scenario.


2011 ◽  
Vol 14 (4) ◽  
pp. 457-465 ◽  
Author(s):  
Tsung-Hsi Tu ◽  
Jau-Ching Wu ◽  
Wen-Cheng Huang ◽  
Wan-Yuo Guo ◽  
Ching-Lan Wu ◽  
...  

Object Heterotopic ossification (HO) after cervical total disc replacement (TDR) has been reported to impede artificial disc motion. In all previously reported cases of HO, assessment was based on plain radiographs. The authors hypothesized that CT scan is a more sensitive and accurate detector. The aims of this study were to assess the actual incidence of HO and its effect on outcome in a cohort of patients undergoing cervical TDR with the Bryan disc and to compare HO detection by means of plain radiographs and CT. Methods The authors retrospectively assessed data from medical records, radiological studies, and clinical evaluations of patients who underwent 1- or 2-level cervical TDR with the Bryan disc and were followed up for more than 12 months. The presence and grading of HO according to the McAfee classification were assessed by CT scan, and these findings were compared with findings on plain radiographs. Thirty-six patients (mean age 46.61 ± 7.24 years; range 29–60 years; 21 men and 15 women) who underwent Bryan TDR at 52 levels were included in the study. The mean duration of CT follow-up was 19.03 ± 4.64 months; the mean duration of clinical follow-up was 26.78 ± 7.20 months. Results On the basis of CT, HO was identified in 18 (50%) of 36 patients and 25 (48.1%) of 52 levels treated. Grade 1 HO was present in 9 of the levels treated (17.3%), Grade 2 in 13 levels (25.0%), Grade 3 in 2 levels (3.8%), and Grade 4 in 1 level (1.9%). Nineteen (76%) of the 25 affected levels were in patients who had undergone 2-level TDR. There was no significant association with patient sex or disc pathology. There was a tendency for HO development among older patients, but this finding was not statistically significant (mean age 48.8 ± 6.8 in patients with HO vs 44.4 ± 7.2 in those without HO, p = 0.065). Although HO was found in 25 levels, 96.2% of the treated levels (50 of 52) had segmental range of motion on dynamic (flexion and extension) radiographs. The concordance between HO grading by CT and radiography was high, with an intraclass correlation coefficient of 0.822 (lower limit of 95% CI: 0.710, p < 0.001). Patients who had HO had the same clinical success rate as those who did not (94.4% vs 94.4%, p = 1.00). The visual analog scale scores for neck and arm pain were significantly improved in both the HO and the non-HO group. Conclusions The rate of HO detected by CT scan in this cohort of patients undergoing cervical TDR with a Bryan disc was 48.1% per level treated and 50% per patient with minimal limitation of segmental motion (96.2% of levels remained mobile), but plain radiograph is an acceptable detection tool. Two-level surgery has a higher risk of HO, although development of HO does not affect clinical outcome.


2006 ◽  
Vol 6 (3) ◽  
pp. 242-247 ◽  
Author(s):  
Russel C. Huang ◽  
Patrick Tropiano ◽  
Thierry Marnay ◽  
Federico P. Girardi ◽  
Moe R. Lim ◽  
...  

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