Surgery Section - Artificial Intervertebral Disc

IMPORTANT REMINDER

Regence Medical Policies are developed to provide guidance for members and providers regarding coverage in accordance with contract terms. Benefit determinations are based in all cases on the applicable contract language. To the extent there may be any conflict between the Medical Policy and contract language, the contract language takes precedence.

PLEASE NOTE: Contracts exclude from coverage, among other things, services or procedures that are considered investigational or cosmetic. Providers may bill members for services or procedures that are considered investigational or cosmetic. Providers are encouraged to inform members before rendering such services that the members are likely to be financially responsible for the cost of these services.

DESCRIPTION

Artificial intervertebral disks, also known as intervertebral disc prostheses,  are synthetic replacements for damaged intervertebral discs in the cervical or lumbar regions of the spine.

There are a number of artificial cervical and lumbar discs that are under investigation, some of which have received approval for marketing from the U.S. Food and Drug Administration (FDA):

POLICY/CRITERIA

Total disc replacement with artificial intervertebral discs is considered investigational.

POSITION STATEMENT

The evidence is insufficient to permit conclusions about the long-term benefits and safety of total disc replacement with artificial intervertebral discs (TDR). (2-19)

• Data from short-term randomized, controlled clinical trials of TDR have reported encouraging results, but are not adequate to establish the long-term safety and effectiveness of artificial discs in the treatment of degenerative disc disease (DDD). (2-17)
• Device performance, durability, revisability, complication rates, and effects on adjacent vertebral levels  remain unknown beyond two years post-surgery. These are important considerations for the relatively young population in whom these devices are being studied.
• There are no evidence-based clinical practice guidelines from U.S. neurosurgery or orthopedic professional associations that recommend TDR as a surgical option for the treatment of DDD.
• Although a European guidance document from the National Institute for Clinical Excellence (NICE) listed TDR as a surgical option for DDD, conclusions were based on professional opinion and unreliable case series data.  The guideline cautions that patients should be informed of its uncertain long-term effectiveness. (20,21)
• Each of the randomized trials on which final FDA approval was based was limited to two-year outcomes. All FDA approvals require that the sponsors of each artificial disc submit additional data that “evaluates the long-term safety and effectiveness”. The post-approval studies are expected to demonstrate the 5-year data for lumbar discs, and 3-, 5-, 7-, and 10-year data for cervical discs.  In addition, the sponsors of the cervical discs are required to conduct five-year enhanced surveillance studies of adverse events in a broader patient population. (22-26) Data from all of these trials are not yet available.

Evaluating the safety and effectiveness of TDR requires randomized comparisons with fusion, which is the current standard for surgical treatment of degenerative disc disease (DDD).    Postoperative follow-up of at least five years is recommended to assess the long-term effects of TDR on overall health outcomes. (2-4,18,19,27)  Long-term data are required for the following reasons:

• Patterns of degenerative changes following TDR or fusion take at least five years to become measurable; thus, the impact of motion preservation are unknown
  
• The benefits of spinal surgery are known to deteriorate over time; therefore, it cannot be assumed that early benefits seen at one to two years following TDR will remain stable in the mid- and long-term.
• Complications and adverse effects for spinal surgery tend to increase over time.

Effectiveness

The extensive information in U.S. and international published literature for artificial intervertebral discs is encouraging and supports the need for further research. (2-4,18, 28-32)

The advantage most often cited for TDR over fusion is the preservation of mobility at the operative level. The hypothesis is that this motion preservation may eliminate or slow the development of degenerative disc disease at adjacent vertebral levels compared with fusion. The available evidence is insufficient to permit conclusions as to whether TDR affects the postsurgical development of clinically significant adjacent segment degenerative disc disease.

• There is controversy in the published literature as to whether fusion of a spinal segment leads to early degeneration in adjacent segments. (33-37)
  
• It is unknown to what degree any degenerative changes to adjacent segments following spinal surgery may be clinically relevant or impact clinical outcomes. (18,19,38-40)
  
• The pivotal trials used in the FDA approval process reported that motion at the operative level did not correlate with clinical success. (22-26)
  
• These FDA trials also demonstrated that the motion at the adjacent levels, as measured by dynamic radiographs, was not significantly different for the TDR groups compared with the fusion control groups.
• As part of FDA approval for marketing of these devices, sponsors are prohibited from making any claims or suggestions relating preservation of motion with clinical success.
  
• FDA also prohibited any mention by TDR sponsors of prevention of adjacent level disease. 

Safety

Long-term safety and complications for TDR are unknown compared to other therapies. Specific concerns include the following:

• The rate of failure of the TDR device itself is unknown compared with other therapies, including the durability and replacement rates. (38-42)
  
• The expected lifespan of the various devices is unknown.
  
• It is unknown if subsequent surgical options are limited if revision is needed due to complications or device failure. (41-45)
  
• It is unknown whether TDR increases the rate of degenerative disc disease in adjacent discs compared to other therapies.
  
• It is unknown whether TDR increases the rate of degeneration in the facet joints at the level of the implant compared to other therapies.

Specific complications reported in the literature to date include the following (41-55):

• Allergic reaction to implant materials
• Vertebral body and pedicle fractures
• Excessive wear, bending or breakage of any component of the artificial disc device
• Loosening, migration or dislodging of the artificial disc device
• Collapse of the artificial disc device into the bone (subsidence)
• Fusion (heterotopic ossification) or loss of motion at the level of the implant
• Errors in positioning or prosthesis size (e.g., under sizing)
• Wear debris from the polyethylene component of the prosthesis has been found in surrounding tissue.
• Chronic inflammatory reaction and osteolysis has been found in periprosthetic tissue.
• Concerns have been published related to the release of metallic ions into the body due to friction on the metallic components of the prosthesis during movement. The long-term effect of these ions in the body is unknown.
• Acquired spondylolysis
• Retrograde ejaculation has been reported following lumbar TDR in some men.

Cervical Discs

There are currently six randomized trials in the English literature reporting outcomes two years following fusion or TDR. (5- 10) There are no randomized, controlled trials reporting longer outcomes. As noted above, two years is not sufficient duration for determining the long term effects of cervical TDR on health outcomes.

In addition to the short duration, all six studies had significant design and analysis flaws that limit interpretation of the data:

• Three randomized trials did not permit scientific conclusions because of the small number of patients studied. (5-7) Small study populations limit the ability to rule out the role of chance as an explanation of study findings.
  
  
• The report on the FDA trial for the PRESTIGE cervical disc was an interim analysis that included only 80% of the TDR group and 75% of the fusion control group. (8) Data on the full cohort is not yet available.
  
  
• Well-executed randomization is particularly important in studies which include subjective outcomes such as pain, patient satisfaction, and quality of life. This was not achieved in the FDA trial for the Bryan cervical disc. (10,11) Of the 582 patients initially randomized, 117 (37 from the TDR group and 80 from the fusion group) declined surgery. This 20% loss of patients following randomization undermines the randomization, potentially confounding the treatment effect observed. This flaw is compounded in this study by the treatment crossover of 13 patients following randomization, 12 from the TDR group to the fusion group and one from the fusion group to the TDR group. Since patients were not blinded to their treatment assignment, this crossover after randomization likely reflects patient bias toward which treatment they felt would be most beneficial.   
  
  
• The study endpoints were unclear, inconsistent or incomplete.
  
  For example, in the study on which FDA approval for the PRESTIGE device was based, the primary endpoint was the patient’s “overall success” which was calculated using: Neck Disability Index (NDI) scores; ill-defined neurological status scores; and the absence of implant or related surgical adverse events or “second surgery classified as a failure”.  Other components of pain and function (i.e., SF-36 scores, neck and arm pain scale scores) were evaluated separately but were not included in determining overall success. In addition, the criteria by which a second surgery is classified as a success or failure were not defined. 
  
  
• The population studied may not be reflective of typical surgical candidates for DDD. Although the inclusion criteria for the FDA trials only required six weeks of medical management, the AAOS guidance for the design of clinical trial of artificial intervertebral discs recommends six months of conservative therapy before the patient is considered a surgical candidate. (27)

Lumbar Discs

There is only one randomized, controlled trial of sufficient duration to begin to measure long-term health outcomes. (17) Five-year outcomes were reported on a subset of the original 375 patient cohort in the two-year CHARITE IDE trial. Of the initial 14 investigational sites, six sites declined participation in the five-year continuation study, and an additional eight patients were excluded from analysis. Of the remaining 233 patients, the five-year assessment included only 57% (n=133), or 30% of the original study population. Given the limitations of the original IDE trial and the 43% to 70% loss to follow-up, the results from the five-year follow-up cannot be interpreted.

The remaining published randomized trials of TDR in the lumbar spine do not permit conclusions regarding long-term health outcomes. (12-16) Data from these studies are unreliable due to the following design flaws which undermine the validity of the results:

• The maximum study duration was limited to two years. All of the authors of articles related to the FDA trials for the CHARITE and ProDisc-L discs specifically noted that two years follow-up does not allow conclusions about the impact of TDR on adjacent-level DDD compared with fusion.
  
  
• In the pivotal trial for the ProDisc-L, conclusions are not possible due to missing data. Eleven percent of fusion patients and 7.5% of ProDisc-L patients were excluded from the results. No intent-to-treat analysis was provided.

REFERENCES

1. BlueCross and BlueShield Association Medical Policy Reference Manual, Policy No. 7.01.87 and Policy No. 7.01.108
2. TEC Assessment: Artificial Lumbar Disc Replacement, 2007; BlueCross and BlueShield Association Technology Evaluation Center. Vol. 22, No. 2
3. TEC Assessment: Artificial Intervertebral Disc Arthroplasty for Treatment of Degenerative Disc Disease of the Cervical Spine, 2007; BlueCross and BlueShield Association Technology Evaluation Center Vol. 22, No. 12
4. BlueCross and BlueShield Association Technology Evaluation Center Assessment. Artificial Intervertebral Disc: Cervical Spine, 2009 in press
5. Coric D, Finger F, Boltes P. Prospective randomized controlled study of the Bryan Cervical Disc: early clinical results from a single investigational site. J Neurosurg Spine. 2006;4(1):31-5
6. Sasso RC, Smucker JD, Hacker RJ, et al. Clinical outcomes of BRYAN cervical disc arthroplasty: a prospective, randomized, controlled, multicenter trial with 24-month follow-up. J Spinal Disord Tech 2007;20(7):481-91
7. Porchet F, Metcalf NH. Clinical outcomes with the Prestige II cervical disc: preliminary results from a prospective randomized clinical trial. Neurosurg Focus. 2004;17(3):E6
8. Mummaneni PV, Burkus JK, Haid RW, et al. Clinical and radiographic analysis of cervical disc arthroplasty compared with allograft fusion: a randomized controlled clinical trial. J Neurosurg Spine. 2007;6(3):198-209
9. Murrey D, Janssen M, Delamarter R, et al. Results of the prospective, randomized, controlled multicenter Food and Drug Administration investigational device exemption study of the ProDisc-C total disc replacement versus anterior discectomy and fusion for the treatment of 1-level symptomatic cervical disc disease. Spine J 2009;9(4):275-86
10. Heller JG, Sasso RC, Papadopoulos SM et al. Comparison of BRYAN cervical disc arthroplasty with anterior cervical decompression and fusion: clinical and radiographic results of a randomized, controlled, clinical trial. Spine 2009;34(2):101-7
11. Anderson PA, Sasso RC, Riew KD. Comparison of Adverse Events Between the Bryan Artificial Cervical Disc and Anterior Cervical Arthrodesis. Spine 2008;33(12):1305–12
12. Geisler FH, Blumenthal SL, Guyer RD et al. Neurological complications of lumbar artificial disc replacement and comparison of clinical results with those related to lumbar arthrodesis in the literature: results of a multicenter, prospective, randomized investigational device exemption study of Charité intervertebral disc. J Neurosurg Spine 2004;1(2):143-54
13. Blumenthal S, McAfee PC, Guyer RD, et al: A prospective, randomized, multi-center Food and Drug Administration investigational device exemptions study of lumbar total disc replacement with the CHARITE artificial disc versus lumbar fusion: Part I. Evaluation of clinical outcomes. Spine 2005;30(14):1565-75
14. McAfee PC, Cunningham B, Holsapple G, et al. A prospective, randomized, multicenter Food and Drug Administration investigational device exemption study of lumbar total disc replacement with the CHARITE artificial disc versus lumbar fusion: part II: evaluation of radiographic outcomes and correlation of surgical technique accuracy with clinical outcomes. Spine. 2005;30(14):1576-83; discussion E388-90
15. Zigler J, Delamartar R, Spivak JM, et al. Results of the prospective, randomized, multicenter Food and Drug Administration investigational device exemption study of the ProDisc-L total disc replacement versus circumferential fusion for the treatment of 1-level degenerative disc disease. Spine 2007;32(11):1155-62; discussion 1163
16. Berg S, Tullberg T, Branth B, et al. Total disc replacement compared to lumbar fusion: a randomised controlled trial with 2-year follow-up. Eur Spine J. 2009 Jun 9. [Epub ahead of print]
17. Guyer RD McAfee PC, Banco RJ et al. A prospective, randomized, multicenter Food and Drug Administration investigational device exemption study of lumbar total disc replacement with the CHARITE artificial disc versus lumbar fusion: five-year follow-up. Spine J 2009;9(5):374-86
18. Peng-Fei S, Yu-Hua J. Cervical disc prosthesis replacement and interbody fusion - a comparative study. Int Orthop 2008;32(1):103-6
19. Riew KD, Buchowski JM, Sasso R et al. Cervical disc arthroplasty compared with arthrodesis for the treatment of myelopathy. J Bone Joint Surg Am 2008; 90(11):2354-64
20. National Institute for Health and Clinical Excellence (NICE) Practice Guideline: Prosthetic intervertebral disc replacement in the cervical spine. http://www.nice.org.uk/nicemedia/pdf/ip/IPG143guidance.pdf (Verified 5/28/08)
21. National Institute for Health and Clinical Excellence (NICE) Practice Guideline: Prosthetic intervertebral disc replacement. http://www.nice.org.uk/guidance/index.jsp?action=download&o=30929 (Verified 5/28/08)
22. U.S. Food and Drug Administration. PRESTIGE® Summary of Safety and Effectiveness Data.  Accessible at http://www.accessdata.fda.gov/cdrh_docs/pdf6/P060018a.pdf (Verified 9/21/09)
23. U.S. Food and Drug Administration. Charite® Summary of Safety and Effectiveness Data.  Accessible at http://www.accessdata.fda.gov/cdrh_docs/pdf4/P040006a.pdf (Verified 9/21/09)
24. U.S. Food and Drug Administration. ProDisc®-L Summary of Safety and Effectiveness Data.  Accessible at http://www.accessdata.fda.gov/cdrh_docs/pdf5/P050010a.pdf (Verified 9/21/09)
25. U.S. Food and Drug Administration. ProDisc®-C Summary of Safety and Effectiveness Data.  Accessible at http://www.accessdata.fda.gov/cdrh_docs/pdf7/P070001a.pdf (Verified 9/21/09)
26. U.S. Food and Drug Administration. BRYAN® Summary of Safety and Effectiveness Data. Accessible at http://www.accessdata.fda.gov/cdrh_docs/pdf6/P060023a.pdf (Verified 9/21/09)
27. Proposed guidance document for pre-clinical and clinical trial design for cervical and lumbar disc replacement systems. American Academy of Orthopaedic Surgeons. Available online at http://www.fda.gov/ohrms/dockets/dockets/05d0113/05d-0113-gdl0001-01-vol1.pdf (Verified 9/21/09)
28. Freeman BJ, Davenport J. Total disc replacement in the lumbar spine: a systematic review of the literature. Eur Spine J.2006;15 Suppl 3:S439-47
29. Benzel EC. Cervical disc arthroplasty compared with allograft fusion. J Neurosurg Spine 2007;6:197
30. Zindrick MR, Tzermiadianos MN, Voronov LI, et al. An evidence-based medicine approach in determining factors that may affect outcome in lumbar total disc replacement. Spine (Phila Pa 1976). 2008;33(11):1262-9
31. de Kleuver M, Oner FC, Jacobs WC.  Total disc replacement for chronic low back pain: Background and a systematic review of the literature. Eur Spine J 2003;12(2):108-116
32. Siepe CJ, Korge A, Grochulla F, et al. Analysis of post-operative pain patterns following total lumbar disc replacement: results from fluoroscopically guided spine infiltrations. Eur Spine J. 2008;17(1):44-56
33. Harrop JS, Youssef JA, Maltenfort M, et al. Lumbar adjacent segment degeneration and disease after arthrodesis and total disc arthroplasty. Spine (Phila Pa 1976). 2008 Jul 1;33(15):1701-7
34. Kim SW, Limson MA, Kim SB, et al. Comparison of radiographic changes after ACDF versus Bryan disc arthroplasty in single and bi-level cases. Eur Spine J. 2009 Feb;18(2):218-31
35. Hayashi T, Arizono T, Fujimoto T, et al. Degenerative change in the adjacent segments to the fusion site after posterolateral lumbar fusion with pedicle screw instrumentation--a minimum 4-year follow-up. Fukuoka Igaku Zasshi. 2008;99(5):107-13
36. Resnick DK, Watters WC. Lumbar disc arthroplasty: a critical review. Clin Neurosurg. 2007;54:83-7
37. Ghiselli G, Wang JC, Bhatia NN, et al. Adjacent segment degeneration in the lumbar spine. J Bone Joint Surg Am. 2004;86-A(7):1497-503
38. Anderson PA, Sasso RC, Riew KD. Update on cervical artificial disk replacement. AAOS Instr Course Lect 2007; 56:237-46
39. Phillips FM, Garfin SR. Cervical disc replacement. Spine 2005; 30(17 suppl):S27-33
40. Wigfield C, Gill S, Nelson R et al. Influence of an artificial cervical joint compared with fusion on adjacent-level motion in the treatment of degenerative cervical disc disease. J Neurosurg 2002; 96(1 suppl):17-21
41. Wagner WH, Regan JJ, Leary SP, et al. Access strategies for revision or explantation of the Charité lumbar artificial disc replacement. J Vasc Surg 2006;44(6):1266-72
42. Leary SP, Regan JJ, Lanman TH, et al. Revision and explantation strategies involving the CHARITE lumbar artificial disc replacement. Spine. 2007;32(9):1001-11
43. De Maat GH, Punt IM, van Rhijn LW, et al. Removal of Charite lumbar artificial disc prosthesis: surgical technique.  J Spinal disord Tech 2009;22(5):334-9
44. McAfee, PC, Geisler FH, Saiedy SS, et al. Revisability of the CHARITE artificial disc replacement: analysis of 688 patients enrolled in the U.S. IDE study of the CHARITE Artificial Disc. Spine 2006;31(11):1217-26
45. Jeon SH, Choi WG, Lee SH. Anterior revision of a dislocated ProDisc prosthesis at the L4-5 level. J Spinal Disord Tech. 2008;21(6):448-50
46. Punt IM, Visser VM, van Rhijn LW, et al. Complications and reoperations of the SB Charité lumbar disc prosthesis: experience in 75 patients. Spine 2008;17(1):36-43
47. van Ooij A, Oner FC, Verbout AJ. Complications of artificial disc replacement: a report of 27 patients with the SB Charité disc. J Spinal Disord Tech 2003;16(4):369-83
48. Mathew P, Blackman M, Redla S, et al. Bilateral Pedicle Fractures Following Anterior Dislocation of the Polyethylene Inlay of a ProDisc® Artificial Disc Replacement; A Case Report of an Unusual Complication. Spine 2005;30(11) 30:E311–E314
49. Tortolani PJ, Cunningham BW, Eng M, et al. Prevalence of heterotopic ossification following total disc replacement. A prospective, randomized study of two hundred and seventy-six patients. J Bone Joint Surg Am  2007;89(1):82-8
50. Mehran C, Suchomel P, Grochulla F, et al. Heterotopic ossification in total cervical artificial disc replacement. Spine 2006;31(24):2802-6
51. Leung C, Casey AT, Goffin J, et al. Clinical significance of heterotopic ossification in cervical disc replacement: a prospective multicenter clinical trial. Neurosurgery. 2005;57(4):759-63
52. Schulte TL, Lerner T, Hackenberg L, et al. Acquired spondylolysis after implantation of a lumbar ProDisc II prosthesis: case report and review of the literature. Spine (Phila Pa 1976). 2007;32(22):E645-8
53. Punt IM, Cleutjens JP, de Bruin T, et al. Periprosthetic tissue reactions observed at revision of total intervertebral disc arthroplasty. Biomaterials 2009;30(11):2079-84
54. van Ooij A, Kurtz SM, Stessels F, et al. Polyethylene wear debris and long-term clinical failure of the Charité disc prosthesis: a study of 4 patients. Spine 2007;32(2):223-9
55. Cavanaugh DA, Nunley PD, Kerr EJ 3rd, et al. Delayed hyper-reactivity to metal ions after cervical disc arthroplasty: a case report and literature review. Spine (Phila Pa 1976) 2009;34(7):E262-5

Cross References

Lumbar Spine Surgery, Regence Medical Policy Manual, Surgery, Policy No. 101

Surgery for Degenerative Diseases of the Cervical Spine Surgery, Regence Medical Policy Manual,  Surgery, Policy No. 103

Total Facet Arthroplasty, Regence Medical Policy Manual, Surgery, Policy No. 171

Regence Consumer Tx: Back Surgery - Degenerative Spinal Disc

Surgery Section Table of Contents