Becker's Spine Review

31 DEVICES & IMPLANTS 6 Texas Back Institute surgeons reflect on 20 years of artificial disc replacement By Alan Condon T his year marks the 20th anniversary of the first artificial disc replacement in the U.S. Originating in Europe more than 30 years ago, Scott Blumenthal, MD, of Texas Back Institute in Plano, engaged in extensive re- search before performing the first artificial disc replacement in the country in 2000. Now, the Center for Disc Replacement at Texas Back Institute performs about 400 ar- tificial disc replacements a year. e procedure allows patients to retain mo- bility in the cervical and lumbar spine and has demonstrated great success in patients suffering from herniated discs and degener- ative disc disease. As of Feb. 5, 2020, the practice performed 3,664 artificial disc replacements; 1,494 cer- vical spine; and 2,170 lumbar spine proce- dures. Here, six spine surgeons from Texas Back In- stitute, including Dr. Blumenthal, share their insight on the development of the procedure and how they see it progressing in the future. Question: How do you see total disc replacement developing in spine over the next five years? Note: Responses are lightly edited for style and clarity. Scott Blumenthal, MD: Lumbar disc re- placement will continue to be performed in Centers of Excellence like the Center for Disc Replacement at Texas Back Institute and patients will continue to travel for this motion preserving procedure. However, LDR will continue to see slow growth be- cause payers are still only covering a single level. We hope to see changes in LDR cov- erage over the next few years with coverage of two-level or hybrid constructs covered by insurance. e use of CDR is growing and fast approaching to be the gold standard of care for cervical disc disease, which does not involve significant deformity. e cov- erage of one- and two-level CDR is nearly universal, which helps promote the adop- tion of disc replacement. Richard Guyer, MD: CDR will become the new gold standard for symptomatic cervical radiculopathy. e adoption of LDR will continue to increase as fusion for degener- ative disc disease becomes harder to receive insurance approval. Newer forms of mo- tion preserving interbody implants will be developed to lessen the impact of adjacent segment disease with long fusions. Implants will migrate to those that have little or no artifact on MRI. Animal studies will prove that discs can be reproduced with scaffolds and stem cells. Peter Derman, MD: I am optimistic the use of cervical and lumbar disc replacement rather than fusion will become more wide- spread. e literature supporting it is robust and constantly growing. As more surgeons become familiar with the data and surgical techniques, disc replacement should become the standard of care, with spinal fusion being the exception rather than the rule. Increased insurance coverage of multilevel as well as hybrid constructs will be necessary to facili- tate this transition. I believe disc replacement will ultimately be utilized in the setting of deformity and more advanced degenerative pathology — whether this is possible with the current generation of devices or requires the introduction of novel technology remains to be seen. Jack Zigler, MD: Total disc replacements are the most extensively studied spinal im- plants we use. Long term follow-up stud- ies continue to validate the safety and ef- fectiveness of these devices over fusion as well as the protective effect on adjacent levels. Insurance penetration has improved steadily over the past 10 years. Surgeon re- imbursement remains the largest obstacle to acceptance. Over the next five years, reimbursement dis- crepancies between arthroplasty and spinal fusion procedures will diminish, encourag- ing surgeons to do more disc replacements as recovery and outcomes are more predict- able than with fusions. Patient awareness will increase, and more patients will insist on motion-preservation technology. Lastly, improved materials and designs will produce even better outcomes than the first genera- tion discs we are currently using and follow- ing scientifically. Isador Lieberman, MD: Today disc re- placement is a valuable tool in the treatment of painful disc degeneration of the cervical and lumbar spine. However, today's tech- nology is limited in replicating the patient specific global alignment, the level-specific morphology and the level-specific kinemat- ics. In the effort to preserve/protect adja- cent level function over the lifetime of the patient, the future of disc replacement will be dependent on new technology that can tailor the fit and custom tune the biome- chanics of a patient- and level-specific disc replacement. is will serve to maintain spinal alignment, neutralize the deforming forces and arrest the degenerative cascade while retaining physiologic function. is will also fill the unmet need in the treatment of conditions such as spondylolisthesis and degenerative scoliosis, which are currently treated with some form of fusion. Michael Duffy, MD: e advent of total disc arthroplasty has already begun to change the way patients view spinal fusion, particularly in the cervical spine. e peer-reviewed lit- erature undeniably supports the use of ADR, both in the cervical and lumbar spines. As time progresses, the general public will like- ly become more aware of these favorable re- sults, further shiing the pendulum toward utilizing artificial disc replacement. Current ADR technology has advanced be- yond the early designs, and there are multiple options for ADRs, all with level one data sup- porting their use. e current knowledge of design concepts will continue to evolve, po- tentially giving rise to a more perfect bearing apparatus and endplate design, which may altogether eliminate the concern for wear, de- bris and loosening, all of which are currently a minimal occurrence. n

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