Cervical Disc Replacement: Surgeon Reluctance to Adopt the Technology
We recently sat down and asked Orthopaedic Spine Surgeon Dr. Mark Mikhael about cervical disc replacement. This is what he shared with us.
Disc herniation in the neck can lead to symptomatic and disabling arm pain due to pinched nerves (cervical radiculopathy) or pinched spinal cord (myelopathy). When patients have persistent symptoms that affect their quality of life despite the typical non- operative treatment options for 6–8 weeks, surgery is often offered. Historically, anterior cervical discectomy and fusion (ACDF) has been a very successful surgical option for these patients with abundant data demonstrating successful outcomes in function, return
to work, and pain improvement for quality of life. ACDF surgery was first described in the late 1950s (1) and involves removing the problematic disc and replacing it with a bone graft to fuse the two vertebrae together. The addition of a titanium plate was later introduced to help facilitate better fusion rates. A later study (2) looking at a database of patients from 2005 to 2011 (over 200,000 surgeries) demonstrated that ACDF can carry a 2.9% incidence of disc disease adjacent to the fusion, and 25% of patients developing new symptoms with 10 years. While still a very successful surgery with demonstrated excellent outcomes, ACDF can be complicated by failure of fusion (pseudoarthrosis). This can lead to recurrent pain and may necessitate another surgery to correct. Issues such as pseudoarthrosis and adjacent
segment disease are what initiated interested in motion sparing technology such as cervical disc replacement (CDR).
In hopes of maintaining near normal kinematics (motion) in the neck, CDR was developed to replace the problematic disc with a device that maintains cervical segment motion. Although CDR can be complicated by device migration or subsidence and surrounding bone growth (heterotopic ossification), several randomized studies have emerged over the years comparing ACDF to CDR. Some studies have shown equivalency
between the two, while others have demonstrated superiority of CDR compared to ACDF. A recent study (3) looked at over 2000 patients randomized to either ACDF or CDR. In regard to quality of life outcomes, pain relief scores, return of function (strength/sensory recovery), and surgical complications, the results showed that CDR was significantly superior in all categories compared to ACDF. Other recent studies (4, 5, 6)
have demonstrated similar findings but have also suggested that the reoperation rate for ACDF patients in 3.6 times higher compared to CDR patients (minimum 4 year follow- up). Despite this recent compelling data, spine surgeons still maintain reluctance to adopt this technology.
The AOSpine society put together a recent survey (7) to help understand surgeon reluctance to change practice from ACDF to CDR. A population of almost 400 surgeons responded and almost 85% of them preferred ACDF as their primary technique to treat cervical disc disease. Most commented that they were unaware of the evidence that suggested the superiority of CDR in the outcome measures and reoperation rates listed above. Most admitted that a clear advantage of CDR over ACDF is quicker return to work and activities of daily living. Unfortunately, the sentiments stated in the survey do
not match clinical evidence and suggest that part of surgeon reluctance is due to lack of knowledge of current literature. The surgeons were also skeptical of the true decreased risk for adjacent segment disease and were concerned about the possibility of increased implant costs and tougher revision surgeries.
In this current healthcare climate, cost implications are being scrutinized more than ever. Several studies have also recently emerged to analyze the cost-effectiveness of CDR versus ACDF (8–11). Several of these studies investigated cost effectiveness over 5-year and 7-year time span. The analysis included patient outcome data, return to work, office
visits, x-ray and other clinical expenses, hospitalization, reoperation and other cost analysis parameters to determine the cost implications of the two procedures. Although none of these studies are perfect in their assumptions, they have all demonstrated that CDR has been shown to be either as cost-effective or more so than ACDF over several years when treating both single-level and two-level disease. Despite the prospect of CDR demonstrating cost-saving care, reluctance still remains amongst surgeons to adopt the
technology, many citing “cost” as the reason. Lack of knowledge of the clinical trials and literature, lack of training, resistance to change, and conflict of interest are all potential reasons there has been a significant lag in
surgeon preference for CDR over ACDF. Despite surgeons’ misconceptions from survey analysis, CDR has been trending over the last decade to demonstrate superior outcomes, lower reoperation rates and cost-effectiveness when compared to ACDF in the treatment of one-level or two-level cervical disc disease. As the data becomes increasingly abundant, perhaps surgeon practice will follow.
For more information regarding Dr. Mikhael and Illinois Bone and Joint Institute please click on the link below.
www.IBJI.com
References:
1. Smith GW, Robinson RA. The treatment of certain cervical-spine disorders by anterior removal of the intervertebral disc and interbody fusion. J Bone Joint Surg Am. 1958;40-A:607–24.
2. Hilibrand AS, Carlson GD, Palumbo MA, et al. Radiculopathy and myelopathy at segments adjacent to the site of a previous anterior cervical arthrodesis. J Bone Joint Surg Am. 1999;81:519–28.
3. Hu Y, Lv G, Ren S, et al. Mid- to long-term outcomes of cervical disc arthroplasty versus anterior cervical discectomy and fusion for treatment of symptomatic cervical disc disease: a systematic review and meta-analysis of eight prospective randomized controlled trials. PLoS One 2016;11:e0149312.
4. Davis RJ, Kim KD, Hisey MS, et al. Cervical total disc replacement with the Mobi-C cervical artificial disc compared with anterior discectomy and fusion for treatment of 2- level symptomatic degenerative disc disease: a prospective, randomized, controlled multicenter clinical trial. J Neurosurg Spine. 2013;19:532–45.
5. Davis RJ, Nunley PD, Kim KD, et al. Two-level total disc replacement with Mobi-C cervical artificial disc versus anterior discectomy and fusion: a prospective, randomized, controlled multicenter clinical trial with 4-year follow-up results. J Neurosurg Spine. 2015;22:15–25.
6. Xie L, Liu M, Ding F, et al. Cervical disc arthroplasty (CDA) versus anterior cervical discectomy and fusion (ACDF) in symptomatic cervical degenerative disc diseases (CDDDs): an updated metaanalysis of prospective randomized controlled trials (RCTs). Springerplus. 2016;5:1188.
7. Chin-See-Chong TC, Gadjradj PS, Boelen RJ, et al. Current practice of cervical disc arthroplasty: a survey among 383 AOSpine International members. Neurosurg Focus. 2017;42:E8.
8. McAnany SJ, Merrill RK, Brochin RL, et al. Comparing the 5-year health state utility value of cervical disc replacement and anterior
9. McAnany SJ, Merrill RK, Overley SC, et al. Investigating the 7-year cost-effectiveness of single-level cervical disc replacement compared to anterior cervical discectomy and fusion. Global Spine J. 2017:1–8.
10. Radcliff K, Lerner J, Yang C, et al. Seven-year cost-effectiveness of ProDisc-C total disc replacement: results from investigational device exemption and post-approval studies. J Neurosurg Spine. 2016;24:760–8.
11. Ament JD, Yang Z, Nunley P, et al. Cost-effectiveness of cervical total disc
replacement vs fusion for the treatment of 2-level symptomatic degenerative disc disease. JAMA Surg. 2014;149:1231–9.
