- Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, California, USA
- Department of Orthopedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, California, USA
- Neuromotor Recovery and Rehabilitation Center, David Geffen School of Medicine, University of California, Los Angeles, California, USA
- Brain Research Institute, University of California, Los Angeles, California, USA
Daniel C. Lu
Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, California, USA
Department of Orthopedic Surgery, David Geffen School of Medicine, University of California, Los Angeles, California, USA
Neuromotor Recovery and Rehabilitation Center, David Geffen School of Medicine, University of California, Los Angeles, California, USA
Brain Research Institute, University of California, Los Angeles, California, USA
DOI:10.4103/sni.sni_386_15Copyright: © 2017 Surgical Neurology International This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms.
How to cite this article: Tianyi Niu, Haydn Hoffman, Daniel C. Lu. Cervical artificial disc extrusion after a paragliding accident. 07-Jul-2017;8:138
How to cite this URL: Tianyi Niu, Haydn Hoffman, Daniel C. Lu. Cervical artificial disc extrusion after a paragliding accident. 07-Jul-2017;8:138. Available from: http://surgicalneurologyint.com/surgicalint-articles/cervical-artificial-disc-extrusion-after-a-paragliding-accident/
Background:Cervical total disc replacement (TDR) is an established alternative to anterior cervical discectomy and fusion (ACDF) with excellent long-term outcomes and low failure rates. Cases of implant failure and migration are scarce and primarily limited to several years postoperatively. The authors report a case of anterior extrusion of a C4-C5 ProDisc-C (DePuy Synthes, West Chester, PA, USA) cervical artificial disc (CAD) 14 months after placement due to minor trauma.
Case Description:A 33-year-old female who had undergone C4-C5 CAD implantation presented with neck pain and spasm after experiencing a paragliding accident. A 4 mm anterior protrusion of the CAD was seen on x-ray. She underwent removal of the CAD followed by anterior fusion. Other cases of CAD extrusion in the literature are discussed and the device's durability and testing are considered.
Conclusion:Overall, CAD extrusion is a rare event. This case is likely the result of insufficient osseous integration. Patients undergoing cervical TDR should avoid high-risk activities to prevent trauma that could compromise the disc's placement, and future design/research should focus on how to enhance osseous integration at the interface while minimizing excessive heterotopic ossification.
Keywords: Anterior cervical discectomy and fusion, cervical artificial disc, cervical spine trauma, osseous integration, total disc replacement
Cervical total disc replacement (TDR) is an alternative to anterior cervical discectomy and fusion (ACDF) for the treatment of radiculopathy that has the benefit of preserving motion and still allowing adequate neural decompression. This approach was developed to reduce the incidence of adjacent segment disease (ASD) and eliminate the adverse event of pseudarthrosis that can occur after ACDF. Multiple randomized clinical trials for the treatment of cervical radiculopathy have shown no difference between TDR and ACDF in regard to postoperative pain, disability, and neurological outcomes.[
On 2/12/2015, a 33-year-old female presented with a 2-year history of posterior neck pain and right C5 radiculopathy that failed conservative therapies. Magnetic resonance imaging (MRI) revealed a large right posterior paracentral and foraminal C4-C5 disc herniation, and the patient underwent resection of the disc and replacement with ProDisc-C (DePuy Synthes, West Chester, PA, USA) without intraoperative complications. [
On 4/16/2015, she presented to the clinic with a 2-week history of neck pain and spasms without focal deficits. She had experienced a paragliding accident on 3/29/2015 during which she fell, tumbled, and severely flexed her neck upon landing. Cervical spine X-ray obtained on 4/16/2015 now demonstrated a 4 mm anterior protrusion of the artificial disc [
Anterior access to the C4-C5 space was obtained through the previous incision and the extruded artificial disc was encountered. After clearing the scar tissue superficial to the disc, the vertebral body distraction pins were inserted rostral and caudal to the disc and expanded. This opened the vertebral body and allowed decompression of the central disc core. The central polyethylene core was separated and removed [Figures
The patient's postoperative course was unremarkable. At 3-week follow-up she had no focal neurological deficits and all instrumentation was unchanged in position [
Cervical TDR is becoming an increasingly favored approach to treating cervical radiculopathy, and initial results are encouraging.[
CAD dislocation is a rare event, and documentation is primarily limited to case reports.[
The ProDisc-C TDR consists of a ball and socket design that allows for motion around a fixed center of rotation in the treated segment. It includes anterior-posterior oriented keels on the superior and inferior endplates that allow for stable fixation between both vertebral bodies. We hypothesize that our patient's CAD extrusion was the result of insufficient osseous integration at the titanium keels and end-plate interfaces as the extrusion included the endplates and the inlay. The artificial disc must achieve a fine balance between too much and too little integration. Too much osseous integration will likely result in heterotopic ossification, a well-documented dynamic phenomenon with a reported occurrence rate as high as 64.2%, that can limit motion at the treated segment.[
Guidelines for the surgical management of artificial disc herniation are not available. We described our approach in detail here. Adequate decompression of the artificial disc core and careful removal is critical to avoid pushing the core posteriorly into the spinal canal and causing neurologic compromise. After core removal, the endplates can be dislodged with osteotomy. Care must be taken to ensure the osteotome does not encroach into the spinal canal during this step. ACDF has been described in other cases of CAD herniation with good results.[
In summary, this case demonstrates anterior artificial disc extrusion following trauma and the surgical approach to management. This is the first detailed report of anterior extrusion of a ProDisc-C artificial disc. Furthermore, techniques for removal of the ProDisc-C device have not been described previously. The steps we have outlined can be applied to future cases of CAD removal. While cervical TDR has a generally safe adverse effect profile and has been shown in multiple studies to allow earlier return to normal activity, this case serves to emphasize the potential complications even at 2 months postoperatively. To our knowledge, there were no published anterior graft and core migration failure of the Pro-Disc C due to trauma. The uniqueness of the case report is that it occurred in the subacute setting, during a traumatic episode in which there were no fractures. We believe that this report should be presented as the Pro-Disc C is presented as safe particularly to the athletic patient, in which our case cautions otherwise. Our patient was fortunate that the dislocation was anterior and not posterior into the spinal canal. The degree of osseous integration is an inherent difficult balance for any articulating metallic implant. Future research should focus on ways to maximize ossification at the keel-endplate interface while minimizing excess ossification at the articulating center. Patients undergoing cervical TDR should be counseled to avoid high-risk activities since in vitro testing[
The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.
Financial support and sponsorship
This research was made possible by generous support from J. Yang & Family Foundation. D.C.L. is a 1999 Paul & Daisy Soros New American Fellow.
Conflicts of interest
There are no conflicts of interest.
1. Brenke C, Schmieder K, Barth M. Core herniation after implantation of a cervical artificial disc: Case report. Eur Spine J. 2014. 24: S536-9
2. Fan H, Wu S, Wu Z, Wang Z, Guo Z. Implant failure of Bryan cervical disc due to broken polyurethane sheath: A case report. Spine. 2012. 37: E814-6
3. Lebl DR, Cammisa FP, Girardi FP, Wright T, Abjornson C. The mechanical performance of cervical total disc replacements in vivo: Prospective retrieval analysis of prodisc-C devices. Spine. 2012. 37: 2151-60
4. Malham GM, Parker RM, Ellis NJ, Chan PG, Varma D. Cervical artificial disc replacement with ProDisc-C: Clinical and radiographic outcomes with long-term follow-up. J Clin Neurosci. 2014. 21: 949-53
5. Murrey D, Janssen M, Delamarter R, Goldstein J, Zigler J, Tay B. 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: 275-86
6. Nabhan A, Ahlhelm F, Pitzen T, Steudel WI, Jung J, Shariat K. Disc replacement using Pro-Disc C versus fusion: A prospective randomised and controlled radiographic and clinical study. Eur Spine J. 2007. 16: 423-30
7. Thorey F, Menzel H, Lorenz C, Gross G, Hoffmann A, Windhagen H. Enhancement of endoprosthesis anchoring using BMP-2. Technol Health Care. 2010. 18: 217-29
8. Tracey RW, Kang DG, Cody JP, Wagner SC, Rosner MK, Lehman RA. Outcomes of single-level cervical disc arthroplasty versus anterior cervical discectomy and fusion. J Clin Neurosci. 2014. 21: 1905-8
9. Traynelis VC, Leigh BC, Skelly AC. Return to work rates and activity profiles: Are there differences between those receiving C-ADR and ACDF?. Evid Based Spine Care J. 2012. 3: 47-52
10. Tumialán LM, Ponton RP, Garvin A, Gluf WM. Arthroplasty in the military: A preliminary experience with ProDisc-C and ProDisc-L. Neurosurg Focus. 2010. 28: E18-
11. Updated December17, 2007; cited July 19, 2015. Available from: http://www.accessdatafda.gov/cdrh_docs/pdf7/p070001b.pdf.
12. Viezens L, Schaefer C, Beyerlein J, Thietje R, Hansen-Algenstaedt N. An incomplete paraplegia following the dislocation of an artificial cervical total disc replacement. J Neurosurg Spine. 2013. 18: 255-9
13. Yi S, Oh J, Choi G, Kim TY, Shin HC, Kim KN. The fate of heterotopic ossification associated with cervical artificial disc replacement. Spine. 2014. 39: 2078-83
14. Zigler JE, Delamarter R, Murrey D, Spivak J, Janssen M. ProDisc-C and anterior cervical discectomy and fusion as surgical treatment for single-level cervical symptomatic degenerative disc disease: Five-year results of a Food and Drug Administration study. Spine. 2013. 38: 203-9