Comparing Heterotopic Ossification in Two Cervical Disc Prostheses

Spine, vol. 45, pp. 1329–1334

Abstract

STUDY DESIGN: Retrospective analysis using data from randomized clinical trials. OBJECTIVE: To compare the occurrence of heterotopic ossification (HO) between two cervical disc prostheses. Clinical outcome and range of motion (ROM) were also evaluated. SUMMARY OF BACKGROUND DATA: Cervical arthroplasty was reported to be able to maintain the segmental ROM. However, controversy exists since the difference of the occurrence of HO concerning cervical prosthesis is still huge. METHODS: Patients who underwent anterior cervical discectomy with arthroplasty for a cervical radiculopathy due to a herniated disc from the The Netherlands Cervical Kinematics (NECK) trial (activC; metal endplates with a polyethylene inlay and a keel for primary stability) and the PROCON trial (Bryan; metal-on-polymer with titanium coated endplates without a keel) were analyzed for HO at 12 and 24 months postoperatively. HO was scored according to the McAfee-Mehren classification. Segmental ROM was defined by a custom developed image analysis tool, and global cervical ROM was measured by Cobb's angle. Clinical outcome was evaluated by means of the neck disability index (NDI) as well as physical-component summary (PCS) and mental-component summary (MCS). RESULTS: At 2-year follow-up, the occurrence of HO was 68% in patients treated with the activC prosthesis (severe HO 55%), which was comparable with 85% (P = 0.12) in patients with the Bryan disc (severe HO 44%; P = 0.43). The HO progression was similar between groups. Clinically, the patients had comparable NDI, PCS, and MCS at 2-year follow-up, and comparable improvement of clinical outcomes. The global ROM in the Bryan group (56.4 ± 10.8°) was significantly higher than in the activC group (49.5 ± 14.0, P = 0.044) at 2-year follow-up. CONCLUSION: In comparison of two cervical disc prostheses the development of HO is independent on their architecture. Although global ROM was higher in the Bryan prosthesis group, this difference was not deemed clinically important, particularly because the clinical condition of patients with and without severe HO was comparable. LEVEL OF EVIDENCE: 2.

Authors 6

1. Xiaoyu Yang corresponding Aachen Department of Neurosurgery, Leiden University Medical Centre China Scholarship Council Department of Neurosurgery of the Leiden University Medical Centre reprint requests to Xiaoyu Yang

   Leiden University · Leiden University Medical Center

   Affiliation as printed

   Department of Neurosurgery, Leiden University Medical Centre, Leiden, The Netherlands

   China Scholarship Council and the Department of Neurosurgery, Leiden University Medical Centre, The Netherlands funds were received in support of this work. The Netherlands Cervical Kinematics (NECK) trial was sponsored by B. Braun Medical and the Department of Neurosurgery of the Leiden University Medical Centre, the Netherlands

   E-mail: [email protected]

   Relevant financial activities outside the submitted work: royalties

   The legal regulatory status of the device(s)/drug(s) that is/are the subject of this manuscript is not applicable in my country

   reprint requests to Xiaoyu Yang, MD, MSc, J11-R-83: Department of Neurosurgery, Leiden University Medical Centre, Albinusdreef 2, Leiden, 2300 RC, The Netherlands

2. Roland D. Donk Aachen China Scholarship Council Department of Neurosurgery, Leiden University Medical Centre Department of Neurosurgery of the Leiden University Medical Centre

   Leiden University · Leiden University Medical Center · Kliniek ViaSana

   Affiliation as printed

   Department of Orthopaedic Surgery, Via Sana Clinics, Mill, The Netherlands

   China Scholarship Council and the Department of Neurosurgery, Leiden University Medical Centre, The Netherlands funds were received in support of this work. The Netherlands Cervical Kinematics (NECK) trial was sponsored by B. Braun Medical and the Department of Neurosurgery of the Leiden University Medical Centre, the Netherlands

   Relevant financial activities outside the submitted work: royalties

   The legal regulatory status of the device(s)/drug(s) that is/are the subject of this manuscript is not applicable in my country

3. Ronald Bartels Aachen China Scholarship Council Department of Neurosurgery, Leiden University Medical Centre Department of Neurosurgery of the Leiden University Medical Centre

   Leiden University · Radboud University Nijmegen · Leiden University Medical Center · Radboud University Medical Center

   Affiliation as printed

   Department of Neurosurgery, Radboud University Medical Centre, Nijmegen, The Netherlands

   China Scholarship Council and the Department of Neurosurgery, Leiden University Medical Centre, The Netherlands funds were received in support of this work. The Netherlands Cervical Kinematics (NECK) trial was sponsored by B. Braun Medical and the Department of Neurosurgery of the Leiden University Medical Centre, the Netherlands

   Relevant financial activities outside the submitted work: royalties

   The legal regulatory status of the device(s)/drug(s) that is/are the subject of this manuscript is not applicable in my country

4. Mark P. Arts Aachen China Scholarship Council Department of Neurosurgery, Leiden University Medical Centre Department of Neurosurgery of the Leiden University Medical Centre

   Leiden University · Leiden University Medical Center · Medisch Centrum Haaglanden · Stichting Haaglanden Medisch Centrum

   Affiliation as printed

   Department of Neurosurgery, Haaglanden Medical Centre, The Hague, The Netherlands

   China Scholarship Council and the Department of Neurosurgery, Leiden University Medical Centre, The Netherlands funds were received in support of this work. The Netherlands Cervical Kinematics (NECK) trial was sponsored by B. Braun Medical and the Department of Neurosurgery of the Leiden University Medical Centre, the Netherlands

   Relevant financial activities outside the submitted work: royalties

   The legal regulatory status of the device(s)/drug(s) that is/are the subject of this manuscript is not applicable in my country

5. Bart P. Depreitere Aachen China Scholarship Council Department of Neurosurgery, Leiden University Medical Centre Department of Neurosurgery of the Leiden University Medical Centre

   Leiden University · Leiden University Medical Center · Universitair Ziekenhuis Leuven

   Affiliation as printed

   Department of Neurosurgery, University Hospitals Leuven, Leuven, Belgium

   China Scholarship Council and the Department of Neurosurgery, Leiden University Medical Centre, The Netherlands funds were received in support of this work. The Netherlands Cervical Kinematics (NECK) trial was sponsored by B. Braun Medical and the Department of Neurosurgery of the Leiden University Medical Centre, the Netherlands

   Relevant financial activities outside the submitted work: royalties

   The legal regulatory status of the device(s)/drug(s) that is/are the subject of this manuscript is not applicable in my country

6. Carmen L. A. Vleggeert-Lankamp Aachen Department of Neurosurgery, Leiden University Medical Centre China Scholarship Council Department of Neurosurgery of the Leiden University Medical Centre

   Leiden University · Leiden University Medical Center

   Affiliation as printed

   Department of Neurosurgery, Leiden University Medical Centre, Leiden, The Netherlands

   China Scholarship Council and the Department of Neurosurgery, Leiden University Medical Centre, The Netherlands funds were received in support of this work. The Netherlands Cervical Kinematics (NECK) trial was sponsored by B. Braun Medical and the Department of Neurosurgery of the Leiden University Medical Centre, the Netherlands

   Relevant financial activities outside the submitted work: royalties

   The legal regulatory status of the device(s)/drug(s) that is/are the subject of this manuscript is not applicable in my country