Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Dec;12(6):1760-1767.
doi: 10.1111/os.12743. Epub 2020 Oct 12.

The Assessment of Paravertebral Ossification Progression After Cervical Disc Arthroplasty Based on CT Images: A Long-term Follow-up

Affiliations

The Assessment of Paravertebral Ossification Progression After Cervical Disc Arthroplasty Based on CT Images: A Long-term Follow-up

Cheng Zeng et al. Orthop Surg. 2020 Dec.

Abstract

Objective: This study focused on the assessment of paravertebral ossification (PO) after cervical disc arthroplasty (CDA) using computed tomography (CT) images.

Methods: In this retrospective study, 52 patients (from 2004 to 2010) who received CDA at a single center were included (32 males). Preoperative and follow-up X-ray and CT images of all patients who underwent single-level CDA were collected. PO from the C2/3 to C7/T1 in each patient was graded based on a CT grading system. Each segment was divided into operative level, adjacent level, or non-adjacent level. The McAfee' classification system was used to grade PO using X-ray plain film. The range of motion (ROM) and scores of neurological symptoms (Japanese Orthopaedic Association [JOA] score and Neck Disability Index [NDI]) at both preoperative and final follow-up time were acquired. Progression and classification of PO in each group was compared using the chi-square test. ROM between groups were compared using independent t-test. JOA score and NDI between groups were compared using Mann-Whitney U test.

Results: The average follow-up time was 81.2 months. In comparison with the preoperative status, the progression of PO development in left and right areas (the Luschka joints areas) in the operative level groups was significantly more severe (area L,χ2 value = 36.612, P < 0.001; area R, χ2 value = 39.172, P < 0.001) than the non-adjacent level groups. In contrast, although the prevalence of PO in all areas of the adjacent level groups was higher than that of the non-adjacent level group in the same segments, there was no significant difference (P > 0.05) in the progression of PO development. The follow-up high-grade (grades III and IV) PO incidence rate using X-ray grading system (3.85%) was significantly lower than that using CT grading system in area L (42.31%) and R (38.46%), but close to that in area A (5.77%) and P (1.92%). The final follow-up ROM was not significantly different with preoperative ROM in patients with low-grade PO (9.47° ± 4.12° vs. 9.76° ± 3.69°, P = 0.794). However, in patients with high-grade PO, the final follow-up ROM was significantly lower than preoperative ROM (5.77° ± 3.32° vs. 9.28° ± 4.15°, P < 0.001). There was no significant difference for JOA score and NDI at follow-up between patients with high-grade and low-grade PO (JOA, 16.2 ± 1.1 vs. 16.8 ± 0.9, P = 0.489; NDI, 8.9 ± 6.1 vs. 8.0 ± 7.3, P = 0.317).

Conclusion: High-grade PO was observed in the areas of the Luschka joints at the operative level after CDA, which was difficult to observe using X-ray plain film. The PO formation at adjacent segments was not significant.

Keywords: Cervical artificial disc replacement; Cervical disc arthroplasty; Cervical spine; Heterotopic ossification; Paravertebral ossification.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Suggested areas of the revised CT PO grading system: a circle made in the center of the vertebra body divided into 12 equal clockwise parts. Area A (anterior) includes parts 1, 2, 11, and 12. Area P (posterior) includes parts 6 and 7. Area L (left) includes parts 8, 9, and 10. Area R (right) includes parts 3, 4, and 5.
Fig. 2
Fig. 2
The revised CT PO grading system: grade 0 (A), no ossification; grade I (B), not extending across the adjacent disc space; grade II (C), extending across the adjacent disc space; and grade III (D), complete bridging of the adjacent disc space.

References

    1. Heidecke V, Burkert W, Brucke M, Rainov NG. Intervertebral disc replacement for cervical degenerative disease‐ clinical results and functional outcome at two years in patients implanted with the Bryan cervical disc prosthesis. Acta Neurochir, 2008, 150: 453–459. 10.1007/s00701-008-1552-7. - DOI - PubMed
    1. Lei C, Lin N, Li Z, et al Fusion versus Bryan cervical disc in two‐level cervical disc disease: a prospective, randomised study. Int Orthop, 2009, 33: 1347–1351. 10.1007/s00264-008-0655-3. - DOI - PMC - PubMed
    1. Rhee JM. Cervical arthroplasty: a success, failure, or both? Spine J, 2010, 10: 731–732. 10.1016/j.spinee.2010.06.002. - DOI - PubMed
    1. Xuesong Z, Xuelian Z, Chao C, et al Randomized, controlled, multicenter, clinical trial comparing BRYAN cervical disc arthroplasty with anterior cervical decompression and fusion in China. Spine, 2012, 37: 433–438. 10.1097/brs.0b013e31822699fa. - DOI - PubMed
    1. Demetriades AK, Ringel F, Meyer B. Cervical disc arthroplasty: a critical review and appraisal of the latest available evidence. Adv Tech Stand Neurosurg, 2014, 41: 107–129. 10.1007/978-3-319-01830-0_5. - DOI - PubMed