title: Bone loss of vertebral bodies at the operative segment after cervical arthroplasty: a potential complication?
abstract: OBJECTIVE Bony overgrowth and spontaneous fusion are complications of cervical arthroplasty. In contrast, bone loss or bone remodeling of vertebral bodies at the operation segment after cervical arthroplasty has also been observed. The purpose of this study is to investigate a potential complication-bone loss of the anterior portion of the vertebral bodies at the surgically treated segment after cervical total disc replacement (TDR)-and discuss the clinical significance. METHODS All enrolled patients underwent follow-up for more than 24 months after cervical arthroplasty using the Baguera C disc. Clinical evaluations included recording demographic data and measuring the visual analog scale and Neck Disability Index scores. Radiographic evaluations included measurements of the functional spinal unit's range of motion and changes such as bone loss and bone remodeling. The grading of the bone loss of the operative segment was classified as follows: Grade 1, disappearance of the anterior osteophyte or small minor bone loss; Grade 2, bone loss of the anterior portion of the vertebral bodies at the operation segment without exposure of the artificial disc; or Grade 3, significant bone loss with exposure of the anterior portion of the artificial disc. RESULTS Forty-eight patients were enrolled in this study. Among them, bone loss developed in 29 patients (Grade 1 in 15 patients, Grade 2 in 6 patients, and Grade 3 in 8 patients). Grade 3 bone loss was significantly associated with postoperative neck pain (p < 0.05). Bone loss was related to the motion preservation effect of the operative segment after cervical arthroplasty in contrast to heterotopic ossification. CONCLUSIONS Bone loss may be a potential complication of cervical TDR and affect early postoperative neck pain. However, it did not affect mid- to long-term clinical outcomes or prosthetic failure at the last follow-up. Also, this phenomenon may result in the motion preservation effect in the operative segment after cervical TDR.
authors.affiliation: Department of Neurosurgery, Spine Center, The Leon Wiltse Memorial Hospital, Gyeonggi-do, Korea.
authors.forename: Dong Hwa
authors.initials: DH
authors.lastname: Heo
authors.affiliation: Department of Neurosurgery, Spine Center, The Leon Wiltse Memorial Hospital, Gyeonggi-do, Korea.
authors.forename: Dong Chan
authors.initials: DC
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Spine Center, The Leon Wiltse Memorial Hospital, Gyeonggi-do, Korea.
authors.forename: Jong Yang
authors.initials: JY
authors.lastname: Oh
authors.affiliation: Department of Neurosurgery, Spine Center, The Leon Wiltse Memorial Hospital, Gyeonggi-do, Korea.
authors.forename: Choon Keun
authors.initials: CK
authors.lastname: Park
mesh_terms: D000328:Adult; D001178:Arthroplasty / Q000009:adverse effects*; D001847:Bone Diseases / Q000000981:diagnostic imaging / Q000209:etiology*; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000601:surgery*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology*; D016059:Range of Motion, Articular / Q000502:physiology; D012189:Retrospective Studies; D013122:Spinal Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D018709:Statistics, Nonparametric; D013997:Time Factors; D015898:Tomography Scanners, X-Ray Computed
keywords: AP = anteroposterior; NDI = Neck Disability Index; ROM = range of motion; TDR = total disc replacement; VAS = visual analog scale; bone loss; bone remodeling; cervical vertebrae; neck pain; total disc replacement