title: Solid radiographic fusion with a nonconstrained device 5 years after cervical arthroplasty.
abstract: Cervical disc arthroplasty (CDA) has been gaining popularity as a surgical alternative to anterior cervical discectomy and fusion. Spontaneous fusion following a CDA is uncommon. A few anecdotal reports of heterotrophic ossification around the implant sites have been noted for the BRYAN, ProDisc-C, Mobi-C, PRESTIGE, and PCM devices. All CDA fusions reported to date have been in devices that are semiconstrained. The authors reported the case of a 56-year-old man who presented with left C-7 radiculopathy and neck pain for 10 weeks after an assault injury. There was evidence of disc herniation at the C6-7 level. He was otherwise healthy with functional scores on the visual analog scale (VAS, 4.2); neck disability index (NDI, 16); and the 36-item short form health survey (SF-36; physical component summary [PSC] score 43 and mental component summary [MCS] score 47). The patient underwent total disc replacement in which the DISCOVER Artificial Cervical Disc (DePuy Spine, Inc.) was used. The patient was seen at regular follow-up visits up to 60 months. At his 60-month follow-up visit, he had complete radiographic fusion at the C6-7 level with bridging trabecular bone and no motion at the index site on dynamic imaging. He was pain free, with a VAS score of 0, NDI score of 0, and SF-36 PCS and MCS scores of 61 and 55, respectively. Conclusions This is the first case report that identifies the phenomenon of fusion around a nonconstrained cervical prosthesis. Despite this unwanted radiographic outcome, the patient's clinical outcome was excellent.
authors.affiliation: Department of Neurological Surgery, Rutgers New Jersey Medical School, Newark, New Jersey.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Heary
authors.forename: Ira M
authors.initials: IM
authors.lastname: Goldstein
authors.forename: Katarzyna M
authors.initials: KM
authors.lastname: Getto
authors.forename: Nitin
authors.initials: N
authors.lastname: Agarwal
mesh_terms: D002574:Cervical Vertebrae / Q000601:surgery*; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D008875:Middle Aged; D019838:Neck Injuries / Q000000981:diagnostic imaging* / Q000601:surgery*; D009999:Ossification, Heterotopic / Q000000981:diagnostic imaging*; D011843:Radiculopathy / Q000000981:diagnostic imaging / Q000601:surgery; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D059145:Total Disc Replacement / Q000009:adverse effects / Q000379:methods*; D016896:Treatment Outcome
keywords: ACDF = anterior cervical discectomy and fusion; CDA = cervical disc arthroplasty; HO = heterotopic ossification; IDE = Investigational Device Exemption; MCS = mental component summary score; NDI = neck disability index; PCS = physical component summary score; SF-36 = 36-item short form health survey; VAS = visual analog scale; cervical disc; cervical fusion; nonconstrained device; total disc arthroplasty