Is Anterior Bone Loss the Opposite of Anterior Heterotopic Ossification in Prestige-LP Cervical Disc Replacement?

Abstract BACKGROUND Anterior cervical disc replacement is an alternative to fusion for the treatment of selected cases of radiculopathy and myelopathy. We report clinical and radiological outcomes after disc replacement with the NuNec™ artificial cervical disc (Pioneer® Surgical Technology, Marquette, Michigan) with subgroup analysis. OBJECTIVE To review clinical and radiological outcomes after anterior cervical disc replacement with the NuNec™ artificial cervical disc. METHODS A consecutive case series of patients undergoing cervical disc replacement with the NuNec™ artificial disc was conducted. Clinical outcomes were assessed by questionnaires preoperatively and up to 2 yr postoperatively including neck and arm pain, Neck Disability Index, Euroqol 5-dimensions, and Short Form-36; x-rays from the same period were analyzed for range of movement and presence of heterotopic ossification. RESULTS A total of 44 NuNec™ discs were implanted in 33 patients. Clinical improvements were seen in all outcomes; significant improvements on the Neck Disability Index, Euroqol 5-dimensions, and physical domain of the Short Form-36 were maintained at 2 yr. There was a mean of 4° range of movement at the replacement disc level at 2 yr, a significant reduction from baseline; there was also progression in levels of heterotopic ossification. Complications included temporary dysphagia (10%) and progression of disease requiring foraminotomy (6%); no surgery for adjacent level disease was required. There was no significant difference in the outcomes of the radiculopathy and myelopathy groups. CONCLUSION Clinical outcomes using the NuNec™ disc replacement are comparable with other disc replacements. Although the range of movement is reduced, the reoperation rate is very low.

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Clinical Significance of Heterotopic Ossification in Cervical Disc Replacement: A Prospective Multicenter Clinical Trial

Neurosurgery ◽

10.1227/01.neu.0000175856.31210.58 ◽

2005 ◽

Vol 57 (4) ◽

pp. 759-763 ◽

Cited By ~ 132

Author(s):

Clarence Leung ◽

Adrian Th. Casey ◽

Jan Goffin ◽

Pierre Kehr ◽

Klaus Liebig ◽

...

Keyword(s):

Risk Factors ◽

Heterotopic Ossification ◽

Short Form ◽

Disc Replacement ◽

Cervical Disc ◽

Secondary Outcome ◽

X Rays ◽

Cervical Disc Replacement ◽

Bryan Disc ◽

Grade 3

ABSTRACT OBJECTIVE: Heterotopic ossification (HO) is a well-known complication in joint replacements, but its occurrence and clinical effect on cervical artificial discs has not yet been studied. The purpose of this study was to investigate the incidence of HO in cervical disc replacement, to identify any associated risk factors for HO, and to examine the relationship of HO with clinical outcomes. METHODS: The patient data for this observational study were obtained from the original Bryan Disc Study by the European Consortium. Occurrence of HO was defined by the McAfee classification on the cervical lateral x-rays at 12 months after surgery. Secondary outcome measurements included Odom's criteria and the Medical Outcomes Study Short-Form 36-Item Health Survey. RESULTS: Sixteen (17.8%) of the 90 studied patients experienced HO, and 6 (6.7%) of these patients experienced Grade 3 and 4 HO. Ten patients' (11%) artificial discs were shown to have movement of less than 2 degrees on flexion and extension cervical x-ray at 12 months, with 4 of these patients having HO of Grade 3 or 4. Male sex (χ2 = 4.1; P = 0.0407) and older patients (P = 0.023; odds ratio = 1.10; 95% confidence interval = 1.01–1.19) were associated with development of HO. CONCLUSION: There is a strong association of the occurrence of HO with subsequent loss of movement of the implanted cervical artificial disc. We have found that sex and age are two possible risk factors in the development of HO after cervical disc replacement.

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