Heterotopic Ossification After Cervical Total Disc Replacement at 7 Years—Prevalence, Progression, Clinical Implications, and Risk Factors

Abstract

Background: Heterotopic ossification (HO) is a known risk following cervical total disc replacement (CTDR) surgery, but the cause and effect of HO are not well understood. Reported HO rates vary, and few studies are specifically designed to report HO. The effects on outcomes, and the risk factors for the development of HO have been hypothesized and reported in small-population, retrospective analyses, using univariate statistics.Methods: Posthoc, multiple-phase analysis of radiographic, clinical, and demographic data for CTDR as it relates to HO was performed. HO was radiographically graded for 164 one-level and 225 two-level CTDR patients using the McAfee and Mehren system. Analysis was performed to correlate HO grades to clinical outcomes and to evaluate potential risk factors for the development of HO using demographics and baseline clinical measures.Results: At 7 years, 1-level clinically relevant HO grades were 17.6% grade 3 and 11.1% grade 4. Two-level clinically relevant HO grades, evaluated using the highest patient grade, were 26.6% grade 3 and 10.8% grade 4. Interaction between HO and time revealed significance for neck disability index (NDI; P ¼ .04) and Visual Analog Scale (VAS) neck pain (P ¼ .02). When analyzed at each time point NDI was significant at 48-84 months and VAS neck at 60 months. For predictors 2 analyses were run; odds ratios indicated follow-up visit, male sex, and preoperative VAS neck pain are related to HO development, whereas hazard ratios indicated male sex, obesity, endplate coverage, levels treated, and preoperative VAS neck pain.Conclusions: This is the largest study to report HO rates, and related outcomes and risk factors. To develop an accurate predictive model, further large-scale analyses need to be performed. Based on the results reported here, clinically relevant HO should be more accurately described as motion-restricting HO until a definitive link to outcomes has been established.

Two-level cervical disc arthroplasty versus anterior cervical discectomy and fusion: 10-year outcomes of a prospective, randomized investigational device exemption clinical trial

“…These findings are similar to those reported by Nunley et al of combined total grades III or IV at both levels of 37.4% for two-level CDA with a different CDA device at 7 years postoperatively. 22 Nunley et al did find a significant negative cor- relation between HO grade and ROM. In the current study, while there were patients with reported grade III or IV HO and patients with reduced angular motion, these observations were not frequent enough to negatively influence the overall average angular motion at the index levels of CDA patients, which was maintained over time out to 10 years.…”

Heterotopic Ossification After Prestige-LP Cervical Disc Arthroplasty Is Related to Insufficient Sagittal Coverage of the Endplate By the Prosthesis

“…Different influencing factors have been identified. Pierce [ 9 ] showed that sex, obesity, and follow-up time were risk factors for HO after CDR, while Michael [ 19 ] and Qi [ 10 ] showed that surgical skill proficiency and facet joint degeneration were associated with HO. Nevertheless, HO is a specific complication of CDR, and there is a lack of analytical data for discussing the correlation between CDR surgical factors and postoperative HO.…”

“…The pathogenesis of HO after CDR is still not completely clear. Some studies have shown that sex, age, BMI, number of treatment levels, and follow-up time are risk factors for HO [ 9 , 10 ]. However, few studies have investigated the potential role of surgical techniques in HO occurrence following CDR.…”

The Impact of Smoking on Radiological Outcomes in Patients After Total Arthroplasty of the Cervical Intervertebral Discs

“…В работе P.D. Nunley et al [21] доказано, что мужской пол, ожирение, сохранение элементов замыкательной пластинки, проведение оперативного вмешательства на двух сегментах и степень выраженности болевого синдрома в шейном отделе позвоночника по визуальной аналоговой шкале являются факторами риска развития гетеротопической оссификации в отдаленном послеоперационном периоде. Необходимо отметить, что курение также является доказанным фактором риска высокой частоты встречаемости нежелательных явлений, увеличения продолжительности госпитализации пациентов и снижения скорости образования костной ткани после выполнения операции ригидной стабилизации [10][11][12][13].…”