Heterotopic Ossification Following Arthroplasty for Femoral Neck Fracture.

BACKGROUND: Heterotopic ossification (HO) is a frequent complication following hip surgery. Using data from the Hip Fracture Evaluation with Alternatives of Total Hip Arthroplasty versus Hemiarthroplasty (HEALTH) trial, we aimed to (1) determine the prevalence of HO following total hip arthroplasty (THA) for femoral neck fracture in patients ≥50 years of age, (2) identify whether HO is associated with an increased risk of revision surgery within 24 months after the fracture, and (3) determine the impact of HO on functional outcomes. METHODS: We performed a multivariable Cox regression analysis using revision surgery as the dependent variable and HO as the independent variable. We compared Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores between participants with and those without HO at 24 months. RESULTS: Of 1,441 participants in the study, 287 (19.9%) developed HO within 24 months. HO was not associated with subsequent revision surgery. Grade-III HO was associated with statistically significant and clinically relevant deterioration in the total WOMAC score, which was mainly related to the function component of the score, compared with grade I or II. CONCLUSIONS: The impact of grade-III HO on the functional outcomes and quality of life after THA for hip fracture is clinically important, and HO prophylaxis for selected high-risk patients may be appropriate. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Association of vitamin D deficiency, secondary hyperparathyroidism, and heterotopic ossification in spinal cord injury.

Our objective was to explore the relationship between low vitamin D, secondary hyperparathyroidism, and heterotopic ossification (HO) in patients with spinal cord injury (SCI). Ninety-six subjects with acute or chronic motor complete SCI participated. Levels of serum vitamin D25(OH), calcium, and intact parathyroid hormone (PTH) were collected, and information regarding nutritional patterns and fracture history was obtained from subjects. Evidence of current or previous HO was ascertained through chart review. Of the 96 subjects, 12 were found to have developed HO, 11 with serum vitamin D25(OH) between 5 and 17 ng/mL. Nine subjects exhibited secondary hyperparathyroidism in the range of 72 to 169 pg/mL. Only one subject demonstrated HO in the absence of low vitamin D. However, many subjects with low vitamin D (5-31 ng/mL) did not have hyperparathyroidism or HO. Statistical testing demonstrated a correlation between hyperparathyroidism and HO (p < 0.001) as well as hyperparathyroidism and vitamin D deficiency (<20 ng/mL). Direct correlation between HO and low vitamin D was not observed, but hyperparathyroidism may increase this risk. We believe that those patients who demonstrate low vitamin D and elevated PTH should be screened for HO in addition to beginning vitamin supplementation. Initiating early treatment of low vitamin D to restore therapeutic levels may prevent development of HO.

Did ossification of the posterior longitudinal ligament of the spine evolve in the modern period? A paleopathologic study of ancient human skeletons in Japan.

OBJECTIVE: To investigate the historical origins of ligamentous ossifications of the spine in Japan. METHODS: We studied skeletons of Jomonese of the period 5000-2300 years BP, of Japanese of the 17th-19th century Edo Period, and of Ainu of the 18th-20th century in Japan with special emphasis on spinal ligament ossifications as in the posterior longitudinal ligament. A comparison to our previous study on ancient Chinese skeletons was done. RESULTS: Cervical ossification of the posterior longitudinal ligament (OPLL) was the only ossification that increased significantly in prevalence in people of the near-modern period in comparison to the Neolithic gathering-hunting people. CONCLUSION: Socioeconomic changes from a subsistence gathering-hunting economy to the near-modern livelihood depending on rice-eating and a diet high in vegetable protein are speculated to be responsible for the prevalence increase of cervical OPLL.