Troublesome heterotopic ossification and stroke: Features and risk factors. A case control study

Abstract

Primary objective: To determine the features of stroke-related HO in a large sample of patients and to assess if HO risk is increased by haemorrhagic stroke.

Research design: A case control study (risk factor of a rare event using retrospective analysis).

Methods and procedures: Sixty-one patients with stroke—81 troublesome HOs—were included, each was matched with four controls, i.e. 244 patients with no HO after stroke. Matching criteria were age (±3.5 years) and sex. Data recorded were time from stroke to surgery, ischaemic or haemorrhagic stroke and presence of HO risk factors.

Main outcomes and results: Mean age at time of stroke = 46.02 ± 11.4 years (15.9–76.3) for the case sub-group. Time from stroke to surgery = 23.4 ± 27.8 months (3.6–150.0). There was a significant relationship between haemorrhagic stroke and HO development (OR = 3.01; 95% CI = 1.14–7.98; p < 0.05), but not for ischaemic stroke. This became non-significant when all matching and risk factors were included in the model (adjusted OR = 1.98; 95% CI = 0.60–6.54; p = 0.26).

Conclusion: Haemorrhagic stroke appears to increase the risk of HO development. Further studies are required to determine if this risk factor is independent from other comorbid factors.

• Epidemiology
• hemiplegic
• heterotopic ossification
• stroke

Acknowledgments

The authors wish to thank Pr Didier Guillemot for his technical review of the epidemiological methods, Dr Sophie Baron and Mr Jerome Schuler (from the Medical Information Department) for providing the database of stroke patients and the random selection of patients from the database and Mrs Erica Vlachos (CRA) for the management of the database.

Declaration of interest

We certify that no party having a direct interest in the results of the research supporting this article has or will confer a benefit on us or on any organization with which we are associated AND, if applicable, we certify that all financial and material support for this research (e.g. NIH or NHS grants) and work are clearly identified in the title page of the manuscript.