Increased risk of osteoarthritis in persons with spinal cord injury: a population-based longitudinal follow-up study in Taiwan.

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To assess the relative risk of osteoarthritis (OA) in individuals with newly diagnosed spinal cord injury (SCI) compared to a matched non-SCI group.

SETTING

Taiwan's Longitudinal Health Insurance Database.

METHODS

We identified 1373 individuals aged 20-69 years with newly diagnosed SCI between 2002 and 2005 as the SCI group. A propensity-score-matched non-SCI group (N = 5492) with similar baseline demographic and clinical characteristics was selected for comparison. Both groups were followed until December 2011. OA-free survival was analyzed via Kaplan-Meier curves, and the association between SCI and OA risk was evaluated via stratified Cox proportional-hazards regression. To assess temporal risk variations, we performed landmark analysis with a 1-year cutoff, dividing follow-up into early (0-1 year) and long-term (≥1 year) periods.

RESULTS

The respective incidence rates of OA for the SCI and non-SCI groups were 45.4 per 1000 person-years (95% confidence interval [CI], 40.1-50.1) and 31.6 per 1000 person-years (95% CI, 29.8-33.4). The hazard ratio of OA for the SCI group, as compared to the non-SCI group, was 1.52 (95% CI 1.34-1.72, p < 0.0001).

CONCLUSIONS

This population-based longitudinal follow-up study indicates that there is an increased long-term risk of OA in persons with SCI, underscoring the need for clinical vigilance and early diagnostic measures in this population. Further research is needed to explore the mechanisms underlying the association between these two conditions.