Trends and risk factors for spinal cord injury-induced heterotopic ossification: A retrospective population-based cross-sectional study using the 2016–2021 National Inpatient Sample (NIS)

Heterotopic ossification (HO), the abnormal formation of bone in soft tissue, is a known complication of spinal cord injury (SCI). Prior studies have identified several associated factors but are limited by small sample sizes and provide little insight into the burden on the healthcare system. This study will assesses national trends in hospitalizations for SCI-induced HO in the U.S. from 2016 to 2021 and identifies demographic and clinical factors associated with HO in hospitalized SCI patients. Retrospective, population-based cross-sectional study. Healthcare Cost and Utilization Project’s National Inpatient Sample (NIS) from 2016 to 2021. A total of 380,928 hospitalizations with SCI, with or without HO, were identified. Hospitalizations with a primary or secondary SCI diagnosis, with or without HO complication, were identified using ICD-10 codes. Survey-weighted logistic regression models assessed associations between SCI-induced HO and demographic and clinical factors. Interaction analyses evaluated potential effect modification. Of 380,928 SCI hospitalizations, 181 (0.048%) included an HO diagnosis. Younger age, male sex, hip-pelvic trauma, pressure ulcers, spasticity, thoracic trauma, and thromboembolism were associated with increased odds of HO; lung injury and pneumonia/pneumonitis were associated with decreased odds. Thoracic and complete SCI were independently associated with HO, and a significant interaction was observed between SCI level and completeness (P Hospitalized SCI patients with these risk factors should be closely monitored for HO prevention, early detection, and treatment. The inverse association between HO and lung injury or pneumonia warrants further investigation.

异位骨化（Heterotopic ossification, HO）指软组织内异常骨形成，是脊髓损伤（spinal cord injury, SCI）已知的并发症。既往研究已明确若干相关危险因素，但受限于样本量较小，且鲜有针对其医疗系统负担的深入探讨。本研究旨在评估2016至2021年美国脊髓损伤相关性异位骨化住院病例的全国流行趋势，并明确住院脊髓损伤患者中合并异位骨化的人口学与临床相关因素。本研究为回顾性、基于人群的横断面研究，数据来源于2016至2021年美国医疗成本与利用项目（Healthcare Cost and Utilization Project）的全国住院患者样本（National Inpatient Sample, NIS）。研究共纳入380928例伴或不伴异位骨化的脊髓损伤住院病例，通过ICD-10编码筛选出以脊髓损伤为主要或次要诊断、伴或不伴异位骨化并发症的住院病例。采用调查加权logistic回归模型分析脊髓损伤相关性异位骨化与人口学、临床因素的关联，并通过交互作用分析评估潜在的效应修饰作用。在380928例脊髓损伤住院病例中，181例（0.048%）合并异位骨化诊断。年龄较轻、男性性别、髋骨盆创伤、压疮、痉挛、胸部创伤与血栓栓塞均与异位骨化发生风险升高相关；而肺损伤与肺炎/肺炎性病变则与风险降低相关。脊髓损伤节段为胸椎、完全性脊髓损伤为异位骨化的独立危险因素，且脊髓损伤节段与损伤完全性之间存在显著交互作用（P < 0.001）。针对合并上述危险因素的住院脊髓损伤患者，应加强监测以实现异位骨化的预防、早期检出与治疗。异位骨化与肺损伤或肺炎之间的负相关关联值得进一步研究。