Heterotopic Ossification After Burn Injury Results in Worse Outcomes

Introduction: Heterotopic ossification (HO) is the formation of extra-skeletal bone within soft tissue that occurs after traumatic injuries like severe burns. While the risk of developing HO is associated with burns >30% TBSA, burns on the arms with or without skin grafting, and ventilation days, large clinical studies identifying the risk for HO in burns are not available. Using a large real-world patient database, we aimed to identify factors influencing the development of HO in burn survivors. We also investigated the effects of HO on burn recovery following severe burn. Methods: Using the TriNetX database, a large, federated research network of de-identified patient data, we compared burned patients who developed HO after injury and those who did not. Cohorts were propensity-matched by age, gender, race, ethnicity, and % total body surface area (TBSA) burned before assessment of burn outcomes. We then evaluated the chronological development of HO after burn. Results: A total of 791,552 burn survivors were identified in TriNetX, of which 955 (0.12%) developed HO. Most cases were diagnosed more than 6 months after injury. HO was more common in patients with burn involving the head, upper extremity, or lower extremity (p<0.0001). Patients with HO were older (48.1±19.5 yrs. vs 32.5±22.8 yrs., p<0.001) and predominantly male (60.3% vs 51.1%, p<0.001). Linear regression analysis showed that 33% of patients who developed HO were diagnosed within 3 months of injury, with an increase of 1% each month after burn. Burn patients who developed HO exhibited a more than doubled risk of neuropathy, limited joint mobility, and documented oedema compared to those who did not. Additionally, the risk of skin breakdown, pain, and depression was higher in patients who developed HO while additional reconstructive operations were interestingly lower than the propensity-matched cohort without HO. Conclusions: Burn survivors more likely to develop HO are older, male, and with greater injury severity. Identification of HO was most likely greater than 6 months from injury. After propensity matching for burn severity and demographic factors, those with HO have comparatively poorer outcomes.