To develop a lower extremity (LE) fragility fracture risk score estimation method among adults with chronic spinal cord injury (SCI).
Adults (≥18) with chronic traumatic SCI (n=90, C2-T12, AIS:A-D) participated in a 2-year prospective cohort study. We used a literature search and practice expertise to identify LE fracture predictors. Reference categories (i.e., risk score = 0) were: no prior fracture, 0-9 years post-injury, AIS-CD, no parental history of osteoporosis, and no opioid use. Using logistic regression coefficients, we calculated how far each category is from the base category and computed βi (Wij-WiREF) for each risk factor. In this model, B was the increase in risk associated with each year post injury. The point value for each fracture risk category was calculated by Pointsij=βi (Wij-WiREF)/B. The total points range from 0-21, and the probability of LE fracture is calculated for each point to determine the probability of developing a LE fracture using the formula: 
Most participants had an AIS-A impairment (60.0%), the mean time post-injury=15.23 years (SD=9.58). For the points system (0-17), prior fracture, years post-injury, AIS, Benzodiazepine use, Opioid use, and parental osteoporosis were defined risk factors. An individual’s risk profile can estimate LE fracture risk. A score of 11 equates to 20% or high fracture risk over a 5-year time period.
We describe our preliminary model to estimate LE fracture risk among those with chronic SCI. We plan to apply statistical and machine learning algorithms using Canadian RHSCIR data and US VHA data to validate the model, and increase the model’s predictability.
