Deltoid Tuberosity Index as a Predictor of Hip Fracture Risk in Older Adults.

BACKGROUND

Hip fractures are among the most common osteoporotic injuries in older adults, and early identification of high-risk individuals is essential for their prevention. Although dual-energy X-ray absorptiometry (DEXA) remains the standard method for measuring bone mineral density (BMD), access to this modality is limited in many regions. The deltoid tuberosity index (DTI), which is measured on proximal humeral images and visible on routine chest radiographs, may be a simple and accessible indicator of systemic osteoporosis.

METHODS

This retrospective study included 1,012 patients aged ≥60 years who underwent surgery for hip fractures and had preoperative chest radiographs suitable for DTI measurement. The normal DEXA group consisted of 75 individuals with normal BMD (DEXA T-score ≥ -1.0) who had chest or shoulder radiographs taken within 6 months of their DEXA scan. DTI measurements were independently performed by two observers. Interobserver and intraobserver reliabilities were analyzed using intraclass correlation coefficients (ICC). Group comparisons, age-related associations, and receiver operating characteristic (ROC) analyses were conducted to evaluate the predictive performance of DTI.

RESULTS

DTI was measurable in 74.7% of chest radiographs. The hip-fracture group showed significantly lower DTI values than the normal DEXA group (mean, 1.294; p<0.001). The measurement reproducibility was excellent, with inter- and intraobserver ICC values of 0.95. ROC analysis demonstrated strong discrimination for predicting hip fracture (AUC=0.903). The optimal cutoff value was 1.377, corresponding to 84.6% sensitivity and 86.7% specificity.

CONCLUSIONS

DTI is a simple, reliable, and easily obtainable measurement from routine chest radiographs and is strongly associated with hip fractures and systemic osteoporosis. Its high reproducibility and diagnostic performance highlight its potential as an opportunistic screening tool, particularly in settings with limited access to DEXA.