Can Trabecular Bone Score Enhance Fracture Risk Assessment in Long-Distance Runners With Bone Stress Injuries?

Objective: To evaluate the trabecular bone score (TBS) Z scores in long-distance runners with bone stress injuries (BSIs) in whom the bone mineral density (BMD) Z score is more than -1.0 (Aim 1) and whether the number of runners with abnormal TBS Z scores would be higher in those with BSI in trabecular-rich sites as compared with cortical-rich sites (Aim 2).

Design: Retrospective cohort study.

Setting: Institutional sports medicine center.

Patients: We analyzed Z scores derived from the TBS and BMD in 44 long-distance runners aged 18 to 40 years who had sustained BSIs between 2017 and 2023 and undergone a dual-energy x-ray absorptiometry scan with reported TBS measurements within 1 year before or 2 years after their injuries.

Independent variables: Bone mineral density and TBS Z scores.

Main outcome measures: Evaluation of BMD and TBS Z scores in long-distance runners with BSIs, further stratified according to cortical-rich and trabecular-rich BSIs.

Results: Bone mineral density assessments revealed an average Z score of -0.96 ± 0.99. In this cohort of 44 runners, 55% (n = 24) of runners were reported to have BMD Z score more than -1.0. Within this subgroup, 54% (n = 13) displayed abnormal TBS. Stratifying BSIs by trabecular- (n = 23) and cortical-rich (n = 19) sites, we found no significant difference in sex, mean BMD, or the number of runners with abnormal TBS between the 2 groups.

Conclusions: Trabecular bone score Z scores in sports medicine may provide complementary information to BMD in long-distance runners with BSI, particularly when the BMD Z scores are more than -1.0. However, further research is needed to validate the usefulness of TBS Z scores in this context.

Study design: Cohort study.

Level of evidence: Retrospective Case Series, IV.