Muscle volume, CT attenuation, and bone mineral density in relation to trochanteric fragment formation in older women with intertrochanteric femur fractures.

PURPOSE: Greater and lesser trochanter fragments are common in intertrochanteric femur fractures and may reflect fracture morphology and instability. Although fragment formation has been discussed in relation to the attached muscles, the associations of muscle quantity, muscle quality, bone mineral density, and anthropometric factors with trochanteric fragment formation remain unclear. This study investigated factors potentially related to trochanteric fragment formation in older women.

METHODS

This retrospective study included 90 women aged ≥ 65 years with intertrochanteric femur fractures. Fractures were classified using the Shoda classification and categorized by the presence of greater and lesser trochanter fragments. Volumes and CT attenuation values of the gluteus medius, gluteus minimus, piriformis, iliacus, and psoas major were measured using artificial intelligence-based CT analysis as surrogate measures of muscle morphology and composition. Contralateral total hip and femoral neck T-scores were used as BMD indices. Group comparisons and univariate and multivariable logistic regression analyses were performed.

RESULTS

No significant differences in muscle volume, CT attenuation, contralateral bone mineral density, age, height, or weight were detected between patients with and without greater or lesser trochanter fragments. Neither univariate nor multivariable logistic regression identified a statistically significant association between fragment formation and any of the analyzed factors.

CONCLUSION

In this cohort of older women with intertrochanteric femur fractures, no statistically significant relationships were detected between trochanteric fragment formation and peri-trochanteric muscle characteristics, BMD, or anthropometric factors. Larger, adequately powered studies are needed to further investigate whether these factors are related to fragment formation.