Effect of Hydroxyapatite Augmentation on Femoral Lag Screw Insertion in Intertrochanteric Femoral Fractures in the Elderly: A Biomechanical Study.

BACKGROUND

This study aimed to investigate the effect of hydroxyapatite (HA) augmentation on the maximum lag screw insertion torque (TMax) using extracted human femoral heads.

MATERIALS AND

METHODS

Hemispherical femoral heads extracted from patients who underwent bipolar hip arthroplasty were used. These samples were divided into the HA treatment group (HA group) and the non-HA treatment group (N group). After drilling, HA was inserted into the femoral heads in the HA group. A lag screw was inserted into the femoral head using a dedicated jig in both groups. The bone mineral density of the uninjured contralateral femoral neck (f-BMD), TMax, and the TMax/f-BMD ratio were evaluated.

RESULTS

Twenty-seven samples were analyzed in this study: 14 samples in the HA group and 13 samples in the N group. No significant differences were observed in f-BMD and TMax between the two groups (HA: 0.49 ± 0.11 vs. N: 0.48 ± 0.092 g/cm2, p = 0.90; HA: 5.6 ± 1.9 vs. N: 4.3 ± 1.9 N･m, p = 0.78). Considering bone mineral density, the HA group showed a significantly higher TMax/f-BMD ratio than the N group (11.7 ± 3.3 vs. 8.9 ± 3.2 N･m･cm2/g, p = 0.036). Correlation coefficients between f-BMD and TMaxin both groups were moderately strong (r = 0.50 vs. 0.50).

CONCLUSION

Our results suggest that HA augmentation improves lag screw fixation strength in the treatment of osteoporotic intertrochanteric femoral fractures.