Background: We compared T-scores of each femoral neck and trochanteric portion in the femoral neck fracture patients group (NFP) and intertrochanteric fracture patients group (IFP). Our hypothesis is that T-score of neck portion is lower than T-score of trochanteric portion in NFP and vice versa in IFP. We evaluated how FRAX® probability is meaningful and sensitive in hip fracture patients.
Methods: From April 2003 to September 2012, 180 hip fracture patients (98 for NFP group, 82 for IFP group) were included, and the BMD of all patients was evaluated within two weeks after surgery. We evaluated the correlation between localised femoral BMD (T-scores) and fractures site of the hip. We compared the average of T-scores between the neck portion and trochanteric portion in each group. Differences between regional BMD (T-score) of the neck portion and trochanteric portion were calculated in each group. The average of the differences was compared between the two groups. We calculated FRAX® probability in all patients and compared the average of FRAX® probability between NFP and IFP. We evaluated how many patients were included in the high risk group by FRAX® designation, defined as 10-year major osteoporotic fracture probability (MOF) ≥20% or hip fracture probability ≥3%. Our study was approved by IRB.
Results: In NFP, the average T-score in the neck portion was lower (-3.23) than that of the trochanteric portion (-2.55). In IFP, the average T-score of the neck portion was also lower (-2.93) than that of the trochanteric portion (-2.56). These BMD differences between the neck and trochanteric portion in the two groups were statistically significant (p<0.001). In NFP, the average of difference between regional BMD (T-score) of neck portion and trochanteric portion (neck: -3.23, trochanteric: -2.55, difference: 0.68) was greater than the average of difference in IFP (neck: -2.93, trochanteric: -2.56, difference: 0.37) with statistical significance (p=0.001). FRAX probability of MOF in NFP (14.4%) was higher than in IFP (11.1%, P=0.009). FRAX® probability of hip fracture in NFP (8.6%) was higher than IFP. (5.9%, P=0.008) 19.5% of NFP and 10.1% of IFP were classified as high risk group for MOF. 77.3% of NFP and 80.8% of IFP were classified as high risk group for hip fracture.
Conclusion: The average T-score in the neck portion was lower than that of the trochanteric portion in both groups. In NFP, the average difference between T-scores in neck portion and trochanteric portion was higher than IFP. It supports that localised femoral T-scores are relevant to the fracture sites of the hip. High risk group designated by FRAX® probability is meaningful and sensitive tool to evaluate the hip fracture in osteoporotic patients.
Disclosure: The authors declared no competing interests.