Femoral Neck Width Predict Low Bone Mass in Patients with Multiple Hereditary Exostoses

Background: Recent report revealed multiple hereditary exostoses (MHE) patients showed the osteoporosis. This study aimed to determine if proximal femur deformities can indicate low bone mass in MHE patients and to investigate the correlation between Z-score or T-score and hip geometry parameters. Patients and Methods: Twenty MHE patients from unrelated families were included in this study. Bone mineral density (BMD) of both femoral neck (n = 40) was examined using dual-energy x-ray absorptiometry. We examined femoral neck axis length (FNAL), femoral head diameter (FHD), femoral neck width (FNW), femoral shaft width (FSW), and femoral neck angle (FNA) and calculated the femoral head-neck ratio (FHNR=FHD/FNW). We examined the correlation between these parameters and Z-score or T-score using linear regression analysis followed by Spearman rank correlation coefficient.Results: Of the patients, 91.7% (22 of 24) male and 100% (16 of 16) female had a Z-score <0 in the femoral neck area. Results also showed that the femoral neck area of 62.5% (15 of 24) male and 56.3% (9 of 16) female patients are within the range for osteopenia. The femoral neck are of seven patients (17.5%) were found to be within the range for osteoporosis. These results suggest that MHE patients tend to have low bone mass. We found a significant correlation between FNW and Z-score (r = -0.3924, P = 0.0123), but there was no significant difference between Z-score and FNAL, FHD, FSW, NSA, and FHNR. We also found that there were significant differences between T-score and FNW and T-score and FHNR (r = -0.4787, P = 0.0018 and r = 0.3636, P = 0.0211, respectively). There was no significant difference between T-score and the other parameters.Conclusions: We found that the femoral neck width significantly correlates with Z-score or T-score. These results suggest that the femoral neck width may be a reliable predicting factor of bone mineral density.

Morphometric Parameters of the Proximal Femur in Nepalese Population: A Cross-sectional Study

Background: Most of the proximal femur fractures are managed surgically by internal fiation with a variety of implants. Improperly designed or ill-fited implant may lead to a failure of fiation, breakage of implant and nonunion, thus increasing the morbidity and the cost of treatment. This study was conducted to evaluate the radiographic morphometry of the proximal femur which may be helpful in designing the implants for the Nepalese population. Methods: In this cross-sectional study, 84 patients aged 18 years and above with traumatic unilateral hip fracture were enrolled. Anthropometric measurements were recorded. The postoperative check X-ray in the antero-posterior view of the pelvis and bilateral hip were assessed. Various morphometric parameters of the proximal femur were measured and recorded in the radiograph of the unaffcted limb using a digital caliper. Results: Out of 84 patients, 47 were male. The mean ± SD femoral neck width, femoral neck length, femoral axis length, cervico-diaphyseal angle, acetabular tear-drop distance, and great trochanter-pubic symphysis distance were 36.10 ± 5.67 mm, 28.29 ± 4.18 mm, 104.51 ± 9.56 mm, 130.35 ± 8.67°, 32.56 ± 11.05 mm, and 163.07 ± 10.71 mm respectively. The femoral neck width was found to be signifiantly larger in males (39.08 ± 3.06 mm) than in females (32.32 ± 5.99 mm, p < 0.001). Conclusion: This study determined the radiographic measurement of the proximal femur and found that the femoral neck width of the males was larger than that of the females.

Genomic expression analysis of rat chromosome 4 for skeletal traits at femoral neck

Hip fracture is the most devastating osteoporotic fracture type with significant morbidity and mortality. Several studies in humans and animal models identified chromosomal regions linked to hip size and bone mass. Previously, we identified that the region of 4q21-q41 on rat chromosome (Chr) 4 harbors multiple femoral neck quantitative trait loci (QTLs) in inbred Fischer 344 (F344) and Lewis (LEW) rats. The purpose of this study is to identify the candidate genes for femoral neck structure and density by correlating gene expression in the proximal femur with the femoral neck phenotypes linked to the QTLs on Chr 4. RNA was extracted from proximal femora of 4-wk-old rats from F344 and LEW strains, and two other strains, Copenhagen 2331 and Dark Agouti, were used as a negative control. Microarray analysis was performed using Affymetrix Rat Genome 230 2.0 arrays. A total of 99 genes in the 4q21-q41 region were differentially expressed ( P < 0.05) among all strains of rats with a false discovery rate <10%. These 99 genes were then ranked based on the strength of correlation between femoral neck phenotypes measured in F2 animals, homozygous for a particular strain's allele at the Chr 4 QTL and the expression level of the gene in that strain. A total of 18 candidate genes were strongly correlated (r2 > 0.50) with femoral neck width and prioritized for further analysis. Quantitative PCR analysis confirmed 14 of 18 of the candidate genes. Ingenuity pathway analysis revealed several direct or indirect relationships among the candidate genes related to angiogenesis (VEGF), bone growth (FGF2), bone formation (IGF2 and IGF2BP3), and resorption (TNF). This study provides a shortened list of genetic determinants of skeletal traits at the hip and may lead to novel approaches for prevention and treatment of hip fracture.

Bone Size and Volumetric Density in Women with Anorexia Nervosa Receiving Estrogen Replacement Therapy and in Women Recovered from Anorexia Nervosa

Anorexia nervosa is associated with bone loss during adulthood, but may also delay skeletal growth and mineral accrual during growth. We asked the following questions. 1) Is anorexia nervosa associated with reduced bone size and reduced volumetric bone mineral density (vBMD)? 2) Is estrogen replacement therapy (ERT) or recovery from anorexia nervosa associated with normal bone size and vBMD? Using dual-energy x-ray absorptiometry, we measured bone size and vBMD of the third lumbar vertebra and femoral neck in a cross-sectional study of 161 female patients: 77 with untreated anorexia nervosa, 58 with anorexia nervosa receiving ERT, 26 recovered from anorexia nervosa, and 205 healthy age-matched controls. Results were expressed as the sd or z-score (mean ± sem). Deficits in vertebral body and femoral neck width in untreated women were −1.0 ± 0.1 and −0.3 ± 0.1 sd (P &lt; 0.001 and P &lt; 0.05, respectively). Deficits in bone width were less in the ERT-treated women than in untreated women at the vertebral body (−0.6 ± 0.1 sd; P &lt; 0.001), but not at the femoral neck (−0.4 ± 0.2 sd;P &lt; 0.05). There were no significant deficits in vertebral body and femoral neck width in recovered women (both −0.3 ± 0.2 sd; P = NS). In untreated women, vertebral and femoral neck vBMD were −1.6 ± 0.1 and −1.1 ± 0.1 sd, respectively (both P &lt; 0.001), less severely reduced in ERT-treated women (−1.2 ± 0.2 and −0.6 ± 0.2 sd, respectively; both P &lt; 0.001), and least reduced in recovered women (−0.6 ± 0.1 and −0.5 ± 0.2 sd;P &lt; 0.01 and P &lt; 0.05, respectively). After adjusting for differences in fat and lean mass, vertebral body and femoral neck width were no longer reduced in untreated, ERT-treated, and recovered women. Adjustment for body composition had little effect on group difference in vBMD. Bone fragility in anorexia nervosa is due to reduced bone size and reduced vBMD. Although causality cannot be inferred in cross- sectional studies, the data are consistent with the view that malnutrition may contribute to reduced bone size, whereas estrogen deficiency may reduce vBMD. The use of ERT early in disease is a reasonable component of management if the chance of recovery appears remote.