Hip Fracture Types in Canadian Men and Women Change Differently with Age: A Population-Level Analysis

Mechano-structural alteration in proximal femora of individuals with alcoholic liver disease: Implications for increased bone fragility

Although increased hip fracture risk is noted in patients with alcoholic liver disease (ALD), their femoral microstructural and mechanical properties were not investigated previously. The present study aimed to analyze the associations between subregional deteriorations in femoral mechano-structural properties and clinical imaging findings to explain increased femoral fracture risk among ALD patients. This study analyzed proximal femora of 33 male cadaveric donors, divided into ALD (n = 13, 57 ± 13 years) and age-matched control group (n = 20, 54 ± 13 years). After pathohistological verification of ALD stage, DXA and HSA measurements of the proximal femora were performed, followed by micro-CT and Vickers microindentation of the superolateral neck, inferomedial neck, and intertrochanteric region. Bone mineral density and cross sectional area of the femoral neck were deteriorated in ALD donors, compared with healthy controls (p < 0.05). Significant ALD-induced degradation of trabecular and cortical microstructure and Vickers microhardness reduction were noted in the analyzed femoral regions (p < 0.05). Still, the most prominent ALD-induced mechano-structural deterioration was noted in intertrochanteric region. Additionally, more severe bone alterations were observed in individuals with an irreversible stage of ALD, alcoholic liver cirrhosis (ALC), than in those with an initial ALD stage, fatty liver disease. Observed osteodensitometric and mechano-structural changes illuminate the basis for increased femoral fracture risk in ALD patients. Additionally, our data suggest bone strength reduction that may result in increased susceptibility to intertrochanteric femoral fracture in men with ALD. Thus, femoral fracture risk assessment should be advised for all ALD patients, especially in those with ALC.

Biomechanical Consequences of Nail Insertion Point and Anterior Cortical Perforation for Antegrade Femoral Nailing

This biomechanical study assessed the influence of changing antegrade cephalomedullary nail insertion point from anterior to neutral to posterior locations relative to the tip of the greater trochanter with or without anterior cortical perforation in the distal femur. Artificial osteoporotic femurs and cephalomedullary nails were used to create 5 test groups each with 8 specimens: intact femur without a nail or perforation, anterior nail insertion point without perforation, neutral nail insertion point without perforation, posterior nail insertion point without perforation, and posterior nail insertion point with perforation. Nondestructive biomechanical tests were done at 250 N in axial, coronal 3-point bending, sagittal 3-point bending, and torsional loading in order to measure overall stiffness and bone stress. The intact femur group vs. all femur/nail groups had lower stiffness in all loading modes (p ≤ 0.018), as well as higher bone stress in the proximal femur (p ≤ 0.027) but not in the distal femur above the perforation (p = 0.096). Compared to each other, femur/nail groups only showed differences in sagittal 3-point bending stiffness for anterior and neutral vs. posterior nail insertion points without (p ≤ 0.025) and with perforation (p ≤ 0.047). Although it did not achieve statistical significance (p ≥ 0.096), moving the nail insertion point from anterior to neutral to posterior to posterior with perforation did gradually increase bone stress by 45% (proximal femur) and 46% (distal femur). No femur or hardware failures occurred. Moving the nail insertion point and the presence of a perforation had little effect on stiffness, but the increased bone stress may be important as a predictor of fracture. Based on current bone stress results, surgeons should use anterior or neutral nail insertion points to reduce the risk of anterior cortical perforation.

Age at hip fracture and life expectancy in Denmark - Secular trends over two decades

BACKGROUND

Recent improvements in the health of the oldest old coexist with a decline in hip fracture rates, in particular in women. We speculated that increased longevity with decreasing hip fracture rates would result in a delay in hip fracture. We conducted an analysis of time trends in the age at hip fracture, by type and gender, for the past two decades using national data.

STUDY POPULATION AND METHODS

We used data from the Danish Hospital Discharge Register (1996-2017) to analyse the age distribution of femoral neck (FN) and pertrochanteric fractures (PT), allowing only the first fracture at each of these two sites to contribute to the analysis in each calendar year. Demographics for the background population at risk including life expectancy tabulations, were also obtained.

RESULTS

The average age at FN fracture in women increased slowly but significantly by 0.035years - or 12.8 days - per calendar year [0.035, 95% CI (0.016; 0.054), p<0.001], resulting in an increase from 79.6 to 80.4 years. There were no significant changes in the age at FN fracture in men or the age at PT fracture in women and men. Further, increases in life expectancy were considerably faster than any change observed in the age at hip fracture. In 1996, the average age at FN or PT fracture exceeded the average life expectancy in both men and women whereas the opposite was the case from 2009 and onwards in men and 2015 and onwards in women.

CONCLUSION

This study demonstrates a significant change in the demographics of hip fractures in Denmark over the past two decades. We observed a significant increase in the age at FN fracture in women but not in men, with no significant increase in the age at IT fracture and PT fracture. This developed much more slowly, however, than the increase in life expectancy in both sexes observed over the same period of time. Taken together, these changes resulted in a large decrease in the female to male incidence rate ratio from 2.6 and 2.5 (FN and PT, respectively) to 1.9 and 1.7.Additional effort is required to prevent hip fractures to ensure that the increasing life expectancy is matched by a similar increase in hip-fracture free life expectancy.

The role of parathyroid hormone (PTH) and vitamin D in falls and hip fracture type

BACKGROUND

Fragility fractures of the hip are associated with high morbidity and mortality, and represent a rather devastating consequence of osteoporosis. Hip fractures are traditionally investigated as a whole, although it has been recently implied that distinct pathogenic mechanisms may lead either to trochanteric or subcapital fractures.

AIMS

To investigate whether differences exist by hip fracture type with respect to serum 25(OH)D (vitamin D) and parathyroid hormone (PTH) levels, in addition to epidemiological and demographic data, including history of falls.

METHODS

The inclusion criteria were met by 116 patients [48 men and 68 women; mean age 80.8 ± 8.5 (range 62-94) years]. Patients were analyzed according to hip fracture type, history of falls, and vitamin D and PTH status.

RESULTS

Older age, recurrent falls, serum levels of PTH > 65 pg/ml, and severe vitamin D deficiency were found to be associated with trochanteric fractures. Additionally, older age, female gender, PTH > 65 pg/ml, and severe vitamin D deficiency were related to recurrent falls. Meanwhile, patients with absence of PTH response to low vitamin D levels, were not repeated fallers and suffered mostly from subcapital fractures.

DISCUSSION AND CONCLUSION

Elevated PTH levels predispose both to falls and trochanteric fractures, while vitamin D-deficient patients with normal PTH levels are mostly related to subcapital fractures. It is thereby indicated that different pathophysiological processes lie behind subcapital and trochanteric fractures. A better understanding of these mechanisms may assist in the development of prevention strategies for individuals recognized at risk for falls and either type of hip fracture.

Mediating Effect of Muscle on the Relationship of Physical Activity and Bone

PURPOSE

This study analyzed prospective associations between distinct trajectories of objectively measured physical activity (PA) and late adolescent bone parameters and explored the mediating effects of lean soft tissue, a surrogate of muscle mass to associations.

METHODS

Physical activity was measured by accelerometry starting at age 5 yr and continuing at 8, 11, 13, 15, and 17 yr in approximately 524 participants from the Iowa Bone Development Study. Sex-specific group-based trajectory modeling was used to construct developmental trajectories of moderate- and vigorous-intensity PA (MVPA) from childhood to late adolescence. At age 17 yr, proximal femur bone mineral density (aBMD) was assessed by dual X-ray energy absorptiometry, and its distribution was calculated by aBMD ratios. Specific geometric measures of the proximal femur were assessed using hip structural analysis.

RESULTS

A significant portion of the total effect of MVPA from age 5 to 17 yr on bone parameters at age 17 yr was explained by an increase in leg lean soft tissue in both sexes. For males and females, indirect effects were observed on the total and all regional proximal femur aBMD, and on the ratio between the inferomedial and superolateral neck aBMD. The effect on the ratio between the trochanter and the total proximal femur was specific to females, whereas the effect on the hip axis length was specific to males. Direct effects of MVPA on aBMD were identified only in males.

CONCLUSIONS

Using robust mediation analysis, this is the first study addressing the indirect effect (through muscle) of PA across childhood and adolescence on proximal femur bone parameters. To improve bone health at the proximal femur, the results suggest PA interventions during growth that increase muscle mass, particularly in females.