Osteoporosis Imaging in the Geriatric Patient

Osteoporotic Distal Femur Fractures: An Overview

Background

Distal femur fractures in geriatric patients present a significant challenge due to age-related factors, including osteoporosis, comorbidities, and diminished functional reserve. These injuries have high morbidity and require nuanced management strategies to optimize outcomes. In the current chapter, we have reviewed the challenges associated with these intricate injuries and the potential solutions for their favorable outcomes.

Method

We reviewed the published literature on epidemiology, pathophysiology, clinical presentation, and current treatment modalities for distal femur fractures in the elderly population, with a focus on advances in surgical techniques, rehabilitation strategies, and outcomes.

Discussion

Operative treatment remains the mainstay, tailored to fracture patterns, patient comorbidities, and bone quality. Locking plates offer strong fixation in osteoporotic bone, while intramedullary nails, especially the newer generation ones, provide better biomechanical stability for unstable fracture types. Total knee replacement and distal femur replacement is a viable option in severe cases with comminution or poor bone quality.

Conclusion

Distal femur fractures in the elderly are complex injuries with high morbidity and mortality. Early surgical intervention, optimized postoperative care, and a focus on addressing osteoporosis are key to improving outcomes and minimizing the long-term impact of these fractures on the vulnerable population. Favorable fracture healing can be achieved with plates, nails and their combinations as long as they are judiciously used.

The correlation between bone mineral density measured at the forearm and at the lumbar spine or femoral neck: a systematic review and meta-analysis

BACKGROUND

Current guidelines for osteoporosis diagnosis do not recommend forearm dual-energy X-ray absorptiometry (DXA) as a standard tool, except in specific cases. This systematic review and meta-analysis investigates the potential correlation between forearm BMD and BMD at the lumbar and/or hip sites.

METHODS

The protocol was registered in PROSPERO (CRD42024568756), and the study adhered to the PRISMA guidelines. Major databases were systematically searched from their inception until August 2024 to identify studies evaluating the ability of forearm DXA scans to detect osteoporosis, particularly in comparison to central sites like the femoral neck and lumbar spine. A meta-analysis was conducted on studies that reported correlation coefficients between these measurements. Quality assessment was conducted independently by 3 reviewers following Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. Additionally, a narrative synthesis of the main findings across different patient groups was performed.

RESULTS

Thirteen studies were included. Published between 1992 and 2023, these studies involved 5941 participants. Forearm scans exhibited strong correlations with lumbar and femoral sites (pooled effect size 0.603, 95%CI 0.579-0.627 and 0.641, 95%IC 0.600-0.680, respectively) demonstrating good predictive value for central osteoporosis. Despite some result variations, forearm DXA scanning emerged as a valid method, especially when lumbar and femoral measures are challenging.

CONCLUSIONS

A DXA scan of the distal forearm proves to be a valuable supplementary tool for identifying osteoporotic conditions. This could be particularly relevant in older patients, where conducting lumbar or hip scans is often challenging or not feasible.

Osteoporosis: Molecular Pathology, Diagnostics, and Therapeutics

Osteoporosis is a major public health concern affecting millions of people worldwide and resulting in significant economic costs. The condition is characterized by changes in bone homeostasis, which lead to reduced bone mass, impaired bone quality, and an increased risk of fractures. The pathophysiology of osteoporosis is complex and multifactorial, involving imbalances in hormones, cytokines, and growth factors. Understanding the cellular and molecular mechanisms underlying osteoporosis is essential for appropriate diagnosis and management of the condition. This paper provides a comprehensive review of the normal cellular and molecular mechanisms of bone homeostasis, followed by an in-depth discussion of the proposed pathophysiology of osteoporosis through the osteoimmunological, gut microbiome, and cellular senescence models. Furthermore, the diagnostic tools used to assess osteoporosis, including bone mineral density measurements, biochemical markers of bone turnover, and diagnostic imaging modalities, are also discussed. Finally, both the current pharmacological and non-pharmacological treatment algorithms and management options for osteoporosis, including an exploration of the management of osteoporotic fragility fractures, are highlighted. This review reveals the need for further research to fully elucidate the molecular mechanisms underlying the condition and to develop more effective therapeutic strategies.

The potential anti-osteoporotic effect of exercise-induced increased preptin level in ovariectomized rats

Osteoporosis increases bone fragility and fractures. Preptin hormone is regulated by moderate exercise training and increases bone formation. Therefore, this study was conducted to see how estradiol administration and moderate exercise training affected osteoporotic changes in ovariectomized (OVX) rats. To achieve this aim, 36 healthy adult female Wistar albino rats were randomized into Sham, OVX, ovariectomized estradiol-treated (OVX + E) (OVX + E rats were treated using subcutaneous estradiol benzoate 2.5 μg/kg body weight/day), ovariectomized practicing moderate exercise training, ovariectomized estradiol-treated and practiced a moderate exercise training, and ovariectomized alendronate-treated (OVX + Alen) (OVX + Alen rats were treated orally with alendronate 3 mg/kg body weight/week) groups. Alendronate was used as a standard anti-osteoporotic drug. Moderate exercise training, including therapy with estradiol and alendronate for OVX rats began on the fourth week and lasted for six weeks. Results showed that OVX rats had estrogen and preptin deficiency in serum. These deficiencies were associated with a significant increase in bone resorption biomarkers (urinary deoxypyridinoline and hydroxyproline), and bone formation biomarkers (serum osteocalcin and bone-specific alkaline phosphatase). Also, serum pro-inflammatory cytokines (tumor necrosis factor alpha and interleukin-6) were increased, while bone osteopontin (OPN) expression was decreased. Subsequently, the osteoporotic alterations were verified based on histopathological changes. From the results, estradiol therapy and moderate exercise training significantly improved these findings to the same extent as that of the standard alendronate treatment. Therefore, through their anti-inflammatory properties, increasing bone OPN expression, and regulating serum preptin; estradiol therapy and moderate exercise training can reduce osteoporotic alterations in OVX rats. Thus, combined estradiol therapy and moderate exercise training could be a promising potential therapeutic protocol to reduce postmenopausal osteoporosis. Also, targeting serum preptin and bone osteopontin regulation could have a critical role in the treatment of postmenopausal osteoporosis.

Current Status of the Diagnosis and Management of Osteoporosis

Osteoporosis has been defined as the silent disease of the 21st century, becoming a public health risk due to its severity, chronicity and progression and affecting mainly postmenopausal women and older adults. Osteoporosis is characterized by an imbalance between bone resorption and bone production. It is diagnosed through different methods such as bone densitometry and dual X-rays. The treatment of this pathology focuses on different aspects. On the one hand, pharmacological treatments are characterized by the use of anti-resorptive drugs, as well as emerging regenerative medicine treatments such as cell therapies and the use of bioactive hydrogels. On the other hand, non-pharmacological treatments are associated with lifestyle habits that should be incorporated, such as physical activity, diet and the cessation of harmful habits such as a high consumption of alcohol or smoking. This review seeks to provide an overview of the theoretical basis in relation to bone biology, the existing methods for diagnosis and the treatments of osteoporosis, including the development of new strategies.

The mechanical loading and muscle activation of four common exercises used in osteoporosis prevention for early postmenopausal women

High impact exercise can reduce postmenopausal bone loss, however stimulus frequency (loading cycles per second) can affect osteogenesis. We aimed to examine the effect of stimulus frequency on the mechanical loading of four common osteoporosis prevention exercises, measuring body acceleration and muscle activation with accelerometry and electromyography (EMG), respectively. Fourteen early postmenopausal women completed randomised countermovement jumps (CMJ), box-drops (BD), heel-drops (HD) and stamp (STP) exercises for continuous and intermittent stimulus frequencies. Sacrum accelerometry and surface electromyography (EMG) of four muscles were recorded. CMJ (mean ± SD: 10.7 ± 4.8 g & 10.0 ± 5.0 g), BD (9.6 ± 4.1 g & 9.5 ± 4.0 g) and HD (7.3 ± 3.8 g & 8.6 ± 4.4 g) conditions generated greater peak acceleration than STP (3.5 ± 1.4 g & 3.6 ± 1.7 g) across continuous and intermittent trials. CMJ and BD generated greater acceleration gradients than STP across continuous and intermittent trials. CMJ generated greater rectus femoris EMG than all other exercises, CMJ and BD generated greater semitendinosus and tibialis anterior EMG than HD across continuous and intermittent trials. CMJ and BD provide greater peak acceleration than STP and remain similar during different stimulus frequencies. CMJ, BD and HD may exceed STP in maintaining postmenopausal bone health.

Nail Properties and Bone Health: A Review

Physicochemical properties of nail may offer valuable insight into the health of bone. Currently, dual-energy X-ray absorptiometry (DXA) is the gold standard technique for evaluating bone health through bone mineral density (BMD). However, only 70% of fractures are explained by low BMD according to DXA. Therefore, the World Health Organisation recommended the need for the development of alternative methods of assessing bone health. Keratin and collagen type I are major proteins in nail and bone, respectively. Both of these proteins undergo post-translational modifications, with a possible correlation between the degree of post-translational modifications in keratin and collagen. Raman spectroscopy is a technique used to detect changes in protein composition and structure. As changes in protein function and structure may be associated with the development of osteoporosis, Raman spectroscopy may be a valuable adjunct to assess bone health and fracture risk. This review critically evaluates various methods and techniques to identify the link between nail properties and bone health. The strengths and limitations of various studies and the potential use of nail protein and minerals to evaluate bone health have been also presented.