Osteoporosis: the need for comprehensive treatment guidelines

Percutaneous upper extremity fracture fixation using a novel glass-based adhesive

Objective

To develop a surgical technique for percutaneous upper extremity fracture fixation using a novel glass-based adhesive.

Methods

Three intact upper extremity cadaveric specimens with undisturbed soft tissues were obtained. Two were used to model a wrist fracture, and the third to model a proximal humerus fracture. Fractures were produced using a small osteotome in a percutaneous fashion. Banna Bone Adhesive (BBA) was delivered to the fracture site percutaneously using a 16 gauge needle under bi-planar fluoroscopic guidance. After setting of the adhesive, the specimens were dissected to qualitatively assess BBA delivery and placement.

Results

The adhesive could readily be delivered through the 16 gauge needle with an appropriate amount of pressure applied to the syringe. Using the fluoroscope, the adhesive could be seen to flow into the fracture site with minimal extravagation into the surrounding soft tissues. Successful bonding of the fracture fragments was observed.

Conclusions

Percutaneous delivery of BBA into a fracture of the distal radius and proximal humerus may be a feasible fracture fixation technique. Biomechanical testing and animal model testing are required to further develop this procedure.

Managing menopause: a critical feminist engagement

Feminist critiques of menopause have been beneficial in opening up important public health debates around menopause. One of the most contentious public health issues concerns the use of Hormone Replacement Therapy (HRT) for the prevention of osteoporosis, heart disease and, more recently, Alzheimer's disease, in postmenopausal women. For preventive purposes, it is recommended that women should take HRT for 10-15 years and preferably remain on the therapy for the remainder of their lives. This is despite reported increased cancer risks associated with HRT, side effects and considerable cost of the therapy. Various studies have shown that up to 50% of women stop taking HRT after 9-12 months. These figures are used in the medical literature as an indication of women's non-compliance. Extending earlier feminist critiques around menopause and HRT, this paper discusses a critical feminist engagement around issues of women's perceived non-compliance with HRT.

Proteomics in bone research

Osteoporosis is prevalent among the elderly and is a major cause of bone fracture in this population. Bone integrity is maintained by the dynamic processes of bone resorption and bone formation (bone remodeling). Osteoporosis results when there is an imbalance of the two counteracting processes. Bone mineral density, measured by dual-energy x-ray absorptiometry has been the primary method to assess fracture risk for decades. Recent studies demonstrated that measurement of bone turnover markers allows for a dynamic assessment of bone remodeling, while imaging techniques, such as dual-energy x-ray absorptiometry, do not. The application of proteomics has permitted discoveries of new, sensitive, bone turnover markers, which provide unique information for clinical diagnosis and treatment of patients with bone diseases. This review summarizes the recent findings of proteomic studies on bone diseases, properties of mesenchymal stem cells with high expansion rates and osteoblast and osteoclast differentiation, with emphasis on the role of quantitative proteomics in the study of signaling dynamics, biomarkers and discovery of therapeutic targets.

Osteoporosis in Long-Term Care Residents with Multiple Sclerosis

OBJECTIVE

To assess the fracture risk of long-term care residents with multiple sclerosis (MS) using ultrasound heel-scan technology and identification of risk factors and areas where intervention by a pharmacist might affect patient outcomes.

DESIGN

Bilateral-heel scans were performed on all patients who consented to take part in the study. A retrospective review of each subject's medical records was performed to identify known risk factors for osteoporosis.

SETTING

A long-term care facility in Omaha, Nebraska.

PARTICIPANTS

All patients with a primary diagnosis of MS residing at the facility were eligible for participation. Of 11 patients identified, 10 consented to participate.

MAIN OUTCOME MEASURES

T-scores of the right and left heel as determined by ultrasound-heel scan were used to determine if study participants met criteria for osteopenia or osteoporosis as set forth by the World Health Organization.

CONCLUSION

Patients in our population who have MS are at high risk for fracture. There are several areas in which pharmacists can intervene to prevent fracture and improve patient outcomes, including administration of heel scans for persons believed to be at risk, recommendation of over-the-counter supplements, and education of both patients and health care practitioners.

Modeling the mechanical consequences of vibratory loading in the vertebral body: microscale effects

Osteoporosis affects nearly 10 million individuals in the United States. Conventional treatments include anti-resorptive drug therapies, but recently, it has been demonstrated that delivering a low magnitude, dynamic stimulus via whole body vibration can have an osteogenic effect without the need for large magnitude strain stimulus. Vibration of the vertebral body induces a range of stimuli that may account for the anabolic response including low magnitude strains, interfacial shear stress due to marrow movement, and blood transport. In order to evaluate the relative importance of these stimuli, we integrated a microstructural model of vertebral cancellous bone with a mixture theory model of the vertebral body. The predicted shear stresses on the surfaces of the trabeculae during vibratory loading are in the range of values considered to be stimulatory and increase with increasing solid volume fraction. Peak volumetric blood flow rates also varied with strain amplitude and frequency, but exhibited little dependence on solid volume fraction. These results suggest that fluid shear stress governs the response of the vertebrae to whole body vibration and that the marrow viscosity is a critical parameter which modulates the shear stress.

Bone-Specific Drug Delivery Systems

Despite several decades of progress, bone-specific delivery is still limited by the unique anatomical features of bone, which mainly consists of inorganic hydroxyapatite. A practical approach to this problem is to produce targeted drugs that have a high affinity for hydroxyapatite. Bisphosphonates are a class of synthetic compounds structurally related to pyrophosphate. Bisphosphonates rapidly localise on the bone surface after being administered either intravenously or orally, since the P-C-P portion of the bisphosphonate structure has high affinity for hydroxyapatite. Therefore, bisphosphonate modification might be a promising method for targeting drugs selectively to the bone. Bisphosphonate-conjugated drugs are hydrophilic and highly water-soluble due to the acidic nature of the bisphosphonate moiety at physiological pH, and therefore they hardly permeate through the biological membrane of soft tissues. These physicochemical changes also reduce the intrinsic susceptibility of the drug to metabolism, promoting urinary or biliary excretion as unchanged drug. All these physicochemical and pharmacokinetic alterations contribute to the exceptional skeletal disposition of bisphosphonate-conjugated drugs. Bisphosphonate conjugation is based on chemical modification of the targeting molecule, and therapeutically optimised bisphosphonate derivatives have to be custom-developed on a case-by-case basis. The bisphosphonate moiety is usually coupled with the targeting drug through a specific linkage. The high affinity of bisphosphonate conjugates for the bone is not simply dependent on the bisphosphonate moiety but on the resultant molecule as a whole, including the linker and the linked drug. Lipophilicity (represented as log P) appears to be an appropriate index for predicting the osteotropic properties of bisphosphonate derivatives. Several strategies using bisphosphonate-conjugated drugs have been investigated at a laboratory level with the aim of obtaining therapeutically optimised treatments for conditions such as osteoporosis, osteoarthritis and bone cancer. In each case, the intention is to achieve prolonged local exposure to high concentrations of the targeting drug, thereby improving therapeutic index by enhancing pharmacological efficacy and minimising systemic adverse effects. Although most examples of bone-specific drug delivery via bone-seeking agents still remain in preclinical studies, several phosphonate-coupled radiopharmaceuticals, such as samarium-153 complexed to tetraphosphonate, are expected to be an effective pain palliation therapies for metastatic bone cancer and are currently being developed in clinical trials. Furthermore, recent reports on bisphosphonate-modified proteins have illustrated the feasibility of bone-specific delivery of biologically active protein drugs, such as cytokines and growth factors.

Guidelines for the diagnosis of osteoporosis by densitometric methods

BACKGROUND

Osteoporosis is a major health hazard for postmenopausal women and elderly people. Local, national, and international organizations developed clinical practice guidelines for the diagnosis and management of osteoporosis and the prevention of osteoporotic fractures. Low bone mineral density (BMD) is the most important risk factor for fragility fractures. Bone densitometry is the best method to measure BMD in an individual. Many risk factors contribute to the development of osteoporosis and increase the fracture risk independently from BMD. Guidelines must be comprehensive, factual, simple to implement, and should provide the clinician, patients, governments, and payers with the best evidence available.

OBJECTIVES

The objectives of this article were to review national and international guidelines to establish a congruent set of parameters that may aid the clinician in the decision-making process for the diagnosis of osteoporosis.

DATA SOURCES

An online search of several databases provided 18 guidelines for this review. Comparison among the guidelines was made on 10 different aspects: format, focus, significance of hip and vertebral body fractures, primary diagnostic considerations, BMD measurement technology, interpretation, reporting and follow-up, equipment reliability and quality control, risk factors considered, and methodologic quality of the guidelines. Tables were created for easier comparison on the aspects covered and supported by each guideline.

RESULTS

None of the guidelines reviewed fulfills all the requirements of good clinical practice guidelines.

CONCLUSIONS

Further works should finally provide all those interested with a more complete and thorough set of guidelines based on the best evidence available.

Patients with prior fractures have an increased risk of future fractures: a summary of the literature and statistical synthesis

Numerous studies have reported increased risks of hip, spine, and other fractures among people who had previous clinically diagnosed fractures, or who have radiographic evidence of vertebral fractures. However, there is some variability in the magnitudes of associations among studies. We summarized the literature and performed a statistical synthesis of the risk of future fracture, given a history of prior fracture. The strongest associations were observed between prior and subsequent vertebral fractures; women with preexisting vertebral fractures (identified at baseline by vertebral morphometry) had approximately 4 times greater risk of subsequent vertebral fractures than those without prior fractures. This risk increases with the number of prior vertebral fractures. Most studies reported relative risks of approximately 2 for other combinations of prior and future fracture sites (hip, spine, wrist, or any site). The confidence profile method was used to derive a single pooled estimate from the studies that provided sufficient data for other combinations of prior and subsequent fracture sites. Studies of peri- and postmenopausal women with prior fractures had 2.0 (95 % CI = 1.8, 2.1) times the risk of subsequent fracture compared with women without prior fractures. For other studies (including men and women of all ages), the risk was increased by 2.2 (1.9, 2.6) times. We conclude that history of prior fracture at any site is an important risk factor for future fractures. Patients with a history of prior fracture, therefore, should receive further evaluation for osteoporosis and fracture risk.

Geriatric neurorehabilitation

Rehabilitation of the elderly patient with a neurologic disease consists primarily of the coordinated actions of an interdisciplinary team of physicians. Key aspects of this process are remediation to reduce neurologic impairments, prevention of secondary complications and comorbidities, compensation to offset and adapt to residual disabilities, and maintenance of function over the long term.

The morbidity of bone disease in thalassemia

As thalassemia patients age, bone disease becomes a serious cause of morbidity. The frequency and type of bone disease is affected by the underlying type of thalassemia and its treatment. Problems include rickets, scoliosis, spinal deformities, nerve compression, fractures and severe osteoporosis. In early stages, patients may be asymptomatic but can present with back pain, a limp, dyspnea, neurological emergencies, or sudden fractures. The etiologies are often multifactorial, culminating with increased bone resorption and remodeling. They include hormonal deficiency, bone marrow expansion, nutritional deficiency, or desferal toxicity. Particular risk factors include older patients, low baseline hemoglobin, delayed puberty, hormonal failure, and high iron stores. Nutritional deficiencies may further compound the patient's risk for bone disease. Increasing evidence suggests that these complications and their associated long-term morbidity can be prevented if an annual screening is done, followed by long-term intervention. Patients treated with amino biphosphonates inhibit bone resorption and may demonstrate rapid healing. Intra-nasal calcitonin has also been successful in treating osteopenia. Early use of estrogen and testosterone appears to markedly lower the risk for selective patients. Both transfused and non-transfused patients should be educated about risk factors and early symptoms. All patients should be screened annually for bone disease. Once adolescence occurs, annual testing in selected cases should include bone density studies with X-ray absorptiometry.

Can alendronate help my osteoporosis?

Bone is an active tissue, undergoing continuous remodeling to renew and replace the skeleton. Remodeling involves resorption (breakdown) followed by formation.