Multi-ancestry genome-wide analysis identifies shared genetic effects and common genetic variants for self-reported sleep duration

Both short (≤6 h per night) and long sleep duration (≥9 h per night) are associated with increased risk of chronic diseases. Despite evidence linking habitual sleep duration and risk of disease, the genetic determinants of sleep duration in the general population are poorly understood, especially outside of European (EUR) populations. Here, we report that a polygenic score of 78 European ancestry sleep duration single-nucleotide polymorphisms (SNPs) is associated with sleep duration in an African (n = 7288; P = 0.003), an East Asian (n = 13 618; P = 6 × 10-4) and a South Asian (n = 7485; P = 0.025) genetic ancestry cohort, but not in a Hispanic/Latino cohort (n = 8726; P = 0.71). Furthermore, in a pan-ancestry (N = 483 235) meta-analysis of genome-wide association studies (GWAS) for habitual sleep duration, 73 loci are associated with genome-wide statistical significance. Follow-up of five loci (near HACD2, COG5, PRR12, SH3RF1 and KCNQ5) identified expression-quantitative trait loci for PRR12 and COG5 in brain tissues and pleiotropic associations with cardiovascular and neuropsychiatric traits. Overall, our results suggest that the genetic basis of sleep duration is at least partially shared across diverse ancestry groups.

Prenatal Pb exposure is associated with reduced abundance of beneficial gut microbial cliques in late childhood: an investigation using Microbial Co-occurrence Analysis (MiCA)

Background

Many analytical methods used in gut microbiome research focus on either single bacterial taxa or the whole microbiome, ignoring multi-bacteria relationships (microbial cliques). We present a novel analytical approach to identify multiple bacterial taxa within the gut microbiome of children at 9-11 years associated with prenatal Pb exposure.

Methods

Data came from a subset of participants (n=123) in the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) cohort. Pb concentrations were measured in maternal whole blood from the second and third trimesters of pregnancy. Stool samples collected at 9-11 years old underwent metagenomic sequencing to assess the gut microbiome. Using a novel analytical approach, Microbial Co-occurrence Analysis (MiCA), we paired a machine-learning algorithm with randomization-based inference to first identify microbial cliques that were predictive of prenatal Pb exposure and then estimate the association between prenatal Pb exposure and microbial clique abundance.

Results

With second-trimester Pb exposure, we identified a 2-taxa microbial clique that included Bifidobacterium adolescentis and Ruminococcus callidus, and a 3-taxa clique that added Prevotella clara. Increasing second-trimester Pb exposure was associated with significantly increased odds of having the 2-taxa microbial clique below the 50th percentile relative abundance (OR=1.03,95%CI[1.01-1.05]). In an analysis of Pb concentration at or above vs. below the United States and Mexico guidelines for child Pb exposure, odds of the 2-taxa clique in low abundance were 3.36(95%CI[1.32-8.51]) and 6.11(95%CI[1.87-19.93]), respectively. Trends were similar with the 3-taxa clique but not statistically significant.

Discussion

Using a novel combination of machine-learning and causal-inference, MiCA identified a significant association between second-trimester Pb exposure and reduced abundance of a probiotic microbial clique within the gut microbiome in late childhood. Pb exposure levels at the guidelines for child Pb poisoning in the United States, and Mexico are not sufficient to protect against the potential loss of probiotic benefits.

A60 DOWN WITH THE SHP-1: CHRONIC HELMINTH INFECTION DISRUPTS BILE ACID HOMEOSTASIS AND SIGNALLING RECEPTOR ACTIVATION IN THE MURINE SMALL INTESTINE TO POTENTIALLY IMPACT GUT IMMUNITY

Background

Helminths (parasitic worms) use immunomodulatory mechanisms to maintain their presence in the host intestines. Understanding how helminths reduce inflammation in the guts may lead to new therapeutic options for inflammatory bowel diseases. Our lab uses a helminth which infects the proximal small intestine of mice to identify new, potentially immunomodulatory molecules. In this project, we examined the impact of helminth infection on bile acids (BA)s; a class of metabolites that can function as immunomodulatory signalling molecules. To our knowledge, how helminth infection alters BA homeostasis, and the potential consequences for proximal small intestine immunity have not yet been reported.

Purpose

Our aims were to determine whether helminth infection alters (1) the intestinal BA pool, (2) expression of BA transporters in the small intestine, and (3) expression and/or activation of the Farnesoid X receptor (FXR), a BA signalling receptor.

Method

We used a murine model system to study the effects of the mouse-specific helminth Heligmosomoides polygyrus on BA homeostasis, BA transporter gene expression, and BA signalling receptors in the small intestine. Male and female littermate mice were used. Targeted metabolomics was used to assess the composition of the BA pool in the small intestine. Reverse transcription qPCR was used to quantify gene expression of BA transporters/signalling molecules in tissues. All data were segregated by sex of mice for data analysis.

Result(s)

We found that helminth infection disrupts the BA pool of mice, with consistent reductions in T-CDCA and T-αMCA during helminth infection. In the proximal small intestine, expression of the genes that encode the apical sodium dependant BA transporter (ASBT) and organic solute transporter alpha (OSTα) were unaffected during helminth infection, however expression of the organic solute transporter β (OSTβ) gene, which encodes half of the basal BA transporter, was decreased. Expression of Shp-1, an indicator of activation of BA receptor FXR, and expression of the Fxr gene were significantly decreased in both the proximal and distal small intestine. Lastly, expression of the gene encoding Gpbar1 trended upwards in the proximal and distal small intestine of female mice.

Conclusion(s)

Infection of mice with a proximal small intestine-dwelling helminth impacts BA homeostasis in the small intestine. Helminth infection decreases expression of a BA transporter in the proximal small intestine, although whether this contributes to or is caused by perturbations in the BA pool during infection remains to be seen. The downregulation of BA signalling we see during helminth infection in the proximal small intestine points to a potential functional impact on the host immune response which we now intend to explore. Understanding the immunomodulatory mechanisms used by helminths to dampen the host immune response could lead to further advancements in treating intestinal inflammatory disorders such as Crohn’s and Colitis.

Disclosure of Interest

None Declared

Anabolic agents: what is beyond osteoporosis?

Osteoporosis is a common skeletal disorder characterized by low bone mass, which leads to reduced bone strength and an increased risk of fractures. Anabolic agents have been shown to improve bone mass and decrease fracture risk in osteoporosis patients by directly stimulating osteoblasts to produce new bone. Currently, two anabolic agents are available in the USA: recombinantly produced teriparatide (TPTD), which is the fully active (1-34) amino active sequence of human parathyroid hormone (PTH), and abaloparatide (APTD), a synthetic analog of parathyroid hormone-related peptide (PTHrP). At present, both agents are approved only for treatment of patients with osteoporosis at high risk of fracture. Nonetheless, their anabolic properties have led to off-label application in additional settings which include spine fusion, osteonecrosis of the jaw, arthroplasty, and fracture healing. In this article, we summarize available scientific literature regarding the efficacy, effectiveness, and safety of TPTD in these off-label settings.

The Answer is Vitamin D! From Pediatrics to Geriatrics in Orthopaedics

Vitamin D is necessary for the regulation of calcium and phosphate in the human body. Decreased vitamin D levels can alter the bone mineralization process. The prevalence of vitamin D deficiency in the general population is high, and low vitamin D levels are associated with disorders such as rickets and osteoporosis. As knowledge about vitamin D metabolism increases, physicians of all specialties are becoming more attentive to the vitamin D status of their patients. Similarly, orthopaedic surgeons, through various initiatives such as "Own the Bone," are making greater efforts to medically manage skeletal disorders. Unfortunately, universal guidelines for the optimization of vitamin D levels have not been adopted by orthopaedic surgeons, and, despite substantial efforts, vitamin D is not an integral part of most orthopaedic residency training programs. Although this may be partially attributed to attitudes among orthopaedic surgeons, the large number of vitamin D recommendations in the literature may be confusing and require substantial effort to synthesize into a viable approach for a given patient. Despite this confusion, orthopaedic surgeons should understand how to diagnose and manage disorders related to vitamin D and calcium deficiency.

Surgery for a fracture of the hip within 24 hours of admission is independently associated with reduced short-term post-operative complications

AIMS

We aimed to characterise the effect of expeditious hip fracture surgery in elderly patients within 24 hours of admission on short-term post-operative outcomes.

PATIENTS AND METHODS

Patients age 65 or older that underwent surgery for closed femoral neck and intertrochanteric hip fractures were identified from the American College of Surgeons National Surgical Quality Improvement Program between 2011 and 2014. Multivariable propensity-adjusted logistic regressions were performed to determine associations between early surgery within 24 hours and post-operative complications, controlling for selection bias in patients undergoing early surgery based on observable characteristics.

RESULTS

A total of 26 051 patients were included in the study; 5921 (22.7%) had surgery within 24 hours of admission, while 20 130 (77.3%) patients had surgery after 24 hours. Propensity-adjusted multivariable logistic regressions demonstrated that surgery within 24 hours was independently associated with lower odds of respiratory complications including pneumonia, failure to extubate, or reintubation (odds ratio (OR) 0.78, 95% confidence interval (CI) 0.67 to 0.90), and extended length of stay (LOS) defined as ≥ 6 days (OR 0.84, 95% CI 0.78 to 0.90).

CONCLUSION

In elderly patients with hip fractures, early surgery within 24 hours of admission is independently associated with less pulmonary complications including pneumonia, failure to extubate, and reintubation, as well as shorter LOS. Cite this article: Bone Joint J 2017;99-B:1216-22.

Patients with prior vertebral or hip fractures treated with teriparatide in the Direct Assessment of Nonvertebral Fractures in Community Experience (DANCE) observational study

SUMMARY

In patients in the Direct Assessment of Nonvertebral Fractures in Community Experience (DANCE) observational study with and without a prior vertebral or hip fracture, the incidence of nonvertebral fractures was lower with >6 months of teriparatide treatment than during the first 6 months.

INTRODUCTION

Clinical evidence on the effect of teriparatide in patients with prior fracture is limited. In the DANCE observational study, the incidence of nonvertebral fragility fractures (NVFX) decreased significantly in patients receiving teriparatide for >6 months (6-24 months) versus >0 to ≤6 months (reference period).

METHODS

We performed a post hoc analysis to assess the effect of teriparatide 20 μg/day in patients who entered DANCE with prior vertebral or hip fractures. The incidence of patients experiencing a NVFX for four 6-month intervals during and after treatment was compared with the reference period.

RESULTS

Overall, 4085 patients received ≥1 dose of teriparatide. Of 3720 with sufficient data for efficacy analysis, 692 had prior vertebral fracture, including 179 with previous kyphoplasty/vertebroplasty; 290 had prior hip fracture. These patients were older, and those with prior vertebral fractures had more comorbid conditions at baseline than those without prior vertebral fractures. The incidence of patients experiencing NVFX declined over time in all patient groups. The fracture incidence rate declined 49 and 46%, respectively, in patients with and without prior vertebral fracture and was 63 and 46% lower in patients with previous kyphoplasty/vertebroplasty and without prior vertebral fracture. NVFX declined 43 and 48% in patients with and without prior hip fracture. The reduced incidence over time was consistent in the subgroups (all interaction p values >0.05). Patients with prior fracture were more likely to experience serious adverse events.

CONCLUSION

The incidence of NVFX decreased over time in patients receiving teriparatide in DANCE regardless of prior fracture status.

Effect of osteoporosis medications on fracture healing

Antiosteoporotic medications are often used to concurrently treat a patient's fragility fractures and underlying osteoporosis. This review evaluates the existing literature from animal and clinical models to determine these drugs' effects on fracture healing. The data suggest that these medications may enhance bone healing, yet more thorough prospective studies are warranted. Pharmacologic agents that influence bone remodeling are an essential component of osteoporosis management. Because many patients are first diagnosed with osteoporosis when presenting with a fragility fracture, it is critical to understand how osteoporotic medications influence fracture healing. Vitamin D and its analogs are essential for the mineralization of the callus and may also play a role in callus formation and remodeling that enhances biomechanical strength. In animal models, antiresorptive medications, including bisphosphonates, denosumab, calcitonin, estrogen, and raloxifene, do not impede endochondral fracture healing but may delay repair due to impaired remodeling. Although bisphosphonates and denosumab delay callus remodeling, they increase callus volume and result in unaltered biomechanical properties. Calcitonin increases cartilage formation and callus maturation, resulting in improved biomechanical properties. Parathyroid hormone, an anabolic agent, has demonstrated promise in animal models, resulting in accelerated healing with increased callus volume and density, more rapid remodeling to mature bone, and improved biomechanical properties. Clinical data with parathyroid hormone have demonstrated enhanced healing in distal radius and pelvic fractures as well as postoperatively following spine surgery. Strontium ranelate, which may have both antiresorptive and anabolic properties, affects fracture healing differently in normal and osteoporotic bone. While there is no effect in normal bone, in osteoporotic bone, strontium ranelate increases callus bone formation, maturity, and mineralization; forms greater and denser trabeculae; and improves biomechanical properties. Further clinical studies with these medications are needed to fully understand their effects on fracture healing in order to simultaneously treat fragility fractures and underlying osteoporosis.

Cardiovascular Considerations for Joint Replacement Surgery

Heart disease is the leading cause of death in the United States. Cardiovascular complications are associated with higher morbidity and mortality rates for patients who undergo orthopaedic surgery. Therefore, the clinical importance of a comprehensive preoperative evaluation and medical clearance is crucial and may substantially improve postoperative outcomes. A thorough knowledge of cardiovascular perioperative planning and management can enable healthcare professionals to identify patients who are potentially at risk for cardiovascular complications, and eventually improve both short- and long-term patient outcomes and satisfaction.

Perioperative Treatment of Patients with Rheumatoid Arthritis

Rheumatoid arthritis is an autoimmune disease mediated by a widespread, chronic, and systematic inflammatory process that causes joint deterioration, which leads to pain, disability, and poor quality of life. The increased use of disease-modifying antirheumatic drugs has been shown to markedly slow disease progression, which has translated into a decrease in the need for orthopaedic intervention in this population. However, in a substantial percentage of patients with the disease, optimal pharmacologic treatment fails and surgical intervention is required. A thorough understanding of medical considerations in these patients and improved knowledge of the medical complications caused by the disease process and the pharmacologic therapy used to treat it may lead to improved preoperative planning and medical clearance, which may ultimately improve the overall postoperative outcome.

Effect of Vitamin D on Joint Replacement Outcomes

Vitamin D is a steroid hormone that affects not only bone metabolism and strength but also a variety of musculoskeletal health and surgical outcomes that are relevant to orthopaedic medicine. Risk factors for vitamin D deficiency include sex, age, skin pigmentation, obesity, and preexisting conditions such as nephritic syndrome and malabsorption syndrome. Furthermore, vitamin D deficiency is associated with the development of postoperative complications, such as an increased risk of infection, morbidity, and mortality. The standardization of vitamin D terminology as well as a thorough understanding of the medical considerations associated with vitamin D deficiency can improve preoperative planning and clearance, and, ultimately, patient outcomes and satisfaction.

Effect of Smoking on Joint Replacement Outcomes: Opportunities for Improvement Through Preoperative Smoking Cessation

Because orthopaedic surgeons focus on identifying serious potential complications, such as heart attack, stroke, and deep vein thrombosis, during the preoperative assessment, correctable factors, such as smoking, may be overlooked. Chronic exposure to nicotine has been correlated with perioperative complications that lead to worse outcomes, including decreased patient satisfaction, longer hospitalization periods, and an increased rate of hospital readmission. It has been proven that smoking is a negative risk factor for decreased bone mineral density, which leads to increased fracture risk, heightened pain, postoperative wound and bone healing complications, decreased fusion rates, and postoperative tendon and ligament healing complications. Physician-led preoperative smoking cessation programs that include, but are not limited to, pharmacotherapy plans have been shown to improve primary surgical outcomes and smoking cessation rates. Smoking has detrimental effects on specialty-specific physiology; however, there are many effective options for intervention that can improve primary outcomes.

Theoretical consideration of the effect of drug holidays on BMD and tissue age

It has been suggested that some patients undergoing prolonged treatment for osteoporosis with anti-resorptive agents may benefit from discontinuing treatment. Here we use a computer simulation of bone cell activity to estimate changes in bone mineral density (BMD) and tissue age when treatment is discontinued.

INTRODUCTION

Although anti-resorptive agents are effective at reducing fracture risk, questions remain regarding how long patients should continue treatment and how long treatment should be discontinued. Suspending treatment as part of a drug holiday may reduce the risk of adverse effects, but may also lead to reduced BMD.

METHODS

We use a computer simulation of the bone remodeling process to estimate how BMD and mean tissue age are changed after treatment is suspended. Mean tissue age is studied because increased tissue age has been associated with impaired bone quality and has been linked to the risk of adverse effects.

RESULTS

Our simulations suggest that BMD gains from anti-resorptive therapy can be lost over time, especially with anti-resorptive agents that have little residual effects. With regard to mean tissue age, the simulations suggest that increases in tissue age from anti-resorptive treatment are long lasting; increases in mean tissue age caused by treatment may remain for as long as 15 years after treatment is suspended. After stopping treatment, reductions in BMD are expected to occur long before mean tissue age returns to normal.

CONCLUSIONS

Our simulations suggest that, when using a long-lasting anti-resorptive agent, 1- to 5-year drug holidays may have little effect on BMD in most patients but that drug holiday intervals that maintain BMD are unlikely to reverse alterations in tissue age caused by treatment. Our analysis echoes recent reviews suggesting patient selection and monitoring when anti-resorptive treatment is discontinued.

Comparison of unipedicular and bipedicular balloon kyphoplasty for the treatment of osteoporotic vertebral compression fractures

This is a prospective randomised study comparing the clinical and radiological outcomes of uni- and bipedicular balloon kyphoplasty for the treatment of osteoporotic vertebral compression fractures. A total of 44 patients were randomised to undergo either uni- or bipedicular balloon kyphoplasty. Self-reported clinical assessment using the Oswestry Disability Index, the Roland-Morris Disability questionnaire and a visual analogue score for pain was undertaken pre-operatively, and at three and twelve months post-operatively. The vertebral height and kyphotic angle were measured from pre- and post-operative radiographs. Total operating time and the incidence of cement leakage was recorded for each group.

Both uni- and bipedicular kyphoplasty groups showed significant within-group improvements in all clinical outcomes at three months and twelve months after surgery. However, there were no significant differences between the groups in all clinical and radiological outcomes. Operating time was longer in the bipedicular group (p < 0.001). The incidence of cement leakage was not significantly different in the two groups (p = 0.09).

A unipedicular technique yielded similar clinical and radiological outcomes as bipedicular balloon kyphoplasty, while reducing the length of the operation. We therefore encourage the use of a unipedicular approach as the preferred surgical technique for the treatment of osteoporotic vertebral compression fractures.

Cite this article: Bone Joint J 2013;95-B:401–6.

Osteoporosis drug therapy strategies in the setting of disease-modifying agents for autoimmune disease

The purpose of this systematic review is to evaluate the effects of methotrexate (MTX) and tumor necrosis factor-alpha (TNF-α) inhibitors on bone mineral properties in the clinical literature. A systematic review of the literature identifying relevant case reports, population-based studies, cohort studies, case control studies, and randomized controlled trials in Pubmed and Web of Science databases from inception to December 31, 2011 was conducted. The following keywords were used: "bone turnover," "bone mineral density," "TNF-α inhibitors," "infliximab," "adalimumab," "etanercept," and "MTX." The bibliographies of all retrieved studies were also reviewed to identify additional articles. Based on these results, a rational drug therapy strategy was suggested for treating osteoporosis in patients with inflammatory disease. MTX and TNF-α inhibitors do not appear to have an adverse effect on BMD in patients with inflammatory disease. Their negative effects on BMD and bone turnover in pre-clinical models appear to be outweighed by their anti-disease effects in clinical studies. Treatment with MTX or TNF-α inhibitors has no adverse effect on BMD in patients with inflammatory disease. Future studies will focus on developing optimal drug strategies when combining DMARDs with anti-osteoporotic agents in this patient population.

The effects of ABCG5/G8 polymorphisms on HDL-cholesterol concentrations depend on ABCA1 genetic variants in the Boston Puerto Rican Health Study

BACKGROUND AND AIMS

ATP-binding cassette transporters G5/G8 (ABCG5/G8) are associated with HDL-C concentrations. To assess whether the effect of ABCG5/G8 genetic variants on HDL-C concentrations is dependent on ATP-binding cassette transporters A1 (ABCA1), we studied potential interactions between single nucleotide polymorphisms (SNPs) at ABCG5/G8 (i7892T > C, 5U145A > C, T54CA > G, T400KC > A) and ABCA1 (i27943G > A, i48168G > A, K219RG > A, i125970G > C, 3U8995A > G) genes with HDL-C concentrations.

METHODS AND RESULTS

ABCG5/G8 and ABCA1 SNPs were genotyped in 788 subjects (228 men and 560 women) who participated in the Boston Puerto Rican Health Study. Biochemical measurements were determined by standard procedures. Genotyping was performed using TaqMan assays according to routine laboratory protocols. Significant gene-gene interactions for HDL-C were found between ABCG8 (5U145A > C, T54CA > G, T400KC > A) SNPs and ABCA1_i48168G > A genetic variant (P = 0.009, P = 0.042 and P = 0.036, respectively), in which carriers of the 5U145C and 54C alleles, and homozygotes for the T400 allele at ABCG8 genetic variants displayed lower HDL-C concentrations than homozygotes for the 5U145A and T54 alleles, and heterozygotes for the 400K allele at ABCG8 SNPs, only if they were also homozygous for the minor allele (A) at the aforementioned ABCA1 SNP.

CONCLUSIONS

The gene-gene interactions reported in the present study support the hypothesis that the effect of ABCG5/G8 genetic variants on HDL-C concentrations is dependent on ABCA1 expression. Replication of these analyses to further populations, particularly with low HDL-C, is clearly warranted.

Fragility fractures of the hip and femur: incidence and patient characteristics

SUMMARY

Using national discharge and medical claims data, we studied the epidemiology of femoral fractures from 1996 to 2006. The annual hip fracture incidence declined from 600/100,000 to 400/100,000, without decline in the more rare femur fractures. Incidence rates for subtrochanteric and femoral shaft fractures were each below 20 per 100,000.

INTRODUCTION

This study's purpose is to describe the site-specific epidemiology of femur fractures among people aged 50 and older.

METHODS

Using the National Hospital Discharge Survey from 1996 to 2006 and a large medical claims database (MarketScan), we studied epidemiology of all femur fractures. Hip fractures were grouped together; subtrochanteric, shaft, and distal femur fractures were kept separate.

RESULTS

In females, the overall hospital discharge rates of hip fracture decreased from about 600/100,00 to 400/100,000 person-years from 1996 to 2006. Subtrochanteric, femoral shaft, and lower femur rates remained stable, each approximately 20 per 100,000 person-years. Similar trends but lower rates existed in males. No significant trends were found in any of these fractures during the more recent years of 2002-2006 (MarketScan data). Using MarketScan, the overall incidence of hip fracture was <300/100,000 person-years; incidence of subtrochanteric and femoral shaft fractures combined was <25/100,000 person-years and distal femur fracture incidence was <18/100,000 person-years in females; rates were lower in males. The incidence of hip and other femur fractures increased exponentially with age.

CONCLUSIONS

We found no evidence of an increasing incidence of any femoral fracture. Hip fracture incidence is declining but the incidence of each of the more rare femur fractures (distal to the lesser trochanter) is stable over time.

Association of low-energy femoral fractures with prolonged bisphosphonate use: a case control study

SUMMARY

Recent evidence has linked long-term bisphosphonate use with insufficiency fractures of the femur in postmenopausal women. In this case-control study, we have identified a significant association between a unique fracture of the femoral shaft, a transverse fracture in an area of thickened cortices, and long-term bisphosphonate use. Further studies are warranted.

INTRODUCTION

Although clinical trials confirm the anti-fracture efficacy of bisphosphonates over 3-5 years, the long-term effects of bisphosphonate use on bone metabolism are unknown. Femoral insufficiency fractures in patients on prolonged treatment have been reported.

METHODS

We performed a retrospective case-control study of postmenopausal women who presented with low-energy femoral fractures from 2000 to 2007. Forty-one subtrochanteric and femoral shaft fracture cases were identified and matched by age, race, and body mass index to one intertrochanteric and femoral neck fracture each.

RESULTS

Bisphosphonate use was observed in 15 of the 41 subtrochanteric/shaft cases, compared to nine of the 82 intertrochanteric/femoral neck controls (Mantel-Haenszel odds ratio (OR), 4.44 [95% confidence interval (CI) 1.77-11.35]; P = 0.002). A common X-ray pattern was identified in ten of the 15 subtrochanteric/shaft cases on a bisphosphonate. This X-ray pattern was highly associated with bisphosphonate use (OR, 15.33 [95% CI 3.06-76.90]; P < 0.001). Duration of bisphosphonate use was longer in subtrochanteric/shaft cases compared to both hip fracture controls groups (P = 0.001).

CONCLUSIONS

We found a significantly greater proportion of patients with subtrochanteric/shaft fractures to be on long-term bisphosphonates than intertrochanteric/femoral neck fractures. Bisphosphonate use was highly associated with a unique X-ray pattern. Further studies are warranted.

Vertebral height restoration in osteoporotic compression fractures: kyphoplasty balloon tamp is superior to postural correction alone

INTRODUCTION

Kyphoplasty has been shown to restore vertebral height and sagittal alignment. Proponents of vertebroplasty have recently demonstrated that many vertebral compression fractures (VCFs) are mobile and positional correction can lead to clinically significant height restoration. The current investigation tested the hypothesis that positional maneuvers do not achieve the same degree of vertebral height correction as kyphoplasty balloon tamps for the reduction of low-energy VCFs.

METHODS

Twenty-five consecutive patients with a total of 43 osteoporotic VCFs were entered into a prospective analysis. Each patient was sequentially evaluated for postural and balloon vertebral fracture reduction. Preoperative standing and lateral radiographs of the fractured vertebrae were compared with prone cross-table lateral radiographs with the patient in a hyper-extension position and on pelvic and sternal rolls. Following positional manipulation, patients underwent a unilateral balloon kyphoplasty. Postoperative standing radiographs were evaluated for the percentage of height restoration related to positioning and balloon kyphoplasty.

RESULTS

In the middle portion of the vertebrae, the percentage available for restoration restored with extension positioning was 10.4% (median 11.1%) and after balloon kyphoplasty was 57.0% (median 62.2%). This difference was statistically significant (p<0.001). Thus, kyphoplasty provided an additional 46.6% of the height available for restoration from the positioning alone. With operative positioning, 51.2% of VCFs had >10% restoration of the central portion of the vertebral body, whereas 90.7% of fractures improved at least 10% following balloon kyphoplasty (p<0.002).

CONCLUSION

Although this study supports the concept that many VCFs can be moved with positioning, balloon kyphoplasty enhanced the height reduction >4.5-fold over the positioning maneuver alone and accounted for over 80% of the ultimate reduction. If height restoration is the goal, kyphoplasty is clearly superior in most cases to the positioning maneuver alone.

Mass vaccination and surveillance/containment in the eradication of smallpox

The Smallpox Eradication Program, initiated by the WHO in 1966, was originally based on mass vaccination. The program emphasized surveillance from the beginning, largely to track the success of the program and further our understanding of the epidemiology of the disease. Early observations in West Africa, bolstered by later data from Indonesia and the Asian subcontinent, showed that smallpox did not spread rapidly, and outbreaks could be quickly controlled by isolation of patients and vaccination of their contacts. Contacts were usually easy to find because transmission of smallpox usually required prolonged face-to-face contact. The emphasis therefore shifted to active searches to find cases, coupled with contact tracing, rigorous isolation of patients, and vaccination and surveillance of contacts to contain outbreaks. This shift away from mass vaccination resulted in an acceleration of the program's success.

Prevention and treatment of osteoporotic fractures

With the aging international population, osteoporosis has become an epidemic. This painless disease is characterized by a decreased bone mass, resulting in decreased structural integrity of bone, and often goes undiagnosed. Typical osteoporotic fractures include vertebrae, hip, and wrist fractures, and these may have a dramatic impact on quality of life, even if the fracture is successfully treated. Many antiresorptive agents have demonstrated the ability to reduce the risk of osteoporotic fractures, and newer anabolic agents may further reduce risk. Non-medical treatments, such as external hip protectors and balance and low-impact strength training, are also very effective in preventing fractures. Before specific treatments can be addressed, however, osteoporosis must first be considered as a diagnosis in any patient with a low-energy fracture. This requires continued public health initiatives involving patient and physician education regarding the necessity for bone mass measurement and the merits of antiresorptive therapy.

Antioxidant treatment for amyotrophic lateral sclerosis / motor neuron disease

BACKGROUND

Free radical accumulation and oxidative stress have been proposed as contributing to the progression of amyotrophic lateral sclerosis (or motor neuron disease). A range of antioxidant medications are available, and have been studied.

OBJECTIVES

To examine the effects of antioxidant medication in the treatment of people with amyotrophic lateral sclerosis.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group trials register (July 2003), MEDLINE (from January 1966 to July 2003), EMBASE (from January 1980 to July 2003) and other sources.

SELECTION CRITERIA

All randomized or quasi-randomized controlled trials of antioxidant treatment for amyotrophic lateral sclerosis.

DATA COLLECTION AND ANALYSIS

The reviewers independently applied the selection criteria, assessed study quality and two reviewers performed independent data extraction.

MAIN RESULTS

The search identified 21 studies for consideration but only eight studies met the inclusion criteria. Only two studies used our predetermined primary outcome measure, (survival at 12 months treatment). Sufficient data were available from three studies to allow analysis of the primary outcome measure, and a meta-analysis was performed. In the individual studies no significant effect was observed of vitamin E 500 mg twice daily; acetylcysteine 50 mg/kg daily subcutaneous infusion; or a combination of L-methionine 2 g, vitamin E 400 International Units, and selenium 3 x 10-5g three times daily (Alsemet). No significant effect on the primary outcome measure was observed in a meta-analysis of antioxidants in general when combining the results. No significant differences were demonstrated in secondary outcome measures.

REVIEWERS' CONCLUSIONS

There is insufficient evidence of efficacy of individual antioxidants, or antioxidants in general, in the treatment of people with amyotrophic lateral sclerosis. One study reported a mild positive effect, but this was not supported by the analysis we used. Generally the studies were poorly designed, and underpowered, with low numbers of participants and of short duration. Further well-designed trials of medications such as vitamin C and E are unlikely to be performed. If future trials of antioxidant medications are performed, careful attention should be given to sample size, outcome measures, and duration of the trial. The high tolerance and safety, and relatively low cost of vitamins C and E, and other considerations related to the lack of other effective treatments for amyotrophic lateral sclerosis, explain the continuing use of these vitamins by physicians and patients. While there is no substantial clinical trial evidence to support their clinical use, there is no clear contraindication.

The osteoporotic spine

Osteoporotic vertebral fractures represent the most common type of osteoporotic fracture. They can cause significant morbidity and mortality, including physical, functional, and psychosocial impairments. Screening using fracture risk assessments can identify those at greatest risk. Medical and non-medical comprise appropriate, comprehensive treatment programs. The minimally invasive spine procedures vertebroplasty and kyphoplasty can help to significantly reduce pain and deformity in patients with severe pain and deformity from vertebral fracture.

Farm residence and exposures and the risk of allergic diseases in New Zealand children

BACKGROUND

Studies in Europe have reported a reduced prevalence of allergy in farmers' children. We aimed to determine if there is a similar reduction in allergy among New Zealand farm children.

METHODS

Two hundred and ninety-three children participated (60%) aged 7-10 years, from selected schools in small towns and the surrounding rural area. Skin prick tests (SPT) to eight common allergens were performed. Parents completed questionnaires about allergic and infectious diseases, place of residence, exposure to animals, and diet, and they provided dust from the living-room floor. Endotoxin was measured using an Limulus amoebocyte lysate (LAL) assay and Der p 1 using enzyme-linked immunoassay (ELISA).

RESULTS

Current farm abode was found to increase the risk of having symptoms associated with allergy, but not SPT positivity. Independent inverse associations were found for early-life exposures: at least weekly consumption of yoghurt with hayfever (odds ratio (OR) = 0.3, 95% confidence intervals (CI) 0.1-0.7) and allergic rhinitis (OR = 0.3, 95% CI 0.2-0.7); any unpasteurized milk consumption with atopic eczema/dermatitis syndrome (AEDS) (OR = 0.2, 95% CI 0.1-0.8); cats inside or outside with hayfever (OR = 0.4, 95% CI 0.1-1.0) and AEDS (OR = 0.4, 95% CI 0.2-0.8); dogs inside or outside with asthma (OR = 0.4, 95% CI 0.2-0.8); and pigs with SPT positivity (OR = 0.2, 95% CI 0.1-0.9).

CONCLUSIONS

Despite finding a protective effect of early-life animal exposures, we found a greater prevalence of allergic disease on farms.

Patellar metastasis from a squamous carcinoma of the lung: a case report

Bone is a common site of metastasis from lung cancer. Metastasis to the patella, however, is rare. A 76-year-old man presented with knee pain caused by an isolated patellar metastasis from squamous cell carcinoma of the lung. Treatment was delayed secondary to delay in diagnosis. In cases of bone pain that are unexplained or out of proportion to a traumatic event, more extensive diagnostic studies should be done.

Rehabilitation for limb salvage patients: kinesiological parameters and psychological assessment

Osteosarcoma is the most frequently occurring primary malignant tumor of bone, especially in adolescence. Treatment involves either limb salvage surgery or amputation with neoadjuvant chemotherapy. This review article discusses the current treatment modalities for osteosarcoma and also compares the gait patterns and psychosocial profiles of patients treated with either limb salvage surgery or amputation for osteosarcoma. Contemporary orthopedic literature on therapeutic options for osteosarcoma patients is reviewed. Background information on the basic principles of kinesiology, with emphasis on studies of gait pattern differences among patients treated with limb salvage versus amputation, is presented. Finally, several studies of the psychologic profiles of patients after these two procedures for osteosarcoma are reviewed. Trends in contemporary orthopedic literature suggest that functional outcomes, in terms of kinesiologic parameters, are comparable for patients treated with either limb salvage or amputation. Both sets of patients reported quality-of-life problems, including difficulty retaining health insurance and finding appropriate employment, social isolation, and poor self-esteem. The management of patients with osteosarcoma includes not only an individualized surgical plan for each patient but also includes awareness of the patients' psychologic and social needs after surgery.

Comparative study of the activity of total hip arthroplasty patients and normal subjects

The walking activity of normal subjects and total hip arthroplasty (THA) patients from the Wrightington Hospital for Joint Disease and The General Infirmary at Leeds was assessed by means of electronic pedometers. The principal objectives were to establish the extent to which joint arthroplasty patients recover their activity relative to normal subjects and to establish the number of loading cycles to which prostheses should be subjected in joint simulator studies of implant performance. A further objective was to establish an experimental procedure for the assessment of the role of activity in contributing to the well-known scatter in the measurements of femoral head penetration into acetabular cups in in vivo studies of implant performance. The last-mentioned issue is addressed in another article ([1]). The walking activity of 2 normal subjects of disparate ages was assessed during 1 full year. It was concluded that fair estimates of activity could be achieved by recording pedometer readings during successive 2- to 4-week periods. This approach was adopted in the full assessment of the walking activity of cohorts of normal subjects and THA patients. Linear regression expressions relating the number of steps taken daily and the annual number of loading cycles on each leg to age are presented for normal subjects and THA patients. In all cases, activity declines with age, but it is shown that total joint arthroplasty is not at all restrictive on walking activity-a remarkable testimony to the efficacy of total joint arthroplasty. Attention is drawn, however, to different levels of activity of THA patients recorded in the present United Kingdom study and a similar survey conducted in California.

The effect of activity levels of total hip arthroplasty patients on socket penetration

Survivorship of total hip arthroplasties (THAs) has been linked to penetration of the femoral head into the polyethylene acetabular cup and to polyethylene wear. The activity level of patients with THAs is considered to be an important factor affecting wear, and the purpose of this study was to explore the relationship between activity as recorded by pedometers and cup penetration. The measurement of daily activity levels of normal subjects and THA patients of various ages are discussed in another article ([1]). Subjects were monitored continuously during 2- to 4-week periods using simple pedometer devices. Patients (n = 54; mean age, 58 years) from the Centre for Hip Surgery at Wrightington Hospital for whom the penetration data also were available were included in the study. The average activity level for the patient group was 1.426 million loading cycles on each hip joint per year. Radiographic penetration measurements were compared for 81 hips in 54 patients with a mean follow-up of 13.1 years (range, 1.3-26.4 years). The overall correlation of penetration with implantation period is known to be poor, however, and did not improve significantly when the penetration was plotted against a new parameter that took account of not only implant life, but also the level of activity and patient weight. The considerable scatter of penetration levels was noted to increase with increasing implantation period, which indicates that in the multifactorial problem of polyethylene wear, other factors, particularly femoral head surface finish or polyethylene deterioration, may predominate.

An unexpected outcome during testing of commercially available demineralized bone graft materials: how safe are the nonallograft components?

STUDY DESIGN

Radiographic and histologic analyses of commercially available bone graft materials were performed.

OBJECTIVE

To compare the osteoinductive efficacy of commercially available demineralized bone matrix material.

SUMMARY OF BACKGROUND DATA

The relative in vivo bone formation and toxicology of the nonallograft components the make up various commercially available demineralized bone matrix products are not known.

METHODS

An in vivo bone formation model was used in 30 athymic rats. Six different bone grafting materials were tested in subcutaneous and intermuscular locations. After 4 weeks, radiographic and histologic testing of bone formation was performed.

RESULTS

Eight of nine rats implanted with Grafton demineralized bone matrix products died 1 to 4 days after implantation of the bone graft material. None of the remaining 10 animals implanted with the four other grafting materials died. The experiment was modified and completed with a lower dose of bone graft material. Pathologic analysis indicated that the cause of death was hemorrhagic necrosis of the kidneys, most likely caused by a toxic effect on the glomeruli and tubules. A possible causative factor may have been the glycerol in the graft material.

CONCLUSIONS

Although the volume of Grafton product per kilogram of body weight used in this study was approximately eight times the maximum volume used in humans, the authors believe that this data must be reported because this product is used substantially in clinical settings. In addition, the osteoinductive performance and relative safety of the nonallograft components in all commercially available demineralized bone grafts are not known.

cis-hydroxyproline limits work necessary to flex a digit after tendon injury

Present surgical procedures for the repair of tendon injury are complicated by formation of peritendinous collagenous adhesions which restrict tendon gliding. Several sensitive biomechanical tests have been developed to quantitate peritendinous restriction of gliding. Using these tests it was found that cis-hydroxyproline significantly limits net collagen accumulation following tendon injury in a rat model and decreases the adhesive restraints to tendon gliding. cis-Hydroxyproline and other proline analoques offer a method for specifically preventing excessive collagen formation.

Correlation between vertebral body rotation and two-dimensional vertebral bone density measurement

The aim of this study was to determine the effect of vertebral rotation, as seen in idiopathic scoliosis, on bone mineral density determination for the lumbar spine. Bone mineral content, biplanar vertebral segment area and calculated bone mineral density of each vertebra from L1 to L4 were obtained for a human cadaveric specimen. The average density for the entire L1-L4 segment was also recorded. This was done with the spine in the midline position as well as in rotation up to a maximum of 60 degrees either side of the midline. The spine was rotated in each direction using 10 degrees increments and two bone density readings were done at each rotation interval. The measured biplanar vertebral segment area increased with increasing rotation from 0 degrees to 50 degrees but decreased after 50 degrees of rotation (r = 0.73, p<0.001). The bone mineral density was significantly negatively correlated with the degree of rotation (r = -0.92, p<0.001). The decrease in measured bone mineral density was nearly 20% when the lumbar spine was rotated from neutral to 60 . This study demonstrates that degree of spinal rotation influences apparent bone mineral density by increasing the apparent vertebral segment area. The measurement change may be as high as 20%. This fact should be considered when investigating scoliotic patients with vertebral segment rotation.

Bisphosphonate therapy in fibrous dysplasia

Fibrous dysplasia is proliferation of fibrous tissue within the bone marrow causing osteolytic lesions and pathologic fractures. Recently, second generation bisphosphonates have shown promise in the treatment of patients with fibrous dysplasia. In the current study, six patients with fibrous dysplasia were treated with either oral alone or oral and intravenous bisphosphonates. The participants were observed for changes in N-telopeptide, pain score, and radiographic changes. In the current study, the combination bisphosphonate therapy diminished pain, prevented fractures, lowered N-telopeptide values, and led to partial resolution of fibrous dysplasia lesions.

Interleukin-4 transgenic mice develop glomerulosclerosis independent of immunoglobulin deposition

Mice with constitutive transgenic (tg) expression of IL-4 develop autoimmune-type disorders resembling human lupus nephritis. The kidneys show progressive glomerulosclerosis with immunoglobulin (Ig) and complement deposition. This study investigated the roles of renal IL-4 expression and glomerular Ig deposition in the pathogenesis of glomerulosclerosis in IL-4 tg mice. Treatment of these mice with IL-4 neutralizing antibody prevented renal disease. IL-4 tg mice treated with methylprednisolone (MP) showed increased mesangial collagen deposition with only trace amounts of glomerular Ig. To analyze the relevance of Ig deposition in the development of the renal lesions, IL-4 tg mice were cross-bred with mu chain-deficient mice (muMT-/-), which are unable to produce Ig. IL-4 tg/muMT-/- mice developed progressive glomerulosclerosis with mesangial accumulation of collagen types I, IV and V despite complete absence of glomerular Ig deposits. Renal IL-4 expression was observed in both anti-IL-4- and MP-treated IL-4 tg mice as well as in IL-4 tg/muMT-/- mice. No statistical difference in the number of glomerular T cells and macrophages between any of the groups was evident. Our data demonstrate that in this model glomerulosclerosis can develop independently of and prior to Ig deposition, and suggest that the initial accumulation of glomerular extracellular matrix is due to renal IL-4 expression. Our results point to a novel mechanism for the development of glomerulosclerosis which may have implications for human disease.

Limb salvage using distraction osteogenesis

Distraction osteogenesis is a novel technique for the biological restoration of segmental bone defects. Definitive treatment of musculoskeletal tumors often requires large bony resections that can leave patients with significant osseous defects. Limb salvage using distraction osteogenesis is an attractive reconstructive alternative that may, in fact, offer advantages over other conventional techniques. We present our initial experience with the use of distraction osteogenesis in limb salvage.

Bone growth factors

Osteoblastic culture models, experimental, and clinical models have revealed that bone growth factors influence cellular activity. Growth factors including bone morphogenetic proteins, transforming growth factor beta, platelet-derived growth factor, insulin-like growth factors I and II, and acidic and basic fibroblast growth factors, are powerful tools for fracture healing and bone grafting. Understanding the role that bone growth factors play in bone repair is necessary to apply these factors in a clinical setting.

Routine vaginal cuff smear testing in post-hysterectomy patients with benign uterine conditions: when is it indicated?

BACKGROUND

By the age of 60 years, an estimated 33% of women will have undergone a hysterectomy. Approximately 85% of these hysterectomies are performed for benign disease. The object of this study was to evaluate cytologic findings from vaginal cuff smears in patients who have undergone hysterectomy for benign uterine conditions.

METHODS

We conducted a community-based retrospective study and follow-up of women with vaginal cuff cytologic smears who had had a hysterectomy for benign uterine conditions. A total of 220 women were randomly selected who had one or more vaginal cuff smears. The main outcomes measures were invasive carcinoma, dysplastic lesions, and infections detected by vaginal cuff smear testing. The setting was a large inner-city hospital.

RESULTS

Ninety-seven percent of 220 women who underwent hysterectomy for benign uterine conditions and who were observed for an average of 89 months had no cytologic abnormalities on vaginal cuff smears. Cytologic evaluation found no invasive carcinomas. Dysplastic lesions were detected in 7 patients (3%). Seventy percent of patients (n = 154) had one or more infections; these infections included bacterial vaginosis (106), trichomoniasis (95), candidiasis (40), koilocytosis suggestive of human papilloma virus (HPV) infection (3), and cytopathic effect of herpes (4). The prevalence of koilocytosis was much higher in the patients with dysplasia (P = .0003).

CONCLUSIONS

Most routine vaginal cuff cytology screening tests need not be performed in women who have had a hysterectomy for benign uterine conditions.

Clinical applications of bone graft substitutes

Autogenous bone grafting remains the gold standard for osseous reconstruction in clinical practice. It is associated with several limitations. The search for an alternative bone graft substitute with combined osteoinductive, osteoconductive, and osteogenic properties continues. This article highlights the properties of the various bone grafting materials currently available and discusses their efficacy in clinical practice.

The use of growth factors in cartilage repair

Articular cartilage, which enables smooth gliding of joints during skeletal motion, is vulnerable to injuries and degenerative diseases over time. Bone growth factors have a role in the preservation of the cartilage matrix. This article reviews the potential to treat cartilage damage for bone morphogenetic proteins, insulin-like growth factors, hepatocyte growth factor, basic fibroblast growth factor, and transforming growth factor beta.

Osteoporosis

Osteoporosis is a disorder of decreased bone mass, microarchitectural deterioration, and fragility fractures. Osteoporosis is widespread and can affect people of all ethnic backgrounds and many older women and men. An essential element in preventing osteoporosis is the achievement of normal peak bone mass. Adequate nutrition, appropriate calcium and vitamin D intake, regular menstrual cycles and a well balanced exercise program of exercise are essential elements in achieving peak bone mass. At menopause women undergo accelerated bone loss. Thereafter, women and men gradually lose bone mass. A loss of one standard deviation give rise to an enhanced twofold risk of spine fractures or a 2.5 risk of hip fracture. Bone mass is determined by dual energy x-ray absorptiometry, quantitative computed tomography scan, and a peripheral ultrasound. Dual energy x-ray absorptiometry has outstanding precision (within 1% to 2%), and has the ability to show the efficacy of drug intervention. Peripheral measurements may identify osteoporosis but only have a 70% correlation with hip and spine bone mass. Dual energy x-ray absorptiometry determines bone mass in a patient but the bone collagen breakdown products (N-telopeptide crosslinks) establish the current rate of bone loss. Major risk factors leading to fragility fracture include low body weight, history of fracture, family history of osteoporosis, and smoking. All individuals should ingest adequate calcium and vitamin D, exercise, and prevent falls. Women with low bone mass, high urinary bone collagen breakdown products, and/or major risk factors should consider hormone replacement therapy or a selective estrogen receptor modulator (Evista), calcitonin and bisphosphonates (alendronate). These agents successfully increase bone mass and limit fracture risk. Men at risk for fragility fractures respond similarly as women to alendronate and calcitonin. Although vertebral compression fractures can occur spontaneously, hip fractures are attributable to low bone mass coupled with a fall. Hence, fall prevention programs in addition to medical treatment are critical in the prevention of fragility fractures.