Recovery from skeletal fluorosis (an enigmatic, American case)

Skeletal fluorosis secondary to methoxyflurane use for chronic pain

Skeletal fluorosis is rare and occurs secondary to chronic high amounts of fluoride consumption, manifesting as diffuse osteosclerosis, skeletal pain, connective tissue calcification, and increased fracture risk. Methoxyflurane is a volatile, fluorinated hydrocarbon-inhaled analgesic, and the maximum recommended dose is 15 mL (99.9 % w/w) per wk. A rodent study found increased skeletal fluoride after methoxyflurane exposure. However, skeletal fluorosis secondary to methoxyflurane use in humans has rarely been reported. We present the case of a 47-yr-old female with diffuse osteosclerosis secondary to fluorosis from methoxyflurane use for chronic pain, presenting with 3 yr of generalized bony pain and multiple fragility fractures. Lumbar spine BMD was elevated. CT and radiographs demonstrated new-onset marked diffuse osteosclerosis, with calcification of interosseous membranes and ligaments, and a bone scan demonstrated a grossly increased uptake throughout the skeleton. Biochemistry revealed an elevated alkaline phosphatase and bone turnover markers, mild secondary hyperparathyroidism with vitamin D deficiency, and mild renal impairment. Zoledronic acid, prescribed for presumed Paget's disease, severely exacerbated bony pain. Urinary fluoride was elevated (7.3 mg/L; reference range < 3.0 mg/L) and the patient revealed using methoxyflurane 9 mL per wk for 8 yr for chronic pain. A decalcified bone biopsy revealed haphazardly arranged cement lines and osteocytes lacunae and canaliculi, which was consistent with an osteosclerotic process. Focal subtle basophilic stippling around osteocyte lacunae was suggestive of fluorosis. Although fluorosis is not a histological diagnosis, the presence of compatible histology features was supportive of the diagnosis in this case with clinical-radiological-pathological correlation. Skeletal fluorosis should be considered as a cause of acquired diffuse osteosclerosis. Methoxyflurane should not be recommended for chronic pain. The risk of repeated low-dose exposure to fluoride from methoxyflurane use as analgesia may be greater than expected, and the maximum recommended dose for methoxyflurane may require re-evaluation to minimize skeletal complications.

Abbreviated abstract

Skeletal fluorosis is rare and occurs secondary to chronic high amounts of fluoride consumption, manifesting as diffuse osteosclerosis, skeletal pain, connective tissue calcification, and increased fracture risk. We present the case of a 47-yr-old female with skeletal fluorosis secondary to long-term methoxyflurane for chronic pain. The risk of repeated low-dose exposure to fluoride from methoxyflurane use for analgesia may be greater than expected, and the maximum recommended dose for methoxyflurane may require re-evaluation to minimize skeletal complications.

A skeleton in a huff: insights in etiologies of osteosclerosis

A 30-yr-old man developed right lower leg pain and a palpable solid mass. Radiographic imaging revealed a periosteal reaction with an exostotic mass arising from the right distal fibula. Generalized skeletal osteosclerosis with periosteal reaction was discovered on a radiographic skeletal survey. A biopsy of the right fibular mass revealed reactive woven bone. The patient was referred to a metabolic bone disease clinic, where laboratory values were consistent with secondary hyperparathyroidism and increased bone turnover. A DXA bone density scan revealed high bone density, with an L1-4 spine Z-score of +9.3, a left femoral neck Z-score of +8.5, and a total hip Z-score of +6.5. A dental exam revealed generalized gingival inflammation, teeth mobility, generalized horizontal alveolar bone loss and widening of the periodontal ligament space, increased bone density around the teeth, and thickening of the radicular lamina dura. An extensive evaluation was performed, with the result of a single test revealing the diagnosis. The differential diagnoses of osteosclerosis affecting the skeleton, teeth, and oral cavity are discussed.

Assessing the water contaminants in San Luis Potosi and its effects on its inhabitants: An interdisciplinary study on environmental contamination and public health

Water shortage and contamination is a problem worldwide, impacting the human health. This research provides a comprehensive assessment of water quality and its possible impact on public health in San Luis Potosi, a region in Mexico facing critical water challenges. Throughout the study of various pollutant sources, the contaminants were identified and analyzed. The study focuses on four contaminants; fluoride, zinc, Total Dissolved Solids (TDS), and arsenic, which are prevalent in the region's water sources. By analyzing water samples from 28 locations over an 8-year period and correlating the data with health information, the study identifies potential links between water quality and prevalent diseases. Analytical methods adhere to international standards, including the official Mexican standards (NOM), as well as data from authoritative sources like the National Water Commission (CONAGUA) and the ministry of health. With the quantification of the impact on human health, this research paper contributes to associating the main diseases in the population with the contaminants and the main activities of the city. The consequence of each compound is described in detail. The findings suggest that waterborne diseases and health issues may be related to the presence of contaminants in water. To integrate hydrological and health data, Geographic Information Systems (GIS) were employed to spatially align the data, allowing for the examination of potential spatial correlations between water quality and public health. This research emphasizes the urgent need for targeted water quality management and public health interventions to safeguard the well-being of the local population and promote sustainable water management practices.

Skeletal Fluorosis in a Patient With Computer Cleaner Inhalant Abuse

Skeletal fluorosis is a metabolic bone disease caused by excessive consumption of fluoride from fluoride-contaminated water or foods. Such a condition often takes place in developing countries without proper handling of drinking water or food. However, in recent years, multiple cases of skeletal fluorosis have been observed in the United States due to the increasing frequency of recreational substance abuse. In this case report, a 26-year-old male with a history of polysubstance use disorder presented to the emergency department after being assaulted by store employees when attempting to steal computer cleaner inhalants. On evaluation for acute traumatic injury, he was incidentally found to have diffuse sclerosis of all visualized bones on knee, femur, and hip X-rays. Labs were significant for elevated serum alkaline phosphatase levels, secondary hyperparathyroidism, and hypovitaminosis D. Given the patient's history of computer cleaner inhalant misuse and imaging findings, serum and urine fluoride levels were obtained and supported the diagnosis of skeletal fluorosis. Skeletal pain and diffuse sclerosis on imaging should prompt clinicians to include skeletal fluorosis in the differential diagnosis. Cessation of substance use is the primary treatment of fluorosis in the setting of computer cleaner inhalant abuse. However, clinical symptoms and laboratory and imaging abnormalities may take decades to resolve due to the prolonged half-life of fluoride in bone. Proper hydration is crucial, as nephrolithiasis and hypercalciuria have been described during the skeletal unloading of fluoride.

Skeletal fluorosis secondary to harmful inhalant use

INTRODUCTION

Inhalants are common household items that may be abused for the desired effect of euphoria. Skeletal fluorosis is an uncommon and debilitating bone disorder caused by excess fluoride deposition. We report a case of skeletal fluorosis from chronic inhalation of an electronic duster product containing 1,1-difluoroethane.

CASE

A 33-year-old male with inhalant use disorder presented to the emergency department with prominent bilateral hand swelling and long bone deformities. The patient reported five years of inhaling "surf onn.© electronic duster" (1,1-Difluoroethane). Diagnostic testing demonstrated urine fluoride 64.5 mg/L (ref <3) and serum fluoride 1.8 mg/L (ref <0.13). Radiographs demonstrated diffuse periosteal new bone formation and sclerosis consistent with skeletal fluorosis.

CONCLUSION

Skeletal fluorosis is an uncommon complication of inhalant use disorder with products containing fluoride.

Periarticular calcifications containing giant pseudo-crystals of francolite in skeletal fluorosis from 1,1-difluoroethane "huffing"

Inhalant use disorder is a psychiatric condition characterized by repeated deliberate inhalation from among a broad range of household and industrial chemical products with the intention of producing psychoactive effects. In addition to acute intoxication, prolonged inhalation of fluorinated compounds can cause skeletal fluorosis (SF). We report a young woman referred for hypophosphatasemia and carrying a heterozygous ALPL gene variant (c.457T>C, p.Trp153Arg) associated with hypophosphatasia, the heritable metabolic bone disease featuring impaired skeletal mineralization, who instead suffered from SF. Manifestations of her SF included recurrent articular pain, axial osteosclerosis, elevated bone mineral density, maxillary exostoses, and multifocal periarticular calcifications. SF was suspected when a long history was discovered of 'huffing' a computer cleaner containing 1,1-difluoroethane. Investigation revealed markedly elevated serum and urine levels of F^-. Histopathology and imaging techniques including backscattered electron mode scanning electron microscopy, X-ray microtomography, energy dispersive and wavelength dispersive X-ray emission microanalysis, and polarized light microscopy revealed that her periarticular calcifications were dystrophic deposition of giant pseudo-crystals of francolite, a carbonate-rich fluorapatite. Identifying unusual circumstances of F^- exposure is key for diagnosing non-endemic SF. Increased awareness of the disorder can be lifesaving.

Skeletal Fluorosis: A Case of Inhalant Abuse Leading to a Diagnosis of Colon Cancer

Skeletal fluorosis is a long-term bone disease that develops when prolonged fluoride toxicity leads to osteosclerosis and bone deformities that result in crippling pain and debility. The disease is endemic to many countries due to environmental or industrial exposures. However, rare cases in the United States have been reported from various causes including heavy toothpaste ingestion, excessive tea consumption, voriconazole use, and inhalant abuse. Here, we present a case of a 41-year-old man who presented for weight loss and severe joint pains due to bony sclerotic lesions found on X-rays. Social history revealed that he had been recreationally inhaling compressed air dusters used for cleaning electronics. Owing to concern for malignancy, he underwent an extensive work-up which led to a diagnosis of colon cancer, but positron emission tomography/computed tomography (PET/CT) and bone biopsy were unexpectedly negative for metastatic bone disease. Further characterization of his lesions by skeletal survey led to a diagnosis of skeletal fluorosis secondary to inhalant abuse. As in this patient, the disease can be difficult for clinicians to recognize as it can be mistaken for various boney diseases such as metastatic cancer. However, once there is clinical suspicion for skeletal fluorosis, various tests to help confirm the diagnosis can include serum and urine fluoride levels, skeletal survey, and bone ash fluoride concentration. Treatment of skeletal fluorosis primarily involves cessation of fluoride exposure, and recovery can take years. Ultimately, further study is required to develop recommendations and guidelines for diagnosis, management, and prognosis of the disease in the United States.

Non-endemic skeletal fluorosis: Causes and associated secondary hyperparathyroidism (case report and literature review)

Skeletal fluorosis (SF) is endemic primarily in regions with fluoride (F)-contaminated well water, but can reflect other types of chronic F exposure. Calcium (Ca) and vitamin D (D) deficiency can exacerbate SF. A 51-year-old man with years of musculoskeletal pain and opiate use was hypocalcemic with secondary hyperparathyroidism upon manifesting recurrent long bone fractures. He smoked cigarettes, drank large amounts of cola beverage, and consumed little dietary Ca. Then, after 5 months of Ca and D₃ supplementation, serum 25(OH)D was 21 ng/mL (Nl, 30-100), corrected serum Ca had normalized from 7.8 to 9.4 mg/dL (Nl, 8.5-10.1), alkaline phosphatase (ALP) had decreased from 1080 to 539 U/L (Nl, 46-116), yet parathyroid hormone (PTH) had increased from 133 to 327 pg/mL (Nl, 8.7-77.1). Radiographs revealed generalized osteosclerosis and a cystic lesion in a proximal femur. DXA BMD Z-scores were +7.4 and +0.4 at the lumbar spine and "1/3" radius, respectively. Bone scintigraphy showed increased uptake in two ribs, periarticular areas, and proximal left femur at the site of a subsequent atraumatic fracture. Elevated serum collagen type I C-telopeptide 2513 pg/mL (Nl, 87-345) and osteocalcin >300 ng/mL (Nl, 9-38) indicated rapid bone turnover. Negative studies included hepatitis C Ab, prostate-specific antigen, serum and urine electrophoresis, and Ion Torrent mutation analysis for dense or high-turnover skeletal diseases. After discovering markedly elevated F concentrations in his plasma [4.84 mg/L (Nl, 0.02-0.08)] and spot urine [42.6 mg/L (Nl, 0.2-3.2)], a two-year history emerged of "huffing" computer cleaner containing difluoroethane. Non-decalcified histology of a subsequent right femur fracture showed increased osteoblasts and osteoclasts and excessive osteoid. A 24-hour urine collection contained 27 mg/L F (Nl, 0.2-3.2) and <2 mg/dL Ca. Then, 19 months after "huffing" cessation and improved Ca and D₃ intake, yet with persisting bone pain, serum PTH was normal (52 pg/mL) and serum ALP and urine F had decreased to 248 U/L and 3.3 mg/L, respectively. Our experience combined with 15 publications in PubMed concerning unusual causes of non-endemic SF where the F source became known (19 cases in all) revealed: 11 instances from high consumption of black tea and/or F-containing toothpaste, 1 due to geophagia of F-rich soil, and 7 due to "recreational" inhalation of F-containing vapors. Circulating PTH measured in 14 was substantially elevated in 2 (including ours) and mildly increased in 2. The severity of SF in the cases reviewed seemed to reflect cumulative F exposure, renal function, and Ca and D status. Several factors appeared to influence our patient's skeletal disease: i) direct anabolic effects of toxic amounts of F on his skeleton, ii) secondary hyperparathyroidism from degradation-resistant fluorapatite bone crystals and low dietary Ca, and iii) impaired mineralization of excessive osteoid due to hypocalcemia.

Skeletal Fluorosis: An Unusual Manifestation of Computer Cleaner Inhalant Abuse

Skeletal fluorosis is a metabolic bone disease caused by accumulation of fluoride and is generally associated with chronic exposure to fluoride-contaminated groundwater, a phenomenon endemic to developing countries. Whereas elevated water fluoride concentrations do not constitute a public health issue in the United States, emergence of skeletal fluorosis as a sequela of chronic recreational exposures has been described. In this case report, our 33-year-old male patient with a history of major depressive disorder and substance abuse was hospitalized for hyperkalemia and acute kidney injury discovered on routine bloodwork due to concomitant nonsteroidal anti-inflammatory drugs (NSAID) and antihypertensive use. Upon hospital admission, he was found to be anemic with a significantly elevated alkaline phosphatase. Given a history of low back pain in the setting of these laboratory abnormalities, lower spine and pelvic imaging revealed diffusely increased bone density and sclerosis. Hematologic evaluation ensued to include a peripheral smear and bone marrow biopsy. Given the patient’s history of computer cleaner inhalant abuse, serum and urinary fluoride levels were obtained. Serum fluoride returned within normal limits though urinary fluoride was increased. Bone marrow histopathology revealed prominent diffuse sclerosis which in conjunction with urinary fluoride levels and computer cleaner inhalant abuse history supported the diagnosis of skeletal fluorosis. Skeletal fluorosis in the United States is rare and presents with non-specific findings requiring a high index of suspicion based on a detailed patient history for expedient diagnosis.

Fluoride Exposure Induces Inhibition of Sodium-and Potassium-Activated Adenosine Triphosphatase (Na+, K+-ATPase) Enzyme Activity: Molecular Mechanisms and Implications for Public Health

In this study, several lines of evidence are provided to show that Na + , K + -ATPase activity exerts vital roles in normal brain development and function and that loss of enzyme activity is implicated in neurodevelopmental, neuropsychiatric and neurodegenerative disorders, as well as increased risk of cancer, metabolic, pulmonary and cardiovascular disease. Evidence is presented to show that fluoride (F) inhibits Na + , K + -ATPase activity by altering biological pathways through modifying the expression of genes and the activity of glycolytic enzymes, metalloenzymes, hormones, proteins, neuropeptides and cytokines, as well as biological interface interactions that rely on the bioavailability of chemical elements magnesium and manganese to modulate ATP and Na + , K + -ATPase enzyme activity. Taken together, the findings of this study provide unprecedented insights into the molecular mechanisms and biological pathways by which F inhibits Na + , K + -ATPase activity and contributes to the etiology and pathophysiology of diseases associated with impairment of this essential enzyme. Moreover, the findings of this study further suggest that there are windows of susceptibility over the life course where chronic F exposure in pregnancy and early infancy may impair Na + , K + -ATPase activity with both short- and long-term implications for disease and inequalities in health. These findings would warrant considerable attention and potential intervention, not to mention additional research on the potential effects of F intake in contributing to chronic disease.

Skeletal Fluorosis Due to Fluorocarbon Inhalation from an Air Dust Cleaner

Skeletal fluorosis (SF) is an osteosclerotic metabolic bone disorder caused by excessive ingestion or inhalation of fluoride. SF is extremely rare in developed countries. We report a case of SF due to inhalational abuse from a fluoride-containing air dust cleaner. A 33-year-old man with no past medical history presented with progressively worsening low back pain for 2 years. Physical examination was notable for loss of lumbar lordosis and tenderness over the lumbar spine. Radiographs were notable for uniform generalized osteosclerosis in the long bones, entire spine, rib cage, and pelvic bones, and loss of the normal lumbar curvature. DXA scan showed Z-scores of +10.7 at the lumbar spine, +6.5 at the total hip, and +1.0 at the 1/3 radius. Laboratory studies were notable for elevated serum alkaline phosphatase (334 U/L, ref: 40-129 U/L) compared to a normal value 3 years prior, suggesting acquired osteosclerosis. Serum fluoride concentration returned elevated (2.8 mg/L, ref: 0.0-0.2 mg/L). Initially, the source of fluoride excess could not be identified. At a follow-up visit, he was found inhaling from a can of an air duster hidden in an inner pocket. He admitted "huffing" 2-7 cans weekly from a fluorocarbon-containing air dust cleaner for the past 3 years to achieve a euphoric feeling, explaining the source of his SF. Fluoride inhalation can be a potential source for SF, and should be suspected in patients with acquired osteosclerosis, as inhalant abuse is increasingly practiced in many countries.

Quality in dual-energy X-ray absorptiometry scans

Dual-energy X-ray absorptiometry (DXA) is the gold standard for measuring bone mineral density (BMD), making the diagnosis of osteoporosis, and for monitoring changes in BMD over time. DXA data are also used in the determination of fracture risk. Procedural steps in DXA scanning can be broken down into scan acquisition, analysis, interpretation, and reporting. Careful attention to quality control pertaining to these procedural steps should theoretically be beneficial in patient management. Inattention to procedural steps and errors that may occur at each step has the possibility of providing information that would inform inappropriate clinical decisions, generating unnecessary healthcare expenses and ultimately causing avoidable harm to patients. This article reviews errors in DXA scanning that affect trueness and precision related to the machine, the patient, and the technologist and reviews articles which document problems with DXA quality in clinical and research settings. An understanding of DXA errors is critical for DXA quality; programs such as certification of DXA technologists and interpreters help in assuring quality bone densitometry. As DXA errors are common, pay for performance requiring DXA technologists and interpreters to be certified and follow quality indicators is indicated.

Black Tea Source, Production, and Consumption: Assessment of Health Risks of Fluoride Intake in New Zealand

In countries with fluoridation of public water, it is imperative to determine other dietary sources of fluoride intake to reduce the public health risk of chronic exposure. New Zealand has one of the highest per capita consumption rates of black tea internationally and is one of the few countries to artificially fluoridate public water; yet no information is available to consumers on the fluoride levels in tea products. In this study, we determined the contribution of black tea as a source of dietary fluoride intake by measuring the fluoride content in 18 brands of commercially available products in New Zealand. Fluoride concentrations were measured by potentiometric method with a fluoride ion-selective electrode and the contribution of black tea to Adequate Intake (AI) and Tolerable Upper Intake Level (UL) was calculated for a range of consumption scenarios. We examined factors that influence the fluoride content in manufactured tea and tea infusions, as well as temporal changes in fluoride exposure from black tea. We review the international evidence regarding chronic fluoride intake and its association with chronic pain, arthritic disease, and musculoskeletal disorders and provide insights into possible association between fluoride intake and the high prevalence of these disorders in New Zealand.

Skeletal Fluorosis Due To Inhalation Abuse of a Difluoroethane-Containing Computer Cleaner

Skeletal fluorosis (SF) is endemic in many countries and millions of people are affected worldwide, whereas in the United States SF is rare with occasional descriptions of unique cases. We report a 28-year-old American man who was healthy until 2 years earlier when he gradually experienced difficulty walking and an abnormal gait, left hip pain, loss of mobility in his right wrist and forearm, and progressive deformities including enlargement of the digits of both hands. Dual-energy X-ray absorptiometry (DXA) of his lumbar spine, femoral neck, total hip, and the one-third forearm revealed bone mineral density (BMD) Z-scores of +6.2, +4.8, +3.0, and -0.2, respectively. Serum, urine, and bone fluoride levels were all elevated and ultimately explained by chronic sniffing abuse of a computer cleaner containing 1,1-difluoroethane. Our findings reflect SF due to the unusual cause of inhalation abuse of difluoroethane. Because this practice seems widespread, particularly in the young, there may be many more such cases. © 2016 American Society for Bone and Mineral Research.

Risk Assessment of Fluoride Intake from Tea in the Republic of Ireland and its Implications for Public Health and Water Fluoridation

The Republic of Ireland (RoI) is the only European Country with a mandatory national legislation requiring artificial fluoridation of drinking water and has the highest per capita consumption of black tea in the world. Tea is a hyperaccumulator of fluoride and chronic fluoride intake is associated with multiple negative health outcomes. In this study, fifty four brands of the commercially available black tea bag products were purchased and the fluoride level in tea infusions tested by an ion-selective electrode method. The fluoride content in all brands tested ranged from 1.6 to 6.1 mg/L, with a mean value of 3.3 mg/L. According to our risk assessment it is evident that the general population in the RoI is at a high risk of chronic fluoride exposure and associated adverse health effects based on established reference values. We conclude that the culture of habitual tea drinking in the RoI indicates that the total cumulative dietary fluoride intake in the general population could readily exceed the levels known to cause chronic fluoride intoxication. Evidence suggests that excessive fluoride intake may be contributing to a wide range of adverse health effects. Therefore from a public health perspective, it would seem prudent and sensible that risk reduction measures be implemented to reduce the total body burden of fluoride in the population.

Fluoride Modulates Parathyroid Hormone Secretion in vivo and in vitro

The study objective was to investigate the effects of fluoride on intact parathyroid hormone (iPTH) secretion. Thyro-parathyroid complexes (TPC) from C3H (n = 18) and B6 (n = 18) mice were cultured in Ca²⁺-optimized medium. TPC were treated with 0, 250, or 500 µM NaF for 24 h and secreted iPTH assayed by ELISA. C3H (n = 78) and B6 (n = 78) mice were gavaged once with distilled or fluoride (0.001 mg [F⁻]/g of body weight) water. At serial time points (0.5-96 h) serum iPTH, fluoride, total calcium, phosphorus, and magnesium levels were determined. Expression of genes involved in mineral regulation via the bone-parathyroid-kidney (BPK) axis, such as parathyroid hormone (Pth), calcium-sensing receptor (Casr), vitamin D receptor (Vdr), parathyroid hormone-like hormone (Pthlh), fibroblast growth factor 23 (Fgf23), α-Klotho (αKlotho), fibroblast growth factor receptor 1c (Fgf1rc), tumor necrosis factor 11 (Tnfs11), parathyroid hormone receptor 1 (Pth1r), solute carrier family 34 member 1 (Slc34a1), solute carrier 9 member 3 regulator 1 (Slc9a3r1), chloride channel 5 (Clcn5), and PDZ domain-containing 1 (Pdzk1), was determined in TPC, humeri, and kidneys at 24 h. An in vitro decrease in iPTH was seen in C3H and B6 TPC at 500 µM (p < 0.001). In vivo levels of serum fluoride peaked at 0.5 h in both C3H (p = 0.002) and B6 (p = 0.01). In C3H, iPTH decreased at 24 h (p < 0.0001), returning to baseline at 48 h. In B6, iPTH increased at 12 h (p < 0.001), returning to baseline at 24 h. Serum total calcium, phosphorus, and magnesium levels did not change significantly. Pth, Casr,αKlotho,Fgf1rc,Vdr, and Pthlh were significantly upregulated in C3H TPC compared to B6. In conclusion, the effects of fluoride on TPC in vitro were equivalent between the 2 mouse strains. However, fluoride demonstrated an early strain-dependent effect on iPTH secretion in vivo. Both strains demonstrated differences in the expression of genes involved in the BPK axis, suggesting a possible role in the physiologic handling of fluoride.

Compact DD generator-based neutron activation analysis (NAA) system to determine fluorine in human bone in vivo: a feasibility study

The subject of whether fluorine (F) is detrimental to human health has been controversial for many years. Much of the discussion focuses on the known benefits and detriments to dental care and problems that F causes in bone structure at high doses. It is therefore advantageous to have the means to monitor F concentrations in the human body as a method to directly assess exposure. F accumulates in the skeleton making bone a useful biomarker to assess long term cumulative exposure to F. This study presents work in the development of a non-invasive method for the monitoring of F in human bone. The work was based on the technique of in vivo neutron activation analysis (IVNAA). A compact deuterium-deuterium (DD) generator was used to produce neutrons. A moderator/reflector/shielding assembly was designed and built for human hand irradiation. The gamma rays emitted through the (19)F(n,γ)(20)F reaction were measured using a HPGe detector. This study was undertaken to (i) find the feasibility of using DD system to determine F in human bone, (ii) estimate the F minimum detection limit (MDL), and (iii) optimize the system using the Monte Carlo N-Particle eXtended (MCNPX) code in order to improve the MDL of the system. The F MDL was found to be 0.54 g experimentally with a neutron flux of 7   ×   10(8) n s(-1) and an optimized irradiation, decay, and measurement time scheme. The numbers of F counts from the experiment were found to be close to the (MCNPX) simulation results with the same irradiation and detection parameters. The equivalent dose to the irradiated hand and the effective dose to the whole body were found to be 0.9 mSv and 0.33 μSv, respectively. Based on these results, it is feasible to develop a compact DD generator based IVNAA system to measure bone F in a population with moderate to high F exposure.

Coexistence of two sclerotic bone diseases manifesting as spondyloarthropathy: Double trouble

Hypoparathyroidism and fluorosis are two distinct sclerotic bone diseases. Both have high BMD but they behave differently. Fluorosis causes secondary hyperparathyroidism and has been reported to cause renal dysfunction. Here we discuss a case that coincidentally had both the disorders and their interaction.

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Hypoparathyroidism and fluorosis both have high BMD but they behave differently.

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Both the disorders may present as spondyloarthropathy.

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These two disorders interact with each other to modify the clinical, biochemical and radiological outcome.

Rapid-Onset Diffuse Skeletal Fluorosis from Inhalant Abuse: A Case Report

CASE

A thirty-year-old man presented with severely debilitating left hip pain and stiffness. Radiographs demonstrated diffuse osteosclerosis and heterotopic bone formation with near ankylosis of the left hip. The patient underwent successful joint-preserving surgery to restore hip range of motion. After disclosing a history of inhalant abuse, which was confirmed by elevated serum fluoride levels, he was diagnosed with diffuse skeletal fluorosis.

CONCLUSIONS

To the best of our knowledge, we present the first reported case of diffuse skeletal fluorosis caused by inhalant abuse of 1,1-difluoroethane. Skeletal fluorosis is uncommon in the United States but is important to consider in the differential diagnosis when a patient presents with otherwise unexplained joint pain and osteosclerosis.

Friend or foe: high bone mineral density on routine bone density scanning, a review of causes and management

A finding of high BMD on routine DXA scanning is not infrequent and most commonly reflects degenerative disease. However, BMD increases may also arise secondary to a range of underlying disorders affecting the skeleton. Although low BMD increases fracture risk, the converse may not hold for high BMD, since elevated BMD may occur in conditions where fracture risk is increased, unaffected or reduced. Here we outline a classification for the causes of raised BMD, based on identification of focal or generalized BMD changes, and discuss an approach to guide appropriate investigation by clinicians after careful interpretation of DXA scan findings within the context of the clinical history. We will also review the mild skeletal dysplasia associated with the currently unexplained high bone mass phenotype and discuss recent advances in osteoporosis therapies arising from improved understanding of rare inherited high BMD disorders.

Total knee arthroplasty in a patient with skeletal fluorosis

Published reports on patients with skeletal fluorosis undergoing total knee arthroplasty are rare. Skeletal fluorosis is a chronic condition that occurs secondary to the ingestion of food and water that contain high levels of fluoride. Although fluorosis may be described as osteosclerotic and marble-like in appearance, features may also include characteristics of osteomalacia and osteoporosis. This article describes the case of a 67-year-old man with skeletal fluorosis who underwent total knee arthroplasty complicated by fracture. An intramedullary guide was used for the proximal tibia and distal femoral bone cuts intraoperatively. Following the completion of the femoral bone cuts, it was noted that the drill used to open the femoral canal had breached the medial femoral cortex. Multiple fractures were seen in both femoral condyles. A revision femoral stem was chosen to complete the total knee arthroplasty but, after further manipulation of the femur, it appeared that the fracture had displaced. A LISS plate (Synthes, West Chester, Pennsylvania) was used to ensure fracture reduction and implant stability. The remainder of the procedure was completed without complication. One year postoperatively, functional knee range of motion was limited to 70° of flexion. Radiographs showed signs of healing and satisfactory implant position. This case highlights the importance of the preoperative examination and the need to fully appreciate the bone quality of patients prior to undertaking an orthopedic procedure. Variation from the use of intramedullary guides should be considered in patients with questionable bone quality undergoing total knee arthroplasty.

Nutrition, bone, and aging: an integrative physiology approach

Osteoporosis, a condition associated with significant morbidity and mortality, is prevalent in the growing elderly population. Aging is associated with characteristic changes in the complex pathways of bone remodeling and in patterns of food intake. Whereas the traditional focus of nutritional supplementation for protection of bone health has centered around calcium and vitamin D, a multitude of nutrients have been identified with effects on bone, both individually and in combination. An integrative physiology approach can assist in formulating a deeper understanding of the complex interactions of nutrition and aging with bone, with the goal of identifying modifiable risk factors for the prevention of bone loss.

Periostitis secondary to prolonged voriconazole therapy in a lung transplant recipient

This article reports a case of perostitis deformans in a lung transplantation patient taking the fluoride-containing medication voriconazole, a relatively new and potent anti-fungal. The patient had a normal range of motion in all joints and a normal gait. On radiographs at presentation, multifocal areas of periostitis were visualized involving the left-hand first, second, and third proximal phalanx shafts. Similar periostitis was present on the left-hand third, fourth, and fifth middle phalanx shafts. Plain radiographs of the right hand also demonstrated multifocal periostitis of the third and fourth proximal and middle phalanges. Aggressive periostitis at the level of the right fourth proximal and middle phalanges was also present. Given her long-term treatment with voriconazole and a presentation consistent with periostitis deformans, voriconazole was presumed to be the offending agent and was replaced with itraconazole. The patient's symptoms resolved shortly after withdrawal of voriconazole.Voriconazole-associated periostitis has only recently been reported in the literature. Food and Drug Administration-approved in 2002, voriconazole is efficacious in treating serious, invasive fungal infections that are generally seen in immunocompromised patients. Due to the novel nature of voriconazole and the uncommon indications for its long-term use, the periostitis deformans described in this article may be unfamiliar to the orthopedic surgeon. Consequently, a patient presenting with bone pain and periosteal involvement on plain radiographs may provoke a broad, expensive, and ultimately unnecessary diagnostic evaluation. The clinical case and imaging findings presented here can help to promote understanding of this benign condition and its simple cure: voriconazole discontinuation.

Skeletal fluorosis due to excessive tea and toothpaste consumption

We describe the case of a 53-year-old woman who presented with a metatarsal fracture and was found to have a bone mineral density (BMD) T-score of +11 in the lumbar spine and +7.6 in the hip. Subsequent investigation revealed very high serum, urine and tissue fluoride levels, associated with excessive tea and toothpaste consumption. The case emphasises the need to exclude fluorosis in individuals with unexpectedly high BMD levels.

Skeletal fluorosis from brewed tea

BACKGROUND

High fluoride ion (F(-)) levels are found in many surface and well waters. Drinking F(-)-contaminated water typically explains endemic skeletal fluorosis (SF). In some regions of Asia, however, poor quality "brick tea" also causes this disorder. The plant source of brick, black, green, orange pekoe, and oolong tea, Camellia sinensis, can contain substantial amounts of F(-). Exposure to 20 mg F(-) per day for 20 yr of adult life is expected to cause symptomatic SF. High F(-) levels stimulate osteoblasts and enhance bone apposition but substitute for OH(-) groups in hydroxyapatite crystals and thereby result in skeletal fragility and perhaps lead to secondary hyperparathyroidism. Beginning in 2005, we showed that daily consumption of 1-2 gallons of instant tea made from this plant can lead to SF.

AIM

We describe a 48-yr-old American woman who developed SF from brewed tea.

PATIENT AND METHODS

Our patient had elevated bone mineral density revealed by dual-energy x-ray absorptiometry (spine Z-score, +9.9), severe chronic bone and joint pain, and kyphosis after consuming 1-2 gallons of brewed orange pekoe tea daily for more than three decades. F(-) levels were high in her serum, urine, and clippings of fingernails and toenails, as well as in our reproduction of her beverage. Renal function was normal. She had vitamin D deficiency. Elevated serum PTH levels were unresponsive to adequate vitamin D supplementation. Pain resolved over several months when she stopped drinking tea and continued ergocalciferol.

CONCLUSION

Our patient shows that SF can result from chronic consumption of large volumes of brewed tea.

Distribution of Z-scores in a University cohort with an emphasis on "high" bone mineral density

High bone mineral density (BMD) is currently not defined by the International Society for Clinical Densitometry with a specific Z-score cutoff; however, it has been suggested that a Z-score greater than or equal to 2.5 is not normal. Institutional Review Board approval was obtained. We evaluated a University dual-energy X-ray absorptiometry database over the previous 24 mo to define Z-score distributions. A Z-score greater than or equal to 2.5 was selected as the outcome event of interest in a logistic regression for adjusted odds ratio. The covariates were height; weight; body mass index (BMI); gender; menopausal status; use of female hormones; presence of insufficiency fractures after 50 yr of age; previous fractures; previous surgeries (back surgeries, vertebroplasty, or kyphoplasty); transplant history; presence of long-term chronic conditions (asthma, lupus, rheumatoid arthritis, or cystic fibrosis); eating disorder; current use of glucocorticoids; smoking status; and current and past use of osteoporosis pharmacological therapies. The study included a total of 8216 patients; 7212 (87.8%) were females, and 1044 (12.2%) were males. In the total population, 13.6% had a Z-score greater than or equal to 2.5 at the lumbar spine, femoral neck, or total hip. Only 0.2% of the males and 0.8% of the females had a Z-score greater than or equal to 2.5 at all 3 sites. The 97.5th percentiles for Z-scores in our population for men and women, respectively, were 3.4 and 3.9 at the lumbar spine, 1.5 and 2.1 at the femoral neck, and 1.6 and 2.2 at the total hip. The 99th percentile for Z-scores for men and women, respectively, were 4.9 and 4.7 at the lumbar spine, 2.4 and 2.7 at the femoral neck, and 2.2 and 2.7 at the total hip. At the lumbar spine, female gender and weight were found to be risk factors for a high Z-score (≥ 2.5). The use of glucocorticoids, bone-active medications, BMI, and smoking were significantly less likely to predict a lumbar spine Z-score greater than or equal to 2.5. A high total-hip Z-score is predicted by increasing weight, whereas those patients using bone-active medications were less likely to have high BMD at the total hip. At the femoral neck, there were no significant risk factors related to a Z-score greater than or equal to 2.5; those taking bone-active medications were significantly less likely to have a high Z-score. These data suggest that a high Z-score is common at 1 or more sites. Further research about the criteria for the diagnosis of high BMD is warranted.

Osteosclerosis owing to Notch gain of function is solely Rbpj-dependent

Osteosclerosis is a pathologic bone disease characterized by an increase in bone formation over bone resorption. Genetic factors that contribute to the pathogenesis of this disease are poorly understood. Dysregulation or mutation in many components of the Notch signaling pathway results in a wide range of human developmental disorders and cancers, including bone diseases. Our previous study found that activation of the Notch signaling in osteoblasts promotes cell proliferation and inhibits differentiation, leading to an osteosclerotic phenotype in transgenic mice. In this study we report a longer-lived mouse model that also develops osteosclerosis and a genetic manipulation that completely rescues the phenotype. Conditionally cre-activated expression of Notch1 intracellular domain (NICD) in vivo exclusively in committed osteoblasts caused massive osteosclerosis with growth retardation and abnormal vertebrae. Importantly, selective deletion of a Notch nuclear effector--Rbpj--in osteoblasts completely suppressed the osteosclerotic and growth-retardation phenotypes. Furthermore, cellular and molecular analyses of bones from the rescued mice confirmed that NICD-dependent molecular alterations in osteoblasts were completely reversed by removal of the Rbpj pathway. Together, our observations show that the osteosclerosis owing to activation of Notch signaling in osteoblasts is canonical in nature because it depends solely on Rbpj signaling. As such, it identifies Rbpj as a specific target for manipulating Notch signaling in a cell-autonomous fashion in osteoblasts in bone diseases where Notch may be dysregulated.

Vitamin D metabolism and rickets in domestic animals: a review

Rickets and osteomalacia are increasing in prevalence in people because of cultural practices, breast-feeding, decreased sun exposure, and increased sunscreen usage. Several hereditary forms of rickets owing to either renal phosphate wasting or defects in vitamin D metabolism are also reported in people. Rickets is well recognized in domestic animals, but published reports are not always supported by microscopic findings, and diagnoses based on clinical signs and radiology are unreliable. Most cases in domestic animals are caused by dietary deficiency of either vitamin D or phosphorus, but occasional inherited forms are reported in pigs, sheep, cats, and dogs. There is variation between species in susceptibility to dietary vitamin D and phosphorus deficiency and in the ability to manufacture vitamin D in their skin. A number of mouse models have been discovered or created to study human skeletal diseases and skeletal homeostasis. With the discovery that vitamin D is involved in not only calcium and phosphorus homeostasis but also in the immune system and cancer, there is great potential for new and existing animal models to generate valuable information about vitamin D and its many functions. This review presents an overview of vitamin D metabolism and rickets in domestic and laboratory animals and makes comparisons where appropriate with the disease in humans.

Skeletal fluorosis from instant tea

INTRODUCTION

Skeletal fluorosis (SF) can result from prolonged consumption of well water with >4 ppm fluoride ion (F(-); i.e., >4 mg/liter). Black and green teas can contain significant amounts of F(-). In 2005, SF caused by drinking 1-2 gallons of double-strength instant tea daily throughout adult life was reported in a 52-yr-old woman.

MATERIALS AND METHODS

A 49-yr-old woman developed widespread musculoskeletal pains, considered fibromyalgia, in her mid-30s. Additionally, she had unexplained, increasing, axial osteosclerosis. She reported drinking 2 gallons of instant tea each day since 12 yr of age. Fluoxetine had been taken intermittently for 5 yr. Ion-selective electrode methodology quantitated F(-) in her blood, urine, fingernail and toenail clippings, tap water, and beverage.

RESULTS

Radiographs showed marked uniform osteosclerosis involving the axial skeleton without calcification of the paraspinal, intraspinal, sacrotuberous, or iliolumbar ligaments. Minimal bone excrescences affected ligamentous attachments in her forearms and tibias. DXA Z-scores were +10.3 in the lumbar spine and +2.8 in the total hip. Her serum F(-) level was 120 microg/liter (reference range, 20-80 microg/liter), and a 24-h urine collection contained 18 mg F(-)/g creatinine (reference value, <3). Fingernail and toenail clippings showed 3.50 and 5.58 mg F(-)/kg (control means, 1.61 and 2.02, respectively; p(s) < 0.001). The instant tea beverage, prepared as usual extra strength using tap water with approximately 1.2 ppm F(-), contained 5.8 ppm F(-). Therefore, the tea powder contributed approximately 35 mg of the 44 mg daily F(-) exposure from her beverage. Fluoxetine provided at most 3.3 mg of F(-) daily.

CONCLUSIONS

SF from habitual consumption of large volumes of extra strength instant tea calls for recognition and better understanding of a skeletal safety limit for this modern preparation of the world's most popular beverage.