Extensive Osteonecrosis After Glucocorticoids: Clinical Response to Bisphosphonate.

Osteonecrosis is a devastating complication of long-term glucocorticoid therapy that has been described in both malignant and nonmalignant diseases. Its incidence has been found to greater than 50% using magnetic resonance imaging in asymptomatic patients, thus osteonecrosis is likely underdiagnosed. Recent studies have suggested that treatment with bisphosphonates can improve pain and mobility and decrease bone marrow edema. We describe a patient with acute lymphoblastic leukemia who presented with debilitating osteonecrosis after treatment with prednisone for a total cumulative dose of 5100 mg. Magnetic resonance imaging revealed extensive infarcts of her bilateral tibiae and femora and left humerus, talus, and calcaneus consistent with osteonecrosis that had persisted for more than 2 years. Her severe knee, shoulder, and ankle pain was treated with 1 dose zolendronic acid. Despite a prolonged acute phase reaction, the patient's symptoms improved with near total resolution of pain.

Severe FGF23-based hypophosphataemic osteomalacia due to ferric carboxymaltose administration.

Ferric carboxymaltose (FCM) is a novel iron formulation increasingly prescribed due to its effectiveness and fast infusion time. FCM administration can cause an asymptomatic hypophosphataemia secondary to fibroblast growth factor 23 (FGF23) dysregulation. In patients with chronic iron needs, however, a severe, long-lasting hypophosphataemia can lead to osteomalacia with associated bone pain. Lack of awareness of this complication results in delayed time to diagnosis and significant morbidity. We report a case of a patient with Crohn's disease and chronic iron-deficiency anaemia receiving multiple doses of FCM who developed severe hypophosphataemic osteomalacia with urinary phosphate loss and increased FGF23. FGF23 excess and osteomalacia resolved only months after FCM discontinuation and aggressive phosphate repletion. Potential mechanisms of FGF23 dysregulation are discussed, with the aim of raising awareness of this significant side effect for prescribers of chronic intravenous iron supplementation, and to help guide future studies to determine the safety of FCM in all patient populations.

Subchondral insufficiency fracture of the knee: a non-traumatic injury with prolonged recovery time.

Subchondral insufficiency fractures are non-traumatic fractures that occur immediately below the cartilage of a joint. Although low bone density may be present concurrently, it is not the underlying cause of subchondral insufficiency fractures in the majority of patients. Patients with subchondral insufficiency fracture characteristically have unremarkable plain radiographs, while MRI examination may reveal extensive bone marrow oedema and subchondral bone collapse. This article presents a 51-year-old postmenopausal woman, a physician, who had subchondral insufficiency fractures of the knee associated with prolonged standing during clinical work. She was treated with partial weight bearing on crutches until 14 months after the injury, viscosupplementation at 4 months to treat osteoarthritis and teriparatide treatment to improve bone healing at 7 months. By 26 months after the injury, she tolerated independent walking with a fabric knee support but still experienced mild posterolateral knee pain and numbness on prolonged standing.

Associations between Body Composition, Hormonal and Lifestyle Factors, Bone Turnover, and BMD.

BACKGROUND: The relative importance of body composition, lifestyle factors, bone turnover and hormonal factors in determining bone mineral density (BMD) is unknown. We studied younger postmenopausal women to determine whether modifiable or nonmodifiable risk factors for osteoporosis have stronger associations with BMD. METHODS: In multivariable linear regression models, we tested associations between non-bone body composition measures, self-reported measures of physical activity and dietary intake, urinary N-telopeptide (NTx), sex hormone concentrations, and BMD in 109 postmenopausal women aged 50 to 64 years, adjusting for current hormone therapy use and clinical risk factors for low BMD. Lean mass, fat mass and areal BMD (aBMD) at the lumbar spine, femoral neck, total hip and distal radius were measured using dual energy X-ray absorptiometry. RESULTS: Higher body weight and self-reported nonwhite race were independently associated with higher aBMD at the lumbar spine, femoral neck, total hip and distal radius. Lean and fat mass were not independently associated with aBMD. Older age and higher urinary NTx were independently associated with lower aBMD at the distal radius but not at weight-bearing sites. Sensitivity analyses demonstrated lack of an independent association between total daily protein or calorie intake and BMD. CONCLUSIONS: BMD, weight and race were the most important determinants of aBMD at all sites. Older age and higher bone turnover were independently associated with lower aBMD at the distal radius. In a limited analysis, self-reported physical activity, dietary protein and calorie intake were not associated with aBMD after adjustment for the other variables.

Follicle-stimulating hormone is independently associated with lean mass but not BMD in younger postmenopausal women.

PURPOSE: Increased follicle-stimulating hormone (FSH) has been associated with lower bone mineral density (BMD) in animal models and longitudinal studies of women, but a direct effect has not been demonstrated. METHODS: We tested associations between FSH, non-bone body composition measures and BMD in 94 younger (aged 50 to 64 years) postmenopausal women without current use of hormone therapy, adjusting for sex hormone concentrations and clinical risk factors for osteoporosis. Lean mass, fat mass and areal BMD (aBMD) at the spine, femoral neck and total hip were measured using dual energy X-ray absorptiometry (DXA). Volumetric BMD (vBMD) was measured at the distal radius using peripheral quantitative computed tomography (pQCT). RESULTS: FSH was inversely correlated with lean and fat mass, bioavailable estradiol, spine and hip aBMD, and vBMD at the ultradistal radius. In the multivariable analysis, FSH was independently associated with lean mass (ß=-0.099, p=0.005) after adjustment for age, race, years since menopause, bioavailable estradiol, bioavailable testosterone, LH, PTH, SHBG and urine N-telopeptide. FSH showed no statistically significant association with aBMD at any site or pQCT measures at the distal radius in adjusted models. Race was independently associated with aBMD, and race and urine N-telopeptide were independently associated with bone area and vBMD. CONCLUSIONS: After adjustment for hormonal measures and osteoporosis risk factors, higher concentrations of FSH were independently associated with lower lean mass, but not with BMD. Previously reported correlations between FSH and BMD might have been due to indirect associations via lean mass or weight.