Skeletal fluorosis: an uncommon cause, yet a rescue treatment?

PURPOSE: Skeletal fluorosis (SF) results from chronic exposure to fluoride (F-) causing excessive aberrantly mineralized brittle bone tissue, fractures, and exostoses. There is no established treatment other than avoiding the source of F-. Still, excess F- can persist in bone for decades after exposure ceases. CASE PRESENTATION: A 50-year-old woman presented with multiple, recurrent, low AQ2 trauma fractures yet high radiologic bone mineral density. Serum F- was elevated, and osteomalacia was documented by non-decalcified transiliac biopsy. She reported intermittently "huffing" a keyboard cleaner containing F- (difluoroethane) for years. Following cessation of her F- exposure, we evaluated the administration of the parathyroid hormone analog, abaloparatide, hoping to increase bone remodeling and diminish her skeletal F- burden. CONCLUSION: Due to the prolonged half-life of F- in bone, SF can cause fracturing long after F- exposure stops. Anabolic therapy approved for osteoporosis, such as abaloparatide, may induce mineralized bone turnover to replace the poorly mineralized osteomalacic bone characteristic of SF and thereby diminish fracture risk. Following abaloparatide treatment for our patient, there was a decrease in bone density as well as a reduction in F- levels.

A rare side effect of methotrexate therapy: drug-induced osteopathy with multiple fractures of the lower limb.

Methotrexate is associated with bone lesions that are rare and, although presenting with a typical localisation to the lower extremities and appearing with a characteristic radiologic morphology, largely unknown and often misdiagnosed as osteoporotic insufficiency fractures. The correct and early diagnosis, however, is key for treatment and prevention of further osteopathology. Here, we present a patient with rheumatoid arthritis who developed multiple painful insufficiency fractures in the left foot (processus anterior calcanei, tuber calcanei) and in the right lower leg and foot (anterior and dorsal calcaneus and at the cuboid and distal tibia) during therapy with methotrexate, which were all misdiagnosed as osteoporotic. The fractures occurred between 8 months and 35 months after starting methotrexate. Discontinuation of methotrexate resulted in rapid pain relief and no further fractures have occurred. This case powerfully demonstrates the importance of raising awareness of methotrexate osteopathy in order to take appropriate therapeutic measures, including and perniciously discontinuing methotrexate.

Elevated Bone Hardness Under Denosumab Treatment, With Persisting Lower Osteocyte Viability During Discontinuation.

Denosumab is a potent osteoclast inhibitor targeted to prevent osteoporotic bone loss and thereby reduce fractures in the aging population. Recently, an elevated risk of rebound fractures following denosumab discontinuation was identified, unless patients were transitioned to an alternative antiresorptive medication. How denosumab affects the interaction of mechanosensitive osteocytes and bone quality remains unknown. We hypothesized that denosumab influences osteocyte function contributing to bone reorganization and increased fractures during discontinuation. Bone quality and osteocytes were assessed in archived iliac crest bone biopsies obtained from patients with high fracture occurrence from 2011 to 2016. Biopsies were obtained due to high fracture occurrence prior and during osteoporosis therapy from (i) patients with at least two semiannual subcutaneous injections of 60 mg denosumab, (ii) patients with rebound fractures during discontinuation, and (iii) patients of a treatment-naive group. In total, biopsies from 43 individuals were analyzed (mean age, 65.5 ± 12.1 years). Our results showed that during denosumab treatment, iliac cortical bone had a higher bone tissue hardness compared to treatment-naive bone (p = 0.0077) and a higher percentage of mineralized osteocyte lacunae (p = 0.0095). The density of empty osteocyte lacunae was higher with denosumab compared to treatment-naive (p = 0.014) and remained high in trabecular bone during discontinuation (p = 0.0071). We conclude that during denosumab treatment, increased bone hardness may contribute to improved fracture resistance. In biopsies from patients with high fracture occurrence, denosumab treatment reduced osteocyte viability, an effect that persisted during treatment discontinuation. High-resolution imaging of osteocyte viability indicates a role for osteocytes as a potential future mechanistic target to understand rebound bone loss and increased fractures with denosumab discontinuation.

[Multiple Vertebral Fractures after Denosumab Discontinuation: How to Avoid Them?] / Fractures vertébrales multiples à l'arrêt du denosumab: comment les éviter?

Multiple Vertebral Fractures after Denosumab Discontinuation: How to Avoid Them? Abstract. Denosumab is a monoclonal antibody raised against the RANK ligand that inhibits the maturation and activity of osteoclasts. It decreases bone resorption, increases bone density and reduces fracture risk. However, after its discontinuation, a significant rebound effect appears that lasts about two years. It results in increased markers of bone remodeling, a loss of bone density that may be greater than gain, and an increased risk of multiple vertebral fractures. These fractures occur at a frequency of 1 to 10 %. Due to this high risk, denosumab should be a second-line treatment limited to very specific indications. At denosumab discontinuation, in order to limit the rebound effect, the current recommendation is to prescribe a strong bisphosphonate (alendronate, zoledronate) and regularly monitor the bone resorption markers.

Fracturas múltiples y consumo inusual de pastillas Juanola(R) de regaliz / Multiple fractures and unusual consumption of licorice pastillas Juanola(R)

El regaliz (Glycyrrhiza glabra) se ha considerado una planta medicinal desde hace miles de años, y actualmente se utiliza en multitud de preparados por su sabor, poder endulzante y efecto antiinflamatorio. No está exento de efectos secundarios, entre ellos, la hipertensión por su efecto mineralcorticoide. Además, los flavonoides presentes en el extracto de regaliz producen un aumento de la hormona paratiroidea (PTH) y de los niveles de calcio en la orina. Presentamos un caso de una mujer de 60 años con fracturas múltiples asociadas a un consumo inusual y exagerado de pastillas Juanola® (PJ®), producto a base de extracto de regaliz

Licorice (Glycyrrhiza glabra) has been considered a medicinal plant for thousands of years, and it is included in several compounds for its flavor, sweetener and anti-inflammatory properties. It is not free of side effects, including high blood pressure due to its mineralocorticoid effect. In addition, there are flavonoids in licorice extract which increase serum parathyroid hormone (PTH) and urinary calcium levels. We report a case of a 60-year-old woman with multiple bone fractures associated with an unusual and exaggerate consumption of pastillas Juanola (PJ), product based on licorice extract