Severe bone disease caused by primary hyperparathyroidism: a case report and review of the literature

Preclinical Rodent Models for Human Bone Disease, Including a Focus on Cortical Bone

Preclinical models (typically ovariectomized rats and genetically altered mice) have underpinned much of what we know about skeletal biology. They have been pivotal for developing therapies for osteoporosis and monogenic skeletal conditions, including osteogenesis imperfecta, achondroplasia, hypophosphatasia, and craniodysplasias. Further therapeutic advances, particularly to improve cortical strength, require improved understanding and more rigorous use and reporting. We describe here how trabecular and cortical bone structure develop, are maintained, and degenerate with aging in mice, rats, and humans, and how cortical bone structure is changed in some preclinical models of endocrine conditions (eg, postmenopausal osteoporosis, chronic kidney disease, hyperparathyroidism, diabetes). We provide examples of preclinical models used to identify and test current therapies for osteoporosis, and discuss common concerns raised when comparing rodent preclinical models to the human skeleton. We focus especially on cortical bone, because it differs between small and larger mammals in its organizational structure. We discuss mechanisms common to mouse and human controlling cortical bone strength and structure, including recent examples revealing genetic contributors to cortical porosity and osteocyte network configurations during growth, maturity, and aging. We conclude with guidelines for clear reporting on mouse models with a goal for better consistency in the use and interpretation of these models.

Pediatric hyperparathyroidism and ossification of the ligamentum flavum: A case report

Hyperparathyroidism (HPT) is a rare endocrine disorder in the pediatric population. Patients often present with bone pain and abnormal gait along with biochemical findings of hypercalcemia, hypophosphatemia, and elevated parathyroid hormone (PTH). HPT is most commonly due to the unregulated secretion of PTH from a parathyroid adenoma. Diagnosis is usually identified with sonography and scintigraphy to localize parathyroid anomalies. Treatment traditionally involves parathyroidectomy with postoperative monitoring of serum calcium and phosphate levels. Here we present a case of a preadolescent girl with metabolic bone disease secondary to hyperparathyroidism.

Hyperparathyroidism: Unusual location of brown tumors

Brown tumors (BTs) are due to a proliferation of multinucleated giant cells in osteolytic lesions. They complicate the course of hyperparathyroidism. Thanks to an early screening of bone metabolism disorders; BTs are nowadays rare bone manifestations. We demonstrate through these two cases reports unusual locations of BTs in hyperparathyroidism.