Rickets: Defective bone mineralization in children before epiphyseal fusion

Osteomalacia: Defective bone mineralization in adults with fused epiphyses

-The most common cause of osteomalacia: Vitamin D deficiency 

-Drug-induced osteomalacia caused by phenytoin, carbamazepine, valproate, phenobarbital 

Calcipenic rickets occurs in 4 forms:

Nutritional rickets 

Vitamin D-dependent rickets type I

Hereditary vitamin D resistant rickets

Defects in vitamin D metabolism 

Hypophosphatemic rickets occurs in 2 forms: 

-nutritional hypophosphatemic rickets 

-X-linked hypophosphatemic rickets 

Symptoms & Signs 

-can be asymptomatic 

-Weakness, apathy, listlessness, bone pain, proximal muscle weakness

-spasms, convulsions, thickened and widened wrists and ankles 

-Craniotabes: thinning of the bones of the skull, soft, misshapen head, widened sutures, frontal bossing, muscle hypotonia, pronounced potbelly, bowing of the legs, waddling gait  

-Delayed eruption of teeth, pitted teeth 

-Rachitic rosary: Enlargement and cupping of the costochondral junctions resulting in widening of the chest 

-Genu Valgum: ‘Knock knees’ 

-Genu Varum: ‘Bowed legs’ 

-Harrison Groove: Tug of the diaphragm against the softened lower ribs may produce an indentation at the point of insertion of the diaphragm

Kyphoscoliosis or lumbar lordosis is common

-Hypocalcemia: fatigue,lethargy, irritability, depression, paresthesias in the circumoral area, muscle cramps, carpopedal spasm, convulsions, tetany, laryngospasm, and stridor 

-Hypophosphatemia: muscle weakness, reduced endurance, dysphagia, diplopia, cardiomyopathy, respiratory muscle weakness and impaired cognition


Histology: Transcortical bone biopsy 

Radiographs: bilateral bowing deformity of the femora, metaphyseal flaring, physeal widening 


-vitamin D 



Osteoporosis is a systemic skeletal disease characterized by low bone mass, microarchitectural deterioration of the bone tissue, compromised bone strength resulting in bone fragility and increased risk of fractures

-It is more common in women than in men

-The World Health Organization has established criteria for defining osteopenia and osteoporosis based on the T score: 

T score greater than or equal to –1.0, normal; 

T score –1.0 to –2.5, osteopenia 

T score less than –2.5, osteoporosis; 

T score less than –2.5 with a fracture, severe osteoporosis.

-Medication-induced osteoporosis: Glucocorticoids are the most common cause of medication-induced osteoporosis; diabetes medications, thiazolidinediones,SSRIs, proton pump inhibitors, warfarin 

Symptoms & Signs 

-Osteoporosis is often a ‘silent disease’

-Complications: loss of height from vertebral fractures, kyphosis from vertebral fractures, chronic back pain, restrictive lung capacity from thoracic vertebral fractures, hip fractures, low self-esteem, decreased quality of life and independence, isolation and depression

-Most important consequence of osteoporosis: Fractures 

-Most frequent sites of fractures: thoracic and lumbar vertebral bodies, proximal hip, pelvis, proximal humerus, and distal radius 

-The most common osteoporotic fracture: Vertebra

-the most disastrous osteoporotic fracture:Proximal femur


-CBC, CMP, 24-hour urine collection of calcium, serum 25-hydroxy vitamin D, PTH

-Most commonly used tool to determine bone density: Dual-Energy X-ray Absorptiometry (DEXA) 

-Other techniques: single-energy x-ray absorptiometry (SXA), quantitative CT, and ultrasound (US)

-Fracture risk increases with age at any T-score.


Lifestyle modifications: Discontinue smoking, alcohol consumption, Exercise, hip protectors 

Nutritional supplements: Calcium, Vitamin D, protein intake, good sun exposure 


Bisphosphonates: Alendronate, Risedronate, Ibandronate, Zoledronic acid 

PTH analogs: Teriparatide, Abaloparatide, limited to 2-year treatment

SERMS: Raloxifene,tamoxifen; up to 5-year treatment 

RANKL inhibitor: Denosumab; up to 10-year treatment 

Sclerostin inhibitor: Romosozumab; limited to 12 monthly doses