Structural Disorders of Bone and Related Pathologies

A comprehensive vocabulary review of bone structural disorders, clinical manifestations, subtypes, and anatomical distributions based on lecture notes.

Osteoporosis

A condition in which bones lose mass and become subject to pathological fractures, with the hip, wrist, and vertebrae being especially vulnerable.

Kyphosis ("dowager's hump")

An exaggerated thoracic curvature of the spine associated with osteoporosis.

Bis-phosphonates

A class of pharmaceutical agents used as a medical treatment for osteoporosis.

Parathyroid hormone

A hormone utilized as a medical treatment to manage osteoporosis.

Estrogen decline

A postmenopausal endocrine change that results in reduced inhibition of osteoclasts, leading to typical loss of $30\text{--}50\%$ of bone mass by age $70$.

Orthopedics

The branch of medicine concerned with the prevention and correction of injuries and disorders of bones, joints, and muscles.

Acromegaly

A disorder resulting from adult growth hormone hypersecretion, causing thickening of the bones and soft tissues, particularly noticeable in the face, hands, and feet.

Osteitis deformans (Paget disease)

A disorder involving excessive osteoclast proliferation and bone resorption, with compensatory bone deposition by osteoblasts leading to rapid, disorderly remodeling and weak, deformed bones; most common in males over age $50$.

Osteosarcoma

Bone cancer affecting especially the limb bones of adolescents and young adults, producing large tumors often near the knee that can be fatal if not quickly treated due to metastasis to the lungs.

Rickets

Defective mineralization of bone in children that causes bone softening and deformity, especially in the weight-bearing bones of the lower limbs, typically from insufficient sunlight, vitamin D, calcium, or phosphate.

Achondroplastic dwarfism

A genetic disorder caused by a mutation in the FGFR3 gene that affects normal bone growth. It causes shortened arms and legs, while the head and trunk are usually normal-sized. It is the most common form of disproportionate short stature.

Osteopenia

A condition characterized by reduced bone mass

A condition where bone density is lower than normal, making bones weaker and more likely to fracture. It is less severe than osteoporosis and can sometimes progress to osteoporosis.

Brittle bone disease

A congenital disorder of bone fragility

A genetic disorder that causes weak, fragile bones that break easily, usually due to a problem with type I collagen. It can also cause short stature, loose joints, and hearing problems.

Calcipenic rickets

A major class of rickets caused by vitamin D deficiency or resistance, calcium deficiency, or renal rickets secondary to chronic kidney disease (CKD).

Phosphopenic rickets

A major class of rickets characterized by renal tubular phosphate loss, renal Fanconi syndrome, dietary phosphate deficiency, or phosphate malabsorption.

VDDR I

Vitamin D-dependent rickets caused by failure of $1$-hydroxylation of vitamin D due to an inherent deficiency of 1\text{-\alpha}-hydroxylase secondary to gene defects.

VDDR II

A form of calcipenic rickets characterized by end-organ resistance to vitamin D.

Renal Fanconi syndrome

A renal condition causing renal tubular phosphate loss, leading to phosphopenic rickets.

XLHR

X-linked hypophosphatemic rickets; a genetic disorder causing isolated renal tubular phosphate loss.

ARHR

Autosomal recessive hypophosphatemic rickets; a genetic disorder causing isolated renal tubular phosphate loss.

ADHR

Autosomal dominant hypophosphatemic rickets; a genetic mutation causing isolated renal tubular phosphate loss.

Macroglossia

Abnormal enlargement of the tongue observed in acromegaly, which can lead to difficult endotracheal intubation.

Prognathism

Abnormal facial projection and enlargement of the jaw seen in patients with acromegaly.

Dental diastasis

The widening of gaps between teeth resulting from jaw enlargement in acromegaly.

Carpal tunnel syndrome

A neurological manifestation characterized by nerve compression at the wrist associated with acromegaly.

Left ventricular hypertrophy

A cardiovascular manifestation associated with acromegaly involving thickening of the heart muscle.

Knee (osteosarcoma frequency)

The most common anatomical site for osteosarcoma development, accounting for $50\%$ of cases.

Humerus (osteosarcoma frequency)

The upper limb bone accounting for $15\%$ of osteosarcoma occurrences.

Pelvic girdle (osteosarcoma frequency)

The skeletal site accounting for $12\%$ of osteosarcoma tumor distributions.

Femur (osteosarcoma frequency)

The long bone site accounting for $9\%$ of osteosarcoma occurrences (independent of specific knee localization).