Table of contents :

• definitions
• rheumatology (from the Greek "rhêuma" = flow, as pain usually migrates)
• ostealgia / ostalgia : pain in a bone or in the bones
• osteoneuralgia : neuralgia of a bone
• fusion : the formation of an ankylosis / arthrokleisis : immobility and consolidation of a joint due to disease, injury, or surgical procedure

Aetiology :
• injury
• disease
• surgery (arthrodesis / artificial ankylosis)
• extracapsular ankylosis : ankylosis due to rigidity of structures exterior to the joint capsule.
• intracapsular ankylosis : obliteration of joint motion due to disease, injury, or surgical procedure within the joint capsule.
• false, fibrous or spurious ankylosis : reduced mobility of a joint due to proliferation of fibrous tissue
• bony or true ankylosis : the union of the bones of a joint by proliferation of bone cells, resulting in complete immobility
• cricoarytenoid joint ankylosis : fixation of the cricoarytenoid joint due to inflammation; characterized by hoarseness, cough, and difficulty in expectoration.
• stapedial ankylosis : fixation of the footplate of the stapes in otosclerosis, causing a conductive hearing loss.
• deformities and malformations : permanent, not self-correctable (avoid overtreatment !) morphological alterations causing functional (antalgic or anatomical) or aesthetic (absolute or subjective) impairment.
• clear deformities : detected at inspection, comparing to normal hemisoma
• occult deformities : detected only when the disease is already known or when we are looking for it
• functional capacity evaluation : a 1 day test (6 hrs) to determine what patient can do (lift/bend/twist/etc.)
• osteopathies : any disease of a bone
• hereditary bone dysplasia : a heterogeneous group of more than 80 distinct skeletal disorders associated with abnormalities in the size, shape, and proportions of the limbs, trunk, and skull, often resulting in short, disproportionate stature.
• bone infarct : an area of bone tissue which has become necrotic as a result of loss of its arterial blood supply.
• hemihypertrophy / Curtius' syndrome / isolated hemihyperplasia : hypertrophy of one side of the entire body or a portion of one side of the body, as of the face
• complex hemihyperplasia : involvement of half of the body (at least 1 arm and 1 leg); affected parts may be contralateral or ipsilateral
• simple hemihyperplasia is involvement of a single limb
• hemifacial hyperplasia : involvement of one side of the face
• achondroplasia / osteosclerosis congenita : a hereditary, congenital disturbance of epiphyseal chondroblastic growth and maturation, causing inadequate enchondral bone formation and resulting in a peculiar form of dwarfism with short limbs, normal trunk, small face, low nose, normal vault, lordosis, and trident hand, macrocephaly, sometimes hydrocephalus
• chondroectodermal dysplasia / Ellis-van Creveld syndrome : achondroplasia occurring in association with defective development of skin, hair, and teeth, polydactyly, and defect of the cardiac septum
Therapy : targeted overexpression of CNP in chondrocytes counteracts dwarfism in a mouse model of achondroplasia with activated FGFR-3 in the cartilage. CNP prevents the shortening of achondroplastic bones by correcting the decreased ECM synthesis in the growth plate through inhibition of the MAPK pathway of FGF signaling. CNP has no effect on the STAT-1 pathway of FGF signaling that mediates the decreased proliferation and the delayed differentiation of achondroplastic chondrocytes.
• dyschondroplasia / chondrodysplasia : formerly, a general term encompassing both enchondromatosis and exostosis, which has caused some synonyms of one disorder to become incorrectly associated with the other disorder
• thanatophoric dysplasia : a uniformly fatal type of skeletal dysplasia presenting as extreme shortening of limbs, thoracic cage deformity, and relative cephalomegaly.
• Looser-Milkman syndrome : a generalized bone disease marked by multiple transparent stripes of absorption in the long and flat bones
• Bruck's disease : a condition marked by deformity of bones, multiple fractures, ankylosis of joints, and atrophy of muscles
• osteodysplasty : abnormal development of bone.
• osteodysplasty of Melnick and Needles : a hereditary disorder, transmitted as an autosomal dominant trait, in which there are severe congenital bone abnormalities manifested by striking facies (exophthalmos, full cheeks, micrognathia, and malalignment of the teeth), flaring of the metaphyses of long bones, S -like curvature of the leg bones, irregular constrictions in the ribs, and sclerosis of the base of the skull.
• diaphyseal dysplasia / diaphyseal sclerosis / Engelmann's disease : a condition characterized by thickening of the cortex of the mid-shaft area of the long bones, progressing toward the epiphyses, the thickening sometimes occurring also in the flat bones; excessive growth in length of bones of the extremities usually results in abnormal stature
• metaphyseal dysplasia / Pyle's disease : a disturbance in enchondral bone growth, failure of modeling causing the ends of the shafts to remain larger than normal in circumference
• epiphyseal dysplasia (ED) : faulty growth and ossification of the epiphyses, with radiographically apparent stippling and decreased stature, not associated with thyroid disease
• dysplasia epiphysealis hemimelica / tarsoepiphyseal aclasis / Trevor's disease : a rare condition characterized by swellings in the extremities, usually on the inner and outer aspects of the ankles and knees, made up of bone covered with epiphyseal cartilage, and leading to limitation of motion of the joints
• dysplasia epiphysealis multiplex / dysostosis enchondralis epiphysaria / multiple epiphyseal dysplasia (MED) : a developmental abnormality of various epiphyses, which appear late and are mottled, flattened, fragmented, and usually hypoplastic; the digits are short and thick, with blunt ends, and stature may be diminished owing to flattening deformities at the hips, knees, and ankles
• dysplasia epiphysealis punctata / chondrodystrophia calcificans congenita / chondrodystrophia congenita punctata / chondrodystrophia fetalis calcificans / Conradi's disease or syndrome / hypoplastic fetal chondrodystrophy / stippled epiphyses : a heterogeneous group of bone dysplasias, the common characteristic of which is stippling of the epiphyses in infancy. The group includes :
• a severe autosomal recessive form (rhizomelic dwarfism)
• an autosomal dominant form (Conradi-Hünermann syndrome)
• a milder X-linked form
• tall stature : height > 97th percentile for that population
• short stature / dwarfism : compared to a well-nourished, genetically relevant population, short stature is defined as standing height > 2 standard deviations below the mean (or below the 2.5th percentile) for gender

Epidemiology : by definition, 2.5% of the population is short.
Aetiology :
• endocrine aetiology
• GH deficiency (GHD)
• essential or harmonic dwarfism (possible familiarity, growth velocity > 25th percentile (1-4 cm/yr), delayed bone age, possible neonatal hypoglycemia, defects of median line, prognosis depends on therapy)
• adult GH deficiency (AGHD)
• psychosocial deprivation (eventually hyperphagia, behavioural disorders, improvement by improving environment)
• hypothyroidism
• Cushing's syndrome
• hypogonadism after age 10-11
• genetic aetiology
• normal variants :
• genetic or familial short stature : bone age (BA) appropriate for chronologic age (CA), normal growth velocity, and predicted adult height (PAH) appropriate to the familial pattern, no clinical or biochemical alterations, growth velocity > 25th percentile (> 4 cm/yr)
• constitutional delay of growth and development : familial pattern, delayed bone age (BA), normal growth velocity but reduced spurt, and predicted adult height (PAH) appropriate to the familial pattern, no clinical or biochemical alterations. Final height is normal. Patients with constitutional delay typically have a first-degree or second-degree relative with constitutional delay (eg, menarche reached when older than 15 y, adult height attained in male relatives when older than 18 y).
• genetic diseases :
• Turner syndrome
• idiopathic familial short stature : SHOX gene mutations (2.4% of idiopathic short stature) : changes in spontaneous secretion and resistance to GH
• IGF-1 gene mutation
• IGF-1 receptor gene mutation
• insulin receptor gene mutations (leprechaunism)
• Shwachman-Diamond syndrome
• Rubinstein-Taybi syndrome
• Aarskog-Scott syndrome
• chromosomal aneuploidies
• Leri-Weil dyschondrosteosis (LWD), including Langer mesomyelic dysplasia and Madelung deformity, normal GH levels : SHOX gene mutations
• achondroplasia
• Down syndrome (trisomy 21)
• dysmorphic syndromes
• Noonan syndrome 1
• Prader-Willi syndrome (PWS)
• PHPIA / McCune-Albright hereditary osteodystrophy
• intrauterine aetiology
• growth retardation
• small for gestational age (SGA) fetus (birth weight and/or length < mean - 2 standard deviations for gestational age) : 10-15% of SGA fetuses lack the compensatory growth in the first 2-3 years of life and have a final stature < mean - 2 standard deviations; maternal, placental, and fetal anomalies
• Silver-Russel syndrome (SRS) : intrauterine growth delay, relative macrocephalia, small and triangular face, asymmetry
• nutritional (weight is often more compromised than height)
• inadequate nutrition
• starvation
• anorexia
• mineral and/or vitamin deficiencies : rickets
• nutrient loss :
• malabsorption (inflammatory bowel diseases (IBDs), celiac disease (sometimes the only sign of CD : 8.1% of children with short stature is IgG⁺, 2.8% IgA⁺, and 2.5% EMA⁺; gluten-free diet for > 6 months normalize GH levels)
• chronic vomiting (gastrointestinal obstructions, esophageal achalasia, electrolyte alterations, endocranial hypertension)
• dysmetabolism
• uncontrolled diabetes mellitus (high HbA_1c, hepatomegaly)
• hyperthyroidism
• chronic diseases (weight is often more compromised than height)
• lung diseases
• cystic fibrosis
• severe asthma
• chronic obstructive pulmonary diseases (COPD)
• restrictive lung disease
• hypoxemia
• heart disease (always associated with other symptoms & signs!)
• congestive heart failure
• low cardiac output states
• precocious puberty
• renal disease
• chronic renal failure
• renal tubular acidosis
Pathogenesis : according to Kalberg infancy, childhood, puberty (ICP) model, nutrition is the most important growth factor during infancy, GH during childhood and sex steroids and GH during puberty
Laboratory examinations :
• auxological clinical examination
• anamnesis
• auxology
• objective examination :
• morphological evaluation
• dismorphic nots
• evaluation of bone age
• laboratory examination
• psychoscial evaluation (separation, deaths, birth of siblings, school failure, growth at lactation)
• dysostosis : defective ossification; defect in the normal ossification of fetal cartilages.
• hypostosis : deficient development of bone.
• hyperostosis : increase of bone mass per unit of volume, hypertrophy of bone; exostosis
• cleidocranial dysostosis or dysplasia : a rare autosomal dominant condition in which there is defective ossification of the cranial bones, with large fontanels and delayed closing of the sutures; complete or partial absence of the clavicles, so that the shoulders may be brought together, or nearly together, in front; wide pubic symphysis; short middle phalanges of the fifth fingers; and dental and vertebral anomalies.
• craniofacial dysostosis (CFD) / Crouzon's disease : an autosomal dominant disorder characterized by acrocephaly, exophthalmos, hypertelorism, strabismus, parrot-beaked nose, and hypoplastic maxilla with relative mandibular prognathism.
• craniosynostos type 1 (including oxycephaly)
• dysostosis enchondralis epiphysaria / dysplasia epiphysealis multiplex.
• mandibulofacial dysostosis : a hereditary disorder occurring in 2 forms
• complete form (Franceschetti's syndrome) is autosomal dominant and consists of antimongoloid slant of the palpebral fissures, coloboma of the lower lid, micrognathia, hypoplasia of the zygomatic arches, and microtia.
• incomplete form (Treacher Collins syndrome) consists of the same anomalies in less pronounced degree; it occurs sporadically and autosomal dominance is suspected.
• mandibulofacial dysostosis with epibulbar dermoids / oculoauriculovertebral dysplasia
• metaphyseal chondrodysplasia or dysostosis / Jansen's disease : a skeletal abnormality in which the epiphyses are normal, or nearly so, and the metaphyseal tissues are replaced by masses of cartilage, producing interference with enchondral bone formation, and expansion and thinning of the metaphyseal cortices.
• dysostosis multiplex : a term for the widespread skeletal manifestations typical of the mucopolysaccharidoses
• acrofacial dysostosis (AFD) :
• Nager's acrofacial dysostosis : a congenital condition in which mandibulofacial dysostosis is associated with limb deformities consisting of absence of the radius, radioulnar synostosis, and hypoplasia or absence of the thumbs.
• Miller syndrome / Genne-Wiedemann syndrome / postaxial acrofacial dysostosis (POADS) : probably an autosomal recessive trait

Symptoms & signs : extensive facial and limb defects, characterized by malar hypoplasia, downslanting palpebral fissures, micrognathia, cleft lip and palate, cup-shaped ears, lower lid ectropion, postaxial limb deficiencies, and syndactyly. Less frequently present are heart defects and hearing loss
• AFD syndrome of Kelly (autosomal recessive)
• Rodriguez or Madrid form of AFD (autosomal recessive or X-linked recessive)
• Reynolds or Idaho form of AFD (autosomal dominant)
• Arens or Tel Aviv type of AFD (autosomal familiar ?)
• Richieri-Costa syndrome (presumed autosomal recessive)
• Patterson-Stevenson-Fontaine syndrome (autosomal dominant)
• Palagonia-type AFD (autosomal dominant > X-linked dominant)
• Catania-type AFD (autosomal or X-linked dominant)
• oral-facial-digital syndrome (OFD)
• type I / orodigitofacial dysostosis : a male-lethal X-linked dominant disorder characterized by camptodactyly, polydactyly, and syndactyly; by cranial, facial, lingual, and dental anomalies; and by mental retardation, familial trembling, alopecia, and seborrhea of the face and milia.
• type II / Mohr syndrome : an autosomal recessive disorder characterized by brachydactyly, clinodactyly, polydactyly, syndactyly, and bilateral hallucal polysyndactyly; by cranial, facial, lingual, palatal, and mandibular anomalies; and by episodic neuromuscular disturbances
• type III : an autosomal recessive disorder characterized by postaxial hexadactyly of the hands and feet, by ocular, lingual, and dental anomalies, and by profound mental retardation
• megalomelia / macromelia : abnormal largeness of a limb or limbs
• peromelia : congenital deformity of the limbs.
• peromelus : a fetus with malformed limbs.
• sclerodactyly : localized scleroderma of the digits, as in acrosclerosis
• perodactylus : a fetus with deformity of fingers or toes, or both, especially absence of one or more digits.
• tridactylism : the condition of having 3 digits on the hands or feet.
• tetradactyly : the condition of having 4 digits on the hand or foot
• hexadactyly : the occurrence of 6 digits on one hand or foot.
• triphalangism : the presence of 3 phalanges in the longitudinal axis of a digit normally composed of only 2.
• ectromelia : gross hypoplasia or aplasia of one or more long bones of one or more limbs; the term includes
• amelia : congenital absence of a limb or limbs
• meromelia : congenital absence of any part of a limb
• adactyly / adactylia / adactylism : a developmental anomaly characterized by the absence of digits on the hand or foot.
• hemimelia : a developmental anomaly characterized by absence of all or part of the distal half of a limb
• radial hemimelia : hemimelia of the upper limb in which the radial side is absent.
• ulnar hemimelia : hemimelia of the upper limb in which the ulnar side is absent
• fibular hemimelia : hemimelia of the lower limb in which the fibular side is absent.
• tibial hemimelia : hemimelia of the lower limb in which the tibial side is absent.
• phocomelia : a type of meromelia characterized by absence of the proximal portion of a limb or limbs, the hands or feet being attached to the trunk of the body by a single small, irregularly shaped bone

Aetiology : thalidomide use in pregnants
• alterations of bone structure and density
• bone rarefaction
• osteohalisteresis : loss or deficiency of the mineral elements of bones with relative increase of organic component
• halisteresis : osteomalacia; a loss or lack of the lime salts (calcium) of bone.
• halisteresis cerea : waxy softening of the bones.
• rickets : decrease of mineral matrix in childhood

Epidemiology : prevalence = Algeria (35.45% in 1963 => 18.7% in 1984/85), Italy (9.3% in 1972 => 4.3% in 1986/90), USA (20% in 1938 => <5% in 1988), UK (13% in 1944 => 30% in 1973 => 6% in 1982), INndia (20% in 1966/73), China (18% in n1980 => 11% in 1983), Ethiopia (30% in 1965), Finland (16% in 1981), France (10-40% in 1963/69 => 1.3-1.7% in  1983/84 => 0.5-2.6% in 1986), Bangladesh, Near East (e.g. Saudi Arabia (> 30% in 1988), due to genetic predisposition)
Aetiology : hypovitaminosis 1a,25-(OH)₂-vitamin D₃
Symptoms & signs :
• head
• caput quadratum
• delayed closure of an abnormously wide fontanelle
• craniotabes
• hypoplasia of enamel
• anemia
• decreased body growth
• chest
• rachitic beads
• Harrison's groove : a horizontal depression along the lower border of the thorax, corresponding to the costal insertion of the diaphragm, whose traction deforms the chest
• abdomen
• Lucas' sign : distention of the abdomen in the early stages of rickets
• hypotonia => umbilical hernia due to laxity of rectus abdominis muscles
• scoliosis or kyphosis
• lower limb
• coxa vara
• genu varus
• genu valgus
• rachitic ankles
• rachitic bracelet : lack of cartilage mineralization causes enlargement of space between metaphysis and epiphyses
Laboratory examinations :
• increased thickness of metaphysis
• irregular temporary calcification line
• cup-shaped extravasation of the metaphysary side of diaphysis
• delayed and irregular appearance of ossification nuclei
• Quant's sign : a T -shaped depression in the occipital bone, sometimes seen in rickets.
• osteomalacia : inadequate or delayed mineralization of osteoid in mature cortical and spongy bone; it is the adult equivalent of rickets and accompanies that disorder in children. The etiology of osteomalacia and its clinical and biochemical manifestations are as described for rickets

Aetiology :
• chronic acidosis
• renal tubular osteomalacia : osteomalacia occurring as a consequence of acidosis and hypercalciuria, resulting from inability to produce an acid urine or ammonia because of deficient activity of the renal tubules.
• chronic hypocalcemia
• senile osteomalacia : softening of bones in old age due to vitamin D deficiency.
• chronic hypophosphatemia
• antacid-induced osteomalacia : osteomalacia in which low dietary phosphorus intake coupled to excessive, chronic consumption of aluminum hydroxide–containing antacids leads to phosphate depletion, characterized by hypophosphatemia, nephrolithiasis, anorexia, muscle weakness, and bone loss.
• oncogenic or oncogenous osteomalacia / tumour-induced osteomalacia (TIO) : osteomalacia occurring in association with usually benign mesenchymal neoplasms. The tumors appear to produce a substance that impairs renal tubular functions such as phosphate transport and hydroxylation of 25-hydroxyvitamin D; hypophosphatemia secondary to reduced renal resorption of phosphate is a major cause of the bone disease
• primary mineralization disorders
• hereditary : hypophosphatasia
• acquired : etidronate sodium
• fast bone neoformation with or without a corresponding defect in bone reabsorption
• post-surgical period in hyperparathyroidism with cystic fibrous osteitis
• osteopetrosis / Albers-Schönberg or marble bones disease / ivory bones
• matrix synthesis deficiency : fibrogenesis imperfecta ossium
• other forms
• magnesium-dependent conditions
• axial osteomalacia
• parenteral feeding
• aluminum poisoning
• anticonvulsant osteomalacia : osteomalacia occurring in anticonvulsant rickets of children or anticonvulsant rickets occurring in adults
• familial hypophosphatemic osteomalacia : osteomalacia occurring in familial hypophosphatemic rickets
• puerperal osteomalacia : osteomalacia occurring as a consequence of exhaustion of skeletal stores of calcium and phosphorus by repeated pregnancies and lactation.
Laboratory examinations :
• deformations
• pathologic fractures
• decreased total bone mass (reduction of bone mass per volume unit) with normal ratio between organic and mineralized components

Epidemiology : expecially frequent in women after menopause.
Aetiology :
• primary
• type I or postmenopausal osteoporosis (higher prevalence) : that occurring in women within 3 to 20 years after menopause (6 times more frequently than in men), affecting trabecular bone more than cortical bone, and manifested mainly by vertebral fractures of the painful crush type, hip fracture, Colles' fracture, and increased tooth loss.

Pathogenesis : decreased estrogenincretion => decreased TGF-b and IGF-1, decreased OPG-L secretion, increased OAF, decreased 1a-hydroxyase activity => decreased 1a,25-(OH)₂-vitamin D₃ synthesis => decreased intestinal Ca²⁺ absorption => hypercalcemia and hypocalciuria => decreased PTH. Low BMI is a risk factor as adipocytes convert adrenal androstenedione to estrogens and weight stimulates bone turnover. Chronic blood loss may be the primary factor responsible for the rapid and consistent development of postmenopausal osteoporosis via augmented production of hematopoietic microenvironment, relative reduction in the amount of generated bone, and activation of the bone resorptive process in the newly forming osteohematopoietic complex^ref
Replacement therapy :
• postmenopausal women, who typically consume 600 mg of elemental calcium per day, should increase their calcium intake to 1200 mg per day (Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Dietary reference intakes: for calcium, phosphorus, magnesium, vitamin D, and fluoride. Washington, D.C.: National Academy Press, 1997)
• 800-1000 IU of 1a,25-(OH)₂-vitamin D₃ per day — the amount the average postmenopausal woman needs to raise her serum 25-hydroxyvitamin D level to that needed to lower the risk of fracture (> 75 nmol/l or > 30 ng/ml)^{ref1, ref2} and to maximize intestinal absorption of calcium^ref for optimal bone health and the prevention of cancer^ref
• PTH (daily injections, builds new bone; rat trial has shown potential risk of bone cancer)
• SERMs
Confining attention solely to effects on bone mass, one can state with reasonable certainty that the bisphosphonates produce a steady increase in bone mineral mass that, although not linear, averages about 1 percent per year for up to 8 to 10 years. Once-daily parathyroid hormone, administered as either the 1–34 or the 1–84 amino acid form of the molecule, increases central bone mass to a substantially greater extent (8 to 10 percent per year for up to two years of treatment, the period for which data are available). Using these figures as rough benchmarks, the findings from these two studies,3,4 together with those of other studies they cite, allow one to draw a number of conclusions. First, both classes of agents appear to be efficacious as monotherapy. Second, combination therapy with parathyroid hormone and a bisphosphonate appears to increase central bone mass, but to a lesser extent than does parathyroid hormone alone. Third, in the months and years after treatment with parathyroid hormone, some or all of the bone gained during treatment appears to be lost if no further therapy is implemented. Fourth, administering bisphosphonates after a course of parathyroid hormone appears to conserve the bone gained during therapy with parathyroid hormone and adds a further quantum of bone in its own right, roughly similar in magnitude to the short-term effect of bisphosphonates given to previously untreated patients. Finally, parathyroid hormone appears to retain its anabolic effect in patients previously treated with a bisphosphonate, although the effect is probably smaller than that seen in previously untreated patients.
 
• type II or senile osteoporosis : that occurring in men and women over 70 (male-to-female ratio = 1:2), manifested mainly by femur neck and vertebral fractures of the painless multiple wedge type leading to dorsal kyphosis.

Pathogenesis : 5-10 years after menopause, decreased activity of renal 1a-hydroxylase => decreased 1a,25-(OH)₂-vitamin D₃ synthesis => decreased intestinal Ca²⁺ absorption => hypocalcemia => increased [PTH]_plasma => increased activity of osteoclasts uncompensated by decresed activity of osteoblasts
• juvenile idiopathic osteoporosis
• secondary
• genetic diseases
• osteogenesis imperfecta congenita (OIC)
• VDR SNPs (B and b alleles)
• hematological diseases
• thalassemias
• lymphomas
• adult survivors of solid paediatric cancers
• radiotherapy
• allogeneic bone-marrow transplantation (BMT) : during the first 6 months after the graft, related to treatment of graft versus host disease (GVHD) with glucocorticoids and cyclosporine A, and the increase in bone marrow IL-6, which is a potent stimulator of bone resorption in vivo.
• hypothyroidism
• anorexia nervosa
• gastrectomy
• osteoporosis of disuse : decrease in bone substance as a result of lack of re-formation of laminae in the absence of functional stress that ordinarily leads to their replacement in new stress lines (e.g. Preiser's disease)
• Sudeck-Leriche syndrome : post-traumatic osteoporosis associated with vasospasm.
• erosive arthritis
• osteoporosis of disuse : decrease in bone substance as a result of lack of re-formation of laminae in the absence of functional stress that ordinarily leads to their replacement in new stress lines.
• immobilization
• living in low-pressure environments (eg astronauts)
• low sunlight exposure
• low Ca²⁺ intake
• cigarette smoking
• osteolytic bone metastases
• ethanol
• estrogen deficiency
• late menarche
• secondary amenorrhoea
• menopause praecox
• drugs :
• GR agonists increase OPG-L secretion and decrease OPG secretion
• T₃
• thiazide diuretics
• heparin
• phenytoin
• methotrexate
Pathogenesis : local (e.g. Sudeck algodystrophy / reflex sympathetic dystrophy (RSD)) or systemic bone mass reduction with microarchitectural alterations but without alterations in the normal (mineral matrix):(organic matrix):(cell) ratio (65:33:2). Overexertion of the hematopoietic system resulting from constant excessive need for blood cell production could play an important role in the etiology of osteoporosis. It is generally accepted that the development of osteoporosis in postmenopausal women is due to the reduction of estrogen level. However a most striking observation is the fact that in the male organism, which has never been protected by high levels of estrogen, osteoporosis in senescence is significantly less frequent then in the female organism, which has been protected by estrogens for at least 35 years. Healthy women loose about 70 ml of blood every month, which adds up to some 850 ml per year and approximately 30 l over the 35 years of their reproductive life. Blood loss intensifies hematopoiesis by increasing the level of hematopoietic growth factors while, at the same time, stimulating proliferation of osteogenic progenitor cells. Osteogenic activity has, indeed, been detected in the blood of bled animals. The chain of events that converts continuous requiremental pressure on hematopoiesis into development of osteoporosis may be formulated as follows: on the one hand, blood loss creates developmental pressure on the hematopoietic system, augments production of hematopoietic growth factors with subsequent intensified proliferation of hematopoietic progenitor cells, increases the number of hematopoietic cells including osteoclasts, thus intensifying resorption of bone tissue and extension of hematopoietic territories. On the other hand, blood loss leads to stimulation of bone development, extensive proliferation of osteogenic progenitor cells resulting in increased numbers of osteoblasts, followed by new bone formation and, at the same time, increased production and maturation of osteoclasts which then enter the cycle of bone resorption. The bone resorption process itself is characterized by the release of bone morphogenic proteins that induce proliferation of osteogenic cells and subsequent production of osteoclasts that in their turn enter the cycle of bone resorption. Important evidence supporting the substantial role of hematopoietic insufficiency in the development of osteoporosis comes from the field of clinical hematology: hematological diseases accompanied by chronic anemia, such as beta thalassemia major, sickle cell anemia, chronic hemolytic anemia, pernicious anemia, etc., are also characterized by the concomitant development of osteoporosis. Patients suffering from hemophilia tend to develop osteoporosis as well^ref.
Symptoms & signs : only from fractures
• lifetime fracture risk after age 50 : 13.1 % males; 39.7 % females
• femural fractures : 6% males; 17.5 % females.
• vertebral fracture : 5% males; 15.6 % females. Pain is absent while resting, upright or seated (no compression symptoms due to reduced bone tissue and marrow) and appears only during flexoextension maneuvers. Fractures below T12 cause retroperitoneal hematoma => ileus. Pain at downward manual pressure over shoulders while patient is seated. Curved back and decreased heigth
• dowager's hump : popular name for dorsal kyphosis caused by multiple wedge fractures of the thoracic vertebrae seen in osteoporosis.
Therapy : three-point corset, percutaneous vertebroplasty
• Colles' fracture : 2.5 % males ; 16% females
• humeral fracture
• rib fracture
Laboratory examinations : instrumental
• radiography :
• morphological alterations
• compact bone : reduced thickness
• cancellous bone : reduced number of trabecular with compensatory enlargement of remaining trabeculae
• decreased horizontal trabeculae
• increased vertical trabeculae
• empty box
• biconcave vertebrae
• wedge vertebrae
• sandwich vertebrae
Vertebral static histomorphometry measures anterior, intermediate and posterior height of a vertebra and uses rates between these values to define morphological alterations.
• bone densitometry : decrease of bone mineral density (BMD) => increased radiotransparence measured with ...
• single-energy X-ray absorptiometry (SXA)
• dual-energy X-ray absorptiometry (DXA / DEXA) at L1-L4 and left hip (neck, trochanter, intertrochanter region)
• T-score : number of standard deviations from the average value of healthy young white individuals of the same gender. WHO staging, 1994 :
• -1 < T < - 2.5 => osteopenia (RR for fractures = 2-5)
• T < - 2.5 => osteoporosis (RR for fractures > 5)
• severe osteoporosis if fracture(s) already occured (RR for further fractures > 10)
• Z-score : number of standard deviations from the average value of individuals of the same gender and with same age
• single photon absorptiometry (SPA)
• dual photon absorptiometry (DPA)
• quantitative computed tomography (QCT)
• peripheral quantitative computed tomography (pQCT)
• quantitative ultrasound (QUS)
• (SOS-BUA)
• bone fractures
• bone metastases
• regional bone mass reduction
• metabolic
• ESR
• CBC
• protidogram
• [total Ca²⁺, P, AlkP, creatinine]_plasma
• [Ca²⁺]_urine
• unbound [Ca²⁺]_plasma
• [PTH, estrogen, T₃]_plasma
• 25-OH-vitamin D₃
• medullary FNAB
• bone biopsy
• Ca²⁺ metabolism markers
• markers of bone formation
• measured in serum
• markers of cell activation
• total and bone-specific isozyme of AlkP
• osteocalcin / bone Gla protein (BGP)
• markers of organic matrix deposition
• carboxy-terminal propeptide of type I procollagen (PICP)
• markers of bone breakdown
• measured in serum
• marker of cell activation
• TRAP
• markers of organic matrix deposition
• carboxy-terminal telopeptide of type I collagen (ICTP)
• cross-linked C-telopeptides (S-CTx) CrossLaps (measured in bone collagen equivalent (BCE))
• cross-linked N-telopeptides (NTx) CrossLaps (measured in bone collagen equivalent (BCE))
• pyridinoline (PYD)
• deoxypyridinoline (DPD)
• measured in urine
• Ca²⁺ / creatinine ratio in 24 hrs
• Hpr
• Hly glycosides
• pyridinoline (PYD)
• deoxypyridinoline (DPD)
• carboxy-terminal telopeptide of type I collagen (ICTP)
• cross-linked C-telopeptides (U-CTx) CrossLaps (measured in bone collagen equivalent (BCE))
Therapy :
• Ca²⁺
• hormone replacement therapy
• calcitonin
• vitamin D₃ :  there is much evidence that substantial vitamin D supplementation does not affect the level of 1,25-dihydroxyvitamin D^{ref1, ref2, ref3}
• VDR agonists
• xenobiotics :
• bisphosphonates
• bone-forming agents
• distal convoluted tubule diuretics
• weight-bearing exercise (such as brisk walking)
• synthetic mimetics of collagenous ECMs : synthetic poly(ethylene glycol) (PEG)–based hydrogels as cell-ingrowth matrices for in situ bone regeneration. These networks contain a combination of pendant oligopeptide ligands for cell adhesion (RGDSP) and substrates for matrix metalloproteinase (MMP) as linkers between PEG chains. Primary human fibroblasts were shown to migrate within these matrices by integrin- and MMP-dependent mechanisms. Gels used to deliver recombinant human bone morphogenetic protein-2 (rhBMP-2) to the site of critical- sized defects in rat crania were completely infiltrated by cells and were remodeled into bony tissue within 5 weeks. Bone regeneration was dependent on the proteolytic sensitivity of the matrices and their architecture. The cell-mediated proteolytic invasiveness of the gels and entrapment of rhBMP-2 resulted in efficient and highly localized bone regeneration.
Prevention
Web resources : Usenet sci.med.diseases.osteoporosis
• osteoporomalacia : osteoporosis + osteomalacia. Common in elderlies due to concurrent senile osteoporosis and decreased synthesis of 1,25-(OH)₂-vitamin D₃.
• osteolysis : dissolution of bone; applied especially to the removal or loss of the calcium of bone.

Aetiology :
• infection
• inflammation
• endocrine disease
• osteitis fibrosa cystica of hyperparathyroidism
• cancer
• intra-osseous meningiomas
• osteolytic bone metastases
• multiple myeloma
• thalassemia (punched-out lesions of the skull)
• familial expansile osteolysis (FEO) is a rare syndrome involving most of the peripheral skeleton and the skull which was observed world-wide in only 3 kinships and in 2 unrelated American individuals^ref
• Gorham-Stout syndrome / massive osteolysis of Gorham / disappearing bone disease / vanishing bone disease / phantom bone disease is a rare condition of unknown aetiology that is thought to result from a localised endothelial proliferation of lymphatic vessels resulting in destruction and absorption of bone. It was first reported by Jackson in 1838 in a 12-year-old boy with complete osteolysis of the humerus (Jackson JBS. A boneless arm. Boston Med Surg J1838; 18 :368 –369). In 1955, Gorham and Stout further characterized the main pathologic features of this rare disease as nonmalignant intraosseous proliferation of hemangiomatous or lymphangiomatous tissue that caused massive osteolysis (Gorham LW, Stout AP. Massive osteolysis (acute spontaneous absorption of bone, phantom bone, disappearing bone): its relation to hemangiomatosis. J Bone Joint Surg Am1955; 37 :985 –1044). Noncranial imaging features of Gorham disease at conventional radiography, CT, MR, and scintigraphy have been reported elsewhere in the literature^{ref1, ref2, ref3, ref4, ref5} (Donald Rresnick. Osteolysis and chondrolysis. In: Resnick D, ed. Diagnosis of Bone and Joint Disorders. 4th ed. Philadelphia: WB Saunders;2002 :4928 –4931; Igel BJ, Shah H, Williamson MR, Sell JJ. Gorham’s syndrome: correlative imaging using nuclear medicine, plain film, and 3-D CT. Clin Nucl Med1994; 11 :1017 –1019), and most of the cases failed to show the vasculature entity of the lesion, an important pathologic feature of the disease^{ref1, ref2, ref3, ref4}. Moreover, because of a lack of specific findings on conventional images, including those of conventional radiography and CT, the diagnosis of Gorham disease with skull involvement can be difficult. Other diseases such as Paget disease and metastases may have similar appearance. In this report, we present the unique MR imaging findings of a pathologically proved case of Gorham disease of the cranial vault. The syndrome is rarely seen in the facial skeleton and has a variable prognosis. Many treatments have been advocated but only surgery and radiotherapy have had some success^{ref1, ref2}.
• osteosclerosis / osteofibrosis : increased bone mineralization, leading to hardening or abnormal density of bone
• centrosclerosis / centro-osteosclerosis : the filling of the marrow cavity of a bone with osseous material
Aetiology :
• metabolic, toxic or traumatic osteopathies
• endocrinopathies
• primary hyperparathyroidism
• hypothyroidism
• acromegaly
• radiation osteitis
• chemical intoxications
• osteofluorosis : skeletal changes, usually consisting of osteomalacia and osteosclerosis, caused by fluorosis
• elementary phosphorus
• berillium
• arsenic
• lead
• bismuth
• vitamin A
• eburnation : the conversion of a bone into an ivory-like mass. In osteoarthritis, the thinning and loss of the articular cartilage resulting in exposure of the subchondral bone, which becomes denser and the surface of which becomes worn and polished
• localized osteosclerosis associated with condensing osteitis
• osteosclerotic phase of Paget bone disease
• neoplastic addensing osteopathies : osteosclerosis associated with carcinomatous metastases, malignant lymphoma, hematological diseases (myeloproliferative diseases, sickle cell anemia (SCA), leukemia, multiple myeloma, systemic mastocytosis)
• congenital addensing osteopathies
• osteosclerosis due to erythroblastosis fetalis
• osteopetrosis / Albers-Schönberg or marble bones disease / ivory bones / osteosclerosis fragilis : a rare genetic disease characterized by abnormally dense bone, due to defective resorption of immature bone. It occurs as :
• severe autosomal recessive form occurring in utero, infancy, or childhood. The proliferation of bone obliterates the marrow cavity, causing anemia and hepatosplenomegaly, and narrowing the foramina of the skull, causing compression of cranial nerves, which may result in deafness and blindness
• with infantile neuroaxonal dystrophy
• benign autosomal dominant form occurring in adolescence or adulthood
• type I
• type II : normal serum calcium, phosphorus, alkaline phosphatase, and creatinine levels. Bone radiology demonstrates osteosclerosis primarily involving the axial and appendicular skeleton. A plain radiograph of the spine shows end-plate thickening and sclerosis producing the classic "sandwich vertebra" appearance^ref.
• mild autosomal recessive form
• osteopetrosis with renal tubular acidosis / Guibaud-Vainsel syndrome
• lethal osteopetrosis
• ectodermal dysplasia, anhydrotic, with immunodeficiency, osteopetrosis, and lymphedema (OL-EDA-ID)
• hyperostosis corticalis generalisata, benign form of worth, with torus palatinus / hyperphosphatasemia tarda / van Buchem's syndrome : an autosomal recessive disorder, characterized principally by osteosclerosis of the skull, mandible, clavicles, ribs, and diaphyses of long bones, associated with elevated blood alkaline phosphatase; beginning during puberty, it sometimes leads to optic atrophy and perceptive deafness due to nerve pressure exerted by thickening of the base of the skull.
• high bone mass
Bone fractures are common in all forms
• diseases of uncertain classification
• pyknodysostosis : an autosomal recessive symptom complex consisting of dwarfism, osteopetrosis, partial agenesis of terminal digits of hands and feet, cranial anomalies, frontal and occipital bossing, and hypoplasia of the angle of the mandible.
• allelic loss-of-function mutation in LEMD3 / MAN1, which encodes an inner nuclear membrane protein that antagonizes both BMP and activin-TGF receptor–activated Smads during embryogenesis
• Buschke-Ollendorff syndrome (BOS)
• osteopoikilosis / osteitis condensans generalisata / osteopecilia / osteosclerosis fragilis generalisata :  an autosomal dominant trait in which there are multiple sclerotic foci in the ends of long bones and scattered stippling in round and flat bones, usually without symptoms and diagnosed fortuitously by x-ray examination.
• melorheostosis : a form of hyperostosis (rheostosis / flowing hyperostosis) or osteosclerosis extending in a linear track through one of the long bones of an extremity, and consisting of proliferated ivory-like new bone
• osteomyelosclerosis / myelosclerosis / osteosclerosis myelofibrosis : obliteration of the normal marrow cavity by small spicules of bone; the pathogenesis may be similar to that of myelofibrosis
• Camurati-Engelmann disease (CED) / progressive diaphyseal dysplasia (PDP)
• type I

Aetiology : domain-specific mutations in TGF-b₁
• type II
• infantile cortical hyperostosis / Caffey's disease : a disease of young infants characterized by soft tissue swellings over the affected bones, fever, and irritability, and marked by periods of remission and exacerbation
• hyperphosphatasemia : high levels of alkaline phosphatase in the blood
• hyperostosis corticalis deformans juvenilis / juvenile Paget disease / chronic congenital idiopathic hyperphosphatasemia / familial osteoectasia

Aetiology : an autosomal recessive disorder due to mutations in osteoprotegerin (OPG)
Symptoms & signs : beginning in childhood and marked by multiple fractures and bowing of all extremities
Laboratory examinations : thickening of the frontal, parietal, and occipital bones, osteoporosis, and by elevated concentrations of serum alkaline phosphatase and of urinary hydroxyproline
Therapy : recombinant osteoprotegerin^ref
• mixed lesions
• osteonecrosis / avascular or ischemic necrosis of bone : necrosis of bone in areas with at risk circulation due to obstruction of its blood supply

Aetiology :
• septic osteonecrosis : osteomyelitis
• aseptic osteonecrosis :
• idiopathic osteonecrosis
• idiopathic infantile osteonecrosis (osteochondritis)
• idiopathic juvenile osteonecrosis
• idiopathic adult osteonecrosis
• post-trauma osteonecrosis
• ischemic osteonecrosis
• physical agents
• folgoration
• radiations
• toxic agents
• GR agonists
• SARS coronavirus (?)
• ethanol
• long-term bisphosphonate therapy => osteonecrosis of the jaw (ONJ) (the bone tissue in the jaw fails to heal after minor trauma such as a tooth extraction, causing the bone to be exposed. The exposure can eventually lead to infection and fracture and may require long-term antibiotic therapy or surgery to remove the dying bone tissue)^ref
• osteochondritis dissecans
Laboratory examinations : radiological diagnosis only after 8 months

	first phase	hyperemia and cellular infiltrate that replaces fatty tissue in epiphyseal trabeculae seen only at MRI
	first-second phase	demarcation line and hyperemic wall around the necrotic area
	second-phase	crescent line, fibrosis => thickening of the demarcation line
	third phase	collapse, arthrosis (treated with arthroprosthesis)

Complications :
• sequestrum : a piece of dead cortical bone that has become separated during the process of necrosis from the sound bone and persists into an abscess.
• primary sequestrum : a sequestrum that is entirely detached.
• secondary sequestrum : a sequestrum that is partially detached and may be pushed into place.
• tertiary sequestrum : a sequestrum that is separated by only a slight dividing line and remains in its place.
Therapy : sequestrectomy / sequestrotomy : the surgical removal of a sequestrum
• osteodystrophy : defective bone formation

Aetiology :
• primary hyperparathyroidism
• fibrous dysplasia of bone / fibrous osteitis : a disease of bone marked by thinning of the cortex and replacement of bone marrow by gritty fibrous tissue containing bony spicules, producing pain, disability, and gradually increasing deformity. 2 types or stages are distinguished :
• osteitis fibrosa localisata / monostotic fibrous dysplasia : fibrous dysplasia of bone involving only one bone (rarely a vertebra)
• osteitis fibrosa disseminata / polyostotic fibrous dysplasia : a later stage of fibrous dysplasia of bone in which several or many bones are involved; when associated with skin and endocrine disorders, it is known as PHPIA / McCune-Albright hereditary osteodystrophy
• Jaffe-Lichtenstein disease / cystic osteofibromatosis / juvenile fibrous osteitis : a form of polyostotic fibrous dysplasia characterized by an enlarged medullary cavity with a thin cortex, which is filled with fibrous tissue (fibroma)
• renal osteodystrophy : a condition resulting from chronic kidney disease, characterized by impaired renal function, hyperphosphoremia with hypocalcemia or normal calcemia, and stimulation of parathyroid function. Bone disease includes a variable mixture of osteitis fibrosa cystica, osteomalacia, osteoporosis(subperiosteal bone reabsorption ("scratches") due to secondary hyperparathyroidism), and sometimes osteosclerosis (brown tumors are areas of hyperplasia and require differential diagnosis from osteoclastoma and aneurysmal bone cyst). Onset is usually in childhood, resulting in renal dwarfism.
• Paget's disease of bone / osteitis deformans (Paget J. On a form of chronic inflammation of bones (osteitis deformans). Med-Chirurgic.Transact.London 60:37-63 (1877))

Pathogenesis : increased bone turnover (repeated episodes of increased bone resorption followed by excessive attempts at repair), resulting in weakened deformed bones of increased mass.
Symptoms & signs : bowing of long bones and deformation of flat bones; pain and pathologic fractures are associated. When it affects the bones of the skull, deafness may result
Localizations :
• monostotic Paget's disease
• segmentary Paget's disease
• polyostotic Paget's disease
• lumbar rachid-pelvis-femur-tibia
• skull-jaw-humerus-sternum
• scapular limb-girdle-forearm-feet
Laboratory examinations : increased density due to increased trabecular and cortical density with anarchic, foggy (mosaic-like) structure due to overlap, with preserved architecture. Bone volume is increased (differential diagnosis with osteoblastic metastases, expecially from breast carcinoma in dorsal rachid)
Therapy : a single infusion of zoledronic acid produces more rapid, more complete, and more sustained responses in Paget's disease than does daily treatment with risedronate^ref
• osteitis : inflammation of a bone, involving the haversian spaces, canals, and their branches, and generally the medullary cavity, and marked by enlargement of the bone, tenderness, and a dull, aching pain
• panosteitis / panostitis : inflammation of every part of a bone.
• osteitis albuminosa : osteitis with accumulation of a sticky, albuminous liquid.
• caseous osteitis : tuberculous caries of bone.
• central osteitis / endosteitis : inflammation of the endosteum
• cortical osteitis / periostitis : inflammation of the periosteum. The condition is generally chronic, and is marked by tenderness and swelling of the bone and an aching pain. Acute periostitis is due to infection, is characterized by diffuse suppuration, severe pain, and constitutional symptoms, and usually results in necrosis.
• periostitis albuminosa / albuminous periostitis / serous abscess / periosteal gangrene : a form accompanied by the exudation of a clear, albuminous liquid into a flattened cavity beneath the periosteum
• diffuse periostitis : a noncircumscribed periostitis of the long bones.
• hemorrhagic periostitis : a form in which blood is extravasated beneath the periosteum.
• periostitis hyperplastica / hypertrophic pulmonary osteoarthropathy / secondary hyperplastic osteitis
• periostitis interna cranii / external pachymeningitis : inflammation of the outer layers of the dura
• precocious periostitis : syphilitic osteoperiostitis (Treponema pallidum subsp. pallidum) occurring as an early symptom.
• chronic osteitis : central caries or bone abscess; often due to tuberculosis, sometimes syphilis (Treponema pallidum subsp. pallidum)
• malakoplakia of bone^ref
• osteitis condensans ilii : a condition marked by an area of dense sclerosis on the iliac side of the sacroiliac joint.
• osteitis fibrosa cystica generalisata / von Recklinghausen's disease / osteitis fibrosa osteoplastica / parathyroid osteitis / osteodystrophia cystica / osteodystrophia fibrosa : rarefying osteitis with fibrous degeneration and formation of cysts, and with the presence of fibrous nodules on the affected bones; it is due to marked osteoclastic activity secondary to hyperparathyroidism
• osteitis fragilitans / osteogenesis imperfecta congenita (OIC)
• osteitis carnosa, fungosa, or granulosa : chronic osteitis in which the haversian canals are dilated and filled with granulation tissue.
• gummatous osteitis : a chronic form associated with syphilis (Treponema pallidum subsp. pallidum)
• osteitis pubis : sclerosis of the pubic bones, in the region of the symphysis, usually observed as an incidental finding in radiography of the pelvis
• rarefying osteitis : a bone disease in which the inorganic matter is lessened and the hard bone becomes cancellated.
• vascular osteitis : rarefying osteitis in which the spaces formed become occupied by blood vessels.
• subchondral osteitis
• metaphysitis : inflammation of the metaphysis of a long bone.
• diaphysitis : inflammation of a diaphysis
• tuberculous diaphysitis : inflammation involving intermediate segments of the shafts of long bones, caused by Mycobacterium tuberculosis
• osteomyelitis / acute, carious or necrotic osteitis / suppurative periosteitis / bone abscess : inflammation of bone caused by infection, usually by a pyogenic organism, although any infectious agent may be involved. It may remain localized or may spread through the bone to involve the marrow, cortex, cancellous tissue, and periosteum.
• acute hematogenous osteomyelitis : osteomyelitis resulting from localization of blood-borne bacteria in bone, usually seen in the long bones of children following blunt trauma or adjacent infection. When it spreads to the joints it is known as septic or bacterial arthritis.
• subperiosteal abscess : a bone abscess situated just below the periosteum.
• Brodie's abscess : a roughly spherical region of bone destruction, filled with pus or connective tissue, usually found in the metaphyseal region of long bones
• Staphylococcus aureus
• Staphylococcus epidermidis
• Mycobacterium tuberculosis
• Brucella melitensis
• salmonella osteomyelitis : osteomyelitis due to Salmonella spp.; it occurs more frequently than normal in sickle cell anemia (SCA)
• typhoid osteomyelitis : a type of osteomyelitis that usually occurs in the late convalescent stage of typhoid fever
• osteomyelitis variolosa : osteomyelitis due to, or occurring as a complication of, smallpox
Laboratory examinations : => cancellous bone (hyperemia/edema (demineralization) and ischemia (osteonecrosis => sequestrum)) => endosteum => cortical bone => periosteum (subperiosteal abscess) => soft points (fistulae and abscesses); fever, increased ESR, neutrophilic leukocytosis
• chronic osteomyelitis
• conchiolin osteomyelitis : a condition seen in workers in mother-of-pearl, probably due to the inhaled dust being deposited in the bone marrow
• diffuse sclerosing osteomyelitis : chronic diffuse inflammatory response of bone to low-grade infection, with inflammatory cell infiltrate, fibrous replacement of marrow, and dense sclerotic masses of trabecular bone. Neutrophils, plasma cells, and focal osteoblasts may be present. Oral lesions occur predominantly in the mandible of older persons and are often sequelae of chronic periodontal disease.
• focal sclerosing osteomyelitis / condensing, formative or productive osteitis / osteitis ossificans : chronic confined inflammatory response of bone to low-grade infection, with formation of dense trabecular bony masses with little interstitial marrow tissue. It occurs particularly in the mandible of children and young adults, adjacent to the apex of a tooth with long-term pulpitis
• primary chronic sclerosing nonsuppurative osteomyelitis / Garré's osteomyelitis, osteitis, or disease / chronic nonsuppurative osteitis / proliferative periostitis / periostitis ossificans : chronic idiopathic osteomyelitis involving the long bones, particularly the tibia and femur, and characterized by a diffuse inflammatory reaction, increased density and spindle-shaped sclerotic thickening of the cortex, and an absence of suppuration. A distinctive type of chronic osteomyelitis associated with gross thickening of the periosteum of the bones (onion skinning) and peripheral reactive bone formation resulting from mild irritation or infections. The condition is seen exclusively in children or young adults. Mandible is more often affected than the maxilla. Clinically it manifests as bony hard, non-tender swelling which is slowly progressive and associated with painful carious tooth^ref.
• ostempyesis : suppuration within a bone.
• syphilitic abscess : one occurring in the bones during tertiary syphilis (Treponema pallidum subsp. pallidum)
Laboratory examinations : Pott's puffy tumor (a circumscribed area of edema surrounding lesions of osteomyelitis of the skull)
• osteanabrosis : atrophy of bone.
• osteectopia / osteectopy : displacement of a bone.
• osteoanagenesis / osteanagenesis : regeneration of bone
• osteoanesthesia : the insensitiveness of bone
• osteoaneurysm : aneurysm in a bone
• osteophlebitis : inflammation of the veins of a bone
• osteothrombosis : thrombosis of the veins of a bone
• osteothrombophlebitis : inflammation extended through intact bone by a progressive thrombophlebitis of small venules, such as sometimes occurs in the mastoid bone.
• osteocachexia : cachexia due to chronic bone disease; also chronic disease of bone
• osteocampsia / osteocampsis : curvature or bending of a bone, as in rickets
• osteoectasia : bowing of the bones.
• osteocele : bony tumor of the testis or scrotum; a hernia containing bone
• osteochondropathy : any morbid condition affecting both bone and cartilage, or marked by abnormal enchondral ossification
• polyglucose (dextran) sulfate–induced osteochondropathy : an experimentally produced disorder of enchondral ossification characterized by a deficient formation of bone matrix in the metaphyses of long bones
• osteoclasia : the absorption and destruction of bone tissue.
• osteodiastasis : the separation of 2 adjacent bones
• osteopathia striata : multiple condensations of cancellous bone beginning at the epiphyseal line and extending into the diaphysis, an abnormality seen only on radiographic examination.
• alimentary or hunger osteopathy : disturbances of the skeletal system observed in famine areas, characterized by a reduction in the amount of normally calcified bone, and attributed to dietary deficiencies and associated hormonal dysfunction.
• myelogenic osteopathy : any bone disease due to the impaired relation between the medullary and osseous tissues.
• osteophyte / osteophyma : a bony excrescence or osseous outgrowth
• osteophytosis : a condition characterized by the formation of osteophytes.
Aetiology :
• in rachid dehydratation => reduced thickness of intervertebral disk => pulpy mass stirs annulus fibrosus => stirring of tendon insertion => traction of longitudinal ligament => bone neoformation having a transverse extension
• in articular capsules stirred by effusion
• in other locations : in osteogenic peripheral areas to redistribute loads over articular cartilage
• syndesmophyte : an osseous excrescence, or bony outgrowth, from a ligament, arising from the annulus fibrosus and having a vertical extension in the rachid
• osteotylus : the callus enclosing the end of a broken bone
• osteosynovitis : synovitis together with osteitis of the neighboring bones.
• osteolathyrism : a skeletal disorder produced in laboratory animals by diets containing the sweet pea (Lathyrus odoratus) or its active principle, b-aminopropionitrile, or other aminonitriles. Characterized, in rats, by hernias, dissecting aortic aneurysms, lameness of the hind legs, exostoses, and kyphoscoliosis and other skeletal deformities, apparently as the result of defective aging of collagen tissue.
• osteohydatidosis : hydatid disease of bone
• arthropathies => articular rheumatisms (pain during both active and passive movements)
• monoarticular arthropathies
• oligoarticular or pauciarticular arthropathies (2-3 joints)
• polyarticular arthropathies (> 3 joints)
• hemarthrus : hemorrhage in a joint

Aetiology : hemophilia
• calculous concretion / articular or joint calculus / chalk stone : a deposit in a joint; it is usually composed of sodium urate, sometimes of calcium urate
• psychogenous rheumatism
• reflex sympathetic dystrophy (RSD) / algodystrophy
The structure which is initially affected may be :
• articular cartilage : degenerative rheumatisms : osteoarthrosis

Epidemiology :  female:male ratio 2:1
• primary osteoarthrosis (average onset at age 45-55)
• senile osteoarthrosis (> 65 yy)
Aetiology :
• primitive idiopathic osteoarthrosis
• localized
• hand arthrosis
• foot arthrosis
• gonarthrosis
• coxarthrosis
• vertebral spine arthrosis
• glenohumeral arthrosis
• acromioclavicular arthrosis
• tibiotarsal arthrosis
• sacroiliac arthrosis
• temporomandibular joint (TMJ) dysfunction
• generalized (> 3 abovementioned joints according to Kellgren-Moore criteria)
• secondary to
• trauma
• acute trauma
• chronic trauma
• occupational trauma
• sport
• knee and ankle in footballers
• thumb in cricket players
• hip in Zulu dancer
• congenital developmental disorders
• congenital hip (acetabular) dysplasia / subluxation
• osteochondrosis / epiphyseal ischemic necrosis : a disease of the growth or ossification centers in children that begins as a degeneration or osteonecrosis followed by regeneration or recalcification.

Epidemiology : 1.7%
Symptoms : pain
It may affect :
• articular or epiphysary forms (target growing nuclei)
• vertebrae : Scheuermann's disease / vertebral epiphysitis / kyphosis dorsalis juvenilis
• ilium
• epiphysiolysis capitis femoris / slipped femoral capital epiphyses
• capitular epiphysis (head) of the femur : Legg-Calvé-Perthes disease / Waldenström's disease / coxa plana / pseudocoxalgia
• Kohler's second disease
• extraarticular or apophysary forms (target entheses)
• capitellum of the humerus : Panner's disease
• tuberosity of the tibia : Osgood-Schlatter syndrome / apophysitis tibialis adolescentium
• medial condyle of the tibia : osteochondrosis deformans tibiae / Blount's disease / nonrachitic bowleg / tibia vara
• calcaneus (os calcis) : calcaneal apophysitis / Sever-Haglund disease
• navicular (tarsal scaphoid) : tarsal scaphoiditis / Kohler bone disease
• lunate (semilunar) bone : Kienböck's disease / lunatomalacia
• head of the second metatarsal bone : Freiberg's disease or infraction
• metabolic disorders
• alcaptonuria
• hemochromatosis
• Wilson disease
• Gaucher disease
• endocrine disorders
• acromegaly
• hyperparathyroidism
• diabetes mellitus
• dyslipidemias and obesity
• hypothyroidism
• calcium depots-associated diseases
• chondrocalcinosis
• calcium hydroxyapatite crystals
• osteopathies or arthropathies
• localized :
• fractures
• aseptic necrosis
• septic arthritis
• gout
• diffuse :
• Paget's disease of bone / osteitis deformans
• arthritides
• rheumatoid arthritis
• osteopetrosis
• osteochondritis
• neurogenic or neuropathic arthritis or arthropathy / Charcot's arthropathy, disease or joint : chronic progressive degeneration of the stress-bearing portion of a joint, with bizarre hypertrophic changes at the periphery. Loss of sensation leads to relaxation of supporting structures and chronic instability of the joint
• diabetes mellitus (0.5%), including Lisfranc fracture/luxation of tarsometatarsal joints
• dorsal tabes (knees, hips, and ankles)
• myelomeningocoele
• syringomyelia (shoulders, elbows, and wrists)
• amyloidosis
• leprosy
• congenital pain unsensitivity
• Charcot-Marie-Tooth (CMT) peroneal muscular atrophy
• endemic arthrosis
• Kashin-Bek (Kaschin-Beck) disease (KBD) / osteoarthritis deformans endemica : a slowly progressive, chronic, disabling, degenerative disease of the peripheral joints and spine, which principally occurs in children and is endemic in eastern Siberia, northern China (Tibet), and Korea

Aetiology :
• selenium deficiency
• high concentration of organic matter (mainly fulvic acid) in drinking water
• ingestion of cereal grains infected with Fusarium sporotrichiella
• Mseleni disease : Mseleni in Northern Zululand is a remote geographically isolated improverished district in which about 2,000 persons suffer from a crippling joint disease similar to dysplasia epiphysealis multiplex and spondyloepiphyseal dysplasia. 11% of the men and 39% of the women in young adult life are seriously disabled and, with concurrent osteoarthritis, 90% of the population are grossly incapacitated in old age
• Handigodu disease in Karnataka India : hips are destroyed in 80% of cases in the acute form of this disease which is brought on by environmental factors related to subtropical climate, low animal protein intake and intake of a variety of possibly toxic products of vegetable origin
• other diseases
• hemophilias
• hemoglobinopathies
• sickle cell anemia (SCA) dactylytis
• articular effusions during sickle cell anemia (SCA) crises
• osteomyelitis
• bone infarction
• osteonecrosis
• bone alterations secondary to medullary hyperplasia
• septic arthritis
• gouty arthritis
• decompression syndrome
• freezing disease
• drugs
• quinidine
• amphotericine B
• rifampin
• fluoroquinolones
• acyclovir
• cimetidine
• IFNs
• IL-2
• vaccines
Pathogenesis : asymmetric decrease of chondroblasts and amorphous substance with increase in KS / CS and CS IV / CS VI rates, sometimes arthritis (oedema of synovial membrane, angioneogenesis, fibrin depots, fibrosis of capsulae and tendons). Repair occurs along wrong gravity lines => osteophytes.
Symptoms : arthralgia (gonalgia, coxalgia) worsening under effort, improving when resting (on the contrary of arthritis), lasting < 1 hr
Laboratory examinations : X-rays shows decreased intraarticular space, osteophytes, calcifications of vertebral annulus => syndesmophytes.
Therapy :
• glucosamine sulfate
• hyaluronic acid
• synovial membrane : inflammatory rheumatisms :
• osteoarthritis / arthritis / degenerative or hypertrophic arthritis / degenerative joint disease : a noninflammatory degenerative joint disease seen mainly in older persons, characterized by degeneration of the articular cartilage, hypertrophy of bone at the margins, and changes in the synovial membrane. It is accompanied by pain, usually after prolonged activity, and stiffness, particularly in the morning or with inactivity
• acroarthritis : arthritis affecting the extremities
Epidemiology : affecting over 5% of adults (at some degree, about 80% of people aged > 65 years). Women are more seriously affected than men.
Aetiology : a polymorphism in the aspartic acid (D) repeat (D14 allele) of asporin is more common in hip and knee osteoarthritis patients. Asporin suppresses TGF-b-mediated expression of the genes aggrecan (AGC1) and type II collagen (COL2A1) and reduced proteoglycan accumulation in an in vitro model of chondrogenesis. The effect on TGF-b activity is allele-specific, with the D14 allele resulting in greater inhibition than other alleles. In vitro binding assays showed a direct interaction between asporin and TGF-b^ref. ASPN belongs to a family of leucine-rich repeat (LRR) proteins associated with the cartilage matrix. The name asporin reflects the unique aspartate-rich N terminus and the overall similarity to decorin^{ref1, ref2}. Mice defective for aggrecanase / ADAMTS5 are resistant to osteoarthritis^{ref1, ref2}
Therapy :
• exercise and strength training for knee OA (< 5000 dollars/QALY)
• knee bracing
• paracetamol is the most appropriate first-line analgesic
• NSAIDs may be used as second-line analgesia on an as-needed basis (including continuous use), but must be used with caution
• CSI are used if there are risk factors for upper-gastrointestinal complications, but only after considering cardiovascular risk.
• complementary and alternative medicine (CAM) therapies
• acupuncture
• homeopathy
• phytotherapy
• selected nutritional supplements / nutraceuticals : there is little scientific evidence at the cellular and molecular levels to explain their mechanisms of action
• fish oils (e.g. cod liver oil) : gamma linolenic acid (GLA)
• capsaicin
• green tea
• S-adenosyl methionine (SAMe) has a "slower onset of action" than does celecoxib, but the 2 treatments are equally efficacious^ref
• chondroitin sulphate
• glucosamine sulfate is a safe and effective over-the-counter symptomatic relief