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General Definitions



Absence of a limb


A procedure which removes a part through one or more bones as opposed to disarticulation

Aneurismal Bone Cyst

Benign lesion of bone, characterised by lytic expansion of the bone with cavernous blood filled spaces and fibrous septae, containing giant cells and immature bone osteoid

Ankylosing Spondylitis

A chronic inflammatory condition, predominantly affecting the spine and sacro-iliac joints, characterised by osseous proliferation and is associated with HLA B27

Antiseptics(Mild disinfectants)

Relatively nontoxic, non-irritant antimicrobial agents, which can be applied topically to the body

Arthrogryposis Multiplex

Congenital, non progressive limitation of movement, due to soft tissue contractures, affecting two or more joints


Preventing wound contamination by ensuring that only sterile material makes contact with the wound and that airborne transmission of organisms is minimised


Incomplete division of a nerve, such that the axons are divided, but endoneural tubes are undamaged and spontaneous recovery is likely

Blounts Disease

Growth disturbance of medial aspect of the proximal tibial physis, resulting in medial angulation of the tibia in the metaphyseal region

Bone Necrosis

Death of bone from ischaemia; i.e. reduction in O2 supply below the level required to sustain life of the cellular component of bone

Bouchard's Nodes

Osteophytic nodes at the PIP joints, similar to Heberdens in OA

Brodies abscess

Translucent lesion with well defined margin and sclerotic rim, usually in the metaphysis of a long bone, without ballooning of the bone.

C Reactive Protein

An acute phase reactant that precipitates with the C polysaccharide of the pneumococcal cell wall


A reparative tissue made up of connective, cartilaginous or bony tissue, or any combination thereof, which ultimately ossifies


Consist of chondrocytes, enmeshed in a superhydrated matrix of collagen and proteoglycans

Cerebral Palsy

A group of disorders, which result from non-progressive cerebral dysfunction, originating before the central nervous system has matured.


Deposition of calcium pyrophosphate dihydrate crystals in joint tissue, which cause acute and chronic inflammatory joint disease

Compartment syndrome

A condition in which increased tissue pressure within a limited space, compromises the circulation and the function of the contents of that space.

Coxa Vara

Localised bony dysplasia of the femoral neck, characterised by a decreased neck shaft angle and the presence of a triangular ossification defect in the inferior femoral neck (Fairbanks Triangle)

Chemotherapeutic Agents

Chemicals used to kill or inhibit the growth of micro-organisms or neoplastic cells, directly established in tissues of the body


A pathological description, which means cartilage softening


Primary tumour with primary cells produced at cartilage matrix

Dagger Sign

Single dense central line on frontal radiographs, related to ossification of supra-spinous or inter-spinous ligaments


Literally means to relieve tension by an incision, but has also implies removal of debris and dead tissue.


Refers to a change in structure of a previously normal organ

Developmental dysplasia of the hip

Referes to a broad spectrum of conditions, characterised by instability of the hip with subluxation or dislocation, due to acetabular or femoral dysplasia

Diaphyseal Aclasis

Condition characterised by multiple cartilaginous and bony exostoses, protruding from bones preformed in cartilage.

Direct Fracture Healing

The type of fracture healing observed with rigid internal fixation and is characterised by the absence of callus formation, absence of bone surface resorption at the fracture site and direct formation of bone, without intermediary repair tissue.


Substances which kill vegetative forms of potentially infectious organisms and are usually used on surfaces (not the skin)


An abnormal position of the osseous structures, such that there is no longer contact between the normally opposing articulating surfaces

Dupuytrens Contracture

Fibroblastic proliferation in the volar surface of the hand leading to contracture of fingers, as a late but significant result of the disease


Pathological diminution in stature, which may be either proportionate or disproportionate


Used to describe a generalised developmental disorder of bone or cartilage


Process in which bone becomes hard and dense like ivory (Latin ebur = ivory) and occurs where bone becomes exposed and subjected to wear

Ehler's Danlos Syndrome

An uncommon familial disorder of connective tissue, related to a genetic defect in Type I collagen


A benign tumour of cartilage, originating within the medullary cavity


Condition characterised by circumscribed masses of cartilage, arranged in linear fashion in the interior of bones.

Olliers' disease refers to a condition where the enchondromata are distributed unilaterally


Inflammation of insertion sites of tendons and ligaments into bone, with or without transient arthritis

Erb's Palsy

An obstetric brachial plexus palsy, affecting the 5th, 6th and perhaps 7th cervical roots, resulting in paralysis of the external rotators of the shoulder, flexors of the elbow and forearm supinators


Exposure of collagen fibres or fibrils following the loss of proteoglycans ? roughening and eventually cracking of the cartilage surface

Fibrous Dysplasia

A benign fibro-osseous pathologic entity of undetermined aetiology, characterised by expanding fibro-osseous tissue in the interior of affected bones (predominantly a lesion of the growing skeleton)

Felty's Syndrome

Chronic rheumatoid arthritis, associated with splenomegally, lymphadenopathy, anaemia, thrombocytopenia, leukopenia (neurtophils only) and may be associated with hyperpigmentation and leg ulcers


A sudden rupture of a structure, which occurs when the internal stress produced by load exceeds the limits of strength

Fracture Consolidation

Complete repair; calcified callus is ossified and attempted angulation is painless. Repair is complete and further protection is unnecessary.

Fracture Delayed union

A fracture that has not united, in a time-window considered reasonable, for a fracture of that type in that location

Fracture Malunion

Consolidation of the fracture has occured in a deformed position

Fracture Non-union

A fracture that will not unite without surgical intervention (may be hypertrophic, oligotrophic, dystrophic, neuretic, or atrophic)

Fracture Union

Incomplete repair; the bone moves as one, but cliniclly it is still a little tender and attempted angulation is painful. The fracture is clearly visible on X-Ray with fluffy callus and is not safe to be left unprotected


A benign lump, characterised by mucinous degeneration within the capsule of a joint, tendon sheath or tendon, usually lacking a recognisable lining of differentiated cells (differentiate from a synovial cyst)

Giant Cell Tumour of Bone

A benign, but often aggressive tumour of bone, characterised by the presence of giant osteoclast like cells in a vascular stroma of plump mononuclear spindle cells


Disorder of purine metabolism, characterised by hyperuricaemia and recurrent attacks of acute synovitis, due to urate crystal deposition


A group of clinical states, which manifest by an abnormality of the coagulation mechanism, caused by functional deficiencies of specific clotting factors


Restoration of the original integrity and is considered completed, when the bone has regained its normal stiffness and strength.


Absence of part of a limb, which may either be transverse or paraxial (longitudinal)

Histiocytosis X

A non-neoplastic proliferation of histiocytes with reactive inflammation

Indirect Fracture Healing

Bone healing as observed in nontreated or fractures treated without rigid fixation, where callus formation is predominant and bone formation results from a process of transormation of fibrous and or cartilaginous tissue to bone


A condition of a joint, caracterised by an abnormal increased range of motion due to injury of ligaments, capsule, menisci, cartilage or bone

Juvenile Chronic Arthitis

Non infective, inflammatory arthritis in children under the age of 16 years of age

Kienbock's Disease

Avascular necrosis of the carpal lunate

Klumpke's Palsy

An obstetric brachial plexus palsy, predominantly affecting the lower roots of the plexus (C8 & T1), resulting in flexion contracture of the elbow with posterior subluxation or dislocation of the radial head and paralysis of long finger flexors and extensors, as well as intrinsic muscles of the hand


Slackness or lack of tension. Looseness; reffering to a normal or abnormal range of motion of a joint

Magnetic Resonance Imaging

A non invasive method of imaging, by measuring the emitted energy from a certain atomic nuclei in a magnetic field, when stimulated by a radiofrequency energy


Denotes a primary abnormality of development

Muscle Dystrophies

Familial disorders, characterised by progressive weakness of muscle, associated with areas of degeneration and regeneration, due to a primary defect in the muscle (Duchenne, Beckers)

Muscle Atrophies

Disorders characterised by weakness, where muscles cells show degeneration within areas of normal tissue, where the muscle changes are secondary to disorders of its innovation


Physiological interruption of a nerve, where the axon is intact and there is degeneration of the myelin sheath


Not a tumour, but an overgrowth of neural connective tissue, following trauma, e.g. amputation, pressure, causing pain and localised tenderness

Neuropathic Joints (Charcot)

A joint in which the appreciation of pain and position sence is lost or significantly deminished


Complete division of a nerve or scaring, such that the nerve cannot regenerate spontaneously


A degenerative joint disorder, in which there is progressive loss of articular cartilage accompainied by new bone formation and capsular fibrosis


The commonest benign tumour of bone (affecting only bones formed in cartliage), characterised by a bony projection from the metaphysis covered with a cartilage cap

Osteochondritis Dissecans

A joint affliction, characterised by partial or complete detachment of a fragment of articular cartilage and bone

Osteogenesis imperfecta

A connective tissue disorder, characterised by osteoporosis, fragile bones, dentinogenesis imperfecta, deafness, blue sclera, ligamentous hypermobility, herniae and easy bruising.

Osteoid Osteoma

A benign tumour of bone, characterised by a nidus of less than 1 cm diameter consisting of a maze of osteoid tissue with trabeculae of newly formed and poorly mineralised bone, in a vascular connective tissue network, which is usually encased in dense reactive bone


Rickets and osteomalacia are different expressions of the same disease and are characterised by inadequate mineralisation of bone

Osteomyelitis (Acute)

Inflammation of marrow and hard tissue elements of bone, as a result of infection

Osteomyelitis (Chronic)

Clinical or radiological evidence of infection of bone of greater than six weeks duration


The composition of bone is normal, but the amount of bone per unit volume is less than normal


Primary tumour arising from bone and producing bone, with variants depending on the appearance of the prominent cell type

Paget's Disease

Condition characterised by high rates of bone resorption and disorganised immature new bone formation, causing abnormal remodelling of bone


Granulation tissue composed of proliferating fibroblasts, numerous small blood vessels and various types of inflammatory cells

Pathological Fracture

A fracture through abnormal bone, resulting from a force that would not disrupt normal bone

Perthes Disease

Osteonecrosis of the proximal femoral epiphysis in a growing child, caused by poorly understood, non-genetic factors


Absence of central elements with foreshortening of the extremity

Pigmented Villo Nodular Synovitis

Diffuse proliferation of synovial lining and stroma of synovial joints or tendons


A disease caused by the polio virus, which affects the anterior horn cells, particularly in the lumbar and cervical segments of the spinal cord, leading to muscle weakness, wasting and limb shortening

Protrusio Acetabulae

Medial displacement of the floor of the acetabulum : If the medial wall of the acetabulum is 3 mm or more medial to the ilioischial line in a male or 6 mm medial to it in a female (normally 2 mm lateral to this line)

Reflex Sympathetic Dystrophy

An abnormal reaction to injury, characterised by pain, swelling, stiffness, vasomotor changes and osteoporosis of the affected part

Reiters Disease

A seronegative spondylo-arthropathy that follows a non-specific urogenital or bowel infection. The clasical triad of arthritis, urethritis and conjunctivitis was described by H. Reiter in 1916

Rheumatoid Arthritis

Chronic inflammatory disease, in which non suppurative inflammation of diarthrodial joints is associated with a variety of extra articular manifestations.

Rheumatoid Factor

Immunoglobin that acts against the FC portion of IgG, usually multivalent IgM. However, many patients have both IgG and IgA rheumatoid factor in their sera. IgE Rh factor which acts against different portions of the IgG structure have also been identified. Sheep agglutination test, depends on presence of multivalent IgM

Rheumatoid Nodule

Granulomatous lesion with central necrosis surrounded by palisades of radially disposed local histiocytes and surrounded by inflammatory granulation tissue


A disease of calcium and phosphate metabolism in children, due to a deficiency of Vitamin D, which chiefly affects areas of active enchondral ossification


Granulomatous disorder of unknown aetiology, affecting multiple organ systems, especially in young adults


Lateral curvature of the spine of 10° or more with associated vertebral rotation (SRS)


Vitamin C deficiency, leading to failure of collagen synthesis and osteoid formation, which is most marked in infants in juxta-epiphyseal bone


Chronic inflammatory condition, characterised by the presence of anti-nuclear antibodies.

Slipped Epiphysis

Progressive displacement of the femoral head relative to the neck, through an open growth plate.

Spinal Dysraphism

Condition where the posterior vertebral arch is unfused, with or without protrusion or dysplasia of the spinal cord or its membranes

Spinal Shock

The complete cessation of all voluntary and reflex activity, below the level of a spinal cord injury, immediately following that injury. Reflex activity returning within 24 hours to 3 months


Loss of intervertebral disk height and extensive new bone formation, resembling infection, without clinical or laboratory evidence to support the diagnosis


Injury resulting in stretching or tearing of ligament fibres, but does not completely disrupt the ligament (as apposed to ligament rupture)


Process where by all living organisms including spores are destroyed


The resistance of a structure to deformation, which is dependent on Young's modulus of elasticity (changes in the geometry are much more critical than changes in material properties)

Strain: (Mechanical)

Ratio of change in length of a substance, when loaded or stressed to its original length (relative deformation)

Strain: (Muscular)

Stretching injury to a musculo-tendinous attachment to bone


The ability to withstand load, without structural failure


Ratio of load to cross sectional area

Stress Fracture

Fracture produced in normal bone, by abnormal repetitive load


A partial dislocation, in which there is abnormal position of the osseous structures forming a joint; however a portion of the opposing articular surfaces are still in contact


Ossification within the annulus fibrosus, leading to thin vertical radio dense areas. Predominantly in anterior and lateral aspects of the spine

Synovial Chondromatosis

Proliferation of islands of irregular cellular cartilage in the synovium of a joint, without underlying arthritis


Release of tendons from restricting adhesions


Disease secondary to a neurotoxin, produced by Clostridium tetani

Unicameral Bone Cyst

Benign developmental lesion of bone characterised by a single fluid filled, symmetrically expanding cavity, but may be multilocular and even multicameral after fractures.

Wormian Bones

Detached portions of the primary ossification centres of adjacent membrane bones. Should be more than 10 to be significant and should measure 6mm x 4mm. Arranged in a mosaic pattern. (Claus Wormius, Danish anatomist)Seen in Cleidocranial dysplasia, Pykinodysostosis, Hypoposphatasia and Hypothyroidism

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