Key Terminology & Definitions - Musculoskeletal II Flashcards
(119 cards)
1
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Fibrous joint
A
United by fibrous tissue (little movement); e.g. sutures (skull), syndesmoses, and gomphoses (periodontal ligament of tooth root)
2
Q
Sutures
A
= Cranial sutures, fibrous joints that connect the bones of the skull
3
Q
Syndesmosis
A
Complex fibrous joint between two bones and connected by ligaments + strong mem, slight movement e.g. distal tibiofibular syndesmosis/inferior tibiofibular joint
4
Q
Gomphosis
A
Fibrous mobile peg-and-socket joint e.g. periodontal ligament (tooth root) + alveolar bone
5
Q
Cartilaginous joint
A
Union consists of either hyaline or fibrocartilage or a combination, sub-types = synchondrosis, symphysis
6
Q
Synchondrosis
A
Primary cartilaginous joint mainly found in developing skeleton e.g. growth plates
7
Q
Symphysis
A
Fibrocartilaginous joint in which the physis (body) of one bone meets the body of another all but two of the symphyses lie in the vertebral (spinal) column, all but one contain fibrocartilage as a constituent tissue
8
Q
Synovial (diarthrodial) joint
A
Hyaline articular cartilage, articular capsule, joint space with synovial fluid (ligaments, fibrocartilaginous menisici, more complex, involved in supporting structures, most common joint
9
Q
Articular cartilage synovial joint anatomy
A
Has loops of type II collagen embedded in hyaluronic acid matrix, no blood vv. or nerves in cartilage
10
Q
Joint capsule synovial joint anatomy
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Continuous with periosteum
11
Q
Subchondral bone synovial joint anatomy
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More deformable than normal bone, shares load when weight bearing, joint diseases makes bone denser - more strain on cartilage and worse damage e.g. esteosclerosis
12
Q
Synovial membrane
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Comprised of two types of synoviocytes, synovial fluid should be clear, colourless to light yellow + viscous
13
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Type A synoviocytes
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Macrophage-like, phagocytose and degrade debris
14
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Type B synoviocytes
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Produce synovial fluid (hyaluronic acid and glycosaminoglycans)
15
Q
Intervertebral disc
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Provides elasticity and shock absorption (buffer)
16
Q
Nucleus pulposus
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Intervertebral disc component - water and proteoglycans, few collagen fibres (fluid),
17
Q
Annulus fibrosus
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Intervertebral disc component - collagen fibres and some fibrocartilage (+ hyaline cartilage)
18
Q
Degenerative joint disease (DJD)
A
= Osteoarthrosis/degenerative arthropathy, 1^y and 2^y gross lesions are identical (any joint/articular incongruence/misalignment will turn into DJD
19
Q
Monoarticular
A
One joint
20
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Polyarticular
A
Multiple joints
21
Q
Primary DJD
A
Inevitable consequence of ageing, no predisposing cause, common incidental finding at PM in old animals
22
Q
Secondary DJD
A
Due to an underlying abnormality or injury in the joint, cartilage degenerates prematurely
23
Q
Osteosclerosis
A
Abnormal inc in density + hardening of bone
24
Q
Osteochondromatosis
A
Benign neoplasm involving synovial mem, cartilage develops by metaplasia of connective tissue cells of mem
25
Osteophyte
Bony lumps/spurs
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Eburnation
Painful bone-on-bone contact causing polishing of articular the surface (complete loss of articular cartilage)
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High motion joint e.g. + DJD
Gradual cartilage erosion, subchondral bone sclerosis, chronic synovitis + joint capsule fibrosis -> stiffening e.g. metacarpophalangeal (fetlock) - most commonly affected by DJD, distal interphalangeal joint (coffin joint)
28
Low motion joint e.g. + DJD
Maximum loading is focused on a small area -> full-thickness cartilage necrosis with limited wearing, can result in ankylosis e.g. hock, proximal interphalangeal joint (pastern joint)
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Ankylosis
Abnormal stiffening + immobility of joints due to fusion of the bones
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Ringbone
DJD of interphalangeal joints, most common in forelimbs, older horses, early lesion is joint capsule fibrosis, progresses to osteophyte formation + ankylosis later
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High ringbone
DJD of proximal interphalangeal joint (pastern joint)
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Low ringbone
DJD of distal interphalangeal joint (coffin joint)
33
Spavin
Gross changes in tarsal/metatarsal, usually on medial aspect, starts as fibrous ankylosis and progresses to bony ankylosis
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Bog spavin
Excess synovial fluid in early tarsal DJD (occupying larger area)
35
Bone spavin
Firm swelling due to bone remodelling in chronic tarsal DJD
36
Navicular syndrome
Loss of articular cartilage and bone resorption of distal sesamoid bone, periarticular osteophytes form, bone resorption follows nutrient arteries, usually forelimbs, bilateral
37
Chondrodystrophic breeds
Short legs, long backs e.g. Dachshunds, Basset hounds
38
Intervertebral disc disease (IVDD)
Mainly dogs, faster in chondrodystrophic breeds, collagen content of nucleus pulposus increases and decrease of proteoglycans with age
39
Disc herniation
Two types (Hansen type I & II), both usually dorsal (thinner annulus fibrosus than ventral)
40
Hansen type I IVDD
Massive extrusion of disc material into spinal canal, almost exclusively w/ chondrodystrophic breeds w/ disc degeneration, all discs are mineralised but usually only one herniate, may damage vessels leading to haemorrhage, ascending myelomalacia in some cases, extruded disc promote inflammation, can adhere to dura mater.
Non-chondrodystrophic breeds - can occur due to trauma but liquid disc means milder damage (Hansen type III)
41
Malacia
Softening and necrosis of nervous tissue - complete loss of architecture and cells
42
Hansen type II IVDD
Bulging of annulus fibrosis causing protrusion into spinal canal, non-chondrodystrophic breeds, obesity, nucleus pulposus stays mucoid until middle or old age, won't degenerate, degeneration of annulus fibrosus allows slow protrusion of the disc, common in areas of high vertebral mobility, no rupture and no extrusion of contents = milder clinical signs
43
Areas of high vertebral mobility
Thoracolumbar region - distal/caudal thoracic vertebrae + cranial lumbar vertebrae
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Spondylosis (or spondylosis deformans, ankylosing spondylosis (multiple vertebrae), bridging spondylosis
Osteophytes form along ventral vertebral bodies and can bridge between them, due to degenerative changes in ventral annulus fibrosus (stretching and tearing), dogs, bulls (+ rams + pigs)
45
Osteochondrosis
Failure of endochondral ossification, 3 forms, typically associated with initial necrosis within growth plate/articular epiphyseal cartilage complex, young, growing animals, often bilaterally symmetrical, regions of thickened, depressed, wrinkled cartilage due to collapse of necrotic cartilage, later can form a cleft that separates the cartilage from the bone -> cartilage flap, can break off into joint cavity = painful
46
Cervical myelopathy 'wobbler' syndrome
Horses + dogs - articular facet of vertebrae can predispose this, two forms, grossly thickened ligamentum flavum (ventral aspect of neural arches) + dorsal lamina, articular facet osteophytes
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Cervical myelopathy - static form
Horses + dogs - show clinical signs w/o flexion/extension, articular facets are displaced ventromedially (towards spinal canal)
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Cervical myelopathy - dynamic form
Horses only - clinical signs when neck flexed
49
Hip dysplasia
Lack of conformity between the femoral head and acetabulum -> joint laxity + DJD, large/giant dog breeds common, joint subluxation in dogs, sporadic cases in other species (e.g. Hereford cattle), lesions most prominent on weight-bearing areas or femur and dorsal acetabulum, femoral head becomes flattened and neck of femur thickens, formation of marginal osteophytes may make acetabulum look deeper than it is
50
Atlantoaxial subluxation
Small breed dogs - odontoid process of axis fails to fuse with body, dens is too small (severe dorsal displacement), corrected via surgery
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Patellar luxation
Common in dogs, infrequent in horses, rare in other species, unilateral or bilateral, variable severity, joint instability predisposes to DJD
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Patellar luxation - dogs
Usually medial luxation, small breeds (lateral luxation less common, usually seen in larger breeds), defects in stifle angle and direction of tension on patellar ligament, once patellar is out of the groove, it remains shallower and worsens risk of luxation and DJD
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Patellar luxation - horses
Congenital hypoplasia of lateral ridge of trochlea, heritable in miniature horses, ponies
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Synovitis
Inflammation of synovial membrane
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Tenosynovitis
Inflammation of synovial joint + adjacent tendon sheaths
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Arthritis
Inflammation of synovial membrane and other components of joint
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Osteoarthritis
Inflammation secondary to degenerative joint disease
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Pannus
Covers e.g. entire articular surface / formation, erosion of joint margins = granulation tissue
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Infectious inflammatory joint disease
Young livestock, horses, sequel to systemic disease (neonatal bacteraemia) e.g. cystitis, generally affects multiple joints (polyarthritis) + may have osteomyelitis, penetrating wounds
60
Fibrinous arthritis
Bacterial - fibrin clots, abundant turbid synovial fluid, villous hyperplasia, articular cartilage not affected unless covered by pannus (granulation tissue) , pannus -> adhesions + ankylosis. early lesions may have periarticular oedema, chronic = lymphplasmacytic e.g. group A streptococci, erysipelas
61
Suppurative/purulent arthritis
```
Abundant neutrophils (degenerate + non-degenerate) in synovial fluid + membrane, more destructive than fibrinous arthritis, causes cartilage destruction at weight bearing areas, articular margins, if cartilage erodes, infection can get into underlying bone -> cartilage separation + ulceration + involvement of subchondral bone (epiphysis = osteomyelitis)
Septic arthritis (bacteria) = degenerative neutrophils
Non-degenerate neutrophils = mycoplasma, Borrelia, some viruses
Non + degenerate neutrophils = immune-mediated arthritis
```
62
Diskospondylitis
Inflammation of the vertebral disc + associated vertebrae, due to primary bacteraemia, large breed dogs (lumbosacral, Staphylococcus pseudintermedius), pigs (upper thoracic, upper lumbar, erysipelas, T. pyogenes, staphylococci, Brucella suis), early lesions = soft, grey-yellow, extend into spinal canal/bone, later = disc destroyed, fibrosis, osteophytes
63
Erysipelas rhusiopathiae
Pigs (pig to pig transmission) - fibrinous polyarthritis, vacc inc risk
Lambs (omphalitis, tail dock/castration infection) - fibrinopurulent polyarthritis, high morbidity/low mortality
64
Steptococci
Calves - no obvious joint swelling - sub-clinical, PM to isolate pathogen
Lambs - polyarthritis (second most common behind erysipelas)
Pigs (S. suis) - purulent arthritis (uncommon)
65
Escheria coli
Calves - poly arthritis, tenosynovitis
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Staphylococci
Livestock (S. aureus) - polyarthritis
Dogs (S. aureus) - monoarticular - foreign body disease/trauma
Pigs (S. hyicus) - fibrinopurulent (elbow, tarsus)
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Haemophilus parasuis
Pigs - polyarthritis (Glasser's disease) = fibrinous/fibrinosuppurative
68
Histophilus somni
Lambs - fibrinopurulent
| Cattle - fibrinous, affects one or two joints
69
Borella (Borrelia burgdorferi = Lyme disease)
Dogs - intermittent arthritis involving one or more joints, lymphplasmacytic synovitis (non-specific), infection more common than disease
70
Chlamydophila pecorum
(Only chlamydia that causes arthritis in animals)
Calves - polyarthritis, usually fatal systemic disease
Lambs - high morbidity/low mortality, joint stiffness resolves with exercise (self-remission)
71
Mycoplasma
Livestock - polyarthritis, persistent antigen causes inflammation long after agent is gone
Pigs (M. hyorhinis > M. hyosynoviae) - fibrinopurulent polyarthritis
Goats > sheep - fibrinopurulent arthirits, hyperplastic synovitis
Cattle (M. bovis) - sporadic arthritis in any age group, half of feedlot cattle with M. bovis pneumonia also have fibrinosuppurative arthritis
72
Caprine arthritis and encephalitis virus (CAEV)
Transmitted in colostrum and milk, virus damages vascular supply to synovial structures, infection more common in goats w/ variable morbidity, lameness, high prevalence of carpal hygromas (chronic flattened, fluctuant, subcutaneous distention over cranial carpus full of yellow or bloody fluid +/- fibrinous clots), don't typically communicate w/ tendon sheath, thickened joint capsule +/- mineral, joints distended by clear yellow fluid (carpus, stifle), villous hypertrophy, cartilage erosion, pannus, lymphoplasmacytic arthritis
73
Hygromas
Fluid-filled sacs that develop as a result of repeated trauma or pressure over a bony prominence
74
Fungi (inflammatory joint disease)
Dogs (blastomycosis, Histoplasma capsulatum, Coccidiosis immitis, cryptococcus neoformans, Sporothrix schenkii) - occasional cause of pyogranulomatous arthritis
75
Protozoa (inflammatory joint disease)
Dogs, cats (Leishmaniasis) - other manifestations more typical
76
Bursae
Fluid-filled pockets at regions of friction, can be part of normal anatomy (synovial) or acquired (adventitious), important in horses (nuchal ligament and underlying bursae)
77
Cranial nuchal bursae
Between atlas and nuchal ligament (horses)
78
Caudal nuchal bursa
Between axis and nuchal ligament (horses)
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Supraspinous bursa
Between spinous process of T2 and nuchal ligament (close to saddle area) (horses)
80
Bursitis
Inflammation of the bursae, infectious (Actinomyces bovis, streptococci, staphylococci, Brucella abortus)/non-infectious (sterile = trauma, less likely to fistulate to surface)
81
Fistula
Abnormal connection
82
Poll evil
Inflammation of the cranial/and or caudal nuchal bursa
83
Fistulous withers
Inflammation of the supraspinous bursa
84
Adventitious bursae
From outside the joint capsule over bony prominences subjected to trauma (similar to sterile seroma), horses (capped elbow (olecranon, capped hock (tuber calcaneus), ruminants (carpal bursitis (hygroma), dogs (elbow hygroma), pigs (capped hocks), can be inflamed but not primary inflammatory lesions
85
Seroma
Build-up of clear fluid, not at a pressure point
86
Immune-mediated polyarthritis (IMPA)
Dogs + cats - can resemble infectious arthritis, non-degenerative neutrophils, hocks, carpi, stifle predisposed, erosive (cartilage destruction) and non-erosive (cartilage spared) forms
87
Erosive IMPA
Rare (1% of cases), greyhounds, immune complexes deposit in synovium and cause complement fixation, inflammation + degradation of cartilage matrix e.g. rheumatoid arthritis
88
Rheumatoid arthritis
Formation of rheumatoid factor = antibodies to immunoglobulins, rare in animals but can affect dogs -> destruction of cartilage + bone
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Non-erosive IMPA
Most common, usually idiopathic, young, large breed dogs, antigen-antibody complexes deposit in synovium + recruit lymphocytes + neutrophils (pleocellular inflammatory response), no cartilage erosion, four types, can be vaccine/drug-induced - brief
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Type I non-erosive IMPA
Uncomplicated - most common, source of complexed unknown
91
Type II non-erosive IMPA
Reactive - associated with distant infection or inflammation
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Type III non-erosive IMPA
Enteropathic - associated with gastrointestinal or hepatic disease
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Type IV non-erosive IMPA
Associated with carcinomas, leiomyosarcoma, lymphoma
94
Familial shar pei fever
Non-erosive IMPA - due to mutation caused inc hyaluronic acid production = characteristic folds. degradation of hyaluronic acid triggers immune system -> cyclic fever, pain, hock swelling (periarticular cellulitis +/- articular inflammation) (23% affected)
95
Hyaluronic acid
Substance found in the fluids in the eyes and joints - acts as a cushion and lubricant in the joints and other tissues
96
Systemic lupus erythematosus (SLE)
Non-erosive IMPA - uncommon, associated with signs of disease elsewhere e.g. cutaneous disease/visceral involvement, LE cells can be present in synovial fluid = pink material, displaces nucleus to periphery
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Lupus erythematosus (LE) cells
Neutrophils with partly degraded phagocytosed nuclear material
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Histiocytic sarcoma
Most common joint tumour in dogs, less common in cats, DC/type A synoviocyte origin, disseminated or local forms, chronic joint inflammation predisposes its development, stifle > elbow, shoulder, coxofemoral joint, carpus, tarsus, soft multilobulated tan mass infiltrating into join + surrounding soft tissues, vacuoles on cyto (malignant)
99
Synovial myxoma
Second most common joint tumour in dogs, seen in cats, stifle, digit >tarsus, elbow, carpus, vertebral facets, soft white translucent nodules that extend into surrounding tissues, slow growing, produces abundant viscous fluid, benign but can cause bony lysis (neoplastic osteolysis), soindle cells with a lot of myoxid matrix, middle-aged, large breed dogs predisposed, long history of clinical signs before diagnosis
100
Myoid
Connective tissue that looks more blue or purple compared to normal connective tissue on histo
101
Synovial chondromatosis
Osteochondromatosis if nodules ossify (have both components, bone + cartilage), shoulder > digits, elbow, tarsus, can transform to chondrosarcoma, hard pearly nodules attached to synovium but some can detach, large breed dogs, males, cats, horses, pigs
102
Primary synovial chondromatosis
Develops spontaneously, no underlying cause, more nodules than 2^y
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Secondary chondromatosis
Develops due to degenerative joint disease (cartilage fragments break off and lodge in synovium or synovium undergoes chondroid metaplasia)
104
Synovial cyst
Rare, periarticular cavity lined by synovium + containing synovial fluid, usually communicate w/ joint space + associated joint has DJD, due to herniation of synovium from joint space, old cats around elbow, sometimes digits, dogs - spine + compresses SC, horses, digital flexor tendon sheath (superficial/deep), sometimes spine
105
Ganglion cyst
Contain viscous fluid but no synovial lining
106
Kyphosis
Excessive outward curvature of spine
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Lordosis
Inward curve of the lumbar spine
108
Scoliosis
Abnormal lateral curvature of the spine
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Chondrones
Chondrocyte cells at the periphery of damaged joint that have proliferated to form clusters + secrete matrix
110
Synovial pannus
Arises from synovium at joint capsule insertion line, may arise from subchondral capillary bed beneath ulcerated articular surface, increased O2 tension from capillaries kills chondrocytes while inflammatory mediators destroy matrix -> flat sheet of granulation tissue
111
Sclerosis
Hardening of tissue due to overgrowth of fibrous tissue and other changes
112
Spontaneous osteoarthritis (OA)
Can occur early in equine athletes, or later in older horses, arthroscopic grading systems (carpus, fetlock) + biomarkers related to macroscopic and histologic cartilage lesions
113
Osteochondrosis pigs
```
V. common, usually latens
Dorsal acetabulum
Humeral head
Humeral condyles
Occasionally physes
Medial femoral condyle
```
114
Osteochondrosis in horses
One of most common predisposing causes for Wobbler syndrome - cervical vertebrae instability (cervical articular facets)
Lateral trochlear ridge, medial femoral condyle, patella
Distal tibia, tarsus
Fetlocks
Young, active (due to repeated trauma)
115
Osteochondrosis in dogs
Young, male, large breed
| Humeral head
116
Osteochondrosis in cows
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Lateral trochlear ridge
Tibiotarsal joint
Occipital condyles (lesser prevalence)
Humeral head
Elbow
Distal radius
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117
Canine rheumatoid arthritis
Unknown cause, immune-mediated (humoral and cell-mediated immunity) - AB (rheumatoid factor) of IgG or IgM produced in response to unknown stimulus, factors involve steric configuration of IgG, persistent bacterial cell wall components that cross-react w/ normal proteoglycans, anticollagen antibodies + defective suppressive T lymphocyte activity, characterised by exuberant pannus formation
118
Joint subluxation
Results as joint margins are reduced
119
Joint ankylosis
Occurs in high-load/low-motion joints
