Orthopaedics: Cattle Lameness, Arthritides, Tendons, Ligaments and Muscle Flashcards
What is lameness commonly mistaken for?
Disease
Lameness is a sign not a disease
Why is lameness on farms important to monitor and aim to reduce?
Animal welfare- painful
High yielding animals more susceptible and reduced lactation yield
Cows have delayed cyclicity
Increased ovarian cycts
Lower oestrus intensity
Prolonged calving intervals
Increased culling
Reduced eating/DMI
Low BCS
Costs- treatment, labour, reduced yields, culling
How can lameness be monitored?
Mobility scoring and lesion recording
How is mobility scored?
Different ways- fortnightly
Video analytics
Scale 0-3
0- even weight baring, rhythm, long strides, flat back
action- none needed, routine trimming
1- steps uneven, strides shortened, affected limb not identifiable
action- could benefit from routine foot trimming, further observation
2- Uneven weight baring on an identifiable limb, shortened stride usually with an arch
action- lame, likely to benefit from treatment, identify the cause, attend ASAP
3- unable to walk as fast as brisk human pace, signs of score 2
actions- very lame, treatm urgent attention, don’t make walk, cull?
What are the different foot lesions?
Sole bruising
Sole ulcer
White line disease
Digital dermatitis
Heel erosion
Interdigital growths
Heel ulcer
Foul
Axial wall fissure
Toe necrosis
Foreign body
Toe ulcer
How are hocks assessed?
Score 1- no swelling, no hair missing
Score 2- not swelling, bald area
Score 3- swelling, lesion through the hide
Score the rear hock
Define the following terms:
Foot
Claw
Claw capsule
Cannon bone
Axial Surface
Abaxial surface
Dorsal surface
Flexor surface
Solear surface
Dewclaw
Wall
Exostosis
foot- the region from hock to apex of claw
Claw- end of the digit
Claw capsule- structure composed of horn- pedal bone fit
Cannon bone- bone between the hock and fetlock (metatarsal)
Axial surface- the surface of the claw facing the space between the claws
Abaxial surface- the surface of the claw facing away from the claws
Flexor surface- back of the limb
Dorsal flexure- transition from axial to abaxial
Solear- sole
Dewclaw- miniature editions of claw
Wall- coronary segment of claw
Exostosis- bony growth protruding the surface
Label the following bones
Hind limb
What are the different labels?
What are lamellae and laminae?
Lamellae- these are leaflets of horn lining the inside of the wall
Laminae- leaflets of connective tissue, collagen fibres blood vessels and nerves that fit between lamellae
What attaches the pedal bone to the dermal lamellae?
Collagen fibres
What are the biomechanics of the cows foot?
Continuous growth
Continuous wear
Forelimbs attached to the body by more elastic componsnet
Lateral claws outgrow mdeial
Solar dermis is under pressure between the pedal bone and the sole
How should a foot be ideally trimmed?
What angle?
What is the dutch method to functional claw trimming?
- Start with medial hind claw
- Trim dorsal wall length to 7, 5-8cm
- Reduce sole depth at the toe to approx 5 to 7 mm
- Spare the heel
- Correct wall length
- Model- dish out
- Deeper and wider modelling of the lateral hind/medial foreclaw
What are the infectious and non-infectious lesions that cause lameness?
Infectious- digital dermatitis, foul, interdigital dermatitis, heel horn erosion
Non- infectious- sole haemorrhages/bruising, sole ulcers, white line lesions
What are arthritides?
What is arthritis?
Conditions causing pain and dysfunction related to joints
Arthritis- inflammation/degeneration of the joint including osteoarthritis, inflammation, infective
What is a diarthrodial joint?
A specialised joint consisting of a synovial cavity allowing articulation between two or more bones
Common examples- bone and socket
What is osteoarthritis?
Why is it important?
the degenerative condition ultimately leading to cartilage breakdown and loss of function
Importance-
Cause of pain and suffering- welfare
Cost to clients- drugs, milk loss
Loss of function- joint diseases most common cause of euthanasia with horses
What is synovial fluid?
What is in the fibrous joint capsule of synovial joints?
Synovial fluid- ultra filtrate of the plasma plus protein- hyaluronic acid
Fibrous joint capsule- synovial membrane, nerves and blood vessels- proprioception, supportive ligaments/tendons- collateral
What is articular cartilage?
Highly specialised- predominantly extracellular matrix with a low density of articular chondrocytes
Chondrocytes are responsible for the maintenance of the matrix
Matrix mainly- collagens, proteoglycans and water-
collagens confer shear resistance, hydrates proteoglycans provide compression
Limited repair
Dynamic loading/unloading- loading important for health of joint
What is osteoarthritis?
What are predisposing factors?
Classically thought of as articular cartilage disease
Number of tissues- contributing to progression- articular cartilage, subchondral bone, synovial membrane, joint capsule, ligaments, fat pad
Predisposing factors-
Excercise, trauma, biomechanics- normal joint, abnormal forces
sclerosis, intra-articular fracture, soft-tissue surgery
DOD- normal forces, abnormal joints-
hip and elbow dysplasia, osteochondrosis
Obesity- weight stress
Sepsis
Repeat medication- corticosteroids
Ageing- wear and tear
What history needs to be taken for osteoarthritis?
Describe the clinical exam for a dog with potential osteoarthritis?
History-
age, signalment, use
level of excercise
determine onset and progression of disease
response to medication
Clinical examination-
general physical examination
TPR, thoracic auscultation
Assessment of body condition, confirmation, muscling
Lamenss examination- observation, palpation, manipulation, movement
Diagnostic imaging
What are the radiographic signs of osteoarthritis?
- Soft tissue swelling
- Oestoephysis- new bone formation around the joint- extensions along margins- painful and restrictive
- Enthesiophytosis- new bone formation in soft tissues
- Subchondral bone sclerosis- increased bone density
- Intra-articular mineralisation- meniscus
- Fragmentation/joint mice
- Collapsed joint space
- Subchondral bone cysts
How does immune-mediated joint disease often present?
What is the cause?
Describe the pathophysiology
How is it diagnosed?
Usually, polyarthritis and can be erosive or non-erosive
Predominantly idiopathic- may be related to extra-articular disease- genetic
Most relate to abnormal activity of immune cells and antigen presentation
Path- early changes occur in the synovium
Chronic antigenic stimulation
Antibodies to infective agents or macromolecule modification leading to inappropriate immune response
Development of immune complexes
Diagnosis-
Multiple limb joint pain/swelling, generalised stiffness, shifting lameness, neck pain
Variable and intermittent, secondary to OA and fibrosis
How is immune-mediated joint disease managed and treated?
Managment-
Synoviocentesis- cell count, protein smear, differentiate from sepsis
Full clinical exam- characterise the involvement of other body systems, haematology
Diagnostic imaging- early non-specific effusion
Treatment- corticosteroids