Tendons, ligaments + muscles Flashcards
What do tendons do?
*Transfer force generated by muscle to bony attachments
*Support joints
*Store energy
What do ligaments do?
*Attach / stabilise bones/joints
*Protect tendons
*Proprioception
What type of collagen are tendons?
*95% collagen type I
*1-5% type III
What type of collagen are ligaments?
*90% collagen type I
*10% type III
What type of injuries can occur to tendons/ligaments?
*Extrinsic - external trauma (laceration)
*Intrinsic - overload / degenerative
*Intrasynovial / extrasynovial
*Extensor vs Flexor tendon
How are tendon / ligament injuries diagnosed?
*History - age, type, previous injury, recent exercise, wound / laceration
*Clinical exam - stance / gait, palpation
*Diagnostic imaging - ultrasound, radiography, MRI
What should be assessed with ultrasound in tendon / ligament disorders?
*Change in cross sectional area
*Fibre echogenicity
*Margination
*Position - rupture
*Focal lesion vs generalised changes
*Acute vs chronic changes
*Blood flow to assess neovascularisation
What are the clinical signs of acute inflammatory phase of tendon / ligament injury?
*Lameness
*Pain on palpation
*Heat
*Swelling
What is the pathology of acute inflammatory phase of tendon / ligament injury?
*Haemorrhage
*Inflammation
-neutrophils
-macrophages + monocytes
-oedema
-proteolytic enzymes
What are the treatment principles of acute inflammatory phase of tendon / ligament injury?
*Limit inflammation - cold therapy / NSAIDs
*Protect limb / reduce further damage - supporting bandage / rest
What are the clinical signs of proliferative phase of tendon / ligament injury?
*Reduction / absence of lameness
*Resolution of signs of inflammation
*Tendon still palpably enlarged
*signs of re-injury if exercised too early
What is the pathology of proliferative phase of tendon / ligament injury?
*Angiogenesis
*Fibroplasia
What are the treatment principles of proliferative phase of tendon / ligament injury?
*Promote angiogenesis
*Minimise formation of excessive scar tissue
*Early exercise if lesion filled in
What are the clinical signs of tissue modelling phase of tendon / ligament injury?
*Stiffer / thicker tendon
What is the pathology of tissue modelling phase of tendon / ligament injury?
*Fibrosis
*Gradual change from collagen III to I
What are the treatment principles of tissue modelling phase of tendon / ligament injury?
*increased loading + exercise programme
*Improve fitness
*Monitor progress by repeat ultrasound exam
What is an example of a laceration injury + how would you treat it?
*Flexor tendon laceration
*Repair ends if feasible
*Cast
What is an example of an avulsion fracture + how would you treat it?
*Collateral ligament avulsion
*Re-attach avulsed bone fragment
*Arthrodese joint
*Cast
What is an example of an intra-synovial tendon / ligament tear + How would you treat it?
*SDFT tear in digital flexor tendon (horse)
*Debride torn tendon / ligament fibres
What is an example of a joint instability + How would you treat it?
*Cruciate rupture in stifle (dogs)
*TPLO
What are skeletal, smooth muscle and cardiac myopathies?
*Skeletal = weakness / spasm
*SMooth = retention / incontinence, hypermotility / stasis
*Cardiac = circulatory failure
How are muscle conditions diagnosed?
*History
*Clinical exam - acute / chronic
*Biochemistry
*Ultrasound - acute = haematoma, chronic = fibrosis / calcification
*Muscle biopsy
What are general reactions of muscle?
- Atrophy
- Hypertrophy
- Degeneration
- Regeneration and repair
- Calcification and ossification
- Pigmentation
- Circulatory disturbances
What can cause atrophy of muscle?
*Disuse - reversible
*Denervation - irreversible
-Trauma / myaesthenia gravis
What causes hypertrophy?
*increased workload
*Compensatory hypertrophy
What are the 3 different types of degeneration?
*Cellular swelling
*Hyaline degeneration
*Granular degeneration
When does regeneration + repair occur? What happens if it can’t regenerate?
*Regeneration + repair is less severe degeneration = back to normal function
*If irreversibly damaged tissue = Calcification + ossification
What can blockage of main arteries + veins cause in cats, horses + cattle?
Distal aorta / iliacs
=Aortic-iliac thrombosis in horse
=Saddle thromi in cats w left sided cardiomyopathies
Venous
=blockage of large veins = congestion w leakage to muscles = muscle necrosis + fibrosis
*Occurs in prolonged recumbent large animals
What causes white muscle disease?
*Selenium / vitamin E deficiency in calves
What are the clinical signs of white muscle disease?
*Muscle weakness / stiffness, recumbency, dyspnoea
*Arrythmias if myocardium affected
*Myoglobinuria
How is white muscle disease treated?
*Parenteral administration of selenium / vitamin E
How does stiff lamb disease present?
*Neck + tongue muscle stiffness / weakness in young lambs
*Shoulder, thigh, back + intercostal muscle stiffness / weakness in older lambs
*More pronounced calcification than white muscle disease in calves
How is stiff lamb disease treated?
Vitamin E / selenium supplementation
What are the signs of acute exercise induced exertional rhabdomyolysis in horses?
*Unfit horse (colic signs)
*Stiffness to severe pain / recumbency
*Commonly gluteals, semitendinosus, semimembranosus affected
How is acute exercise induced rhabdomyolysis in the horse diagnosed + treated?
Dx = clinical exam, muscle enzymes + myoglobinuria
Tx = Pain relief, fluid therapy, acepromazine
How is chronic exercise induced exertional rhabdomyolysis treated?
*Warm up
*Avoid stress + high energy feeds
What causes polysaccharide storage myopathy? How is it diagnosed + treated?
*Cause = accumulation of glycogen
*Dx = semimembranosus muscle biopsy
*Tx = diet (low carb / high fibre), oil to replace carbs for energy
What animals does eosinophilic myositis affect? What are the clinical signs?
*Large breed dogs - GSD
*Acute recurrent pain + mandibular immobility
*Bilaterally enlarged temporal / masticatory muscles
How is eosinophilic myositis treated?
Corticosteroids
What are some bacterial conditions affecting muscles?
*Blackleg
*Malignant oedema
What are some parasitic conditions affecting muscles?
*Trichonellosis
*Cysticercosis
*Toxoplasmal myositis
*Sarcocysts
What are the signs of atypical myoglobinuria?
- Acute onset, rapid and frequently fatal
- Muscle weakness/recumbency
- Increased CK/AST and myoglobinuria
*Post mortem = widespread myonecrosis (skeletal + cardiac)
