Dog and Cat 5 Flashcards
what are the 7 main steps in investigating lameness
- History
- General physical exam
- Visual assessment
- Gait assessment
- Screening neurological exam
- Orthopaedic exam
- Further investigation
- Diagnostic imaging, Synovial fluid, Cytology / Bio
History for lameness exam what is important
- Antecedent trauma?
- Which limb affected?
- Multiple limbs affected?
- Previous incidents of lameness/previous orthopaedic conditions/injuries
- Establish chronology
- Response to exercise/rest?
- Response to treatment?: NSAID’s, antibiotics
- Is the patient licking the paw/limb
- Diet?
What is involved in visual assessment for lameness exam
- Weightbearing:
- Favouring a limb?
- Holding up a limb
- Digit spread
- Trembling
- Pushing just above MC/MT footpad
- Joint angles
- Conformation
- Stance abnormalities
- Eg. positive sit test.
- Muscle atrophy
- Gross abnormalities
Gait assessment what is involved for lameness exam
- Watch the dog at varying speed
- Watch the dog from in front, the sides, behind and above
- Get the owner to walk the dog up and down stairs.
- > Dogs with lumbosacral disease or hip dysplasia are often reluctant to climb stairs
- Thoracic limb lameness is harder to lateralise
- Bilaterally affected?
- Grade the lameness
- > 0-5 -> 5 no weight bearing
- Recognising neurological conditions:
- > Accentuate ataxia
- > Scuffing of the nails
- > With orthopaedic conditions stride length and gait characteristics abnormal but consistent.
- > Neurogenic atrophy
Screening neurological examination what is important to assess for lameness exam
- Neurological conditions are frequently confused with orthopaedic
- Assess CP
- Assess neck pain
- Assess thoracic/lumbar pain
- Assess for LS pain:
- > LAST (ie after orthopaedic exam)
- > Application of dorsal pressure between L7 and S1
- > Application of lateral pressure
- > Lordosis test:
- If abnormalities identified full neuro exam.
Orthopaedic examination how important for lameness exam and the principles with teh exam
single most valuable diagnostic tool
- off NSAIDS
- cheap but time consuming
- always work with the patient - sedated/anaesthesia, muzzle if needed
- always examine all four limbs in standing and lateral
- always examine the affected limb last, distal t proximal
- assess relative weight bearing
carpus what evaluating there and normal range of motion
- Hinge joint
- Small amount of valgus
- Normal ROM is 30 to 200 deg
- Effusion dorsally
- Test flexion and extension
- Evaluate collateral stability.
Elbow what evaluating there and normal range of motion
- Complex hinge joint
- Normal ROM is 40 to 170 degrees
- Effusion is best appreciated on the lateral aspect
- Triceps tendon
- Forced extension
- Supination and pronation
- provokes a pain response in dogs with fragmentation of the medial coronoid process
Shoulder what evaluating there for lameness, ROM and 2 tests to perform
- Effusion is not palpable
- ROM is 60 to 160 degrees
- Test flexion and extension
- Test internal /external rotation
- Perform deep axillary palpation
- Difficult to differentiate from elbow pain
- Biceps test -> press on biceps tendon while simultaneously flexing shoulder and extending elbow
- Shoulder abduction angle
- > Hand on acromion, distal limb abducted and angle between sagittal plan and humerus measured with goniometry
- > Standing angle and elbow extended
- > Normal is 30 degrees, affected dogs > 50 degrees (subjective) - medial humoral ligament damage
- > Radiology for OA, mineralisation, arthroscopy for definite diagnosis and treatment
- > Use opposite limb for comparison
Hock what evaluating there and ROM
- Constrained hinge joint
- ROM 40 to 165 deg.
- Simultaneous passive stifle flexion/extension
- Effusion
- Test collateral stability
- Assess common calcanean tendon:
- by extending the stifle and flexing the hock
- by palpation
Stifle what evaluating, ROM and what structure important to evaluate and how
- Complex hinge joint:
- ROM 40 to 160 deg
- Effusion
- Collateral integrity
- Cruciate disease: - talk about in cruciate disease lecture
- Biceps atrophy
- Medial buttress
- Cranial drawer
- Cranial tibial thrust
- Patella tracking
Hip ROM and what are the 2 main diseases testing for and tests within
- Normal ROM 50 to 160 deg
1) coxofemoral luxation:
1. Position of greater trochanter
§ Loss of triangle
b. Thumb displacement test
§ A thumb is placed between trochanter and ischium and the femoral shaft is externally rotated.
§ In the normal hip this creates a sensation that the thumb is being compressed or pushed out the gutter.
§ In luxation, femoral head moves and thumb is not pinched
2) Specific tests for hip dysplasia:
a. Ortolani test:
§ May be painful not/possible conscious
§ Dorsal pressure applied to femoral shaft.
§ Angle of reduction
§ Angle of subluxation
b. Bardens hip lift
§ Lift femur laterally
What is an important difference with cats and lameness examination
- Cats are not as tolerant of orthopaedic examination
- Cats respond best to minimal restraint
- Exam under sedation or general anaesthesia may be necessary
- Visual assessment often yields the most valuable information.
Arthroscopy what used for, what good to assess and positives
- Diagnostic and therapeutic
- Rapidly developing field
- The best method of assessing cartilage and intra-articular ligaments
- Magnification and illumination
- Minimally invasive
- Infection rates are extremely low
Arthrocentesis what is required for preparation and location in carpus, elbow, shoulder, hock, stifle and hip
- Heavy sedation or general anaesthesia
- Sites:
- Carpus: dorsomedial aspect of radiocarpal joint
- Elbow: Caudolateral aspect of joint,
- Shoulder:
§ 1 cm distal to the acromion
§ Medial to the greater tubercle - Hock:
§ Caudolateral aspect of joint,
§ Cranial aspect of joint: - Stifle: immediately lateral or medial to straight patella ligament
- Hip: dorsal and medial to greater trochanter
Arthrocentesis what to do with the sample
- Inoculate into blood culture medium
§ Negative in 80-90% of cases
§ Synovial biopsy: equivalent positive culture rates to synovial fluid in blood culture
§ Note that the positive culture rate for septic arthritis is very low (approximately 10%) - Air dried smear
- EDTA tube.
- Assess viscosity
bone biopsy technique and how used and risk
technique
- Stab incision in skin
- The needle should be advanced through the cis cortex with the stylet in place, then remove stylet
used
- The centre of the lesion should be sampled
- At least 2 samples (same cortical access hole)
- Samples submitted for C&S, histology
- Impression smear
- Risk of pathological fracture
List the 3 main exit pathways for lameness
1) create rest/NSAID trial
2) amputation
3) euthanasia - will not allow or cannot undergo surgery
when to refer a lameness case
- The client requests it.
- Advanced imaging required
- You cannot localize the lameness
- The patient is a trauma case and requires a level of intensive care that cannot be offered at your practice.
- The patient requires surgery and you cannot offer the appropriate surgery at your practice for the following reasons:
- Appropriate equipment/implants NOT available
- Appropriate expertise not available
- Appropriate analgesia is not available.
Amputation what situations that it is the best solution
- Fracture where the client cannot afford surgery
- Client does not have the time/resources to provide postoperative care.
- Long term prognosis is guarded/poor and the patient requires protracted care or revision surgery
- Intractably painful unilateral joint problem that is not responding to conservative management
Greyhound rotating gallop during racing how does it run and therefore common pathology for cornering or straight line
Cornering
- Run anti-clockwise
- Right front, left front, right hind, left hind
- At one point right hind propels forward
○ Right central bone tarsal fracture most common
- Left front - pivot
Straight line
Left hind the one left
Common injuries in greyhounds
- Tearing or straining of the gracilis m., the origin of the long head of triceps m. or the tensor fascia lata m. - THREE MOST COMMON
- Flexion pain or swelling of the tarsus or carpus
- Metacarpal soreness
○ left 5th and proximal right 2nd - Fractures of the fibula, metacarpals, metatarsals and phalanges.
- Sprains or ruptures of the phalangeal collateral ligaments.
- “Track Leg”
○ striking of the medial tibia on the lateral humeral epicondyle - Lameness from the pad
○ puncture marks,
○ foreign body penetration
○ “corns”
Grade 1 injury for greyhounds what is involved, treatment, clinical signs and where commonly seen
- Routine soreness found when examining greyhounds after exercise
- Straining of the muscle tissue with minimal muscle fibre disruption.
- Self-limiting, will restore with rest
- Clinical signs include
○ localised pain,
○ inability to resist firm palpation,
○ minimal loss of function.
Commonly seen in major power muscle groups - detoids, quadriceps, biceps, triceps, semimem and semiten
Grade 2 injury for greyhounds what is involved, clinical signs and muscle groups
- Palpable tear of fascial sheath
- Clinical signs
○ mild localised swelling and slight heat with
○ increased pain on palpation
○ subtle lameness and loss of function. - Same muscle groups as grade 1 plus trapezius and latissimus dorsi mm.
Grade 3 injury for greyhounds what is involved, clinical signs and what muscles occur in
- Major disruption of muscle fibres and haematoma formation –
- Clinical signs
○ Pain, swelling and palpable disruption of the normal tissue
○ bruising and dependant oedema often developing.
○ Clearly falter during galloping, but dogs aren’t always lame at walk. - Occur in the long head of triceps, gracilis and tensor fascia lata mm.
Treatment basics for greyhound muscle injuries
- Many treatments modalities exist
- Surgical repair of fractures
○ generally increased likelihood of successful return to racing, - Grade 3 muscle injuries ideally surgically repaired if major
○ but rarely are and often return successfully - Time/Patience
- Physiotherapy
- Graded exercise program
- Return to normal function as soon as possible.
- Drug-free racing
Head and neck for greyhound assessment what assessing and how
- Test full range of movement -> should be able to push neck to the sky, head down to the chest
- Palpate neck musculature and spinous processes
- Inability or disinclination to move the neck usually indicates injury to this area and may originate from collisions or race falls.
The brachium and shoulder what assessing
- Examine with muscles relaxed and then under tension
○ Supraspinatus and infraspinatus, Deltoid, Triceps group, Esp. origin of long head, Pectorals - OCD - osteochondritis dissecans
○ Withering of the deltoid
○ Pain on extension
○ Humeral head - Scapula
- Place pressure on the spine of the scapula.
- Scapula fractures from race falls will result in immediate swelling of the infra/supraspinatus
- Examination
○ Check biceps brachii and the transverse humeral ligament
○ Drawing leg caudally with the elbow extended and rotating the shoulder joint inwards.
○ Rupture will result in an increase in the 90° angle
Thoracic and lumbar spine and muscles of the trunk and abdomen assessment for greyhound lameness
Thoracic and Lumbar Spine
- The spinal column is examined for hypomobility, pain, and muscle spasm.
- Indicative of the presence of either a “spinal mechanical fault” or injury to the associated muscles, ligaments and tendons.
Muscles of the Trunk and Abdomen
- Canine Exertional Rhabdomyolysis
○ Marked pain through the thoracic and lumbar muscles - can die from this
○ History -> PU/PD,
- Grade 2 injury of the latissimus dorsi m. (fan) is common.
- Rupture of the external abdominal oblique m. or the rectus abdominis m.
○ Swelling and bruising of the caudal ventral aspect of the abdomen.
The pelvis, hip and tail what assessing with greyhounds lameness
- Fractures of the wing of the Ilium or acetabulum
○ Lameness, swelling and crepitus - Gluteal mm. (hip) common area of myositis
- Palpate lumbosacral and sacro-iliac areas for signs of discomfort.
○ Dorsal process of 7th lumbar vertebra can fracture (lateral instability)
§ Slow acceleration, shortened stride - When examining the tail - elevate and rotate
○ Tail base injuries - common
§ Exceedingly painful and causes pain while defecating and loss of performance
§ Sign - will see a drop in the tail
Stifle and fibula in greyhound lameness what important to assess
Stifle
- Collateral ligament injury is uncommon.
- Cruciate ligament injury is extremely rare - compared to other breeds which is relatively common
Fibula
- Careful palpation of the fibula along its entire length
- Fractures at lateral saphenous vein.
○ swollen and painful
- 4-6 weeks rest is usually adequate for healing
The tarsus what is important to assess in the greyhound
- High incidence of injury
○ Esp. central tarsal bone of right hock - can be career ending - Most fractures of the tarsus are readily apparent
○ May not be present until the greyhound cools down, esp. for 3rd tarsal bone fractures.
○ Crepitus if severe - Tarsal joint flexion will also test for stifle, gastrocnemius muscle, achilles tendon, tarsal and metatarsal injuries.
- The tarsus is palpated carefully to detect pain, callus production or swellings.
- The joint is then fully extended checking for pain on the dorsal surface
Metatarsals what is important to assess in the greyhound
- Firm thumb pressure - needs to be weight bearing (lift the contralateral limb up) ○ metatarsals ○ flexor tendons ○ interosseus muscles. - Metatarsal periostitis - Stress fractures/Callus formation ○ not as common as metacarpals - Fracture of the 3rd or 4th metatarsal - MAIN WEIGHT BEARING DIGITS
What are the 5 main paw/feet conditions in greyhounds and what does loss of flexion indicate
1) split webbing
2) corns- occurs in teh pad - unknown cause - FB or trauma, needs surgical removal
3) sandburn - digital flexor tendons
4) foreign bodies
5) papillomas - highly contagious and painful
Flexion loss - sesamoid or collateral ligament injuries
Metacarpals where high incidence of injury and what related to, treatment. Carpus which common in
- High incidence of injury
○ Left 5 and Right 2 - WEIGHT BEARING DIGITS - Palpated by firm pressure with the thumb along the entire length
Injury is related to age, track bend radius and frequency of runs - treatment with plates
Carpus - Accessory carpal bone fracture - most common, generally evulsion fractures
○ Different types - most common is type 5 which is the only one surgery cannot fix
Osteochondrosis define, locations and pathogenesis
- A disorder affecting the normal process of endochondral ossification occurring in growing animals.
Locations of osteochondrosis - shoulder, elbow, lumbosacral, stifle, hock
Pathogenesis - As vessels from bone marrow anastomose with cartilage canal vessels they are susceptible to microtrauma
○ Microtrauma -> obstruction / necrosis - Cartilage infarct prevents endochondral ossification
- Surrounding blood vessels proliferate and try to grow in to the infarcted region.
○ This creates thickening of cartilage adjacent to the region - Thickened cartilage is degenerate, metabolically deprived and susceptible to mechanical stress
What occurs with normal endochondral ossification and the 4 structures of articular cartilage
Normal endochondral ossification
○ Chondrocytes undergo proliferation, differentiation and calcification.
○ Chondrocytes at metaphyseal vasculature die via apoptosis
○ Osteoclasts remove dead chondrocytes and allow osteoblasts to invade
○ Osteoblasts lay down woven bone
Articular cartilage
1. Superficial zone
2. Transitional zone
3. Radial zone
4. Calcified zone - separated via the tide mark
What are the 3 main fates of infected cartilage with osteochondrosis
- Heal - replace by granulation tissue, which is then converted to bone
- Form subchondral bone cyst
- Fissure, which extends to joint surface, and creates OCD lesion, creating a flap (osteochondritis dissecans) - THE PROBLEM
a. Release of inflammatory mediators leads to synovitis/effusion and clinical signs
b. Flaps may become mineralized
c. Flaps either remain in situ attached to a pedicle or break off and become free within the joint to create a joint mouse
d. Joint mice can enlarge
e. If flaps lodge in a synovial recess they may not cause clinical signs
Non-articular OCD pathogenesis
- Focal interruption of the metaphyseal blood supply
- Endochondral ossification failure - growth plate ossification failure
- Persistent hypertrophic chondrocytes
○ Retained cartilaginous core
○ UAP - ununitedanconeal process
○ IOHC? - incomplete officiation of humoral condyle
§ Don’t unite well -> NOT OFFICIALLY PART OF PATHOGENESIS
what are the 3 main causes of osteochondrosis
- Heredity: polygenetic trait
- Nutritional
○ Rapid growth: seen in large/giant breeds
○ Over-feeding
○ Supplementation with Vit. D and Calcium in Great Danes - Microtrauma/increased load: always in specific locations - IMPORTANT TO REMEMBER
○ Caudal humeral head
○ Medial humeral condyle
○ Lateral femoral condyle
○ Medial (70%) or lateral trochlear ridge of the talus
○ Lumbosacral joint: Craniodorsal corner of the sacral body(90%) and endplate of L7 (10%)
Osteochondrosis clinical signs and radiographs findings
Clinical signs - Signalment ○ Young growing large/giant breed dogs - Lameness and reluctant to walk ○ Can be different in the morning when first waking up - worse - Joint swelling - joint effusion Radiography - Flattening of subchondral bone - Unremarkable in elbows ○ Subtrochlear sclerosis ○ OA in chronic disease - Contrast arthrogram ○ Enhance cartilage surface - Radiograph of contralateral joint
Computed tomography and arthroscopy what assess in osteochondrosis and therefore what good for
Computed tomography
- 3D analysis of the joint - good for complex joints such as the elbow
- Superior to radiographs
○ Visualisation of the coronoid process in the elbow
- Assessment of subchondral bones which cannot be assessed by arthroscopy
- The condition of the articular cartilage cannot be assessed
Arthroscopy
- Cannot assess subchondral bone
- Visualisation of articular surface and magnification
- Assessment of the articular cartilage (modified Outerbridge scoring system)
- Treatment at the same time of diagnosis
○ Debride surface and removal of joint mice
Treatment for osteochondrosis what are the 3 main options
1) conservative management - rest, weight loss, NSAIDS, nutraceuticals (glocosamine)
2) surgical treatment - atrhtrotomy vs arthroscopy, removal of OCD mouse, curettage
3) tissue engineering - resurfacing - osteochondral grafting, stem cell therapy, platelet rich plasma
OCD of the humeral head what part of the humeral head, age, lameness, radiograph, treatment and prognosis
- Caudal part of the humeral head - ALWAYS
○ May also have elbow issues - Young growing large/giant breed
- Unilateral lameness
- Radiograph of contralateral joint
- 50-70% bilateral lesions
- Treatment
○ Conservative treatment
§ Surgery not always necessary if subclinical
○ Flap excision, currette, microfracture - Prognosis is excellent with surgery
○ Large defect gets benefit of resurfacing - OA (osteoarthritis) progression will occur - TRY TO SLOW IT DOWN
OCD of the femoral condyle which condyle, prgnosis and what always occurs
- Lateral femoral condyle - ALWAYS
- Prognosis
○ More guarded than shoulder OCD
○ Grafting good option - OA (osteoarthritis) progression
OCD of the hock where located, which breed most common, prognosis therefore treatmnet opiton
- Medial (70%) or lateral trochlear ridge
- Rottweilers are overrepresented
- Prognosis -> Guarded - WORST
○ Even surgical debridement doesn’t work as well
○ Severe osteoarthritis - Pantarsal arthrodesis in severe cases
- Option> -> amputation
Elbow dysplasia what is it made up of
Syndrome of multiple diseases - IMPORTANT
- Can have multiple diseases occurring at the same time
1. UAP -> ununited anconeal process
2. FMCP (fragmented medial coronoid process) or medial coronoid disease
3. OCD of the medial humeral condyle
4. Elbow incongruity - Medial coronoid disease vs medial compartment disease
Ununited anconeal process what disease part of, occurs, define, uni or bilateral, cause and how manifest
Elbow dysplasia - Separate ossification centre in large breed - Unite at 20 weeks in GSD ○ Therefore have to wait until after 20 weeks until radiograph - Bilateral in 20-35% - Unknown etiology ○ Genetic trait in German Shepherds - Manifestation of non-articular OCD
Ununited anconeal process diagnosis, treatment and prognosis
Diagnosis
- Clinical signs
- Radiography
○ Flexion of the elbow
- CT/arthroscopy for concurrent medial coronoid disease (up to 25%)
- Bilateral up to 20-35%
Treatment
1. Re-attachment using a screw and K-wire - tricky
2. Removal if chronic or too small fragment
3. Proximal ulnar osteotomy
- Prognosis good
- OA (osteoarthritis) progression
○ Leads to Residual lameness after the surgery
Fragmented medial coronoid process and medial coronoid disease what age most common, male or femal and uni or bilateral, what are the 3 main diseases of the medial cornoid and cartilage issues
- 6-18 months of age
- Males > females
- Bilateral up to 80%
Disease in the medial coronoid
1. Microcracks
2. Fissures
3. Fragmentation - then should remove
Cartilage
1. Chondromalacia - softening of the cartilage
2. Fibrillation - wavy abnormal shape of articular surface
3. Fissures
4. Erosion
Fragmented medial coronoid process and medial coronoid disease cause and clinical signs
Etiology - Similar to those of OCD - Incongruity (incompatibility) ○ Trochlear notch dysplasia ○ Elliptical notch that is mismatched - Proximodistal incongruence: Due to short radius and short ulna - Medial coronoid disease can develop without apparent incongruity Clinical signs - Lameness, muscle atrophy over shoulder - Resting with elbow adducted - Joint effusion - Pain on manipulation of the elbow ○ Hyperextension ○ Supination/pronation - Decreased ROM
Fragmented medial coronoid process and medial coronoid disease diagnosis
- Clinical signs
- Radiology
○ May be normal
○ Subtrochlear sclerosis
○ Di35M-PrL oblique - CT for subchondral bone
- Arthroscopy for articular cartilage
START WITH CT SCAN AND THEN DO ARTHROSCOPY - complement each other
Fragmented medial coronoid process and medial coronoid treatment options
1. Conservative management – Rest – NSAIDs – Chondroprotectants – nutraceuticals 2. Surgical management – Arthroscopy vs arthrotomy – Fragment removal – Subtotal coronoidectomy – Curette – Assessment of the articular cartilage status ○ Localised medial coronoid disease ○ Medial compartment disease ○ Bilateral compartment disease
OCD of the medial humeral condyle what part of, treatment and prognosis
Elbow dysplasia - Fragment removal ○ Curetage ○ Microfracture - Tissue engineering ○ Not so good in this location - CUE ○ See medial compartment disease - Prognosis fair
Elbow incongruity what disease part of and the 2 main syndromes and the 2 main diseases within
Elbow dysplasia
- Proximal ulnar osteotomy for short ulna syndrome (1)
- Proximal ulnar ostectomy for short radius syndrome (2)
- medial compartment disease
- bilateral compartment disease (terminal elbow disease)
Medial compartment disease where present and what made up of
- Medial aspect of the articular cartilage erosion of the elbow joint
○ Exposure of the subchondral bone - Terminal disease of the medial compartment
○ Medial coronoid disease
○ OCD
○ Elbow incongruity
○ Kissing lesion
List the 5 main treatment options for medial compartment disease
- HAS TO TREATED SURGICALLY
1. BURP
2. PAUL
3. SHO
4. BODPUO
5. Resurfacing procedure
Describe BURP, PAUL and SHO surgicial procedures and what treatment for
Medial compartment disease
- BURP
- Transection of the biceps ulnar insertion
- Unknown outcome - PAUL
- Less aggressive than SHO - need to cut the ulna
- Clinically well
- Little evidence - SHO
- Changes geometry of the humerus
- Works well
- Aggressive, high complication rate - not done too much
Describe BODPUO and resurfacing procedure for medial compartment disease what is involved
- BODPUO
- Releasing pressure from the medial coronoid
- Maintaining more physiologic congruity - Resurfacing procedure
- Osteochondral grafting
- CUE
- Relatively easy compared to total elbow replacement
- Clinically good result
- No long term outcome - rare procedure
Bilateral compartment disease treatment
- Salvage procedure
○ Total elbow replacement
○ Arthrodesis
○ Amputation - issue when diseases in multiple limbs
Incomplete ossification of humeral condyle (IOHC) what is it, breed most common, uni or bilateral, diagnosis and treatment
- Lateral and medial parts of the humeral condyle not ossified
- Spaniel breeds are overrepresented
- Often bilateral
- Radiographs vs CT
○ Radiograph - superimposed so do CT - Prophylactic screw placement - can do as prevention
○ The management is more challenging after fracture develops
Carpal laxity what common in, result, history, treatment and prognosis
- Young puppies (5-27 weeks)
- May get hyperflexion or hyperextension
- History often includes poor nutrition (over-supplementation, inappropriate diet) or inadequate exercise on slippery surfaces
- Treatment: improve diet, increased, controlled exercise on grippy surfaces
- Prognosis good: dogs typically recover within 1-4 weeks
- Splinting reported but no evidence it results in superior outcome and risk of coaptation complications
Angular limb deformity most common location, cause and pathogenesis
YOUNG ANIMALS - Most common in antebrachium ○ Less in crus, distal humerus or femur Cause 1. Due to physeal injury ○ Conical shape of the distal ulnar physis susceptible to any directional force 2. heritability 3. retained cartilaginous core Pathogenesis - asynchronous growth of paried bones (radius and ulna), external rotation of he carpus, incongruity of carpus and elbow joint
Angular limb deformitiy 4 main diagnosis and treatment options
Diagnosis 1. Clinical signs 2. Radiography ○ Rotation and abnormalities 3. CT ○ Rotation and abnormalities ○ Disruption of the lengths 4. 3D printing Surgery - In young animals with remaining growth potential 1. Distal ulnar osteotomy - cut out part of the ulnar ○ Less invasive ○ May require another surgery to correct limb deformity 2. CORA methodology 3. Acute correction with closing wedge ○ Plate/screws or hybrid/circular ESF 4. Gradual correction with opening wedge ○ CESF with linear motors Other treatment - Addressing to elbow incongruity - AS ABOVE ○ Proximal ulnar osteotomy for short ulna ○ Ulnar ostectomy for short radius
Hip dysplasia what age, causes and 4 steps in teh pathogenesis
YOUNG ANIMALS Etiology - Unknown - Multifactorial 1. Genetics ○ Complex, polygenetic trait ○ Subluxation is heritable, risk of OA (osteoarthritis) 2. Environmental ○ Exogenous estrogen (maternal milk) ○ Exercise 3. Nutritional ○ Feeding quality and quantity ○ Obesity Pathogenesis 1. Subluxation - high mobility 2. Synovitis 3. Erosion of subchondral bone 4. Pain
hip dysplasia signalment and clinical signs
- Predominantly large/giant breed dogs
- Small breed dogs and cats can be affected
- Bunny hopping, spinal sway
- Reluctant to run, jump, or climbing stairs
- Muscle atrophy of the affected pelvic limb
- Bimodal clinical signs - two phases -> acute and chronic
○ Due to laxity/subluxation and synovitis, lame 3-12 moths of age
○ Periarticular fibrosis can make the joint more stable, reducing subluxation and resolving the lameness
○ Long term, progression of OA can lead to lameness/poor hindlimb function - Usually bilateral but can be unilateral
Diagnosis for hip dusplasia
subluxation - doesn’t always lead to hip dysplasia
- Clinical signs
- Palpable click during walk - severe subluxation
- Pain on manipulation (hyperextension) of the hip
- Muscle atrophy
- Orthopaedic tests
a. Lordosis test
b. Ortolani (and Barlow) maneuver
§ Two parts
□ Barlow - subluxation when abduct
□ Ortolani - moving back -> clunk back into place
§ If severe fibrosis and osteochondrosis then will not feel this
§ Important to determine stage of the disease
c. Bardens test
§ Hip joint parallel to the ground and pull up femur
§ Observing how much subluxation is present
what is involved with conservative management for hip dysplasia
- Management of OA
- Weight loss - MOST IMPORTANT
- Life style modification - not running around on the beach, throwing of ball
- Physiotherapy/hydrotherapy
- NSAIDs - also important
- Disease modifying agents / nutraceuticals (more detail in cruciate disease) preventative surgery
What are the 4 main preventative surgery options for hip dysplasia
- Juvenile pubic symphysiodesis (JPS)
○ Arrest the growth of the pubic symphysis
○ Limited to up to 16 weeks of age
§ At this age will not diagnose hip dysplasia BUT if high risk breed and subluxation possible elective surgery
○ The subluxation continues until sufficient rotation is achieved - Double and triple pelvic osteotomy (DPO and TPO)
○ Requirements:
§ No OA 0 if remodelling starting should not do
§ Up to 10 month of age
§ Angle of subluxation <10 degrees - don’t need to remember specific numbers
§ Angle of reduction <30 degrees
§ Extreme subluxation of hips is not suitable - DPO
○ Transection of the ilium and pubis - TPO
○ Transection of the ilium, pubis, and ischium
when to do salvage surgery and what are the 2 options
- If refractory to medical management
1. Excisional arthroplasty (femoral head and neck excision)
§ Able to do in general practice
2. Total hip replacement
§ Expensive, great outcome however can get surgery complications
Hip dysplasia in cats, what type of finding, what see on radiographs, how different to dogs and treatment options
- Higher prevalence in Maine Coons, Himalayans and Persians
- Often an incidental finding
- See subluxation on radiographs
- Degenerative changes typically affected the craniodorsal acetabular margin
- Unlike dogs, the femoral head and neck are minimally affected.
- Treatment options are the same as for dogs but greater likelihood of success with conservative management
Avascular necrosis of the femoral head pathogenesis and signalment
Pathogenesis
- Cause unknown
- Vascular compression
- Proven heritable in Manchester terriers
- Infarction of epiphyseal and metaphyseal bone leading to bone necrosis and collapse of subchondral bone plate
- Deformation of the femoral head and thickening of the articular cartilage.
- Changes are more pounced epiphyseal region
Signalment
- Occurs in young dogs, usually 4-11 months of age
- Especially small dogs/terriers
- Typically unilateral but can be bilateral (10-15%) - do surgery on one leg and in the future uncommon but may need to do the other
Avascular necrosis clinical signs, radigraphic findings, treatment and prognosis
Clinical signs
- Dogs usually present with a chronic progressive lameness
Radiograph
- Radiolucent areas in the femoral head
- Increased width of joint space, thickening of femoral neck
- Deformation of the femoral head
- OA in chronic cases
Treatment
1. Conservative management may help, but usually surgery is required
2. Surgery
○ FHNE (Excisional arthroplasty (femoral head and neck excision)) or THR (total hip replacement)
○ Prognosis is usually good, depending on the remaining muscle mass
Medial patellar luxation what common in, clinical signs and 7 main steps in pathogenesis
- Common in small bred dogs and cats
Clinical signs - Can vary up to stage 5 lameness
Pathogenesis
1. Coxa vara - deformity of the hip where angle of the head and shaft of femur is reduced
2. Genu varum - lower leg is angles inward in relation to femur
3. External rotation of the distal femur
4. Poorly developed medial ridge of the tibia
5. Internal rotation of the tibial tuberosity
6. Internal torsion of the proximal tibia, external torsion of the distal tibia
7. Internal rotation of the foot
Medial patellar luxation what involved, uni or bilateral, why sudden worsening occur and petalle alta
- Hypoplastic medial trochlear ridge - trochlea slides down as cannot
- Loose stifle joint with redundant soft tissue
- Often bilateral
- Medial patella luxation is much more common than lateral
- Sudden worsening of lameness in dogs with patella luxation is often due to:
○ Full thickness cartilage wear on the patella - ulceration of the cartilage - need to explore joint
○ CCL rupture - cranial cruciate ligament - Patella alta - abnormally high patellar
○ Not significant in toy breeds, but important in medium to large breeds
Medial patellar luxation what are the 4 grades and describe
IMPORTANT • Grade 1: - Patella normally in groove - Luxates intermittently - Can be luxated by manipulation but spontaneously pops back into the groove • Grade 2: - Patella normally in groove - Luxates intermittently - Can be luxated by manipulation and stays luxated - Manipulation can return it to the groove • Grade 3: - Patella permanently luxated - Can be manipulated back into groove • Grade 4: - Patella permanently luxated - Cannot be manipulated back into groove
Medial patellar luxation diagnosis and conservative management
- Patella tracking should be assessed in the following way:
○ Assess the relative positions of the patella within the trochlear groove and the tibial tuberosity - AND GRADE
○ By palpating patella while medial/lateral pressure & int/ext rotation is applied
○ Examination under sedation results in worse result
○ Conscious examination with normal muscle tone is optimal - Radiography/CT - osteochondritis, osteophytes
○ Ruling in and out differentials
○ CT may be needed for information for surgery - Assess for femoral/tibial deformity
Conservative management - Exercise/life style modification
- NSAIDs
- Physiotherapy / hydrotherapy
Medial patellar luxation treatment what are the 2 main treatment options and treatments within
1) Soft tissue techniques
a. Imblication
§ Tightening of the joint
b. Medial desmotomy
§ Medial releasing incision at the medial joint capsule and retinaculum
c. Seldom works alone well
§ Likely fail without realignment of the quadriceps-patellar axis
- Need to combine with bone techniques
2) Surgery
a. Tibial tuberosity transposition
§ Align the quadricepspatellar axis by moving the tuberosity
§ Two Kirschner wires +/- tension band wire
b. Wedge trochleoplasty
§ The proximal part of the wedge does not create sufficient depth to support the patella - DO NOT PERFORM
c. Rectangular block trochleoplasty - best one
§ Preservation of superior articular cartilage surface
§ Proximal trochlear groove is effectively deepened
Medial patellar luxation postoperative care and failure of resolution of lameness can be due to
- 8-10 weeks controlled exercise
- Failure of resolution of lameness can be due to:
○ Implant failure
○ Postoperative infection
○ Recurrence of luxation
○ Luxation in the opposite direction
○ Retropatellar cartilage ulceration
○ Cruciate rupture
Panosteilitis what is it, pathogenesis and clinical signs
bone inflammation Pathogenesis - Cause unknown - Mainly large and giant breeds (GSD, Labrador) - Presentation between 5-12 months Clinical signs: - Shifting lameness (different bones may be affected at different times) - Pain on long bone palpation - Waxing and waning in severity
Panosteilitis radiographic finding, treatment and prognosis
Radiographic findings:
- ‘thumb-print’ shaped foci of increased medullary opacity severe
Treatment:
- Rest and NSAID’s - to help with the pain
Prognosis
- Self-limiting
- Excellent
Bone healing what leads to fracture haematoma and the types of bone healing
- Fracture:- Medullary circulation disrupted -> leads to fracture haematoma -> has good nutrients so don’t want to disrupt
1) direct bone healing - no callus formation, anatomical alignment and absolute stability
a. Primary osteonal reconstruction:
i. Contact healing - cortical bone contact
ii. Gap healing: gap needs to be < 1mm. And IFS< 2%.
b. Secondary osteonal reconstruction:
§ Too much strain for primary
§ Resorption and callus reduce strain
2) indirect bone healing - too large a gap or too much instability = callus formation
Indirect bone healing what are the 4 phases
- Inflammatory:
- Soft Callus: - granulation tissue - 100% strain
- Hard callus - fibrocartilage and fibrous tissue - 10% strain
§ Mineralisation of the soft callus occurs:
§ This limits deformation
§ Endochondral ossification then occurs - Remodelling - bone - 2% strain
What is the cause of high vs low energy fractures
High energy: - Massive increase in energy absorbed - Comminution, ST damage - Gunshot - Road traffic accident Low energy: - Normal activity - Jumping from furniture
Physiological forces acting on the repair what are the 2 main ones and what is bone therefore when stronger
1) Weight bearing creates a ground reaction force
○ This creates bending, compressive and rotational moments on the bone
- Front legs -> generally 60% of weight bearing normally
2) Muscle contraction creates tension and rotation -> where muscle attaches is important on where fracture occurs
- Types
○ Bending, compressive, rotational (torsional), shear (combination of rotation and compression)
Anisotropic property
- Bone is anisotropic:
○ Stronger when loaded longitudinally vs transversely
○ Stronger in compression vs tension
most bones are not loaded in pure compression how loaded and what does a curved bone mean and therefore clinical implication
- Most bones are not loaded in pure compression
○ If bones loaded concentrically get pure compression
○ If bones loaded eccentrically (e.g. humerus, femur) compression and bending
§ More load on medial surface, fractures often open at tension side - If bone is curved:
○ compression converted to bending
○ tensile stress on convex side
○ compressive stress concave side - Tension/compression side to bone
what site are plates best applied to and which site is this in radius, ulna, femur, tibia and humerus
PLATE BEST APPLIED TO TENSION SIDE - decrease risk of failure (strongest in tension)
○ Radius: cranial
○ Ulna: caudal
○ Femur, tibia, humerus: craniolateral
tension force on bone what caused by, resultant force
- Caused by muscle contraction -> things being pulled apart
- Tibia ltuberosity, olecranon, calcaneus, greater trochanter (mm attachment sites)
- Net resultant force is compression
Stress and strain ob bone equations and what leads to low and high strain
- Stress = force/cross sectional area
- Strain = Δ length (after applied load) / length
- Inter-fragmentary strain = Δ L/L
○ where L = length of fracture gap (after repair and before loading) - So if ΔL = 2mm and L:
○ = 20mm, IFS = 10% -> small change relative to a large area -> LOW STRAIN
§ Indirect bone healing, heal faster in low strain environment -> not bad to increase fracture length
○ = 2mm, IFS = 100% -> small change relative to a small area -> HIGH STRAIN
What are the 3 parts of the fracture assessment score
- Mechanical factors (stress applied to implants):
- Biological factors (how long for callus?):
- Patient/owner factors (stress applied to implants):
- Scored 1-10 for each category, high scores favourable
Radiological classification what are the 7 ways and classifications within
1) Nature of fracture
- Traumatic, Stress
- Pathologic - bone neoplasia, primary or secondary
2) Energy level of trauma
- low energy (eg. non-displaced fracture)
- high energy (eg. comminutedfracture)
- very high energy (eg. gunshot injury)
3) Completeness
- Complete - all of the corticoices on both views disrupted
- Incomplete - not all the cortices disrupted
4) Number of fracture lines
- Simple, Multiple, Comminuted, Segmental
5) Direction of Fracture Lines
- Oblique, Spiral, Transverse
- Fissure, Avulsion, Depressed - skull fractures
- “T” and “Y” fractures - distal humerus
6) Location of fracture
- Diaphyseal - proximal, distal or mid third
- Metaphyseal, Epiphyseal
- Articular,
7) Relationship of fracture fragments –
- describe the location of major distal fragment relative to the proximal
- Degree of end-to-end apposition
- Alignment, angulation, rotation, Limb/bone shortening, Luxations
8) Soft tissue injury
- Closed
- Open
How to tell that a fracture is open and the 3 types of open fractures
○ gas opacity in soft tissues,
○ bone fragments protruding through skin, and radiopaque debris within soft tissue
○ interposition of soft tissue
○ Types
§ 1 -> soft tissue mildly confused, small wound from bone fragments
§ 2 -> more severe, larger size, not extensive soft tissue, external wound possible bone out
§ 3 -> extensive soft tissue damage - shearing injury (Car accidents), loss of soft tissue, bone, tendons and possible nerve damage
What are the 2 main approaches to fracture repair ad indications for each
1) carpenters approach - complete anatomical reconstruction, need rigid stability: internal fixation
- extensive dissection can be required - loss of extra-osseous blood supply
- Indications: simple or three piece fractures or minor comminution
2) Gardeners approach
- preservation of extraosseous blood supply
- perfect reduction in NOT the goal
- Indications: comminuted fractures
What are the 4 main principles of fracture repair
- Fracture reduction to restore anatomical relationships
- Stability by fixation or splintageas the personality of the fracture or injury requires
- Preservation of the blood supply to soft tissues and bone by careful handling and gentle reduction techniques.
- Early and safe mobilisation of the affected limb and patient
External coaptation how used and what forces are it good and not good at counteracting
- External coaptation can be used as: ○ Primary method of immobilisation ○ Temporary immobilisation ○ Adjunctive support/immobilisation ○ To prevent weight bearing - Only good at preventing BENDING - Can potentially reduce ROTATIONAL forces but only if the joint above and below the fracture are immobilised (easier for distal fractures) - CANNOT prevent AXIAL COMPRESSION and shear - CANNOT prevent TENSION
What are the 2 main types of external coaptation
- ROBERT JONES BANDAGE
a. Good for temporary support
b. Very bulky: creates compression without focal pressure - MODIFIED ROBERT JONES BANDAGE
a. Useful to limit soft tissue swelling
b. Not sufficient for fractures
What are the advantages and disadvantages of external coaptation
AD
1) cheap initially but need revisits, hospitalisation, material, sedation
2) no disruption to extra-osseous blood supply
3) reduced risk of infection.osteomyelitis
DIS
1) aftercare intensive and expensive
2) fracture disease
3) hard to move around in and bandage related complications - pressure sore, vascular obstruction, moist dermatitis
What is important about complications with external coaptation and give some clinical signs
EARLY RECOGNITION IS VITAL
- Change in shape of the splint or cast on the limb.
- Excessive chewing of the splint or cast by the animal.
- Any sign of excessive discomfort.
- Any unusual/bad odours
- Unexplained soiling /strikethrough
- Skin sores
- Swelling of the toes, or the leg above the splint.
- Systemic signs
What are some indications and contraindications fr ecternal coaptation
INDIC
- some metapodial/phalangeal fractures
- SOME long bone fractures below elbow and stigle
CONTRA
- humeral and femoral fractures (Above the elbow or stifle)
- articular fracture or significant force
- open fracture or multiple injuries affecting more than 1 limb
What are the 6 main types of temporary/adjunctive support and what they provide
1) reinforced modified robert jones bandage - provides superior immonilisation
2) full cylinder cast - most rigid form
3) preformed splints - not custom to dogs leg temporary only
4) spica splints - fit to dogs limb
5) velpeau sling - prevents weight-bearing
6) ehmer sling - prevents weight bearing just not in coxofemoral luxation
