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%)
