SA Orthopaedics Flashcards
What is geometric distortion in radiography?
Occurs if structure is towards edge of collimated area or not truly parallel to film
Artefactually short/long etc
Limitations of radiography?
Oblique projections can create apparent artifactual lesions
Poor soft tissue contrast resolution
What is serial radiography?
Repeated radiographs over time
To monitor progression of disease etc
Can be useful if diagnosis is uncertain
What are the radiographic (Rontgen) signs?
Number Size Shape Location Opacity
What soft tissue changes can be seen on radiographs and what can cause them?
Focal atrophy - chronic lameness, neurogenic, fibrosis/scarring
Focal swelling - trauma, abscess/seroma, granuloma, neoplasia
Diffuse swelling - oedema, cellulitis/vasculitis, diffuse neoplasia
Reduction in opacity of bone on radiographs: when is this apparent? Causes?
May be artefactual - compare to soft tissue
30-60% mineral loss required to be apparent
Minimum 7 days to be apparent
Focal loss easier to detect
Generalised - systemic disease e.g. nutritional secondary HPTH
Focal - neoplasia, osteomyelitis
What types of radiographic focal bone loss (lysis) are there?
Geographic = fairly even homogenous widespread loss of opacity - less aggressive
Moth-eaten = coalescing areas of heterogenous lysis
Permeative - more aggressive
How do aggressive bone lesions appear on radiographs?
Long transition zone
Active periosteal reaction
Destruction of cortical integrity
Soft tissue swelling
What to assess about joints on radiography?
Soft tissue swelling Joint space width Subchondral bone opacity Osteophyte/enthesiophytes Periarticular mineralisation
NB can’t see cartilage (not ST opacity)
In which joint can you distinguish between periarticular swelling around the joint and a joint effusion?
Stifle
Because adjacent fat provides contrast
What may be seen on radiography with OA?
Soft tissue swelling/effusion
Periarticular new bone at predictable sites
Subchondral sclerosis
Narrowed joint space
What predilection sites are there for osteochondrosis?
Caudal aspect of humerus head
Medial part of humeral condyle
Lateral femoral condyle
Medial trochlear ridge of talus
What predilection sites are there for osteoarthritis?
Proximal humerus
Distal radius/ulna
Distal femur
Proximal tibia
Ultrasound for musculoskeletal system: Which probe to use? What can be assessed?
Linear (high frequency) probe
Muscles, tendons and ligaments clear
Bone surface depicted well
Imaging deep to surface not possible if cortex intact
Hip dysplasia: Aetiopathogenesis?
Large breed dogs/Devon Rex cat
Genotype, bodyweight, nutrition, growth rate
Laxity due to poor soft tissue cover, then OA change as response
Pain as femoral head hits dorsal effective acetabular rim
Normally presents at 7-8mo
Clinical signs “subside” 12-18mos
How to approach the hip to avoid the sciatic nerve?
Cranio-dorsally (avoid lateral and caudal)
Bony landmarks of the hind leg?
Wings of ileum Greater trochanter Tuber ischi Lateral condyle of femur Patella Tibial tuberosity Lateral malleolus Head of metatarsus
Hip dysplasia: 2 groups of presentation?
Immature dogs <12mo: - unilateral/bilateral HL lameness - bunny hopping - reluctance to exercise - pain upon hip extension/flexion - positive Ortolani test - poorly muscled Adult dogs: - mature - stiffness after rest/exercise - bunny hopping - usually bilateral - pain upon joint manipulation and reduced ROM - differentiate from bilateral stifle and lumbosacral disease
Diagnosis of hip dysplasia?
History and clinical signs Radiography: - VD extended/frog legged - lateromedial view - special views - want 50% of femur head in acetabulum - early changes: wide joint space with medial divergence, centre of femoral head lateral to dorsal acetabular edge
Conservative treatment of hip dysplasia: Success rate?
80% success rate but 50% on NSAIDs Analgesia - NSAIDs, amantadine, gabapentin Physiotherapy/hydrotherapy Weight control Frequent short walks
Surgical treatment options for hip dysplasia?
Only if non responsive to conservative management
Young dogs:
- triple pelvic osteotomy (TPO): cut pelvis in 3 places, rotate onto femoral head, add plate (not used anymore)
- juvenile pubic symphisiodesis (JBS): electrocautery/staples to cause thermal arrest of pubic chondrocytes, shortens pubic bones and fixed in pelvis, results in ventrolateral rotation of acetabulum and better congruity, need to diagnose at 14-16 weeks, no effect if performed after 22 weeks
All dogs:
- femoral head and neck excision (FHNE): salvage procedure, <15kg ideally, craniolateral approach to hip, remove all neck and bony spurs, preserve muscle, point patella to sky when cutting, need lots of exercise after surgery
- total hip replacement (THR) (>9 months): best treatment in dogs, contraindicated if chronic systemic illness e.g. skin, maintained on analgesia, expensive (£4500-7000)
Legg-Calve-Perthe’s disease: Which breeds? Aetiology? Pathogenesis? Diagnosis? Treatment?
Small breeds - onset of lameness 4-11mo
Heritable in WHWT and Manchester terriers (autosomal recessive)
Ischaemia of femoral head bone leads to deformity and collapse
Clinical signs:
- mild cases can be sublclinical
- mild intermittent lameness to acute non weight bearing lameness
- pelvic limb muscle atrophy
- pain and crepitus on manipulation of hip
Diagnosis:
- history and clinical signs:
- radiography: frog leg and VD extended, “apple core” focal bone lysis
Treatment:
- surgical best: FHNE/THR
- post op rehab v important
Capital physial fractures: Which animals? Cause? Clinical signs? Diagnosis? Treatment?
Immature animals (4-7mo) Secondary to trauma Pain upon hip manipulation Diagnosis: - history - clinical signs - radiography Treatment: - three diverging/parallel K or arthrodesis wires - craniolateral or dorsal approach to hip
Coxofemoral luxation: Cause? Which animals? Which direction? Clinical signs? Diagnosis?
Following major trauma e.g. RTA
Usually >12mo
Usually craniodorsal
Clinical signs:
- leg carried in flexion, stifle out, hock in (CD luxation)
- greater trochanter more prominent (look for asymmetry)
- assess triangle between TI, GT and iliac crest
Diagnosis:
- history and clinical signs
- radiography: VD and lateral
Treatment:
- closed reduction (initially) unless HD or avulsion fracture of femoral head, only really for cranio-dorsal
- if re-luxation occurs then open reduction and stabilisation
Closed reduction for coxofemoral luxation: Criteria? Technique?
Within 48h of injury
GA and tie dog to table
Take post-op rads to ensure reduction
Post reduction place in (Ehmer sling) and cage rest for 7-10 days
Keep in surgery if worried
Relaxation due to haematoma or fragments in acetabulum
Open reduction and stabilisation of coxofemoral luxation: Technique?
Craniolateral approach to hip
Remove haematoma and bone fragments from acetabulum and lavage
Replace femoral head with caudal traction of femur
Suture joint capsule
Keep in place by augmenting joint capsule
Function of cranial cruciate ligament?
Prevents tibia moving forwards
CCL rupture: Aetiology?
Aetiology unknown and controversial - trauma least common - degeneration in older dogs (+minor trauma) or predisposed breeds (Lab, terriers) - young large breed dogs Disease related to: - increased collagen metabolism in CCLs in predisposed breeds - increased joint laxity - narrowed intercondylar notches - sloping angle of tibial plateau - immune mediated disease
What makes up the CCL?
Craniomedial band - taut in flexion and extension
Caudolateral band - taut in extension only
Craniomedial band ruptures first = partial tear
Partial tear: positive cranial drawer in flexion, but not in extension as caudo-lateral band intact
CCL rupture clinical signs?
Chronic/acute onset hindlimb lameness
Leg carried flexed or “toe touching”
Stifle effusion (patellar ligament not pencil like)
Medial buttress and OA - chronic
Tibial compression test/cranial drawer test
Diagnosis of CCL rupture?
Clinical exam and history
Radiographs - ML and CrCd
Arthrocentesis - reduced viscosity, increased volume
Conservative treatment for CCL rupture?
Dogs <15kg
Restricted exercise and analgesia for 6-8 weeks
85% will have satisfactory function
Surgical treatments for CCL rupture? Aftercare? Complications?
Intracapsular - OTT
Extracapsular - e.g. lateral fabellotibial nylon sutures
Periarticular - TPLO, TTA
Aftercare:
- re-examine at 4-6 weeks
- progress x rays for osteotomies at 8 weeks
Complications:
- infection
- meniscal tears
Meniscal injury: When happen? Treatment?
At surgery or late meniscal injury
Mostly medial
May respond to conservative management for 4-6 weeks
Surgical removal if persistent lameness
Patellar luxation: Aetiology?
Congenital/developmental or traumatic Medial > lateral Toy breeds/large breeds more common? Cats often asymptomatic Due to developmental malalignment of quadriceps complex
Grading degrees of patella luxation?
1: Intermittent patellar luxation, reduction immediate
2: Frequent luxation, reduction not always immediate
3: Permanent luxation, reduction possible but reluxates
4: Permanent luxation but reduction not possible
Diagnosis of patellar luxation? Treatment?
History and clinical signs - skipping lameness Radiography Conservative treatment: - if none or intermittent clinical signs - restricted, controlled exercise - NSAIDs Surgical treatment: - if recurrent clinical signs, > grade 2 - restore normal alignment of quadriceps mechanism by a combination of reinforcement of lateral retinaculum, release of medial retinaculum, deepening trochlear groove and transposition of tibial tuberosity
Stifle osteochondrosis: How common? Where? Which animals? Clinical signs? Diagnosis?
Not very common Lateral/medial femoral condyle (articular surface) Breed predisposition - labs Male > females OCD if joint mouse Clinical signs: - lameness from 5mo - bilateral crouching gait - joint effusion and discomfort on palpation Diagnosis: - history and clinical signs - radiography: CrCd most used but can see flattening on ML view
Rupture of collateral ligaments of the stifle: Diagnosis? Treatment?
Alone or in combo with CCL rupture
Medial or lateral
Diagnosis:
- abnormal joint movement in medial or lateral direction
- stressed radiographs (check contralateral limb for normality)
Treatment:
- parapatellar approach to side affected
- primary repair of ligament and repair protected by screws and washers at insertion sites
Multiple ligament injuries of the stifle: Aetiology? Diagnosis? Treatment?
Aetiology: - uncommon injuries usually working dogs Diagnosis: - careful clinical examination - stress radiography Treatment: - repair of CCL, collateral ligament(s), removal of damaged meniscus and joint capsule- good prognosis but don’t underestimate repair!! - TAESF
Multiple stifle ligament injuries in the cat: Aetiology and treatment?
Aetiology:
- usually in association with CCL rupture
- meniscal injuries
Treatment similar to dogs:
- transarticular pin across stifle joint for 4 weeks
- TAESF
Treatment for foot fractures? Complications?
Single: external coaptation
Multiple: need internal fixation (plates/wires)
Complications:
- extensive soft tissue injuries: check viability
- synostosis between bones: painful
Interphalangeal luxations (“Sprung toe”): Which breed? Which joint? Treatment?
Commonly seen in greyhounds Mainly proximal interphalangeal Treatment: - reduce and suture collateral ligaments with wire sutures - small ESF - toe amputation
Toe amputation: indications? How?
Single digit amp well tolerated
Indications: severe luxations/fracture/neoplasia
Y shaped incision - preserve pad
OC and OCD of the tarsus?
Common cause of hindlimb lameness in large breed dogs
Medial or lateral trochlear ridge of talus
Very straight conformation and bilateral effusion
Rads- flattening of medial trochlear ridge of talus
Surgical treatment- best option
Tarsus fractures?
Central tarsal bone: - dorsal slab fracture - best treatment is lag screws Calcaneus: - avulsion fractures
Talocrural instability: Causes? Treatment?
Damage to lateral/medial collateral ligaments
Malleolar fracture
Surgical treatment?
If fails then pantarsal arthrodesis
Open luxations/shearing injuries of the tarsus: Treatment?
Extensive wound lavage with sterile saline
Stability achieved with external fixator
May need graft or heal by second intention healing
Calcanealquartal instability of the stifle: Causes? Diagnosis? Treatment?
Trauma or degenerative (shelties/collies)
Rupture degeneration of plantar ligament
Plantigrade stance
Diagnosis - history and clinical signs and stressed views
Calcaneoquartal arthrodesis
Principles for arthrodesis of tarsus?
Dorsal approach to tarsus
Expose joint cavity and all joint levels
Use air driven burr to remove articular cartialge
Bone graft (autogenous from proximal humerus/corticocancellous, ilium in cats or DBM)
Place custom made plate over all joint
Post op:
- gutter splint/cast for 6-12 weeks then re-radiograph
- check weekly
- strict rest
- analgesia
Tarsus achilles tendon rupture?
Traumatic
Gastrocnemius enthesiopathy in Dobermans: middle aged, usually bilateral, acute or gradual onset, SDF usually ok, toe clenching
SDFT over top of calcaenus
Complete rupture inc SDFT - plantigrade stance
Treatment:
- plantarolateral approach
- exposed end of tendon with locking loop/three loop pulleys
- place hock in extension with bone screw
- cast for 6 weeks
- restrict exercise
What must you initially assess/do with a pelvic fracture?
ABC Control haemorrhage if present Fluids and shock therapy Check for thoracic injuries Analgesia - opioids, NSAIDs Assess urinary tract Neuro exam Assess function of pelvic nerve - anal/perineal reflex
Pelvic fracture clinical exam?
Unilateral/bilateral fracture
Palpate pelvis and feel for crepitus, assymetry
Rectal exam - feel crepitus, narrowing, haemorrhage
May be shearing injuries, open wounds
Treatment options for pelvic fractures? Considerations?
75% would recover with conservative treatment
Depends on area of pelvis affected
Small animals > large dogs
Surgery within 5 days
Use of animal
Finance
Conservative:
- suitable for fractures of the non weight bearing axes: pubis, ischium, wing of ilium
- cage rest for 4-6 weeks
- if non ambulatory: frequent turning and soft bedding
- check bladder qid if not urinating consciously
- analgesia: opioids, NSAIDs
Surgical treatment:
- for weight bearing axes
- acetabulum: controversial
- ipsilateral fractures of ilium, pubis, ischium
- iliac shaft
- sacroiliac joint (bilateral)
- fractures causing marked stenosis of pelvic canal
Sacroiliac separations: When seen? Presentation? Treatment?
Commonly seen in cats post-RTAs Unilateral> bilateral (occurs with ipsilateral iliac fractures) Pain +++ if nerve root entrapment Need surgical treatment: - painful - non ambulatory - marked displacement - other contralateral fractures Methods of treatment: - lag screw fixation - transilial pin
Iliac shaft fracture treatment?
Most fractures will require internal fixation (plating)
AO/ASIF or reconstruction plates
Surgical texts for approach- “gluteal roll-up”/dorsal
Other techniques-lag screws, K or arthrodesis wires
Acetabular fractures treatment?
All acetabulum- treat with internal fixation?
Aim to follow AO/ASIF principles
Surgical approach involves trochanteric osteotomy or gluteal tenotomy (read surgical text)
Plate fixation with acetabular/L plate plate or reconstruction plate
Contour on similar pelvis before surgery
Other techniques include screws and PMMA, K wires and tension band in small animals
Small dogs/cats- FHNE
Post op care for pelvic fractures?
Cage rest/restricted room rest for 4-8 weeks
Treat as with conservative management- only short on-lead walks:5-10 minutes until re-radiograph
See at 3, 7-10 days and then 4-8 weeks post-operatively for repeat radiographs
Analgesia, soft bedding- important
Passive physiotherapy/ hydrotherapy?
Gait and clinical exam signs of elbow problem?
Shortened stance phase
Head lift during stance phase on affected limb
Muscle atrophy
Joint effusion
Periarticular thickening (chronic)
Pain/crepitus on elbow manipulation
Assess range of motion - flexion, extension, supination, pronation
Which radiographic views to take of the elbow?
Craniocaudal
Mediolateral
Flexed mediolateral - for hip dysplasia etc
Arthrocentesis for the elbow joint: Which needle to use? Landmarks?
1-1.5”, 21-23G hypodermic needle
Immediately distal to medial or lateral epicondyle
Caudolaterally along anconeal process
Synovial fluid analysis?
Volume
Colour/turbidity
Total and differential cell counts
Cytology:
- OA - low cellularity, mononuclear cells predominate
- IMPA/BIA - highly cellular with neutrophilic inflammation
What elbow incongruities are there? Treatment?
Short radius:
- premature closure of proximal or distal radial growth plate
- contribution to MCD
Short ulna syndrome:
- premature closure of the distal ulna physis
- contribution to MCD and UAP
Treatment with bone lengthening procedures:
- osteotomies to improve congruency
- most commonly for short ulna syndrome
- ulna osteotomy or ostectomy (for young dogs)
- proximal in mature dogs or distal in young dogs
Elbow dysplasia: Which breeds? What are the 4 diseases involved?
Medium-large breeds: labs, rottweilers, Bernese Mountain Dogs
Fragmentation of the medial aspect of the coronoid process (FCP)/Medial Coronoid Disease (MCD)
OCD of the medial aspect of the humeral condyle
Ununited anconeal process (UAP)
Elbow incongruity
Medial coronoid disease (MCD): aetiology and pathophysiology?
Multifactorial: - genetics - nutrition - biomechanics (areas of load) - gender: males 2:1 females Pathophysiology: - short radius in 45% cases - short ulna in 14% cases - mechanical overload: - disturbance of normal endochondral ossification - weak points between retained cartilage and subchondral bone - subsequent fissure and fracture formation
Medial coronoid disease vs medial compartment disease?
Medial coronoid disease - fragment only, normal cartilage
Medial compartment disease - cartilage erosion, exposure of subchondral bone
Diagnosis and treatment of medial coronoid disease?
Radiography:
- can’t see fragments due to superimposition
- subtrochlear sclerosis
CT:
- can see detachment of apex of coronoid process from the ulna (fragment)
Arthroscopy:
- can see fragment
Conservative management:
- NSAIDs, paracetamol/codeine, amantadine, gabapentin, tramadol
- nutraceuticals
- weight control
- controlled exercise
- physiological/hydrotherapy
Surgery:
- e.g. fragment removal, weight shifting procedures, elbow arthrodesis, total elbow replacement if end stage
Elbow OCD: Clinical signs? Diagnosis? Pathogenesis? Treatment?
Clinical signs: lameness and joint effusion
Diagnosis:
- radiography
- arthroscopy
- arthrotomy
Pathogenesis:
- disturbance of the normal orderly process of endochondral ossification
- cartilage of increased thickness
- necrosis deep with thickened cartilage
- may progress to cartilage flap
Treatment:
- cartilage flap removal and debridement of subchondral bne
- osteochondral autogenous transfer (OATS)
- synthetic osteochondral transplant
- fair prognosis
Ununited anconeal process: Which animals? Pathogenesis?
Predisposed breeds - Bassets, GSDs, BMD, mastiffs
Male 2:1 female
Bilateral in 30% cases
Concurrent MCD in up to 30% cases
Pathogenesis:
- secondary centre of ossification only present in 16% of dogs
- joint incongruity (short ulna)
Diagnosis and treatment of UAP?
Clinical exam:
- thoracic limb lameness: chronic, exacerbated by exercise
- joint effusion larger than seen with MCD
Radiography:
- flexed mediolateral view
- consolidation of AP not present until between 16-20 weeks in GSD (earlier in greyhounds, 14-15 weeks)
CT helps diagnose concurrent disease
Conservative treatment if mild lameness
Surgery:
- removal of anconeus (only if other treatment options failed as causes instability), older dogs with severe OA
- anconeal process reattachment
- ulnar osteotomy
- proximal ulnar osteotomy and reattachment
Incomplete ossification of the humeral condyle (IOHC): Aetiology? With breeds? Clinical signs? What can happen?
Failure of secondary centres of ossification of distal humerus to fuse
ESS/Cocker Spaniels overrepresented - also seen in labs
Chronic thoracic lamnesness or asymptomatic
Can progress to fracture of the humeral condyle - lateral condylar or Y-T fracture
IOHC may be detected in contralateral joint of complete fracture cases - so image contralateral limb
Diagnosis of IOHC? Treatment?
Radiography: large fissures can be seen on standard craniocaudal radiographic projections (can’t rule out if not seen)
CT: more sensitive
Around 20% will go on to fracture and 25% will go on to require surgery
Prophylactic surgery?:
- placement of transcondylar screw +/- lateral condylar plating
- 60% complication rate: 30% seroma, 30% surgical site infection risk (may necessitate implant removal)
Surgical indications for IOHC?
Persistent lameness in affected limb
Early remodelling can be detected on the lateral epicondylar crest (precursor to fracture so need prophylactic plate and screw)
Major differentials for shoulder lameness?
Caudal cervical lesion (e.g. disc) with nerve root compression
Brachial plexus tumour or neuritis
Occult thoracic limb disease (e.g. MCD)
How to assess medial collateral integrity with shoulder instability?
Sedation/GA
Variation with breeds and individuals
Increased abduction angle >30 degrees\Interpret with caution
Radiography for the shoulder: Which views?
Mediolateral: elevate head and neck, pull limb cranially, tracheal position (ET tube)
Craniocaudal
Cranioproximal-craniodistal to see bicipital groove
Arthrocentesis for shoulder joint: Which needle? Landmarks?
1-2” 21-23G hypodermic needle
5ml syringe
Enter joint between acromion and greater tubercle
Oritentate needle in craniolateral to caudomedial direction
Arthrography for shoulder joint: Use? Doses?
Highlights soft tissue structures Low volume (1ml 300mg iohexol) or high volume 5-8ml 200mg iohexol)
CT for shoulder?
Can detect:
- OCD
- tendon calcification (interpret with caution)
- OA
CT-arthrography highlights soft tissue structures
OCD of the shoulder: Which animals? Clinical signs? Diagnosis? Treatment?
Usually young large and giant breed dogs Typically 4-8mo Clinical signs: - thoracic limb lameness - not usually painful on palpation - pain of extremes of extension and flexion Diagnosis: - plain radiography - contrast radiography - CT - arthroscopy Conservative treatment: - generally inferior to surgery - exercise until flap detaches Surgery: - flap removal - stimulate fibrocartilage formation: shaver, curette, forage - OATS - good prognosis for minimal OA progression and normal/near normal function
Biceps tendinopathy: clinical signs? Diagnosis? Treatment?
Clinical signs:
- usually middle aged medium to large breeds
- progressive thoracic limb lameness
- becomes worse with exercise
Diagnosis:
- pain on shoulder flexion with concurrent extension of elbow (careful not elbow pain)
- contrast arthrography
- US
- arthroscopy
Conservative treatment:
- usually refractive to NSAIDs
- intra-articular methylprednisolone with strict rest for 4-6 weeks
Surgery:
- tenotomy (arthroscopic or via arthrotomy) +/- tenodesis to proximal humerus
- good long term outcome expected
Ruptured biceps brachii: Diagnosis?
Look for hyperextension of elbow with shoulder in full flexion
Clinical signs of carpal problems?
Thoracic limb lameness (mostly non weight bearing) Abnormal stance Soft tissue swelling Joint effusion Pain/discomfort on manipulation Crepitus on ROM Mediolateral or craniocaudal instability
Radiocarpal bone fractures: Which animals? Types? Treatment?
Males more common Boxers, Springers, Pointers predisposed Dorsal slab midbody sagittal or comminuted most common Surgery: - lag screw and immobilisation - carpal arthrodesis
Accessory bone fractures: Which animals? Presentation? Treatment?
Injury of racing greyhounds
80% right carpus
Lag screw
Remove if small fragment
Carpal hyperextension injury: Cause? Presentation? Which joint affected? Treatment?
Damage to flexor retinaculum and palmar fibrocartilage - traumatic or degenerative
Palmigrade stance
50% carpometacarpal
30% antebrachiocarpal
20% middle carpal
Determine which joint with stressed mediolateral radiographic projections - compare to contralateral limb
Pancarpal arthrodesis:
- dorsal plate most common application
- plate should extend 50% of MCIII length
- palmar plate best location but more challenging
- external fixator rarely used
- plate needed for up to 12mo (slow healing)
Partial carpal arthrodesis not really indicated
CHECK slide before
Complications of pancarpal arthrodesis for a carpal hyperextension injury?
Surgical site infection 18% Implant loosening/breakage 11% Wound complications 7% Fracture 3% Failure of arthrodesis 2%
Implant removed in 18% cases
Pancarpal arthrodesis post op care for a carpal hyperextension injury?
Analgesia - NSAIDs, paracetamol/codeine
Exercise restriction - strict rest for 2 weeks, gradual reintroduction of lead restricted walk
External coaptation - modified RJB for 5-10d, no splint required, no casting
Panoestitis: Clinical signs? Diagnosis? Treatment? Prognosis?
Clinical signs: - classically shifting lameness - acute onset, no trauma - forelimb 4:1 hindlimb - most common in ulna and radius Diagnosis: - signalment (most common in GSD), history, clinical signs - radiography Treatment: - self limiting - exercise control/restriction - analgesia Good prognosis
What is seen on radiography with panosteitis over time?
0-10 days: may be normal
10-20 days: subtle, poorly marginated increased radiodensity in medullary cavity with dome corticomedullary blurring
10-70 days: obvious increase in medullary radiodensity, periosteal and endosteal new bone formation and thickened cortices
70-90 days: remodelling of medullary canal, medullary canal regains normal appearance
Metaphyseal osteopathy: Signalmenet? Aetiology? Clinical signs? Diagnosis?
Signalment: - young rapidly growing medium and large breed dogs (weimeraners) - puppies may present between 2-6mo Aetiology unknown: - vitamin C deficiency? - Distemper? - inherited immunodeficiency in Weimeraners Clinical signs: - vary from mild lameness to severe collapse - pyrexia, anorexia and depression - swollen metaphysis Diagnosis: - history, signalment, clinical signs - radiography
What is seen on radiography with metaphyseal osteopathy? Treatment and prognosis?
Common in distal radius and ulna
Band o increased radiodensisty immediately adjacent to physis
Radiolucent line in metaphysis parallel to physis
Epiphysis and growth plates may appear slightly widened
Latter stages calcification proximal to metaphysis
Treatment:
- mostly self limiting
- supportive care
- analgesia
Prognosis
- good-excellent in mild cases
- sometimes euthanasia due to severity of clinical signs
- possible angular limb deformities
Craniomandibular osteopathy: What is it? Signalment? Clinical signs? Aetiology? Diagnosis? Treatment? Prognosis?
Non inflammatory non neoplastic proliferative bone disease of immature dogs Signalment: - usually present 4-10mo - most common in WHWT, Scottish terrier, Cairn Terrier Clinical signs: - mandibular swelling - inability to open mouth/prehend food - ssalivation - anorexia and weight loss - pain when eating Aetiology: autosomal recessive in WHWT Diagnosis: - signalment - history - clinical findings - radiography Treatment: - supportive care - analgesia - surgery not successful Prognosis: - self limiting at 11-13mo - can be good - euthanasia may be requested
What is seen on radiography with craniomandibular osteopathy?
Changes usually bilateral
Palisading proliferation on the mandible and tympanic bullae
Temporal, frontal and maxillary bones can be affected
Occasionally affects long bones
Slipped capital femoral epiphysis (Feline Metaphysical Osteopathy/Femoral Neck metaphysical Osteopathy): Signalment? Aetiopathogenesis? Clinical signs? Diagnosis? Treatment?
Signalment: - neutered male, overweight cats - <2yo - Siamese overrepresented? Aetiopathogenesis: - unknown - delayed physical closure - gonadectomy, hypotestosteronism Clinical signs: - subtle lameness progressing to acute non weight bearing - inability to jump - pain and crepitus on hip manipulation Diagnosis: - history, signalment and clinical signs - confirmed radiographically Treatment: FHNE, THR
How does slipped capital femoral epiphysis appear on radiography?
Early - mid widening and lateral displacement of the capital femoral growth plate
Late - displacement of proximal femoral metaphysis, resorption and sclerosis of femoral head
Hypertrophic osteopathy: Signalment? Aetiology? Clinical signs? Diagnosis? Treatment?
Signalment: - older dogs and cats - mean age 9yo Aetiology: - paraneoplastic secondary to intrathoracic or abdominal neoplasia - neural mediated (vagus? intercostal?) -> increased peripheral blood flow -> vascular congestion in periosteum -> calcification of periosteum and connective tissue Clinical signs: - lameness can develop over several months - can be non ambulatory - single or multiple limbs - firm swelling along bone of distal extremities - pain in early stages - hyperthermia?, weight loss, depression Diagnosis: - history and clinical signs - thoracic radiographs and abdominal US Treatment: - symptomatic - remove primary cause -> resolution of new bone formation
Radiographic changes with hypertrophic osteopathy?
Periosteal new bone formation
New bone laid down at right angles to periosteum
Increased bone density
Bone cyst types?
Single unicameral bone cysts: - fluid filled cavity lined by fibrous connective tissue - monostotic or polyostotic Aneurysmal bone cyst: - benign exansile osteolytic lesions containing blood sinusoids Subchondral bone cysts: - adjacent to synovial membrane - may communicate with joint space - associated with OCD - only one reported veterinary case
Bone cysts: clinical signs? Appearance on radiographs? Treatment? Prognosis?
Clinical signs: - may be assymptomatic - lameness - painful swelling - acute lameness -> pathological fracture Radiographs: - expansile, locally aggressive lucent lesion with little periosteal reaction - typically metaphysis and diaphysis - eccentrically located - thinned cortices Treatment: - asymptomatic no treatment: re-image in 4-6 weeks - surgical drainage, curettage, cancellous bone grafting - radiation therapy - excision - amputation Prognosis: good-excellent in most cases
Infraspinatus muscle contracture: Signalment? Aetiopathogenesis? Clinical signs? Dynamic assessment? Treatment?
Signalment: typically medium sized working/athletic dogs Aetiopathogenesis unclear Clinica signs: - not painful - at stance shoulder abduction, elbow adduction, lower limb abduction and external rotation - spinouts muscle atrophy - reduced ROM in flexion Dynamic assessment: - weight bearing gait abnormality - circumduction of limb as protracted - carpal flick Treatment: - infraspinatus tendinectomy
Gracilis/semitendinosus muscle contracture: Signalmenet? Aetiopathogenesis? Clinical signs? Gait abnormality? Treatment?
Signalment: - typically GSD - 3-7yo Aetiopathogenesis: - unclear - RSI, trauma Clinical signs: - non painful - weight bearing gait abnormality - firm gracilis/semitendinosus muscle on caudomedial aspect of thigh Gait abnormality: - affected limb raised in jerk like fashion - hyeprflexion of tarsus - internal rotation of metatarsus Treatment: - none required - surgery not beneficial
Quadriceps muscle contracture: Signalment? Aetiology? Clinical signs? Treatment? Prevention?
Signalment: - young fast growing dogs may be predisposed Aetiology: - secondary to femoral fracture (poor limb use) - fibrotic replacement of muscle fibres - adhesions between muscle and bone - periarticular fibrosis and joint ankylosis Clinical signs: - extension of stifle and tarsus - difficulty ambulating - trauma to dorsal aspect of pes - pain over femur Treatment: - most likely amputation Prevention: - good fracture stabilisation - early mobilisation - physiotherapy
Reversible contracture of the flexor carpi ulnaris muscle: Signalment? Aetiology? Clinical signs? Treatment?
Signalment: - young dogs 6-8wo Aetiopathology unknown Clinical signs: - flexed carpus that cannot be extended - tendon of FCU is taut on palpation Treatment: - resolution usually occurs after 2-3 weeks - carpal supports - FCU tendinectomy in rare cases
Tendon healing: How fast? Types of tendons?
Slow!
Paratenon-lined tendons:
- faster healing
- blood supply from paratenon and surrounding soft tissues
- e.g. gastrocnemius, triceps brachii
Sheathed tendons:
- slower healing
- rely on intrinsic blood supply
- e.g. flexor tendons
Return of tensile strength more important than gliding function:
- 4-5 days post repair tendon end lose strength
- gradual increase in strength over next 2 weeks
- 6 weeks post op 56% tensile strength
- 1 year post-op 80% tensile strength
- normal muscle contraction strain tendons to 25-33% of their capacity (so at 6 weeks post-op should withstand gentle exercise)
Principles of tendon repair: How? Which suture types? Aims?
Expose severed tendon ends Debride necrotic tissue Perform anastomoses - 3 loop pulley for round tendons - locking loop for flat tendons - use long acting synthetic absorbable monofilament suture material (PDS II) or non absorbable suture material (nylon) Immobilise to protect from strain for 3 weeks - dressing, ESF, calcaneotibial screw etc Aims: - healing without gap formation - maintain working length - prevent elongation
Severed digital flexor tendons - what should you do?
Manage wound initially and apply support dressings
Identify all tendon ends: 4 superficial, 4 deep
Can place small K-wire through tendon ends to facilitate manipulation
Perform anastomosis - locking loop for flat tendons
Routine closure
Can apply flexion bandage for 3 weeks to protect anastomoses
Nutritional secondary hyperparathyroidism: Aetiology? Clinical signs? Diagnosis? Treatment?
Normal bone production but excessive bone resorption -> osteopenia Aetiology: - diets high in phosphorous or low in Ca - usually meat based dits - ideal Ca:P is 1.21:1 (dogs) and 1:1 (cats) - hypocalcaemia -> increased PTH - induces progressive skeletal demineralisation Clinical signs: - lameness/inability to stand - skeletal pain - swollen metaphysis - pathological fracture Diagnosis: - history and clinical signs - radiography Treatment: - rest - diet correction - oral calcium supplementation - NSAIDs
Radiography for nutritional secondary hyperparathyroidism?
Decreased bone density and thinned cortices
Mushroom shaped metaphysis - may have slight relative increase in opacity
Pathological fracture may be seen
Hypovitaminosis D (Rickets): Aetiology? Clinical signs? Radiography? Treatment?
Insufficient Ca/P/both for mineralisation of newly formed osteoid
Aetiology: dietary deficiency of vitamin D
Clinical signs:
- lameness
- pathological fracture or bowing of long bones
- enlarged costochondral junction an metaphysis
- delayed dental eruption, weakness, listlessness and neurological signs
Radiography:
- thickening of growth plates
- cupping of adjacent metaphysis
- osteopenia, thinned cortices
- bowed diaphysis
Treatment:
- balanced diet
Renal osteodystrophy: Aetiology? Orthopaecic clinical signs? Treatment?
Osteopenia secondary to CKD: - impaired phosphate excretion -> hyperphosphataemia -> hypocalcaemia -> increased PTH -> bone demineralisation - impaired vitamin D production -> depressed enteric calcium absorption -> impaired osteoid mineralisation -> rickets-osteomalacia Orthopaedic clinical signs: - pliable mandible/maxilla (rubber jaw) - loose teeth - skeletal pain - pathological fractures - bowing of long bones Treatment: - reduce P intake/P binder - Ca or calcitriol supplementation
Hypervitaminosis A: Signalmenet? Aetiology? Clinical signs? Radiography? Treatment?
Signalment: feline patients 2-9yo Aetiology: - prolonged intake of excessive levels of vitamin A - liver diets - increased sensitivity of periosteum to trauma Clinical signs: - malaise, anorexia, lethargy - exophthalmus and scurfy, dull coat - early: neck pain - cervical stiffness - abnormal posture - lameness Radiography: - extensive confluent exostoses of cervial and cranial thoracic vertebrae - ankylosing spondylopathy - can also cause DJD and ankylosis of shoulder and elbow Treatment: - balanced diet - skeletal changes don't resolve
What type of fractures do bending, bending and axial compression, axial compression, torsion and high energy forces cause?
Bending -> transverse fracture Bending and axial compression Axial compression -> oblique fracture Torsion -> spiral fracture High energy -> comminuted fracture
Femur
Bending force in femur made of of compressive force and tension force
Wouldn’t place plate on tension force/concave side as would break
Types of dynamic compression plates for fracture repair? How do they work?
Neutral
Buttress
Compression
In contact with the bone to generate friction, to compress the bone
Need to contour the plate to fit the bone
Need two screws either side of fracture
Why should you minimise soft tissue dissection for fracture repair?
Lost most of intra-medullary blood supply
So relying on blood supply from surrounding soft tissue
How do locking plates work?
Screw head locks into the plate not the bone
Stability generated through interface between screw and plate
Don’t need to contour the plate
Like an “internal external fixator”
Shear stresses due to bending/axial loading changed into compression at screw bone interface
Advantages and disadvantages of locking systems for fracture repair?
Advantages:
- excellent for use in poor quality bone: juvenile, osteopenic bone
- improved vascularity (not proven)
- less contouring
- monocortical screws more stable
Disadvantages:
- lag screws can’t be placed through the plate
- more expensive?
- fixed angle systems cannot angle screws away from implants/fracture edges
What different screws are there? How can they be used?
Cortical screws - more turns, used with plates to engage with plate and both cortices
Cancellous screws - less turns, bigger distance between each turn
Can both be used as positional or lag screws
Lag screws - wider hole on outer cortex so head pulls cis cortex in, produces static interfragmental compression (most efficient method of creating compression), angle should perpendicular to fracture site but head should be perpendicular to bone cortex (have to compromise)
Positional - same drill size throughout, bone pieces don’t move relative to eachother
Advantages of external skeletal fixators over plates? Disadvantages?
Advantages: - cheaper - easy application - flexibility - work well below knee and elbow Disadvantages: - more owner management
Pins used for external fixators? What else needed?
Threads wider than shaft (positive threaded) - stronger but more expensive
Threads smaller than shaft (negative threaded) - threads need to be inside bone
Connecting bars
Clamps
Types of external fixator frames?
Type 1 - unilateral (frame) uniplanar
Type 2 - bilateral (frame) uniplanar
Advantages and disadvantages of intramedullary (IM) pins?
Advantages: - good at resisting bending (strength in bending proportional to r4) - in neutral axis of bone - often relatively inexpensive - may be used with other fixation devices Disadvantages: - poor at resisting rotation - poor at resisting shear - interferes with medullary blood supply - difficult in chondrodystrophic dogs
When are IM pins used?
Medium-oblique simple fractures:
- cats: longer straighter diaphyses
- with another fixation device: ESF, cerclage wire
Interlocking mid diaphysial transverse fractures
In combo with other technique for comminuted fractures: ESF, plate
Technique and size of IM pins?
Direct pinning - normograde (drive from one end to other), better but harder
Indirect pinning - retrograde (start at fracture site)
Width as large as possible - 30% diameter if combining with plate or ESF
Length - radiograph intact contralateral bone
Cerclage wires
Used in combo with IM pins for long oblique fractures
Must be tight to provide compression
Can slip along diaphysis - can groove diaphysis or use hemicerclage
What is used to fix avulsion fractures?
Pin and tension band wire
tension band neutralises the proximal pulling force
What does it mean if a lameness is worse on a hard surface?
Most likely distal limb
What does extending the elbow and rotating it inwards and outwards assess?
Medial coronoid process of ulna
Chondrodystrophoid dogs: Which breeds? What is it? Should you do surgery?
Breeds bred for long back, short legs: Dachshund, Frenchies, Bulldogs, Bassets etc
A growth deformity due to genetic mutation
If lame always take orthogonal views of foot to elbow for growth deformities
Often have carpal valgus
Only surgery if causing lameness/pain (otherwise just cosmetic)
Can cause elbow incongruity etc
When would you not use a:
- cast
- IM pin
- ESF
- Plate?
Cast: poor owner compliance, upper limb, no load share
IM pin: young dogs as would disrupt growth plates when passing through
ESF: start to loosen after 10-12 weeks so less ideal for long healing fractures
Plate: not good in young dogs <6mo in salter Harris fractures (would go across growth plate)
What to assess in a post-op fracture radiograph?
Alignment of joints
Apposition of fracture parts (not trying to achieve in comminuted fractures)
Apparatus (implant position etc)
Activity (relative to time post-op)
Diagnose: A 6-month-old German shepherd dog has had 3 weeks of left thoracic limb lameness. Prior to this presentation there was 2 weeks of right pelvic limb lameness. There is pain on manipulation of the left shoulder. Radiographs of the shoulder and elbow joint are within normal limits. There is increased focal radio-opacity in the distal third of the humeral diaphysis.
Panosteitis
Diagnose: A 6-month-old Labrador retriever has had 2 weeks of left thoracic limb lameness. There is pain on manipulation of the left elbow joint and a large joint effusion. Synovial fluid analysis reveals a total cell count of 1.3 x 109/L with 98% mononuclear cells and 2% polymorphs. A mediolateral radiograph of the left elbow joint shows mild osteophytosis on the proximal border of the anconeal process.
Medial coronoid disease
