SA Orthopaedics Flashcards

Question

Closed reduction for coxofemoral luxation: Criteria? Technique?

Answer 1

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

Answer 2

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

Answer 3

Prevents tibia moving forwards

Answer 4

``` 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 ```

Answer 5

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

Answer 6

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

Answer 7

Clinical exam and history Radiographs - ML and CrCd Arthrocentesis - reduced viscosity, increased volume

Answer 8

Dogs <15kg Restricted exercise and analgesia for 6-8 weeks 85% will have satisfactory function

Answer 9

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

Answer 10

At surgery or late meniscal injury Mostly medial May respond to conservative management for 4-6 weeks Surgical removal if persistent lameness

Answer 11

``` Congenital/developmental or traumatic Medial > lateral Toy breeds/large breeds more common? Cats often asymptomatic Due to developmental malalignment of quadriceps complex ```

Answer 12

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

Answer 13

``` 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 ```

Answer 14

``` 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 ```

Answer 15

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

Answer 16

``` 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 ```

Answer 17

Aetiology: - usually in association with CCL rupture - meniscal injuries Treatment similar to dogs: - transarticular pin across stifle joint for 4 weeks - TAESF

Answer 18

Single: external coaptation Multiple: need internal fixation (plates/wires) Complications: - extensive soft tissue injuries: check viability - synostosis between bones: painful

Answer 19

``` Commonly seen in greyhounds Mainly proximal interphalangeal Treatment: - reduce and suture collateral ligaments with wire sutures - small ESF - toe amputation ```

Answer 20

Single digit amp well tolerated Indications: severe luxations/fracture/neoplasia Y shaped incision - preserve pad

Answer 21

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

Answer 22

``` Central tarsal bone: - dorsal slab fracture - best treatment is lag screws Calcaneus: - avulsion fractures ```

Answer 23

Damage to lateral/medial collateral ligaments Malleolar fracture Surgical treatment? If fails then pantarsal arthrodesis

Answer 24

Extensive wound lavage with sterile saline Stability achieved with external fixator May need graft or heal by second intention healing

Answer 25

Trauma or degenerative (shelties/collies) Rupture degeneration of plantar ligament Plantigrade stance Diagnosis - history and clinical signs and stressed views Calcaneoquartal arthrodesis

Answer 26

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

Answer 27

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

Answer 28

``` 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 ```

Answer 29

Unilateral/bilateral fracture Palpate pelvis and feel for crepitus, assymetry Rectal exam - feel crepitus, narrowing, haemorrhage May be shearing injuries, open wounds

Answer 30

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

Answer 31

``` 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 ```

Answer 32

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

Answer 33

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

Answer 34

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?

Answer 35

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

Answer 36

Craniocaudal Mediolateral Flexed mediolateral - for hip dysplasia etc

Answer 37

1-1.5", 21-23G hypodermic needle Immediately distal to medial or lateral epicondyle Caudolaterally along anconeal process

Answer 38

Volume Colour/turbidity Total and differential cell counts Cytology: - OA - low cellularity, mononuclear cells predominate - IMPA/BIA - highly cellular with neutrophilic inflammation

Answer 39

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

Answer 40

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

Answer 41

``` 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 ```

Answer 42

Medial coronoid disease - fragment only, normal cartilage | Medial compartment disease - cartilage erosion, exposure of subchondral bone

Answer 43

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

Answer 44

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

Answer 45

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)

Answer 46

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

Answer 47

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

Answer 48

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)

Answer 49

Persistent lameness in affected limb Early remodelling can be detected on the lateral epicondylar crest (precursor to fracture so need prophylactic plate and screw)

Answer 50

Caudal cervical lesion (e.g. disc) with nerve root compression Brachial plexus tumour or neuritis Occult thoracic limb disease (e.g. MCD)

Answer 51

Sedation/GA Variation with breeds and individuals Increased abduction angle >30 degrees\Interpret with caution

Answer 52

Mediolateral: elevate head and neck, pull limb cranially, tracheal position (ET tube) Craniocaudal Cranioproximal-craniodistal to see bicipital groove

Answer 53

1-2" 21-23G hypodermic needle 5ml syringe Enter joint between acromion and greater tubercle Oritentate needle in craniolateral to caudomedial direction

Answer 54

``` Highlights soft tissue structures Low volume (1ml 300mg iohexol) or high volume 5-8ml 200mg iohexol) ```

Answer 55

Can detect: - OCD - tendon calcification (interpret with caution) - OA CT-arthrography highlights soft tissue structures

Answer 56

``` 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 ```

Answer 57

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

Answer 58

Look for hyperextension of elbow with shoulder in full flexion

Answer 59

``` 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 ```

Answer 60

``` Males more common Boxers, Springers, Pointers predisposed Dorsal slab midbody sagittal or comminuted most common Surgery: - lag screw and immobilisation - carpal arthrodesis ```

Answer 61

Injury of racing greyhounds 80% right carpus Lag screw Remove if small fragment

Answer 62

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

Answer 63

``` Surgical site infection 18% Implant loosening/breakage 11% Wound complications 7% Fracture 3% Failure of arthrodesis 2% ``` Implant removed in 18% cases

Answer 64

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

Answer 65

``` 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 ```

Answer 66

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

Answer 67

``` 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 ```

Answer 68

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

Answer 69

``` 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 ```

Answer 70

Changes usually bilateral Palisading proliferation on the mandible and tympanic bullae Tempral, frontal and maxillary bones can be affected Occasionally affects long bones

Answer 71

``` 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 ```

Answer 72

Early - mid widening and lateral displacement of the capital femoral growth plate Late - displacement of proximal femoral metaphysis, resorption and sclerosis of femoral head

Answer 73

``` 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 ```

Answer 74

Periosteal new bone formation New bone laid down at right angles to periosteum Increased bone density

Answer 75

``` 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 ```

Answer 76

``` 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 ```

Answer 77

``` 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 ```

Answer 78

``` 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 ```

Answer 79

``` 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 ```

Answer 80

``` 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 ```

Answer 81

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)

Answer 82

``` 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 ```

Answer 83

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

Answer 84

``` 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 ```

Answer 85

Decreased bone density and thinned cortices Mushroom shaped metaphysis - may have slight relative increase in opacity Pathological fracture may be seen

Answer 86

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

Answer 87

``` 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 ```

Answer 88

``` 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 ```

Answer 89

``` Bending -> transverse fracture Bending and axial compression Axial compression -> oblique fracture Torsion -> spiral fracture High energy -> comminuted fracture ```

Answer 90

Bending force in femur made of of compressive force and tension force Wouldn't place plate on tension force/concave side as would break

Answer 91

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

Answer 92

Lost most of intra-medullary blood supply | So relying on blood supply from surrounding soft tissue

Answer 93

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

Answer 94

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

Answer 95

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

Answer 96

``` Advantages: - cheaper - easy application - flexibility - work well below knee and elbow Disadvantages: - more owner management ```

Answer 97

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

Answer 98

Type 1 - unilateral (frame) uniplanar | Type 2 - bilateral (frame) uniplanar

Answer 99

``` 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 ```

Answer 100

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

Answer 101

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

Answer 102

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

Answer 103

Pin and tension band wire | tension band neutralises the proximal pulling force

Answer 104

Most likely distal limb

Answer 105

Medial coronoid process of ulna

Answer 106

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

Answer 107

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)

Answer 108

Alignment of joints Apposition of fracture parts (not trying to achieve in comminuted fractures) Apparatus (implant position etc) Activity (relative to time post-op)