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107 terms

Orthopedics

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system for naming luxations
proximal end of distal bone relative to distal end of proximal bone
DDx for lameness
-cranial cruciate ligament rupture
-elbow dysplasia
-hip dysplasia
-carpal hyperextension injury
-foreign body in pad
-torn/overgrown nail
-interdigital dermatitis/abscessation
-fractures
-dislocations/luxations
-bone tumours
-arthritis
-myopathy
-neuropathy
-cat-bite abscess
-Lyme diz.
-other rare infections
approach to a lameness case
-detailed history (onset, duration, progression, previous diz or trt, general health)
-physical exam (general vs ortho vs neuro)
-aides to diagnosis (rads, u/s, MRI/CT, joint tap, arthoscopy, blood tests)
the walk
4, 3, or 2 legs support the animal at one time
the trot
2 contra-lateral legs support the body at one time
the pace
2 ipsi-lateral legs support the body at one time
components of a stride
-stance phase
-swing phase
the gallop
not often used to assess lameness
observations at trot in a lame animal
-swing/stance shortened (to minimize weight bearing/painful time)
-head down on sound (forelimb)
-butt sinks on sound (hindlimb)
two most common questions asked when radiographs are referred for a second opinion
1) is this a tumour?
2) what is wrong with this elbow?
descriptive terms for new bone
-proliferation
-amorphous (tumour)
-florid
-onion/lamellated (recurrent)
-palisading
-extensive (osteomyelitis)
descriptive terms for destruction of bone
-lysis
-motheaten
-permeative
factors affecting skeletal radiograph judgement
-species
-age
-breed
-history
-clinical signs
monostotic
one bone affected
polyostotic
multiple bones affected
polyarthropathy
multiple joints affected
sequestrum
dead bone (radio-opacity) surrounded by a radio-lucent halo on radiograph
notable radiographic soft tissue changes
-atrophy
-mineralisation
-intra-articular (osteochondroma - aka - joint mice)
-displacement
zone of transition
margin between normal and abnormal bone
-longer: aggressive, tumour, infection, early healing
-shorter: benign, quiescent, settled
bone/soft tissue border radiographic considerations
-ill-defined: aggressive
-defined: benign, quiescent, old
when assessing a joint radiographically, check for...
-poor formation (dysplasia/luxation)
-degerenation (OA, DJD)
-joint space changes (osteophytes)
-subchondral bone (retained cartilage)
-periarticular bone (stabilization attempt)
-joint mice
enthesiophyte
new bone laid down at the site of ligamentous or tendinous insertions
categories of diz. detectable radiographically
-congenital
-developmental
-traumatic
-infective
-neoplastic
-nutritional
-degenerative
anatomical classifications of a fracture
-avulsion
-diaphyseal
-physeal
-articular
Salter-Harris type 1
transverse fracture through physis
Salter-Harris type 2
fracture through physis and metaphysis (epiphysis spared)
Salter-Harris type 3
fracture through physis and epiphysis (metaphysis spared)
Salter-Harris type 4
fracture through physis, metaphysis, epiphysis
Salter-Harris type 5
compression fracture of physis, decreased perceived space between epiphysis and diaphysis
Salter-Harris type 6
peripheral physis injury resulting in boney bridge formation +/- angular deformity
SALTER mnemonic
S = slip, straight across
A = above, away from joint
L = lower, below physis
T = through all regions
E = everything, epiphysis
R = ring
Salter-Harris diagram
green-stick fracture
periosteum is intact - fracture line only on one side of bone
primary bone healing
only when using plates and compression - very slow healing, can take up to a year (but rapid return to activity)
secondary bone healing
external skeletal fixator - heal faster
forces that can act on a fracture
-compression
-tension
-rotation
-bending
-shear
factors to consider in fracture management
-assess patient (trauma?)
-is it pathological?
-patient factors (co-morbidities, age)
-owner factors ($$$, commitment)
-environment factors (stairs, farm dog)
-surgeon factors (experience, equipment)
-fracture analysis (open vs closed)
-forces acting on fracture
-is anatomical reduction possible?
force/implant neutralization table
4 As of an implant re-check appointment
-apposition
-alignment
-activity
-apparatus
most important first aid step in managing an acute equine fracture
effective emergency fracture stabilization (localize to a "limb level")
equine limb fractures with a hopeless prognosis (in the majority of cases)
open comminuted # OR complete # of the humerus, tibia and femur in adult horses over 300kg
ideal equine fracture for treatment
-distal limb
-no wound, minimal soft tissue damage
-simple, incomplete, stable
-non-articular
-just one injury
stabilization of a stable level 1 fracture
-no bandage material proximal to antebrachiocarpal (knee) or tarsocrural (hock) joint
-splint should make contact with foot and proximal meta-carpal/tarsal 3
stabilization of a level 2 fracture forelimb
-splint from elbow to ground caudally and laterally over a modified Robert Jones bandage to the elbow
stabilization of a level 2 fracture hindlimb
-plantar and tarsal splints over modified Robert Jones bandage which includes hock
-plantar splint along tuber calcis
stabilization of a level 3 fracture forelimb
-as for level 2 with splint extending laterally up side of chest
stabilization of a level 3 fracture hindlimb
-as for level 2 but bandage as far proximally as possible and extend lateral splint to lateral thigh
ancillary first aid in an acute equine fracture
-tetanus prophylaxis
-IV broad spectrum antimicrobials if wounded
-analgesics (bute, banamine)
complications of (equine) fracture treatment
-osteomyelitis
-delayed union, non-union, malunion
-implant failure
-"breakdown" of contralateral limb
-tendon/ligament laxity in foals
-"fracture diz." if immobilised for a long time
-osteoarthritis
DDx for acute severe lameness in the horse
-fracture
-subsolar abscess
-severe joint diz.
-septic tenosynovitis or bursitis
-severe tendon or ligament strain
-cellulitis, lymphangitis
-laminitis
-rhabdomyolysis
DDx for lameness in the immature large breed dog
-hip dysplasia
-osteochondrosis dissecans
-patellar luxation
-cranial cruciate ligament diz
hip dysplasia (conservative treatment)
-body weight/condition management
-NSAIDs
-low impact exercise/physio (swimming?)
-nutraceuticals
-alternative therapies: omega 3 FA diets, acupuncture
hip dysplasia (surgical options)
-triple pelvic osteotomy (<1 year old, + Ortolani sign, no radiographic OA)
-juvenile pubic symphysiodesis (12-20 week old, no clinical signs but radiographic abnormalities, induces premature symphysis closure)
hip dysplasia (salvage procedures)
-femoral head and neck ostectomy (if all else fails)
-total hip replacement (if owners not cost-prohibited)
osteochondrosis dissecans
-disorder of endochondral ossification
-cartilage flap = dissecans
-secondary OA develops (commonly stifle/tarsus)
-4-8 month large breed dog with effused, painful joint
-conservative management
-flap removal by arthrotomy/arthroscopy
-osteochondral grafts (new)
commonest orthopedic condition in general practice
osteoarthritis
clinical definition of osteoarthritis
a slowly evolving articular disease characterised by the gradual development of joint pain, stiffness and limitation of movement
general and life-style changes to managing OA
-reducing diet if obese
-exercise program (as much as dog can cope with)
-physiotherapy (especially hydrotherapy)
pharmaceutical management of OA
-NSAIDs
-matrix supplements (nutraceuticals, injectable)
-omega-3 essential fatty acid supplements
-other drugs (tramadol, gabapentin, amantadine, amitriptyline)
DMOADs used in managing equine OA
-triamcinolone acetonide
-polysulphated glycosaminoglycan
-IRAP
-cartrophen
-chondroitin sulphate
-glucosamine
bone spavin
-osteoarthritis of distal hock joints (distal intertarsal most commonly affected)
-result of poor conformation, chronic repetitive trauma
DDx for chronic, low-grade lameness in horse
-osteoarthritis
-foot pain (navicular diz. or poor foot balance)
-chronic desmitis (eg. proximal suspensory ligament)
-subchondral bone cyst
-chronic laminitis
carpal joint disease (equine)
-OA in a high motion joint
-often in racehorses due to underlying subchondral bone change
-chip fractures are common, may require removal
commonest cause of hindlimb lameness in the adult dog
cranial cruciate ligament disease
how to Dx cranial cruciate ligament diz.
-history, signalment
-radiography under sedation
-palpation under sedation (cranial drawer and tibial compression test)
surgical options for cranial cruciate ligament repair
-extracapsular suture (cheaper alternative)
-tibial tuberosity advacement (TTA)
-tibial plateau levelling osteotomy (TPLO)
-tibial wedge ostectomy (TWO)
-triple tibial osteotomy (TTO)
post-op care of cranial cruciate repair Sx
-analgesia (opioid, NSAID)
-rehabilitation
-re-assess @ 6 weeks w/radiographs
-complications (infection, fracture, late meniscal injury)
goal of cranial cruciate ligament repair Sx
stabilize stifle by altering mechanics - eliminate craniocaudal shear
DDx for hindlimb lameness in an adult dog
-cranial cruciate ligament disease
-hip osteoarthritis
-trauma (fracture/luxation)
-patellar luxation
-lumbosacral disease
-intervertebral disk disease
-neoplasia
-immune mediated arthritis
-muscle and tendon disorders
-footpad disorders
conservative management plan for medial coronoid disease
-improve body weight/condition
-NSAIDs
-low impact exercise/physio
-neutraceuticals/alternative therapies
components of elbow dysplasia
-medial coronoid disease (common)
-ununited anconeal process
-incomplete ossification of the humeral condyle
treatment options for ununited anconeal process
-conservative management
-excision of fragment (first opinion?)
-ulnar osteotomy and lag screw fixation (referral)
IOHC
-young and spaniels
-painful on elbow extension
-well positioned radigraphs or CT for Dx
-high infection risk with transcondylar screw Sx
most common cause of forelimb lameness in the horse
foot pain
DDx for acute severe lameness in the horse
-subsolar abscess
-acute laminitis
-acute solar bruising
-penetrating injury
-pedal bone fracture
DDx for chronic low grade lameness in the horse
-navicular disease
-foot imbalance
-osteoarthritis
-hoof wall crack
-ossified collateral cartilages
-keratoma
-chronic laminitis
navicular disease
a chronic, degenerative and progressive disease of the navicular bone and surrounding soft tissue structures (bursa, ddft, ligaments)
back conditions in the horse
-fractures (withers)
-kissing spines
-soft tissues (muscle/ligament strain)
-sacro-iliac pain
-osteoarthritis (articular process joints)
-"false" back conditions
*deformities
*spondylosis
management of the horse with back pain
-controlled exercise programme
-NSAIDs
-physiotherapy
-schooling/rider issues
-alternative therapies
body systems to investigate in a horse presenting with poor performance
1 - musculoskeletal (73%)
2 - respiratory (24%)
DDx for hindlimb lameness in an immature small breed dog
-patellar luxation
-avascular necrosis of the femoral head
grading system for patellar luxation
1 - patella in groove, can be displaced but returns spontaneously
2 - patella in groove, can be displaced and remains so until replaced in groove
3 - patella out of groove, can be replaced but spontaneously luxates again
4 - patella out of groove and cannot be replaced
most common surgical treatment for patellar luxation
tibial torsion/rotation repair by tibial tuberosity transposition
how to Dx patellar luxation
-on physical exam
-try to push patella medial/lateral with index finger and thumb while extending stifle
-if permanently luxated, follow patellar ligament up from tibial tuberosity to find patella, try to replace it in the groove
DDx for swollen joints (equine)
-osteochondritis dissecans
-osseous cyst-like lesion
-physitis
-septic polyarthritis & osteomyelitis
-Salter-Harris fracture
-patellar luxation
joints most commonly affected by OCD (horse)
-hock (tarsocrural)
-stifle (femeropatellar)
-fetlock (metacarpophalangeal)
most common site for osseous cyst-like lesions in the horse
stifle joint (medial condyle of distal femur)
compare and contrast septic polyarthritis in foals vs. adults
(foals)
haematogenous spread after ingestion or from distant septic focus
(adult)
spread from adjacent infection, wound, iatrogenic
synovial fluid sampling considerations
-use aspetic technique
-perform cytology, look at WBCs (especially neutrophils) (EDTA purple top tube)
-check proteins (red top tube)
-culture +/- sensitivity
valgus
outward angulation ><
varus
inward angulation <>
management of angular limb deformities
-conservative if normal ossification (box rest, foot trimming/extension, diet restriction) [splint/cast if incomplete ossificaiton]
-surgical (slow or speed up growth with pins/wires through physes; corrective ostectomy)
flexural limb deformity aetiopahogenesis
increased joint flexion due to musculotendinous unit being too short for boney components of limb (contracted tendons) [sagittal plane]
treatment principles for flexural limb deformity
-stretch affected musculotendinous unit (physio, farriery, splint/cast)
-relax musculotendinous unit (oxytet, analgesia, splint/cast, treat underlying ortho. diz.)
-transect check ligament, tendon
common joints for flexural deformity
-DIP <box foot> (stage 1 and 2) - [cons. mgmt. or salvage check ligament/DDFT] respectively
-fetlock <straight leg> - [cons. trt. extend toe/raise heels, fetlock brace] or [Sx. trt. superior/inferior check ligament desmotomy]
flexor tendon laxity treatment
-mild > exercise and supportive care
-severe > light bandage, rasp heel, extend heel shoe
most common site for forelimb disease
elbow
considerations for arthrodesis
1) functional angle of joint
2) cancellous bone graft to speed healing
3) rigid internal fixation with compression
commonest neoplasm of forelimb
osteosarcoma @ proximal humerus (distal radius 2nd)
DDx for multiple limb lameness in the dog
-multiple trauma (RTA)
-digit/pad injuries
-developmental problems (bilateral)
(young)
-nutritional disease
-panosteitis
-metaphyseal osteopathy
-bone cyst
(adult)
-Marie's disease
-hypervitaminosis A (cat)
(all ages)
-immune based polyarthritis
causes of septic arthritis
-wounds
-iatrogenic
-spread from other infections (blood, or adjacent sites)
investigative techniques for septic synovitis
-distension test (inject saline to find draining tract)
-radiography (+/- contrast)
-ultrasound
-synovial fluid sample
-bacteriology
treating septic synovitis
-flush joint with saline arthroscopically - >10L sterile Hartman's
-local and systemic antimicrobials
-general wound mgmt/bandaging/rest
-tetanus prophy.
synovial fluid warning limits for septic synovitis
> 10 x 10^9 / L WBC, >= 90% PMNs
acute phase treatment of tendonitis
-box rest
-application of cold (hosing)
-firm and even bandage applied between cold therapy
-NSAIDs
PSGAG
polysulfated glycosaminoglycan
annular ligament syndrome
restricted SDT and DDFT within fetlock tunnel
-desmitis of annular ligament
-chronic synovitis of tendon sheath
-SDF or DDFT injury
-SQ fibrosis
-causes: strain, direct trauma, septic synovitis