Thoracic Limb Exam 1 Flashcards
Surgical anatomy of carpus
Hinge joint, radiocarpal, ulna carpal, numbered carpal bones
Short intercarpal ligaments, palmar fibrocartilage, collateral ligaments
Carpal hyperextension structural involvement
Trauma - injury to palmar soft tissue structures
- radiocarpal + ulnarcarpal ligaments
- palmar carpal fibrocartilage
- ligaments associated w accessory carpal bone
(Cushings, IMPA)
Signalment & clin presentation of elbow dysplasia
Any size
Variable lameness, soft tissue swelling, joint effusion, hyperextended stance (bi or unilateral)
Diagnosing hyperextension injury
Radiographs of carpi, orthogonal and stressed views
Medial & lateral stressed for concurrent collateral damage
Traumatic hyperextension injury
Conservative management - unrewarding
Splint, rest, analgesics
Surgery for hyperextension injury
Arthrodesis - permanent fusion of a joint, can be partial or full
Partial carpal Arthrodesis
Need a normal radiocarpal joint - trauma needs to be confined to intercarpal or carpometacarpal joints
Fuses the intercarpal and carpometacarpal joints
- normally very little motion in these joints
Preserves motion of the carpus
Pancarpal Arthrodesis
Fusion of all joint that make up carpus
80% achieve excellent limb function
Can have secondary complications from surgery
Principles of Arthrodesis
Complete removal of cartilage
Rigid fixation
Bone graft
Anatomic alignment (10-12th extension)
After care of hyperextension injury
NSAID
Palmar splint - 6-8 weeks, change every 1-2 woks
Strict confinement - reduce catastrophic damage
Radiographs @8 wks
Potential complications of hyperextension
Screw loosening
Implant breakage
Metacarpal fracture
Non healing
Infection
Physiologic tourniquet
Bandaging complications
Juvenile conditions of elbow
Elbow dysplasia
Fragmented medial coronoid process
Osteochondrosis /chondritis dissecans
Ununited anconeal process
Incongruity
United medial epicondyle
Congenital luxation
Adult conditions of the elbow
Incomplete ossification of the humeral condyle
Flexor tendon enthesopathy
Traumatic luxation
Fracture
Neoplasia (joint or long bone)
Anatomy of elbow
Joints - humero radial, humeroulnar, proximal radioulnar
Collateral ligs
Radial, ulna, median nerve
Important landmarks - medial coronoid process & anconeal process
Elbow dysplasia - clin pres
Large fast growing breeds
5-7 months onset of lameness - or in mature dogs w OA
Variable degrees of lameness, worse w prolonged rest & exercise
Elbow effusion
Pain of hyperextension & flexion
Decreased ROM, crepitis palpable thickening
Elbow dysplasia - diagnostic
Radiographs - lateral and craniocaudal, flexed lateral
Ct scan - more sensitive
MRI & ultrasound
Components of elbow dysplasia
Fragmented medial coronoid process
Osteochondritis dissecans
Ununited anconeal process
Incongruence
-
Medial compartment disease/DJD
Flexor tendon enthesopathy
Ununited epicondyle
FMCP
Fissure
Osteochondrosis dessicans
Asynchronous growth
Osteoporosis (vascular abnormalities)
Trauma
Diagnosing FMCP
Radiographs - earliest signs sclerosis of distal aspect of trochlear notch
Management of FMCP
Treat as OA
Remove fragment, subtotal coronoidectomy
OCD
Medial humeral condyle (trochlea)
Failure of endochondral ossification - cartilage defect
Use radiographs, radiolucent subchondral defect
Flap removal - remove, debridement, perpendicular
UAP
Ununited anconeal process
Separated center of ossification
Starts young 11-12 weeks, complete by 16-20 weeks
20-25% bilateral incidence
Easy radiograph diagnosis (over 6 months old)
UAP
Unstable fragment will accelerate progression of OA
Can remove fragment, caudolateral approach, v ROM
Ulnar osteotomy - screw
Radial ulna incongruence
Elevation of coronoid above level or radial head
(Radius too short radius too long)
Caused by coronoid disease, medial compartment, ununited anconeal process, OCD
Radiographs
RUI
Due to asynchronous growth of radius and ulna
Ulna - premature closure of distal physis, radius too long, pressure on anconeal process
Radius - premature closure of either physis, radius too short, pressure on coronoid
Treatment plan for RUI
Aggressively !!!
Could be non healing
Implant breakage
Premature fusion
Infection
Medial compartment disease
Mod to severe cartilage erosion
Secondary to elbow dysplasia
Radiographs
MCD modified outer bridge scale
Chrondromalaica
Partial thickness fibrillation & fissuring
Full thickness fissuring
Full thickness cartilage loss
Treating MCD
Assess cartilage
Remove fragments
Decrease trans articular loads
Resurfacing, partial and total elbow replacement
Elbow arthroscopy complications
Post op lameness 5%
Swelling 2%
Infection 0.2%
Pain 2.8%
Nerupraxia 0.2%
^^ long term lameness 7%
Prognosis of elbow dysplasia
Depends on the case and severity
