51. Shoulder

Question 1

glenoid physis and proximal humeral physis fusion times

Answer 1

glenoid–6 monthsproximal humeral physis–1 yr

Question 2

collateral ligaments of the shoulder

Answer 2

medial collateral or glenohumeral ligament (Y)lateral collateral or glenohumeral ligament (single)

Question 3

passive stabilizers of the shoulder joint

Answer 3

passive (static) stabilizers–allow wide ROM–increases laxity while flexed–joint volume, adhesion/cohesion mx, concavity compression, capsuloligamentous restraints

Question 4

active stabilizers of the shoulder joint

Answer 4

active (dynamic) stabilizers–infra/supraspinatus-subscapularis–teres major

Question 5

sensory receptors in shoulder collateral ligaments for passive stability and joint stability

Answer 5

type I (Ruffini) receptorsmost common and densely packed on cranial aspect of the scapular side of the ligament

Question 6

normal dog and cat ROM (goniometry)

Answer 6

flexion dog 57 cat 32extension dog 165 cat 164

Question 7

describe arthrocentesis of the shoulder

Answer 7

sedate, aseptic technique22 gauge needledirect craniolateral to caudomedial btwn greater tubercle and acromion

Question 8

ddx for shoulder OA

Answer 8

usually a secondary condition to….1. fractures2. OC/OCD3. incomplete ossification of caudal glenoid4. chondocalcinosis5. glenoid dysplasia6. traumatic luxation

Question 9

diagnostics for shoulder pathology

Answer 9

1. PE, ORTHO, NEURO2. Arthrocentesis3. radiographs (include stressed abduction views, +/- arthrography)4. CT bone5. US tendons6. MRI soft tissues7. arthroscopy

Question 10

one current limitation for US of soft tissues surrounding the shoulder

Answer 10

inability to properly visualize the medial joint structures

Question 11

what percent of extraarticular structure pathology would have been missed on arthroscopy alone vs MRI

Answer 11

15% of shoulder pathology would have been missed on arthroscopic exam bc of its extraarticular location

Question 12

T/FOsteochondrosis dissecans is a disease of intramembranous ossification

Answer 12

FALSEendochondral ossificationmost commonly caudocentral or caudomedial humeral head

Question 13

signalment of OC/OCD of shoulder

Answer 13

large-giant breed dogs27-68% bilateralpain on shoulder EXTENSION

Question 14

radiographic changes for shoulder OC/OCD

Answer 14

–loss of trabecular structure–subchondral bone lysis–subchondral bone defect–gas accumulation in joint space (cavitation, vacuum phenomenon)–flattening or irregularity of humeral head–mineralized loose bodies in caudal joint pouch or in tendon sheath of biceps brachii

Question 15

what percentage of NONmineralized cartilage flaps within biceps brachia tendon sheath occur in OC/OCD lesions

Answer 15

10% miss by conventional radiographs

Question 16

T/Fbevel the cartilage edges during debridement of OC/OCD lesions

Answer 16

FALSE avoid beveling the edges of the defect to decrease the risk of fibrillation and erosion of the cartilage of the corresponding surface of the glenoid cavity

Question 17

approaches to the shoulder/humeral head for OC/OCD removal

Answer 17

1. craniolateral approach–+/-tenotomy of infraspinatus/teres minor, +/- osteotomy of acromion, increased exposure, but decrease ROM2. caudal approach–less loss of shoulder ROM and increased weight bearing 1 month post op; caudal to scapular part of deltoid muscle; axillary nerve3. caudolateral approach–btwn two muscle bellies of deltoid +/- teres minor tenotomy

Question 18

glenoid dysplasia leads to what shoulder instability

Answer 18

medial luxation

Question 19

how do animals with medial shoulder luxation hold their limb

Answer 19

elbow flexedadductiondistal extremity abducted

Question 20

treatment options for glenoid dysplasia

Answer 20

–excision arthroplasty +/- excision of the humeral head (“false joint”)–arthrodesis implant failure, delayed union–not shown to be better than excision arthroplasty (lg transarticular lag screw, diverging kwire, plates 105-110 degrees)–amputation

Question 21

proper osteotomy angle to perform glenoid excision

Answer 21

approach to shoulder = lateraldistolateral to proximomedial osteotomyavoid SUPRASCAPULAR nerve

Question 22

what is multiple epiphyseal dysplasia

Answer 22

rare autosomal recessive genetic disorder defect in ossification of epiphysis (multiple bones)seen at 8 weeks of ageseverely lameeuthanized

Question 23

what is pseudogout

Answer 23

chondrocalcinosisdeposition of hydroxyapatite in the articular cartilagefound in plateau region of the humeral head of Greyhoundsunknown clinical relevance

Question 24

most common should lameness in dogs

Answer 24

biceps brachii tendinopathyorigin supraglenoid tubercle(hypovascular area)primary dz due to inflammation from overuse or chronic repetitive injury secondary dz due to intraarticular disease or cartilaginous loose body entrapments or trauma related

Question 25

diagnosis of biceps tendon pain

Answer 25

1. drawer test (does not test instability)2. biceps tendon test (elbow extension, shoulder flexion)3. biceps retraction test

Question 26

imaging for biceps tendinopathy

Answer 26

–survey films–arthrography–flexed craniodistal cranioproximal SKYLINE to ID irregularities/mineralization in intertubercular groove–US–MRI

Question 27

treatment options for biceps tendinopathy

Answer 27

1. 1-2 injections long acting GCC, cage restsurgical options1. open tendonesis–tendon or origin to proximal humerus2. arthroscopic tendonesis3. percutaneous +/- US guided tenotomy4. open or arthroscopic tenotomy5. blind tenotomy

Question 28

differentials for biceps brachii disease

Answer 28

1. biceps tendinopathy (most common)2. medial displacement biceps brachii (rupture transverse ligament)3. tendon rupture of biceps brachii (avulsion, midsubstance, direct laceration)4. dystrophic mineralization of biceps brachii

Question 29

supraspinatus injury in dogs

Answer 29

attaches to greater tubercleRotts and Labs+/- incidentalmay represent avascular region of tendonpain on palpation+/- concurrent biceps brachiitreat: rest, NSAIDS, debride, tenotomy

Question 30

most common direction of shoulder luxation from shoulder instability

Answer 30

MEDIAL (80%)

Question 31

treatment options for shoulder luxation

Answer 31

1. transposition of biceps tendon or supraspinatus tendon (success 85%)2. augment collateral ligament with prosthetic suture reconstruction (screws/bone anchors and suture)3. imbrication of the tendon of the subscapularis muscle4. radio frequency induced thermal capsulorrhaphy via arthroscopy (tightens for stability)-caution axillary neuropathy5. arthrodesis6. excison arthroplasty

Question 32

T/Ftraumatic shoulder luxations in large to giant breed dogs are generally laterally

Answer 32

TRUEAVOID VELPEAU with lateral laxations to avoid ADDUCTION; USE SPICA

Question 33

disruption of muscle fibers most commonly occurs near____________

Answer 33

the musculotendinous junction

Question 34

infraspinatus muscle contracture characteristic gait

Answer 34

fibrous connective tissue replacing muscle secondary to degenerative changes as a result from traumabiphasic history (acute pain that improves then chronic lameness ensues)Muscle atrophy over spineelbow adducted shoulder abducted and ante brachium externally rotatedCIRCUMDUCTION of limb