Ch 50 the shoulder

Question 1

anatomy

Answer 1

two-thirds of the motion the shoulder joint, and one-third the scapulothoracic synsarcosis

the tendon of origin of the biceps brachii muscle passes through the intertubercular groove, held in place by the transverse humeral retinaculum.
The joint capsule blends with tendons > “rotator cuff” muscles in human beings:
- medially: include the subscapularis and coracobrachialis
- laterlly: supraspinatus, infraspinatus, and teres minor

lateral and medial glenohumeral (collateral) ligament

Question 2

At what age do the glenoid and proximal humeral physes fuse?

Answer 2

Glenoid - by 6mo
Proximal humerus - by 12mo

Question 3

What is the ratio of glenoid to humeral head ratio?

Answer 3

1:2.5

the joint is moderately congruent

Question 4

What are the three zones of the labrum?

Answer 4

Transitional zone (collagen fibers in a fishnet-like pattern)
Circular fiber zone
Meniscal fold

The labrum is highly vascularised along the free margin and is loosely attached to the glenoid

Question 5

How thick is the hyaline cartilage of the shoulder joint?

Answer 5

approx 1mm in 20-25kg dogs

Question 6

What shape are the collateral ligaments of the shoulder?

Answer 6

Medial glenohumeral ligament is Y-shaped
Lateral glenohumeral ligament is a thick band

Question 7

What structure function to keep the tendon of the origin of the biceps brachii within the intertubercular groove?

Answer 7

Transverse humeral retinaculum

Question 8

What are the normal flexion and extension angles of the shoulder in the dog and cat?

Answer 8

Dog
- extension 165
- flexion 57

Cat
- extension 164
- flexion 32

Question 9

List the passive mechanisms of shoulder stability

Answer 9

Limited joint volume
Adhesion/cohesion mechanism
Concavity compression
Capsuloligamentous restraints (glenohumeral ligaments, joint capsule, labrum, and biceps brachii tendon origin)

Question 10

What are the main active stabilisers of the shoulder?

Answer 10

Supraspinatus
Infraspinatus
Teres minor
Subscapularis

And to a lesser extent:
- Biceps brachii
- Long head of the triceps
- Deltoideus
- Teres major

respond to stresses created by locomotion and weight bearing. Active mechanisms also improve joint stability and glenohumeral balance by enhancing glenoid concavity compression.

Question 11

What type of mechanoreceptors are within the collateral ligaments?
What is their function?

Answer 11

Type I, II and III mechanoreceptors
Type I (Ruffini) are the most common
Allow ligaments to work as sensory structures to actively contribute to shoulder stability via reflex arcs with the associated musculature

Question 12

immobilization of shoulder joint is entirely reversible, even when the period of immobilization is prolonged.

Question 13

diagnosis

Answer 13

phyiscal exam
begin with a thorough history of the lameness, including signalment
walk, palpation of the shoulder joint and associated musculature, joint range of motion and stability, and pain
neuro: CP deficits, atrophy, neck pain, reduced withdrawal
goniometry

diagnostic intra-articular anesthesia….?

arthrocentesis
valuable information for identifying immune-mediated and septic disease,

Rads
radiographic changes, even mild ones, are strong indicators of intra-articular disease. Osteoarthritis is rarely a primary disease of the shoulder joint
fractures, OCD, incomplete ossification of the caudal glenoid, chondrocalcinosis, glenoid dysplasia, and traumatic luxations
Stress (abduction) views may assist in the diagnosis of instability of the medial side of the shoulder joint, but the highly mobile nature of the normal shoulder joint warrants caution

Arthrography
outlining soft tissue structures and abnormalities of the shoulder joint, such as the tendon of origin of the biceps brachii muscle, osteochondritis dissecans flaps, medial joint stabilizers, intra-articular loose bodies, synovial neoplasms,

CT/MRI
CT and CT arthrography allow visualization of the peri- and intra-articular soft tissue structures except for the teres minor muscle tendon and coracobrachialis muscle

MRI allows identification of both intra-articular and extra-articular structures of the joint.

ultrasound
examination of the tendon also facilitates safe and efficient aspiration of surrounding synovial fluid and therapeutic injections.
The tendons of the supraspinatus, infraspinatus, and teres minor muscles and the caudal aspect of the humeral head can also be reliably imaged ultrasonographically.
limitation medial structures

Question 14

shoulder MRI

Question 15

chondrocyte toxicity

documented of many commonly used local anesthetics in a wide range of species.

One publication suggested that a single intra-articular administration of bupivacaine, because of the drug’s rapid dilution and drop in intra-articular concentration, did not pose a significant risk for chondrocyte damage.

Several in vitro studies document protective effects of vitamin C, N-acetylcysteine, and hyaluronan on chondrocytes prior to exposure to local anesthetics.

Until more is definitively known about the effects of local anesthetics on canine and feline chondrocytes and the clinical utility and effectiveness of protective drugs, intra-articular instillation of local anesthetics should be used as a single administration, if at all

Question 16

What is the optimum concentration of iodine for arthrography when VT angiography is performed?

Answer 16

60mg/ml

Question 17

What percentage of shoulder pathology is extra-articular and therefore would be missed on arthroscopy?

Answer 17

15%

Question 18

mineralization within the tendon

Answer 18

mineralization within the tendon of origin of the biceps brachii muscle and tendon of the supraspinatus muscle

study
unilateral or bilateral thoracic limb lameness revealed that almost 40% of dogs identified by CT scan as having mineralization of periarticular soft tissue structures of the shoulder were not lame on the limb with periarticular mineralization.

Almost 90% of dogs with thoracic limb lameness and concurrent mineralization of periarticular soft tissue structures of the shoulder either had other documented shoulder pathology or had elbow disease.

Question 19

What is the recommended angle for excision arthroplasty of the glenoid?

Answer 19

excision arthroplasty is to form a “false” or fibrous joint between the humeral head and the scapular neck

• Distolateral to proximomedial osteotomy of the scapular neck
• Being careful to protect the suprascapular nerve

excision of humerus head not necessary

Question 20

What is the outcome of excisional arthroplasty?

Answer 20

Good-to-excellent in small dogs
Unknown in large breeds

Question 21

What angle of shoulder is aimed for in arthrodesis?
What landmark should be used for the rotation alignment?

Answer 21

105-110 degrees

The greater tubercle should be positioned craniodistal to the acromion and slightly medial in the sagittal plane

plate should extend from the distal half of the scapula to the proximal half of the humerus (typically at least four or five screws in each bone). The plate is contoured

In small dogs > large transarticular screw or diverging Kirschner wires
clinical outcomes are generally better when plates and screws are used for all sizes of dogs and cats.

Principles of arthrodesis (removal of articular cartilage and rigid fixation of the joint at a functional angle) are followed.

cancellous graft augmentation may not be as critical in the shoulder joint as in other joints because of the normally high cancellous bone content in the humeral head

Question 22

craniolateral approach.
The insertion of the trapezius muscle and the origin of the omotransversarius muscle are elevated from the cranial edge of the scapular spine as needed.

The incision is continued distally along the cranial border of the acromial head of the deltoideus muscle. The omobrachial vein (and cephalic vein, if necessary) is divided, and the incision follows the lateral aspect of the brachiocephalicus muscle to its insertion. The insertion of the superficial pectoral muscle is incised and the muscle elevated and retracted cranially.

Although osteotomies can be performed, tenotomy of deltoideus and supraspinatus tendons may result in fewer complications due to osteotomy nonunion

Answer 22

Elevation of the supraspinatus muscle, uprascapular nerve is identified, The lateral collateral ligament is transected and the joint capsule incised to allow luxation of the humeral head from the glenoid fossa.

A motorized burr is used to remove the articular cartilage from the surfaces of the humeral head and the glenoid fossa. stectomy of the distal tip of the glenoid and corresponding humeral head may be required to create an acceptable degree of contact between

thin bone of the scapula makes screw pull-out and construct failure more likely. Locking plate technology may therefore be preferred, however consider compression

Question 23

What is the reported outcome after shoulder arthrodesis?

Answer 23

Good-to-excellent
Normal or near-normal gait in 12 weeks

Question 24

What is the most common location of shoulder OCD?
How often is this disease bilateral?

Answer 24

caudocentral or caudomedial aspect of the humeral head, usually opposite the caudoventral rim of the glenoid
27-68% bilateral

Question 25

What percentage of OCD cases will have a nonmineralised cartilage flap trapped within the tendon sheath of the biceps?

Answer 25

Approx 10%

Question 26

What are the approach options of debridement of a shoulder OCD flap?

Answer 26

Caudal - requires assistant for retraction - results in less loss of RoM and improve weight bearing in first month Caudolateral interdeltoideus approach - Craniodorsal retraction of infraspinatus and teres minor - Better protection og caudal circumflex humeral artery and axillary nerve Craniolateral - Included tenotomy of infraspinatus tendon - Greater exposure of caudal aspect of humeral head but limits access to caudal joint pouch modified cheli articular access between the supraspinatus muscle and the infraspinatus tendon. Cheli modification > forced hyperflexion. caudal displacement of the acromial deltoid and infraspinatus muscles, further modified by Vezzoni to limited open approach without humeral head luxation

Question 27

a caudolateral approach with craniodorsal retraction of the teres minor muscle (no tenotomy) has been shown to result in increased joint extension and range-of-motion compared with a craniolateral approach with tenotomy of the infraspinatus muscle, but there was less exposure to the articular surface compared with a craniolateral approach

Question 28

What is glenoid dysplasia? What breeds are predisposed? What does it cause? What is the treatment?

Answer 28

Glenoid dysplasia is hypoplasia or aplasia of the glenoid resulting in grossly abnormal articulation Toy breeds (Toy and Min poodle, Chihuahua, Pom, Sheltieetc) Results in medial luxation of the shoulder Tx: Arthrodesis or excision arthroplasty with an acceptable return to function | generally diagnosed in dogs between 3 and 10 months

Question 29

What is multiple epiphyseal dysplasia? What is the treatment?

Answer 29

A rare defect in the ossification of the epiphyses of long bones, vertebrae, cuboidal bones and apophyses Severe lameness, resembles bony changes seen with congenital hypothyroidism Tx: euthanasia

Question 30

In what breed has focal humeral head dysplasia been reported?

Answer 30

Boerboel (Arthrodesis)

Question 31

What is the radiographic hallmark of HOD?

Answer 31

“Double physis” - irregular radiolucent line in the metaphysis, parallel to and seperate from the physis

Question 32

What is chondrocalcinosis? What breeds are overrepresented? What gross lesions are seen? Is it clinically significant?

Answer 32

- Chondrocalcinosis is deposition of hydroxyapatite in the articular cratilage, “pseudogout” - Overrepresented in the Greyhound and GSD - Gross lesions: small pits in cartilage surface, scarring, scoring and cracking, often unilateral - Often found incidentally at necropsy, clinical significance unknown

Question 33

What is this disease? Is it clinically significant?

Answer 33

Incomplete ossification of the caudal glenoid - Often asymptomatic but can be a cause of lameness if mobile - Arthroscopy to comfirm if mobile and can remove the fragment

Question 34

Biceps Brachii Tendinopathy | exact pathophysiologic mechanisms responsible remain unknown.

Answer 34

primary or secondary Primary inflammation of the tendon of origin dt overuse or chronic repetitive injury. area of relative hypovascularity may predispose to mechanical failure (fraying or rupture) Secondary in response to other intra-articular disease or trauma to other tendons of shoulder

Question 35

biceps tendinopathy CS

Answer 35

middle-aged to older, medium- to large-breed dogs. chronic intermittent or progressive weight-bearing thoracic limb lameness, which becomes worse with exercise

Question 36

Lists tests which can be done to test for biceps tendinopathy | true prevalence is unknown

Answer 36

- Biceps tendon test direct digital pressure against the tendon of origin while the shoulder joint is flexed and the elbow extended - Drawer test Places direct pressure against the tendon and associated sheath (doe not test for tearing/rupture) humerus is translated cranially - Biceps retraction test Grasping the tendon of insertion at cranial elbow and pulling caudally whilst weight-bearing **All tests are assessing for a pain response**

Question 37

biceps tendinopathy DX | pro's of u/s?

Answer 37

Rads standard orthogonal flexed craniodistal-cranioproximal (skyline) (view intertubercular groove, mineralization of the tendon + distinguishing mineralization in the tendon of the supraspinatus muscle Contrast arthrography ultrasonographic more sensitive, earlier diagnostic tool, however diseased BT can look normal ID changes within tendon sonolucent line around the tendon; hypoechoic tendon with fiber disruption; proliferative synovium; irregularities of bicipital groove MRI evaluation of all other soft tissue structures of the shoulder joint i.e. Concurrent displacement of the tendon arthrography > tendon avulsions and tears, impingement of the suprapinatus tendon on biceps

Question 38

biceps tendinopathy medical Tx

Answer 38

1. long-acting CCS - methylprednisolone acetate (10 to 40 mg), strict cage rest and a gradual return to activity - intratendon injection vs intraarticular: question the need, anecdotally intra-articular associated with tendon weakening and rupture in human and rabbit - systemic effects of long-acting steroids? - potenital effects on articular tissues to use triamcinolone (5 mg per joint) > no published reports - need for prolonged (4 to 6 weeks) strict confinement - Concurrent physical rehabilitation therapy 2. nonsteroidal antiinflammatory drugs,rest, physio 3. prp, stem cells, no objective studies have been published | corticosteroids reduce the inflammation

Question 39

What are the surgical options for biceps tendinopathy?

Answer 39

1. Tenodesis to the proximal portion of the humerus through a cranial arthrotomy extrapolated from the human medical literature. Good long-term outcomes generally reported in dogs Arthroscopically assisted tenodesis decreases the incidence and severity of complications return 12 to 18 weeks after surgery 2. Tenotomy open or arthroscopically using hooded arthroscope knife or bipolar tendon provide passive restraint to the shoulder joint > Further studies needed to asses if joint stability is effected arthroscopy lateral shoulder joint portal a craniolateral instrument portal tendon is released from its origin on the supraglenoid tubercle joint can be slowly flexed, resulting in tension on the tendon | rehabilitation will maximize the speed and extent of recovery

Question 40

What breeds are predisposed to **medial displacement** of the biceps tendon of origin? What are the surgial options? | Rupture of transverse humeral retinaculum - cause unknown.

Answer 40

Greyhounds, Afghan hounds, GSD, Border Collies Primary reconstruction of the transverse humeral retinaculum and/or augmentation with screws and PDS or staples and polydiaxonone mesh **Prognosis excellent** | displace medially from groove when joint extended and supinated or flexd

Question 41

supination (palm facing upwards), and pronation (palm facing downwards).

Question 42

Rupture of the Tendon of Origin of the Biceps Brachii Muscle

Answer 42

direct laceration, avulsion or midsubstance tear +/- traumatic shoulder joint luxation. pain, swelling, joint instability, and lameness > acute vs chronic Ultrasonographic: inhomogeneous hyperechoic area in tendon's origin on the supraglenoid tubercle Arthroscopic examination Tx: Tenodesis

Question 43

What breeds are predisponsed to calcification of the biceps tendon of origin? pathogenesis

Answer 43

Labs and Rottweilers pathogenesis of dystrophic calcification unknown. tendon trauma results in a disturbance of blood supply, leading to hypoxia. Hypoxia may trigger remodeling into fibrocartilage radiographic abnormality: mineral opacity in the cranial aspect of the shoulder ddx supraspinatus Tx: rest and administration of nonsteroidal antiinflammatory Tenodesis

Question 44

supraspinatus tendinopathy | Rottweilers and Labrador Retrievers predisposed

Answer 44

dystrophic calcification vs incidental finding pathogenesis is unknown - area of hypovascularity in the tendon of the supraspinatus muscle Dx: Signalment, history, and exam similar to biceps brachii - presence of mineralization bilaterally, clinical signs may be unilateral - skyline view, ultrasonography, CT, or MRI may be necessary to confirm the diagnosis and differentiate calcification - Mineralization in the medial aspect adjacent to biceps tendon may be clinically significant > impingement or displacement of the tendon (accurately identified by MRI)

Question 45

What is the surgical treatment of supraspinatus tendinopathy?

Answer 45

Excision of calcified tissue (controversial if medical vs surgical treatment is best) rest and administration of nsaid Sx: variable success rates have been reported, Hypodermic needles and C-arm fluoroscopy can be used intraoperatively Rehabilitation exercises should be performed following surgery

Question 46

What is the most common direction of shoulder subluxation?

Answer 46

Medial instability (approx 80%)

Question 47

Instability or subluxation of the shoulder joint | both large- and small-breed dogs

Answer 47

small dogs the condition may occur as a congenital 3 and 10 months of age usually unilateral. Breed predispositions include Toy and Miniature Poodle, Chihuahua, Pomeranian, Pekingese, Miniature Pinscher, Lhasa Apso, and CKCS may hold the affected limb with the elbow joint flexed and adducted and with the distal part of the limb abducted. Abnormal spatial differences between the acromion and the greater tubercle are appreciated with palpation large dogs the condition is usually considered a sign of repetitive microtrauma secondary osteoarthritis are common

Question 48

pathophysiology of shoulder joint instability

Answer 48

not been fully determined > extrapolation from the human literature 1. loss of concavity compression, > ball in the concavity have greater resistance to translational forces > depth of the concavity through glenoid labrum or ligaments > magnitude of the compressive force provided by periarticular muscles. 2. disruption of glenohumeral balance > net joint reaction force passes through the center of the joint, provided by mucles and capsuloligamentous restraints

Question 49

What is the normal shoulder abduction angle

Answer 49

Approx **30 degrees** (vs 50 with instability) the abduction angle test had good sensitivity but low specificity while an abduction angle > 50° may be consistent with shoulder instability, itmay also any disorder of the thoracic limb that results in significant loss in muscle strength or muscle mass.

Question 50

how dx instability?

Answer 50

hx: chronic lameness, which is often subtle and intermittent nonresponsive to nonsteroidal atrophy of the shoulder muscles ex: during sedated examination because pain and apprehension abduction angle of the shoulder > standing angle. The scapula is stabilized, the humerus is abducted, and the angle formed by the shaft of the humerus and the spine of the scapula Gray et al: variability between individual shoulders, weak to identify subtle changes one study used goniometry: 50 degrees in clinically affected dogs RADS: Subtle degenerative changes, varus and valgus stressed views may identify excessive joint capsule and collateral ligament laxity (caution advised) - Stress Radiography for the Diagnosis of Medial Glenohumeral Ligament Rupture in Canine Shoulders Livet 2019 Arthroscopic: valuable for identifying medial instability, extent and type of degenerative changes (erosion of cartilage of caudal humeral head or medial ridge of glenoid; tearing of the medial glenohumeral ligament; and synovitis) evaluation is very subjective and not reliable

Question 51

What treatment options are available for stabilisation of the shoulder joint? (6) | poorly responsive to conservative therapy

Answer 51

1. Transposition of the tendon of origin of the biceps or supraspinatus (84.5% good to excellent outcome) 2. Augmentation of medial collateral with suture (medial aspect of the scapular neck and humeral head > not alter joint anatomy, and more biomechanical) 3. Imbrication of tendon of subscapularis muscle via craniomedial approach for mild degrees of instability 4. Radiofrequency induced thermal modification (RITM) > Thermal energy is applied to capsule, shrinking the collagen bundles, only if if the tendon of origin of the biceps brachii muscle, articular cartilage, and lateral compartment were normal, NOT effective in mod-severe instability/tear 5. Excision arthroplasty 6. Arthrodesis (85.7% good to excellent) if OA or prior Sx fail Transposition techniques result in altered biomechanics, incongruency and OA. Placement of heavy synthetic suture preferred method in a V-shaped (at attachments of the cr.and ca. medial glenohumeral lig.) with screw and washer bone tunnels or anchours > motion with good congruency, mobility, and less alteration of normal anatomy in 9 of 10 dog

Question 52

medial approach to shoulder joint

Answer 52

- incise superficial and deep pectorials - incise subscapularis and coracobrachialis tendons ->access to medial glenohumeral lig

Question 53

Postoperative Management and Outcomes shoulder instability

Answer 53

**post-op** - allow adequate time for scar tissue to functionally stabilize the joint. Maintenance of the limb in a Velpeau sling for 6 weeks (bandage complications and joint stiffness) - gradual return to function and rehabilitation exercises are recommended for 4 to 6 weeks (to allow properly remodel the collagen scar tissue over time) **outcome** - Thermal damage to glenohumeral ligament during RITM may temporarily injure the proprioceptive function of the ligament - Tendon transposition: 84.5% good to excellent outcome, no long-term studies - augmentation: Clinically, functional outcomes are better - Arthrodesis reportedly yielded good to excellent results in 85.7% of 14 dogs - veterinary literature, limited information is available: Functional outcomes RITM in dogs are somewhat difficult to truly know. numerous potential pitfalls have been acknowledged in the human and veterinary literature. consistently, uniformly, and without deep tissue damage or excessive heating of the collagen, urthermore, the collagen tends to stretch back to its original length with time and use.

Question 54

laterial instablity

Answer 54

Complete tears of the lateral, All dogs had incomplete tears of the medial glenohumeral ligament. Tx: intra-articular 40 mg of methylprednisolone + rested for 4 to 6 weeks. Two of three dogs returned to normal function as reported by the owner; the third dog underwent surgery to reconstruct/augment the lateral glenohumeral ligamen

Question 55

Traumatic Luxation most common direction? in large breed?

Answer 55

most frequently in a medial direction large-breed dogs often results in lateral luxation

Question 56

shoulder luxation - dx

Answer 56

dx identical to the presentation of congenital medial luxations Mediolateral and craniocaudal survey radiographic views are usually sufficient to document the luxation

Question 57

shoulder luxarion conservative options?

Answer 57

tx Conservative treatment of traumatic medial luxation of the shoulder joint is usually successful if the luxation is reduced and stabilized with a Velpeau sling soon after injury Lateral luxation, if the injury is recent and the joint is stable following reduction, can also be treated by closed reduction, but the thoracic limb should be placed in a neutral sling or spica splint, avoiding adduction of the shoulder limited information is available regarding the management of cranial and caudal luxations ehabilitation exercises are recommended for 2 to 6 wks

Question 58

shoulder luxation Sx options?

Answer 58

Sx If closed reduction cannot be accomplished, or if the joint is grossly unstable following closed reduction of luxation, surgical reconstruction or augmentation of the glenohumeral ligament(s) and joint capsule is recommended. transposition of the tendon > joint incongruency and degenerative joint disease modified Campbell prosthetic suture (heavy suture passed through transverse holes in the humeral head and scapular neck to create or augment glenohumeral ligaments Treatment of severe shoulder joint derangement by temporary transarticular bridging with a locking bone plate and screw Salvage procedures such as arthrodesis and excision arthroplasty prognosis: generally good. glenoid excision or arthrodesis should be expected to have some minor degree of gait alteration and limited range

Question 59

What is the range of grades of muscle strain injury? what animals? Tx? which muscles? (7) | difficult to dx, Ultrasonography or MRI to localize

Answer 59

Grade 1 = minimal tearing of individual muscle fibres up to Grade 4 = Complete muscle rupture requiring debridement and repair Tx: grade 1 - 3: ice pack, followed by warm compresses, compressive wraps, nsaid + analgesics, relaxants, rest, and physical rehabilitation grade 4 > surgical debridement and repair of the muscle may be appropriate usually occur in mature athletic dogs and result from overstretching or overuse near the musculotendinous junction muscle is strained to 80% of failure, the strength of muscle contraction is decreased by 30% immediately after injury, by 50% after 24 hours, and by 25% after 48 hours, and recovering to 90% of original function after 1 week susceptible mm: biceps, triceps, pectoral, serratus ventralis, rhomboideus, extensor carpi radialis, flexor carpi ulnaris

Question 60

What are some clinical features of teres minor myopathy? Treatment of choice?

Answer 60

Prominent pain with reduced shoulder flexion Tx: excision of enture muscle, excellent prognosis | Ultrasonography or MRI can be used to localize the lesion

Question 61

What breeds are predisposed to infraspinatus contracture? What is meant by a biphasic history? What are some characteristic gait features? Tx? | everely damaged muscle has little regenerative ability,

Answer 61

Brittany spaniel, Pointers, Labs Biphasic - Acute painful pain, swelling and lameness - Chronic, static, nonpainful gait abnormality with mm atropht/prominent scapular spine Gait - elbow adduction, shoulder abduction - external rotation of antebrachium - circumdution of limb with carpal flip ultrasonographic examination reveals hyperechoic changes in the muscle +/- MRI Tx: Tenotomy of the tendon through a lateral approach, with release of adjacent capsular adhesions Contracture > fibrous connective tissue replacement of muscle secondary to degenerative changes, dt low-grade repetitive trauma from vigorous activity +/- compartment syndrome

Question 62

List the treatment option of villonodular synovitis

Answer 62

Synovectomy Radiation therapy anti-TNF-a administration excision arthroplasty or arthrodesis

Question 63

What is the disease seen in the radiograph? What are the treatment options?

Answer 63

Synovial chondrometaplasia - a proliferative disorder of undiffernetiated stem cells. Fibroblast-like cells are transformed into chondroblastic cells under the influence of the extracellular chondroid matrix material Treatment - Good outcome with debridement of nodules, loos body removal and synovial stripping - Excision arthroplasty or arthrodesis

Question 64

Infraspinatus Bursal Ossification

Answer 64

Infraspinatus bursal ossification has been reported in Labrador Retrievers Radiographic changes include single or multiple mineralizations (osteochondromatosis) within the infraspinatus bursa that are best observed in the craniocaudal view. These mineralizations may not be clinically significant if pain cannot be elicited when pressure is applied directly over the tendon. Treatment with rest and nonsteroidal antiinflammatory drugs or intra-articular long-acting corticosteroids Surgical excision of loose bodies, the infraspinatus bursa, and a portion of the tendon of the infraspinatus muscle

Question 65

Ectopic or heterotopic ossification of soft tissues (other than synovium, supraspinatus muscle, tendon of origin of the biceps brachii muscle, and infraspinatus bursa) can occur in the canine shoulder.

Question 66

Management of medial luxation of the shoulder joint in toy-breed dogs using an antiluxation pin placed lateral to the supraspinatus muscle tendon: 20 limbs (2017–2022) **Takeshi Aikawa 2024**

Answer 66

retrospective study 18 client-owned toy-breed dogs (20 treated limbs). CLINICAL PRESENTATION Toy-breed dogs treated with the antiluxation pin lateral to the supraspinatus muscle tendon Reluxation occurred in 3 limbs final follow-up (median, 18.5 months gait assesment only, use of force plates and kinematic studies are desirable prevented the recurrence of and maintained a good long-term function

Question 67

Synthesis of surgeon and rehabilitation therapist treatment methods of bicipital tenosynovitis in dogs allows development of an initial consensus therapeutic protocol **Lane 2024**

Answer 67

limited canine research available, relevant human research, and what is known about tissue repair,formulate the following recommendations: * No surgery if BT is healthy or if the amount of fiber tearing is ≤ 20%. * BT is 75% torn, surgery approach. Conservative guarded prognosis. * tears between 20% and 75%, a case-by-case decision, ensuring best communication about advantages and disadvantages with the owners is likely the best approach. * NSAIDs only short-term pain control, protracted use may delay healing. NSAIDs are not indicated in chronic cases. * Intra-articular corticosteroids are not an appropriate long-term conservative treatment and are contraindicated * Intratendinous corticosteroid injections must not be performed. If the end goal is tendon necrosis, a biceps tenotomy should be considered instead, using the least invasive approach available. * PRP might be useful > currently a lack of evidence in the published literature * Cage rest is discouraged * Consider multimodal Tx: physio with activity restriction that returns to normal in a staged manner over several months. * Modalities such as ESWT, regenerative medicine, and photobiomodulation should be considered. * At this time, there is insufficient evidence to recommend therapeutic ultrasound, PEMF, or acupuncture.

Question 68

Pilot study of the ultrasonographic examination of the intact and transectedmedial glenohumeral ligament in dogs **Gemignani 2023**

Answer 68

the medial glenohumeral ligament could be identified with a medial ultrasonographic approach of the shoulder and a wider articular space can be a sign of a medial shoulder joint instability. Further studies are needed to confirm these preliminary findings in living dogs, with and without shoulder instability.

Question 69

Functional outcomes of dogs undergoing shoulder arthrodesis with 2 locking compression plates **Phipps 2023** | satisfactory standing angle (110 to 120 degrees)

Answer 69

Retrospective. 12. shoulder arthrodesis with 2 locking compression plates force plate analysis, at least 6 months follow up. ALL cases > satisfactory progression of arthrodesis at 6 weeks postoperatively, defined by loss of the radiolucent line previously present No major complications 11/12 > full functional recovery complication rate favorable compared to previously published fitzpatrick; complications in 50%, 2 catastrophic amputation or euthanasia bone graft 50%, not affect healing outcome shoulder joint exposed through transection of the insertion of the acromial head of the deltoideus, allowing identification of the tendon of insertion of the infraspinatus and teres minor on the proximolateral humerus. Both tendons were transected

Question 70

A recent case report custom manufactured **3-d cutting and reduction guides** for shoulder arthrodesis allowed accurate precontouring of locking plates onto the planned glenohumeral arthrodesis resulted in an excellent outcome and reduced intraoperative time.

Question 71

Ex vivo evaluation of arthroscopically assisted shoulder stabilization in dogs using an intra-articular aiming device **Rocheleau 2023**

Answer 71

Ex-vivo Study. use of intra-articular aiming device for suture-toggle or bone-anchor techniques - both techniques reduced reduction angles - suture-toggle more reliably performed Placement of anchors were not feasible in 3 and mild violations of the articular surfaces were detected in 3 specimens overall neurovascular structures in the region > not be entrapped by the suture tape as it courses over medial side raise the question of tensioning the repair - surgeon subjective

Question 72

Preoperative and postoperative abduction angles were reported as outcome measures by **O'Donell et al**. arthroscopic pre- and post-transection abduction anglesmore recently reported by **Jones et al** and **Livet et al** These more recent studies have called into question the clinical validity of shoulder abduction angles.

Question 73

A Modification of the Cheli Craniolateral Approach for Minimally Invasive Treatment of Osteochondritis Dissecans of the Shoulder in Dogs: Description of the Technique and Outcome in 164 Cases **Vezzoni 2021**

Answer 73

modified Cheli craniolateral approach for shoulder OCD - to reduce invasiveness and post-op complications - forced hyperflexion of the shoulder and hyperextension of the elbow → caudal displacement of acromial head of deltoid and infraspinatus → exposure of caudal humeral head without myotomy/tenotomy - 97.3% complete resolution of lameness intraoperative bleeding > omobrachial vein injury. joint cannot be completely evaluated for other diseases. Cheli approach can be used to allow OATS/synthetic resurfacing implant.

Question 74

Long-term outcome of dogs treated by surgical debridement of proximal humeral osteochondrosis **Zann 2022** a cross-sectional study is a type of observational study that analyzes data from a population, or a representative subset, at a specific point in time—that is, cross-sectional data

Answer 74

Cross-sectional study. 20 dogs (n = 26 shoulders). surgical debridement of proximal humeral OC lesions >12 months prior Orthopedic examination, kinetic gait analysis, radiographs, (CT), and arthroscopy performed. **needle arthroscopy** may be equivalent to conventional arthroscopy for the diagnosis of some shoulder pathology no differences in peak vertical force and vertical impulse between affected and unaffected limbs. 4.4% decrease in load distributed to the operated limb OA + muscle atrophy > all shoulders treated for OC lesions. Arthroscopically > all lesions patchy, incomplete cartilaginous infilling. No more than 60% infilling mechanisms that may explain this finding. 1. Studies in horses> fibrocartilage formed after subchondral curettage is mechanically inferior 2. Studies experimentally created cartilage defects in dog demonstrated decreased bonding of natural reparative fibrocartilage to the subchondral bed most dogs exhibiting subtle lameness on the subjective gait examination. Despite this, owner-perceived mobility was satisfactory The findings underscore the need for further scientific investigation into the most effective management of proximal humeral OC. Surgical debridement > not restore the articular surface or prevent OA but appears clinically beneficial in the majority of dogs.

Question 75

**Voss et al.** has demonstrated that compared with a walking gait, trotting increased the sensitivity accuracy of low-grade lameness detection in dogs

Answer 75

The most effective means of subchondral bone stimulation remains unexplored in the veterinary literature. Curettage: leads to local destruction of chondrocytes and inadvertent removal of healthy tissue This can lead to delayed healing and a poorer quality of fibrocartilage infilling Microfracture: result in increased fibrocartilage infilling volume with a greater percentage of type II collagen content histologic studies: demonstrated that secondary fibrocartilage stimulated by surgical debridement or forage does not have the same mechanical or structural properties of healthy hyaline cartilage

Question 76

Inverted V-shaped extracapsular stabilisation technique and arthroscopic findings in six dogs with medial shoulder instability **Hammer and Grand 2021**

Answer 76

Retrospective. inverted V-shaped extracapsular (coated polyester) stabilisation for MSI - modification of Fitch 2001 to allow early weight-bearing without coaptation - removes need to access two sites of scapular anchorage and extensive dissection - function → full in 4/6, acceptable in 2/6 - implant loosening in 2/6 without requiring revision **The suture material must maintain joint stability until the soft tissues have healed with maturation of scar tissues**.

Question 77

Effects of shoulder distraction on canine shoulder arthroscopy **Aoki 2021**

Answer 77

Leipzig distractor shoulder arthroscopy.ex vivo. use of a shoulder distraction device might improve the outcomes of shoulder arthroscopy by decreasing iatrogenic cartilage injury and arthroscopy time.

Question 78

Measurement of Shoulder Abduction Angles in Dogs: An Ex Vivo Study of Accuracy and Repeatability **Jones (pozzi) 2019**

Answer 78

Shoulder Abduction Angles in Dogs: Ex Vivo poor inter-observer repeatability, good intra-observer - intra-observer repeatability improved with experience Shoulder flexion angle can significantly affect measured abduction angles. shoulder abduction test is not as accurate as the fluoroscopic measurement > end-point may be challenging to discern clinically may be accurate enough for detecting clinically relevant hyperabduction angles. Transection of the medial supporting structures of the shoulder joint resulted in only a limited increase in the abduction angle > inconsistent to reported increase in lit.

Question 79

Stress Radiography for the Diagnosis of Medial Glenohumeral Ligament Rupture in Canine Shoulders **Livet 2019**

Answer 79

Six adult Beagle cadavers, randomly assigned Abduction angles were significantly larger in the AS group as measured by goniometer, image analysis and radiographic stress view than in the NS group. Shoulder abduction angles measured with a stress radiographspecific view provide objective data that may contribute to diagnosis of medial shoulder instability in dogs.

Question 80

Synthetic osteochondral resurfacing for treatment of large caudocentral osteochondritis dissecans lesions of the humeral head in 24 dogs **Murphy 2018**

Answer 80

medium-to-large defects located in the caudocentral aspect limitations:retrospective nature, Incomplete follow-up was obtained at 12 weeks postsurgery in 8/24 dogs Although results are encouraging, widespread implementation would be premature without a prospective clinical trial comparing synthetic resurfacing with debridement alone. complications infection + losening

Question 81

Feline shoulder luxation: a cadaveric study of injury and repair using ligament prostheses **Carwardine 2019**

Answer 81

Feline shoulder luxation cadaveric limbs: medial injury, lateral injury or bilateral injury + bone tunnel repair 4/6 medially injured joints > clinically stable 5/6 laterally injured joints > clinically stable. All bilaterally > deemed unstable (abduction + external rotation) repaired using bone tunnel and prosthetic suture regardless if medial, lateral or bilateral injury > returns the joint to normal….