Lecture 5 1/30/25 Flashcards
What are the differential diagnoses for shoulder disorders?
-luxation
-osteochondritis dissecans
-medial glenohumeral instability
-biceps tenosynovitis
-contracture of infraspinatus muscle
-calcification of supraspinatus muscle
-fracture
What are the characteristics of osteochondritis dissecans in the shoulder?
-local mineralization defect of the articular epiphyseal complex of the proximal humerus
-humeral head is the most common spot
-more common in males than females
-clinical signs begin between 4 and 8 months of age
Which breeds commonly develop OCD in the shoulder?
-bernese mountain dog
-border collie
-boxer
-bullmastiff
-great dane
-pointers
-retrievers
-mastiff
-rottweiler
-saint bernard
-standard poodle
What are the potential causes of OCD in the shoulder?
-genetics
-rapid growth
-nutritional imbalances; excess calcium and energy
-trauma
What are the clinical findings of OCD in the shoulder?
-pain, primarily with full extension
-atrophy of the supraspinatus and infraspinatus
-swelling; may be difficult to detect
-subtle or apparent lameness
How is OCD of the shoulder diagnosed?
-good orthopedic exam
-radiographs
Which radiograph is used to diagnose OCD in the shoulder?
lateral radiograph of the scapulohumeral joint
How does osteochondrosis differ from osteochondritis?
osteochondrosis: constitutes the process, but no flap development
osteochondritis: flap is present
What are the signs of osteochondritis dissecans on radiograph?
-flattened humeral head
-sclerotic humeral head/increased bone density
-fragments of flap
-calcified cartilage flap
What are the characteristics of osteochondrosis?
-disturbance of cartilage formation
-defect in endochondral ossification
-cartilage is thicker at affected joint surface
-genetic, nutritional, traumatic, and vascular components
What are the characteristics of osteochondritis dissecans?
-detachment of cartilage flap
-causes lameness, joint swelling, pain, and inflammation
What are the steps of osteochondritis dissecans?
-stress creates fissure of cartilage surface
-separation of retained cartilage from underlying bone
-synovial fluid helps create inflammation
-dissection of loose cartilage flap
-flap may mineralize
What are the treatment options for OCD in the shoulder?
surgery:
-arthrotomy
-arthroscopy
medical management:
-change diet to large breed growth diet or adult food
-NSAIDs
-rest if just an OC lesion
-no need for surgery if no pain/lameness
What are the characteristics of surgical removal of the cartilaginous flap as treatment for OCD?
-curettage of subchondral defect
-can do a caudal/muscle separation approach or arthroscopy
-prognosis is very good to excellent
What are the aftercare steps for OCD shoulder surgery?
-exercise restricted to leash walks for 4-6 weeks
-NSAIDs
-gentle passive range of motion
-faster recovery with arthroscopic treatment compared to muscle separation
What is the prognosis for OCD shoulder treatment?
-90-95% should have very good to excellent use of limb
-secondary OA may occur but shoulder joint is forgiving
-approximately 50% of dogs with have bilateral disease but may not require bilateral surgery
What are the characteristics of medial glenohumeral instability?
-involves glenohumeral ligament, subscapularis muscle, and subscapularis tendon
-frequency has increased due to agility competitions that require frequent turning/jumping
What are the physical exam findings in medial glenohumeral instability?
-excessive abduction of the shoulder joint while fully extended
-pain at the end of abduction
What are the arthroscopic findings in medial glenohumeral instability?
-torn medial glenohumeral ligament
-tear of subscapularis tendon
-tearing/extensive injury of the medial shoulder joint capsule
What are the nonsurgical management steps for medial shoulder instability?
-hobbles to prevent excessive abduction
-no running/jumping/playing; only leash walks
-extracorporeal shock wave therapy
-PRP or stem cells
-rehab exercises; balance board, lifting opposite forelimbs and hindlimbs, weight shifts, balance ball, walking in figure 8s/circles
-treadmill walks while gently pulling limb
-stretching the shoulder in extension
-laser/cryotherapy/moist heat
What is the shoulder tightrope procedure for MGH instability?
procedure in which holes are made to have suture attach halfway between the cranial and caudal arms of the medial glenohumeral lig. and come out just below the cartilage of the humerus
What is the post-surgical management for medial shoulder instability?
-hobbles
-no passive ROM to shoulder joint for 4-6 weeks
-weight shifting, balance, and low impact walking
-return to functional activities by 12-16 weeks
-more deliberate return to function if stabilization required
What is the signalment for biceps tenosynovitis?
adult, large breeds
What is the history for biceps tenosynovitis?
-insidious onset
-early stage presents with soreness after play or work
-late stage presents with persistent lameness
-can occur following traumatic injury and/or repetitive use
What are the clinical signs of biceps tenosynovitis?
-subtle lameness in gait
-pain with digital pressure on tendon
-pain with flexion of shoulder and extension of elbow
What are the diagnostics for biceps tenosynovitis?
-radiography assessing for bony reaction/calcification of tendon +/- contrast arthrogram
-ultrasound
-MRI
-injection of local anesthetic; looking for relief
What is the pathophysiology of biceps tenosynovitis?
-trauma to tendon with stretching and tearing of fibers
-inflammation of synovial sheath
-may be sequela to OCD of shoulder due to fragments migrating into tendon sheath and/or adhesions of the tendon
-can be acute or chronic
What were the conclusions found when studying biceps tenosynovitis?
-inflammation was variable and may not be a consistent feature of biceps tendonitis
-disease may be a degenerative process rather than inflammatory
What is the early treatment for biceps tenosynovitis?
-activity restriction
-deep friction massage to prevent adhesions
-ice
-stretching of biceps tendon
What is the medical treatment for biceps tenosynovitis?
-NSAIDs and rest
-intra-articular platelet rich plasma
-intra-articular stem cells
-intra-articular corticosteroid; slows tendon healing, must combine with rest
What is the surgical treatment for biceps tenosynovitis?
-open approach with tenotomy and relocation of tendon end to greater tubercle; attach with screw and spiked washer
-possible to perform tenotomy alone arthroscopically
What is the aftercare and prognosis for biceps tenosynovitis surgery?
-restricted to leash walks only for 6 weeks; no running, jumping, playing
-quicker recovery with arthroscopic transection; some dogs may remain lame
-prognosis is good to very good
What are other shoulder disorders that can be seen in dogs?
-infraspinatus muscle contraction
-supraspinatus tendinopathy
