Shoulder disease Flashcards
What is the signalment for OCD of the shoulder in the dog?
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Developmental orthopedic disease
- Biphasic age distribution
- 4-8mo (cartilage injury)
- Middle aged to older (secondary DJD)
- May have bilateral disease
- Young, male, large do giant breed dogs
What are the PE/orthopedic exam findings on a dog with OCD of the shoulder?
- Forelimb lameness
- Head bob–“down on sound”
- Muscle atrophy
- Pain on hyperextension of the shoulder joint
- Pain on flexion of the shoulder joint
- May have unilateral lameness despite bilateral disease (one side can be worse)
What 3 characteristics are required in order for a patient with OCD to qualify for conservative therapy only?
- Small defect
- Minimal to no lameness
- Very young dog (< 6mo)
ALL must be true
Which treatment is typically recommended for OCD of the shoulder (general)?
Surgical
What is involved in conservative treatment of OCD of the shoulder?
Rest
Diet: controlled energy, vitamin D, Ca
NSAIDs
Describe in general terms what is involved in the surgical treatment of OCD of the shoulder
- Surgical treatment is the standard of care
- Flap removal and joint lavage
- Debridement of bone with curette or shaver
- Defect heals with fibrocartilage
- Arthroscopy preferable to arthrotomy
What is the prognosis for OCD of the shoulder?
- Much better with sx than w/o
- Near-normal to normal function w/ sx
- Pet dog–good to excellent
- Working dog–fair to good
- (Assuming sx is done prior to onset of DJD)
- DJD expected w/o surgery
What is the typical pathogenesis of biceps brachii tendinopathy in dogs?
- Repetitive strain microtrauma
- Injury w/ tendon fiber disruption
- Acute to chronic inflammation of tendon and associated synovial tissues
- Both acute and chronic inflammation present histopathologically
- If etiology is repetitive trauma or overuse –> probably seen unilaterally in adult dogs
What is the signalment of biceps brachii tendinopathy in dogs?
- Mature adult dogs
- Medium and large breeds
- Wt.-bearing lameness
- Chronic, intermittent
- Progressive
- Lameness worsens w/ exercise
- Unilateral
What are the PE/orthopedic findings associated with biceps brachii tendinopathy?
Muscle atrophy
Pain
What manipulations are used during the orthopedic exam to evaluate the biceps tendon when biceps brachii tendinopathy is suspected?
- Maximally flex shoulder and extend elbow
- Deep palpation over intertubercular groove
- Apply tension to biceps insertion
- Standing exam, under load: tension to biceps
What is the relationship between the anatomy of the tendon and the ortho exam manipulations?
- Palpate insertion of biceps tendon
- Pressure there applies tension to biceps
- Stretch in biceps tendon elicits pain
- May also be done in lateral recumbency
Why are radiographs taken when diagnosing biceps brachii tendinopathy? Which views are used?
- “Standard” craniocaudal and lateral views taken to rule out other diagnoses
- “Skyline” view and arthrograms exist, but are not commonly used–overlap with other conditions
What are the pros and cons of using ultrasound for biceps brachii tendinopathy?
Pro: non-invasive
Con: requires experience
What are the pros and cons of using MRI for biceps brachii tendinosis?
- Pros
- Cross-sectional anatomy of all soft tissues
- Identify concurrent problems
- Con: over/underinterpretation possible
- Not generally used in clinics
Is arthroscopy helpful for the diagnosis of biceps brachii tendinopathy?
- Diagnostic and therapeutic
- Practical considerations
- If PE suggestive, often used in lieu of other imaging
- Lateral/craniocaudal rads + arthroscopy
What is the treatment for acute presentation of biceps brachii tendinopathy?
- Confinement for 4-6wks
- NSAIDs
- +/- PT
- EBM lacking
What is the treatment for recurrent/persistent lameness presentation of biceps brachii tendinopathy?
- Moderate, acute signs
- Intraarticular corticosteroid injection
- Methylprednisolone acetate (Depo-medrol)
- Sample for joint fluid analysis/culture
- Strict confinement, 4-6wks
- PT
What are the indications for surgical treatment of biceps brachii tendinopathy?
- Refractory to medical therapy
- Radiographic changes
- Mechanical deficits
- Moderate to severe lameness
What is included in surgical treatment of biceps brachii tendinopathy?
- Arthroscopic evaluation of the joint
- Ensures no other problems
- Enotomy of biceps tendon
- Tenodesis of bicipital tendon
What is the difference between tenotomy and tenodesis of the biceps tendon?
- Tenotomy = cutting of tendon and setting free
- Tenodesis = cutting of tendon and fixing in place
What is the prognosis for medical treatment of biceps brachii tendinopathy?
- Good to poor
- Lack of confinement
- PT improves results (presumptively)
What is the prognosis for surgical treatment of biceps brachii tendinopathy?
- Good to excellent
- Tenotomy–excellent results reported
- Tenodesis–“classic treatment”
- Good results reported historically (esp. arthroscopically assisted)
What is the definition of shoulder instability?
- Abnormally increased ROM
- Laxity in support structures of the shoulder
- Medial/lateral glenohumeral ligaments
- Joint capsule
- Subscapularis tendon (medial)
- Teres minor, supra- and infraspinatus (lateral)
What is the etiopathogenesis of shoulder instability?
- Repetitive microtrauma (“overuse” injury)
- ~80% medial shoulder instability
What is the most common direction of shoulder instability?
Medial
What is the typical signalment of shoulder instability?
Medium/large breed
Adult
What is the typical history of a dog with shoulder instability?
- +/- active dog
- Variable lameness
- Usually subtle, intermittent
- Occasionally severe
- Poor response to rest and NSAIDs
What are the typical PE findings on a dog with shoulder instability?
- Muscle atrophy
- Pain on manipulation of joint
- Medial instability–hallmark of diagnosis
- Inc. abduction angle
- Exam requires sedation
- Gross instability palpable
- Normals not well-established
Which tests may be used during an orthopedic exam to detect shoulder instability?
- Radiographs
- MRI
- Arthroscopy
- Angle tests
- Compare with contralateral limb
How do you interpret the sedated examination of the shoulder when evaluating for shoulder instability?
- Normal ~30 degrees
- Abnormal ~50 degrees
- Variation between breeds/individuals
What are the values of using standard radiographic views when evaluating for shoulder instability?
- Rule out other conditions
- Normal or non-specific degenerative changes
- No special fancy views described
Which modality is best for evaluating joints for shoulder instability?
Arthroscopy
Diagnostic and therapeutic if PE is supportive
What are the treatment options for shoulder instability based on?
Degree of instability
What is the treatment for mild shoulder instability?
Rest, PT, Hobbles
What is the treatment for moderate shoulder instability?
- Arthroscopic thermal “capsulorrhaphy”
- Thermal insult induces repair
- Weakens tissue before it strengthens
- Rest, PT, Hobbles
- Must restrict movement after cauterization therapy
What is the treatment for severe shoulder instability?
- Medial glenohumeral ligament reconstruction
- Velpeau sling instead of Hobbles
- Keeps limb against body–takes pressure off joint
When is hobbles recommended for shoulder instability?
- Postop rehab 3wks
- Activity restriction 3-4mo
- Retraining begins 4-6mo
T/F: For the test of craniocaudal instability of the shoulder, it is possible to have a positive “biceps tendon” test and a positive “shoulder drawer” test
TRUE
What is capsulorrhaphy?
The use of heat to shrink and tighten the shoulder capsule, which is the connective tissue around the shoulder joint that helps keep it stable
What is medial glenohumeral ligament reconstruction (in basic terms)?
- Procedure for installing a cannulated bone screw and ligament washer to retain ligament at a bone site
- A first cannula is used in conjunction with selected obturators to engage and relocate the ligament
- A drill is used to drill a bone hole
- A second larger cannula with a driver to screw a bone screw into the bone hole retaining the relocated ligament at the anchoring site
Understand when ligament reconstruction is indicated
Severe shoulder instability
What is the definition of contracture?
Muscle shortening not caused by active contraction
What is the etiology/pathogenesis of muscle contracture?
- Acute, traumatic disruption of muscle fibers
- Fibrosis and contracture secondary to necrosis
- Similar lesion in supraspinatus also documented
Apply the described principles of contracture to similar lesions in the supraspinatus
Rupture of muscle belly–>scar tissue
What is the typical signalment of a dog with infraspinatus contracture?
- Active
- Adult
- Medium to large breeds
- Hunting breeds overrepresented
What is the typical history of a dog with infraspinatus contracture?
- Acute lameness, subsides in 10-14days
- Chronic, static lameness 2-4wks later
- Non-painful, non-weightbearing lameness
- Elbow adducted, antebrachium abducted
What is the pathognomonic stance/physical appearance of a dog with infraspinatus contracture?
- Scapulohumeral joint cannot be internally rotated–scapula elevates when shoulder is rotated
- Limited ROM
- Usually no pain on manipulation of joint
What is the value of conservative treatment for infraspinatus contracture?
None–it’s useless
What are the goals of surgical treatment and aftercare of infraspinatus contracture?
- Tenectomy of infraspinatus tendon
- Release other capsular adhesions
- PT ideal
What is the prognosis following surgical treatment of infraspinatus contracture?
Excellent
What are the palpation findings and limb positioning of a dog with traumatic shoulder luxation?
- Non-wt. bearing lameness
- Pain on palpation of shoulder
- Malpositioning of greater tubercle
- Medial luxation: distal limb abducted
- Lateral luxation: distal limb adducted
What is the nomenclature rule for traumatic shoulder luxation?
Named for the position of the humeral head relative to the glenoid
What is the most common direction of traumatic shoulder luxation?
Medial
What are the indications for a closed reduction following traumatic shoulder luxation?
- Recent injury
- No fractures
Which form of coaptation should be applied for each direction of luxation?
- Medial luxation = Velpeau sling
- Lateral, cranial, caudal luxation = Spica
What are the indications for surgical reduction of traumatic shoulder luxation?
- Chronic/recurrent/unstable luxation
- Accompanying fractures
What is involved in surgical reduction of traumatic shoulder luxation?
- Open reduction + ligament repair
- Simple arthrotomy to evaluate/reduce joint
- Imbrication/repair of capsule during closure
- Glenohumeral ligament reconstruction
Which glenohumeral ligament of the shoulder should be reconstructed for medial luxation? Lateral?
Medial repair for medial luxation
Lateral repair for lateral luxation
What is the expected functional outcome following traumatic shoulder luxation?
- Prognosis: good to excellent
- Closed reduction generally successful
- Restores normal joint function
- Open reduction
- Capsulorrhaphy and MGHL reconstruction
- Goal is to maintain normal joint motion
- Function typically good long-term
- Closed reduction generally successful
- Mild DJD over time may follow trauma
What is the origin of congenital luxation?
Congenital laxity of capsule and ligaments
What is the most common direction of congenital luxation?
Usually medial
Usually unilateral
+/- glenoid dysplasia
What are the PE findings in congenital luxation of the shoulder?
- Greater tubercle relative to the acromion (as for traumatic luxation)
- Joint easily reduced and re-luxated
- Glenoid dysplasia–reduction not possible
- Pain on manipulation may be minimal
What does the term glenoid dysplasia indicate?
Salvage procedure
What is the value of conservative and surgical treatments for glenoid dysplasia?
BOTH WILL FAIL
What are the procedures for congenital luxation vs. traumatic luxation?
- Medical management: nope
- Normal glenoid
- Open reduction/capsulorrhaphy only
- Glenohumeral ligament construction
- Salvage procedures
- Arthrodesis
- Glenoid excision
- Amputation
Compare the 3 salvage procedures for glenoid dysplasia
- Arthrodesis
- Invasive, inexpensive
- Moderate mechanical lameness (“peg leg”)
- Use w/ caution for bilateral disease
- Glenoid excision
- Outcome similar to arthrodesis
- Less technically challenging
- Amputation
