Joint dysplasias Flashcards
1
Q
What are four components of canine elbow dysplasia?
A
- OCD of the medial side of the humeral condyle
- Ununited anconeal process
- medial coronoid process disease
- Medial compartment disease (ulnar-radius incongruency)
2
Q
Heritability of elboe dysplasia
A
- Considered heritable
3
Q
OFFA
A
- Organization that certifies dogs’ hips, elbows, etc.
- Sole purpose is to certify breeding programs
- Very biased information
- True incidence may be much higher than what we are led to believe
4
Q
Pathogenesis of osteochondritis dissecans
A
- Review Dr. Hines’s notes
5
Q
What are aspects of elbow osteochondritis dissecans?
A
- Hypertrophic cartilage (medial side of the humeral condyle on the weight-bearing surface)
- Chondromalacia
- Incomplete ossification
- Weight-bearing forces to cartilage flap formation
6
Q
Pathogenesis of medial coronoid process
A
- Incongruous growth where the radius grows slower than the ulna
- Leads to overloading of the medial side of the coronoid process of the ulna
- Can overload a small spot, leading to disease
- Incongruency
- Conformation
- Myotendonous interaction (?)
7
Q
What types of pathology can be seen with medial coronoid process disease?
A
- Fragmentation
- Chondromalacia
- Chondromalacia/osteomalacia
- Incomplete fissure
- Concurrent erosions
8
Q
What is prognosis based on for medial coronoid process disease?
A
- Erosion based
- If there is a lot of erosion, there’s a poor prognosis for lame free function
9
Q
Pathogenesis of ununited anconeal process?
A
- Asychronous growth of the proximal ulna and radius
- Growth rate of the radius is greater than that of the ulna
- Shearing forces from the humeral condyle
- Results in what is similar to a Salter Harris Type I fracture
10
Q
Who gets ununited anconeal process?
A
- Only dogs with a separate center of ossification for the anconeal process
11
Q
Pathogenesis of medial compartment disease
A
- Incongruency (mild to severe)
- Overloading of the medial compartment of articular surfaces, resulting in marked cartilage erosions
- Can be concurrent with medial coronoid process disease
12
Q
Who gets OCD on the medial side of the humeral condyle?
A
- Large breeds, especially retrievers, Bernese Mountain dogs, Rottweilers
- Males > females
- Same signalment as medial coronoid process disease
13
Q
What age is usually diagnosed with OCD on the medial side of the humeral condyle?
A
- Usually not apparent before 5-8 months of age
14
Q
Clinical signs for OCD of the medial side of the humeral condyle?
A
- Slight to moderate lameness, stilted gait; worse after exercise, prominent after resting
- Discomfort on marked flexion/extension
- “popping” sensation on flexion/extension of the joint to crepitus
- +/- pain with deep palpation over the medial collateral ligament (with a flexed elbow)
- Mild joint effusion (feel between lateral epicondyle and humeral condyle
- Externally rotated paw to unload the medial compartment onto the lateral compartment when standing or sitting
15
Q
Appearance of OCD on the medial humeral condyle
A
- Can be unilateral or bilateral
- Lesion will be on the weight bearing surface (more medial aspect of the medial coronoid process)
- Might see osteophytes coming off the medial epicondylar ridge
- Can be osteophytes on the dorsal border of the anconeal process or off the radial head
- Make sure you know how this differs from medial coronoid process disease
16
Q
What type of imaging should you do to diagnose OCD of the medial humeral condyle?
A
- Bilateral elbow radiographs
- Mediolateral view and craniocaudal view
17
Q
What is typical signalment of coronoid disease?
A
- 5-8 months of age
- Can have “jump down syndrome” where there are clinical signs in dogs >1 year of age (3-5 years is typical)
- Subclinical fissured coronoid that then fragments when jumping down?
- Large breed dogs (retrievers, Bernese mountain dogs, Rottweilers, Males >females)
18
Q
Clinical signs of medial coronoid process disease
A
- Same as medial side of humeral condyle OCD
- Popping sensation on flexion/extension of the joint to crepitus
- +/- pain with deep palpation over the medial collateral ligament with a flexed elbow
- Mild joint effusion
- Externally rotated paw when standing or sitting
- Slight to moderate lameness, stilted gait; worse after exercise, prominent after resting
- Discomfort on marked flexion or extension
19
Q
Medial coronoid disease radiographic diagnosis
A
- Bilateral radiographs
- Similar radiographic lesions, but the kissing lesion on the humeral condyle is unique
- More on the laterial ridge of the medial condyle
- Based on exclusion of other elbow dysplasia diseases (OCD, Ununited anconeal process)
20
Q
If you rule out OCD and ununited anconeal process on radiograph, what’s left for elbow dysplasia disease?
A
- Medial coronoid process disease
- Incongruency or medial compartment disease
- Can differentiate with CT scan
21
Q
How would you differentiate medial compartment disease from medial coronoid process disease?
A
- CT
- Can see a fragmented coronoid (Medial coronoid process disease)
- If you do an arthrotomy, you can see erosions with medial compartment disease
22
Q
Who gets ununited anconeal process?
A
- German shepherds, Basset Hounds, St. Bernard
- Dogs with separate centers of ossification of the anconeal process
23
Q
When do you see clinical signs of ununited anconeal process?
A
- Usually not prior to 7-8 months of age
- 5-8 months for coronoid process disease
24
Q
Clinical signs of ununited anconeal process disease
A
- Slight to moderate lameness
- Circumducted forelimb gait (to avoid flexing the elbow)
- Externally rotated paw when standing or sitting
25
Diagnosis of ununited anconeal process?
- True crepitus of flexion extension**
- Huge amounts of joint effusion
- Externally rotated paw when standing or sitting
- Bilateral radiographs showing failure of the ossification center to fuse with olecranon (5-5.5 months of age)
- Mild to moderate osteoarthritis
26
Which shot is best to see the UAP?
- Flexed lateral
27
Treatment for medial coronoid process disease?
- Arthroscopy or arthrotomy to remove the osteochondral fragment
28
Treatment for OCD of the medial humeral condyle
- Arthroscopy/arthrotomy to remove the flap
29
Treatment for ununited anconeal process
- High osteotomy of the anconeal process (get rid of shear force??)
- Arthroscopy or arthrotomy to remove the AP if they are very degenerative
30
Treatment for medial compartment disease
- Arthroscopy for debridement, curettage, and micro-fracture (increase blood flow)
- Sliding humeral osteotomy (shifts the distal end of the humerus medial to load axis more on the lateral side)
- Proximal ulnar abduction osteotomy (shifts load bearing from medial to lateral compartment)
- Canine unilateral elbow (implant on the humeral condyle and trochlear notch of the ulna to give a new surface)
31
What should be done in addition for all elbow dysplasia cases, surgery or not?
- Multimodal management!!
| - Individualized patient method!!
32
What are some extreme surgical treatments for advanced cases of elbow dysplasia that surgery and multimodal OA doesn't improve function?
- Elbow replacement surgery
- Arthrodesis (fusing the joint, but elbow is a high mobility joint)
- Amputation (won't work with bilateral disease)
33
Prognosis for lame-free function of OCD of the medial humeral condyle
Good
34
Prognosis for lame-free function of medial coronoid disease with no or minimal erosions
- Good to very good
35
Prognosis for lame-free function of medial coronoid disease with marked erosions
- Fair to poor
| - May require osteotomy (SHO, PAUL)
36
Prognosis for lame-free function of Ununited anconeal process with a high ulnar osteotomy
- Very good to excellent
37
Prognosis for lame-free function of ununited anconeal process where you remove the fragment (vs without erosions or medial coronoid disease and with)
- Without erosions and MCD: Very good
| - With erosions and MCD: Guarded
38
Prognosis for lame-free function of medial compartment disease with minimal erosions
- Good
39
Prognosis for lame-free function of medial compartment disease with erosions
- Guarded
40
Prognosis for lame-free function of medial compartment disease with PAUL/SHO
- Good to very good (with the early, short-term results)
41
What is a main point with canine hip dysplasia?
- Common cause of radiographic secondary osteoarthritis in dogs
- Subclinical disease in the majority of dogs with canine hip dysplasia
42
Signalment for canine hipsyaplasia
- Most commonly reported in large to giant breed dogs
- Can see in smaller breeds
- Can also see in Maine Coon cats
43
Bilateral vs unilateral disease for CHD
- Most often bilateral
44
Etiology of canine hip dysplasia
- Multifactorial ultimately
- Genetic (polygenic, non-Mendelian trait)
- Nutritional (unrestricted diets and obesity)
- Other theories aren't confirmed (Rapid growth rates; collagen disorder, abnormal muscle development with decreased pectineus development leading to decreased abduction of the hip)
45
Pathogenesis of canine hip dysplasia
- Laxity of joint capsule and ligamentum teres
| - Lots of force applied to a very narrow point
46
Diagnosis of hip dysplasia
- History
- Clinical gait examination
- Complete PE
- Radiographs
47
History of CHD
- Continuously vs intermittently demonstrating clinical signs
- Stiff to rise, warms out (stop and sit)
- Just stops and sits down (doesn't develop lameness)
- Uncomfortable at night
48
Clinical gait examination with CHD
- Narrowed pelvic limb stance
- Gait abnormalities include "pelvic swing" - side opposite of OA
- "Bunny hop" to avoid extension
49
Complete PE in CHD
- Neurologic examination
- Stifle exam to rule out OCD, patella luxation, genu valgum
- Hip palpation and manipulation (extension*, flexion; abduction*, adduction; internal, external rotation; Ortolani maneuver in young patients**)
50
What view for radiographs of canine hip dysplasia?
- VD
- Lateromedial views too
- For clinical evaluation or OFA certification (VD only)
- Can also do PennHIP
51
PennHIP evaluation
- Extended
- Compression
- Distraction view
- Abduct the limbs together to distract out the hips to see a spacing between the femoral head and acetabulum
- Anything above 0.3 has a higher statistical probability of developing OA
52
What is the problem with both typical radiographic views and PennHIP?
- Won't tell you about clinical development or clinical sequelae
53
Non-surgical treatment of canine hip dysplasia
****TREAT THE DOG AND NOT THE RADIOGRAPH*** (Often radiographic findings are incidental)
- Estimated that 76-86% of immature dogs with severe HD can develop normal range of motion, minimal gait abnormalities after 1 year of age
- Treatment for immature dogs or adults with debilitating clinical signs with HD is based on relieving patient discomfort) - Multimodal OA treatment first and then possibly surgery
54
First line treatment for CHD
- Trial response to multi-modal osteoarthritis management for 4-6 weeks
- Weight control, exercise modification, pharmaceuticals/DMOAs
- Juveniles and adults
- PHYSICAL REHABILITATION****
- Poor or worsening response: may pursue surgical options
55
Second line of treatment for CHD
- Surgery
56
Goals of surgery for CHD in immature or mature HD patients
- Discomfort free movement
- Improve congruency of the articular surfaces of the hip
- Mimic normal congruency and function of the hip
57
What are determinants of CHD surgery?
- Dog's life style: house pet vs hunting, herding, field-trial, lure-coursing, etc.
- Body size
- Financial cost to the owner
58
Juvenile surgeries for HD
- Triple pelvic osteotomy (ventroversion of the acetabulum by rotating the femoral head ventrally or prematurely closing the physis)
- Double pelvic osteotomy
- Pubic symphysiodesis
- CONTROVERSIAL for a dog that might have evidence of CHD because odds are good that the dog will do just fine
59
Adult surgeries for CHD
- Femoral head and neck ostectomy (excisional hip arthroplasty)
- Total Hip replacement (more for a working dog)
60
Who can get a femoral head and neck ostectomy, size wise?
- ANY SIZE DOG
61
Will any of the surgical procedures for CHD cure the dog of the disease?
- NO
| - All surgical procedures are salvage procedures!
62
Who gets patellar luxation (dogs)?
- Dogs and cats
- Toy, miniature, large and giant breed dogs
- Congenital or traumatic (but likely traumatic issue even has an element of congenital issues)
63
What direction is most common for patellar luxation?
- Medial (75-80%)
- 20-25% are bilaterally affected, medially
- Even in those that are bilaterally affected, it's most common to have one be more severely affected
64
Sequela to patellar luxation
- Chondromalacia
- Osteoarthritis (radiographic); minimal to non-existent in small dogs and cats
- Lameness (mechanical)
- Cranial cruciate ligament rupture (in 15-20%)
65
What should you always check for with dogs with luxating patellas?
- Cranial cruciate ligament!
66
Who gets patellar luxation (cats)?
- many breeds
67
What direction are most patellar luxations for cats?
- Medial (85%)
68
How serious are most patellar luxations?
- RARELY clinical
- Most often incidental
- Usually congenital
- 50% bilaterally affected
69
Treatment for most cats with patellar luxation?
- Weight loss!
70
What usually causes medial luxations of the patella?
- Usually congenital (anatomical alignment abnormalities; femur, tibia, quadriceps musculature)
- Clinical grades: I, II, III, and IV
71
What are the over-arching goals of surgery for medial patellar luxation?
- Realignment, stabilization of the patella in the trochlear groove
72
What grade PL do neonates and older puppies tend to get?
- Grade III and IV
| - Can get an "ectopic" patella, which is nowhere where it should be
73
What grade PL do young to mature dogs get?
- Grade II and III
| - Often congenital but had a traumatic episode
74
What grade PL do older animals get?
- Grade I to II
| - often incidental
75
When can dogs get a subclinical grade I-III?
- Any age
76
Grade I MPL?
- Infrequent luxation (subluxation)
- Self-reducing
- Infrequent lameness or absent
77
Grade II MPL?
- Luxation occurs more frequently than I
- Patella easily reduces with minimal manual manipulation
- Intermittent lameness
- Skeletal abnormalities (can be subclinical)
78
Grade III MPL
- Patella is luxated most of the time
- Manual reduction seldom results in reduction of patella
- Frequent lameness
- Advanced musculoskeletal developmental abnormalities (can sometimes be subclinical)
79
Grade IV MPL
- Ectopic patella
- Severe/persistent lameness
- Severe musculoskeletal abnormalities
80
Exam findings of patellar luxation
- Intermittent or persistent lameness ("acrobatics")
- Non-painful patellar manipulations (usually)
- +/- Mild crepitus
- Variable musculoskeletal abnormalities with tibia, femoral condyles, "Patella alta"
81
Is the positive sit test a very reliable finding for patellar luxation?
- Not really
82
What is an occasional finding for severe cases of MPL?
- May walk/run on forelimbs only
83
What are the surgical principles for patellar luxation?
- Realign quadriceps tendon and patella to trochlear groove
| - Stabilize the patella to stay reduced in the trochlear groove during stifle movement
84
What are three surgical procedures that may be used to stabilize a luxating patella
- Imbrication of the joint
- "Deepen" the trochlear groove
- Tibial tubercle transposition
85
Imbrication
- Of joint capsule and periarticular tissues (retinacular imbrication) to tighten the joint and keep the patella in position
86
"Deepen" the trochlear groove
- Trochlear chondroplasty
- Excisional trochleoplasty (sulcoplasty)
- Wedge recession trochleoplasty
- Block recession trochleoplasty
87
Tibial tubercle transposition
- Osteotomy and transposition
88
Complications of patellar luxation stabilization
- Recurrent luxations (50%)
- Infection (rare)
- Osteoarthritis (minimal with small dogs and cats)
- Cranial cruciate ligament rupture (?)
89
Prognosis for lame-free function of patellar luxation post surgery?
- Grade I-III: Good to very good
| - Grade IV: Variable (dependent on skeletal deformation
90
What can make a recurrent luxation more likely with patellar luxation stabilization?
- Grade IV
| - More challenging in larger breeds than small breeds
