Small animal MSK disease 2 Flashcards
(100 cards)
1
Q
Outline the aetiology of carpal hyperextension injuries
A
- Usually traumatic, associated with fall from height
- Can be degenerative (Collies)
2
Q
What other injuries may be associated with carpal hyperextension injuries?
A
Carpal bone fractures esp. when traumatic as well as the rupture of palmar ligaments and fibrocartilage
3
Q
Describe the diagnosis of carpal hyperextension injuries
A
- Characteristic seal stance
- Careful palpation
- Radiographic examination including stressed views - establish joints involved and therefore required treatment
4
Q
Outline the treatment of carpal hyperextension injuries
A
- Pancarpal arthrodesis most common
- Use bespoke plates, bone graft, removal of all articular cartilage
- Further support until partial arthrodesis occurred
- Splints an support bandages will fail
5
Q
Explain the difference between luxation and subluxation
A
- Luxation: cartilage surfaces not in contact at all
- Subluxation: partial contact of cartilage surfaces
6
Q
What is meant by joint incongruency?
A
Abnormal shape to bones and cartilage so cartilage does not fit together properly
7
Q
What are the possible underlying aetiologies of luxations?
A
Trauma (common), congenital (rare), developmental (frequent)
8
Q
Describe how traumatic luxations occur
A
Associated with third degree sprain (except in elbow luxation), joint capsule and other peri-articular structure damage
9
Q
Outline the consequences of traumatic luxation
A
- Traumatic arthritis
- Individual ligaments may never heal
- Capsule thickens to assume some function of the supporting ligaments
10
Q
Outline the treatment of traumatic luxation
A
- Surgery to restore acceptable function of ligaments
- May require salvage procedures
- Talocrural/tibiotarsal luxation - fixator will restore acceptable function
11
Q
Explain the cause of congenital luxations
A
- Malformation of joint, bone or soft tissue leading to abnormal articular surfaces
- Often severe associated bone deformity
12
Q
Describe the typical presentation of congenital luxations
A
- May be symmetrical
- Small breed dogs (e.g. cavvie) with shoulder luxations are rarely lame (mechanical rather than painful lameness)
- Congenital elbow luxation in Staffies
13
Q
Outline the treatment options for congenital luxations
A
- Conservative: first option, pain releif and weight management
- If unsuccessful, attempt surgical but poor success due to abnormal joint surfaces
- Salvage procedures typically required
14
Q
What is the prognosis for surgical treatment of congenital luxations?
A
Guarded
15
Q
Explain the cause of developmental subluxations/incongruencies
A
- Common
- Hip/elbow dysplasia
- Incongruency of joints leading to joint effusion and luxation
16
Q
Describe the typical presentation of developmental subluxation
A
- Commonly bilaterally symmetrical
- Develop secondary arthritis
17
Q
Outline the treatment of developmental luxations
A
- Conservative/medical management of the arthritis
- Salvage surgical procedures
18
Q
Explain the cause of degenerative luxation
A
Very common e.g. cranial cruciate ligament degeneration/rupture leading to cranial subluxation of the tibia
19
Q
Which joints are predisposed to luxation in dogs and cats?
A
- Hip and tarsus
- Patella (intermittent)
20
Q
Outline the assessment for luxation in dogs and cats
A
- Clinical examination (+/- GA): pain,asymmetry
- Laxity (depends on chronicity of disease)
- Orthogonal radiographs of limb, +/- stressed views
21
Q
When qould thoracic and abdominal radiographs be indicated when investigating joint luxation in cats and dogs?
A
Where traumatic luxation has occurred
22
Q
What test would indicate hip luxation on clinical examination of a cat/dog?
A
- Finger and thumb placed between ischial tuberosity and greater trochanter, hold both HLs
- When HLs extended behind animal, luxated limb will be shorter due to dorsal luxation
23
Q
Explain why laxity may not always be a good indicator of joint luxation
A
- Depends on chronicity of condition
- With time, partiarticular fibrosis and muscle contraction can stabilise the joint
24
Q
Outline the principles of repair of acquired/traumatic luxations
A
- Reduce joint into normal anatomical alignment, maintain reduction while capsule and other soft tissues heal
- Re-attach bone if avulsion present
- May require prosthetic ligament
- Post-op support as for sprains
25
What are the 3 main stabilisers of the hip?
- Round ligament
- Joint capsule
- Acetabular rim
26
List the options for the management of hip luxation
- Closed reduction
- Open reduction and stabilisation such as:
- Salvage procedures
- Transarticular pin
- Rectus femoris or ilio-femoral suture for craniodorsal luxation
- Hip toggle
27
Describe closed reduction of hip luxation
- Manipulate hip back into acetabulum without surgery within 1 day of luxation
- Always readiograph after
- Care re/ soft tissue injuries and re-luxation
- May also require Ehmer sling
28
What is the success rate for closed reduction of hip luxation?
50%, higher in dogs than cats
29
Describe open reduction and stabilisation of hip luxation and give success rare
- Always includes soft tissue repair/imbrication
- E.g. transarticular pin, toggle, rectus femoris or ilio-femoral suture
- 75-85% success
30
What salvage procedures may be used for hip luxation?
Replacementof excision
31
Discuss the use of transarticular pins for hip luxation
- Most suitable for cats/small dogs
- Gives reasonable function but limited adduction
- Causes arthritis
- If incongruent may damage articular surface
- Requires 2nd procedure 3 weeks later to remove pin
32
Describe the use of rectus femoris or ilio-femoral suture for craniodorsal hip luxation
- Suture placed through tunnel in base of greater trochanter and either: origin of rectus femoris, or hole made in ventral aspect of ilium
- Suture tightened with hip slightly internally rotated
- May cause slight internal rotation of paw (resolves with suture absorption)
33
Discuss the use of hip toggles for canine hip luxation
- Challenging
- Medium to large dogs best
- Can cause articular damage if hip not congruent
- Very stable, functional joint if correct
- Braided multifilament suture use so some risk of infection
34
Outline the method for the hip toggle in dogs
- Drill hole through acetabular notch
- Then another from origin of teres ligament, through femoral neck to base of trochanter
- Then place suture through hole, as pushed through pull on loop, toggle comes into right angle to hole
- Tightening holds head in acetabulum
35
Outline the approach to traumatic elbow luxation
- Treat Asap, always GA, pre-op radiographs including thorax
- Closed or open reduction can be used
- Check collateral ligaments
- Post-op radiographs required
36
Outline the approach to congenital elbow luxation
- Can be treated conservatively if dog is coping
| - Surgery can be beneficial, but residual lameness common so little benefit over conservative
37
Outline the general approach to acquired luxations
- Reconstruct supporting structures if possible
- Support repair
- Physio improves recovery
- DJD inevitable, warn owner
38
Outline the general approach to subluxations
- very common
- medically manage if milk
- Salvage surgery if not coping
39
Outline the general approach to congenital luxations
- Very rare
- Poorer prognosis
- Grossly dysplastic joint and better left alone
40
What diagnostic techniques can be used for the evaluation of acutely traumatised joints?
- Careful physical examination
- Manipulation under GA
- Radiography
- Ultrasound
- arthroscopy
- CT
- MRI
- Need to look for concurrent injuries
41
Outline the use of ultrasonography for the evaluation of acutely traumatised joints
- Damage to tendons, rarely for ligaments
- Linear scanner
- Bicipital, gastrocnemius and flexor tendons in particular
42
Outline the use of arthroscopy for the evaluation of acutely traumatised joints
- Examine intra-articular ligaments e.g. cruciates
| - And those withinn the joint capsule such as glenohumeral ligaments of the shoulder
43
Outline the use of CT for the evaluation of acutely traumatise joints
- Limited ability to examine soft tissue structures
- Good for demonstration of tendon sheath effusions and tendon mineralisation e.g. around shoulder joint (mineralisation of suprascapularis tendon or infraspinatus)
44
Outline the use of MRI in the evaluation of acutely traumatised joints
- Good for soft tissues
| - Best modality for tendons and ligaments
45
List the different types of non-inflammatory joint disease
- DJD/OA: instability, trauma or developmental disease
| - Coagulopathic joint disease
46
List the different types of inflammatory joint disease
- Septic arthritis
- Non-bacterial: rickettsia, viral, protozoal
- Sterile: IMPA
- Neoplastic arthritis
- Crystal induced arthritis
47
Explain how tick borne diseases lead to arthritis
Immune mediated responses that cause polyarthritis
48
What is the main type of neoplastic arthritis?
Synovial cell sarcomas
49
What tumours may cause neoplastic arthritis?
- Synovial cell sarcomas
- Fibrosarcomas
- Haemangiosarcomas
- Osteosarcomas
50
Describe the common presentation for neoplastic arthritis
- Dogs (rare in cats, large animals)
- Large joints of limb usually (e.g. stifle)
- lameness, joint effusion, soft tissue swelling, lytic areas of bone destruction on radiograph both sides of joint
51
In which species does true gout occur?
Those without uricase enzyme: humans, birds, reptiles
52
How does gout occur in reptiles?
- Production of uric acid normal, secrete as urates in proximal renal tubules
- Damage to kidney raises uric acid in blood
- Deposits in various parts of body incl. kidney, pericardial space, joints
53
Outline crystal induced arthritis in dogs
- White, peri-articular deposits lead to inflammatory reaction
- Rare in dogs
- Peri-articular synovial deposits of calicum pyrophosphate, or Ca phosphate
- Single or multiple can be affected
54
Outline the aetiology of IMPA
- Usually type III hypersensitivity reaction
- Immune complex deposition in synovial basement membrane, complement cascade activation
- Recruitment of inflammatory cells
- Leads to release of nitric oxide, free radicals, proteases, leading to tissue damage
55
Give examples of erosive immune mediated polyarthritis
- Idiopathic erosive polyarthritis
- Rheumatoid arthritis
- Semi-erosive polyarthritis of greyhounds
- Periosteal proliferative polyarthritis in cats (rare)
56
Describe type I non-erosive IMPA
Idiopathic IMPA, most common
57
Describe type II non-erosive IMPA
- Associted with infection remote from joint (25% of cases)
| - Not septic, is an immune reaction
58
Describe type III non-erosive IMPA
- Associated with GI disease (15% of cases)
| - Immune complexes deposited in joint
59
Describe type IV on-erosive IMPA
Associated with neoplastic disease i.e. paraneoplastic syndrome (rare)
60
Describe the involvement of SLE in joint disease
- Multisystemic immune mediated disease, rare
- Joint disease + glomerular disease, or joint disease + skin lesions
- IMHA +/- thrombocytopaenia
- Combination of clinical signs increases potential for multisystemic disease
61
List some unusual syndromes of non-erosive immune mediated polyarthritis
- Polyarthritis/meningitis syndrome
- Polyarthritis/polymyositis syndrome
- Breed associated non-erosive IMPA
- Familial Shar-Pei fever
- Drug induce IMPA
62
List the breeds that are associated with breed related non-erosive IMPA
- Weimaraner
- Boxer
- Akita
- Bernese MD
- GSD
- Spaniels
- Beagles
63
Outline drug induced IMPA
- Immune complex deposition as a result of drug-antibody interaction
- Reported with sulohonamides esp in Doberman
- Post live Calicivirus vaccines in cats
64
Outline the aetiology of septic arthritis in small animals
- trauma
- Post-surgery
- Intra-articualr injection
- Idiopathic
65
What may lead to idiopathic septic arthritis?
Underlying OA in dogs
66
What may cause septic arthritis in multiple joints of adult small animals?
- Haematogenous spread of infeciton in debilitated/immunosuppressed animals
- Non-bacterial causes e.g. Rickettsia, Mycoplasma, fugnal , viral, protozoal (rare)
67
What clinical signs may be seen in cats with septic arthritis as a result of Calcivirus?
- Inflammatory joint disease
- Pyrexia
- Other flu symptoms
68
What may lead to septic arthritis in large animal neonates?
- Failure of passive transfer of immunity
- Umbilical infection
- Haematogenous spread of infection
- Osteomyelitis
69
Describe the signalment for IMPA
- Larger breed dogs <6yrs old
- (Also seen in smaller breeds and mixed beedds)
- More dogs than cats
70
What would a shifting lameness that may wax and wane be suggestive of?
Immune mediated disease
71
Describe the lameness commonly seen in IMPA
Often look stiff rather than lame, more than one limb affected
72
In a case of arthritis in a small animal, what should be included in the physical examination?
- Assess for pyrexia
- Number of limbs/joints affected
- Palpation to assess heat, swelling, ROM, pain, joint affected
- Neck/muscle pain
- Lymph nodes assessed
73
When performing arthrocentesis for the diagnosis of an inflammatory arthritis in small animals, what parameters of the synovial fluid needs to be assessed?
- Colour
- Total and differential white cell counts
- Cell morphology
- Culture and sensitivity
74
When would radiography be indicated in the work up for a case of inflammatory arthritis?
- If joint palpation reveals crepitus, instability, poor ROM, deformity
- If there is poor response to treatment
75
Compare the radiographic findings expected for erosive vs. non-erosive IMPA
- Erosive: subchondral defects, collapsed joint spaces, proliferation and calcification of periarticular soft tissue
- Non-erosive: joint effusion likely only finding
76
When might a diagnosis of erosive IMPA be missed on radiography?
If radiographs taken too early in course of disease - if not responding well to treatment, may be appropriate to repeat radiographs of multiple joints
77
What additional imaging modalities may be required in the investigation of IMPA and why?
- If suspicious of type II, III or IV IMPA or multi-systemic immune mediated disease
- Thoracic radiographs: mets of neoplastic disease, endocarditis
- Abdominal ultrasound
- Echocardiography
78
When might contrast studies be useful in the investigation of inflammatory joint disease?
- Septic arthritis
- Especially in horse
- Look for communication between tracts/sinuses and a joint
- May be able to identify a foreign body
79
Outline the laboratory tests that may be used in the investigation of inflammatory joint disease
- Haematology: inflammatory leukogram? Anaemia of chronic disease? IMHA?
- Biochem: changes consistent with systemic disease
- Urinalysis: proteinuria/evidence of glomerulonephropathy
- Serology: ANA and rheumatoid factor (non-specific in dogs)
- Histopathology: tissue biopsy for unusual syndrome
80
Compare the findings in haematology and biochemistry for IMPA vs non-inflammatory joint disease
- More likely to find changes with IMPA
- Leukocytosis
- Hyperglobulinaemia
- Mild hypoalbuminaemia
81
What are the key aspects of investigation that may aid the identification of IMPA?
- Full flexion of carpi and squeezing to assess pain response
- Subtle enlargement of LNs
- Aspiration of multiple joints
- Changes in >1 joint, no bacteria on cytology or culture
82
Outline the key aspects of the treatment of septic arthritis in small animals
- Must be fast and aggressive
- Systemic and intra-articular antibiotics
- Joint lavage and drainage to clean joint
- Post-op care important
83
Discuss the use of lavage in the treatment of septic arthritis in horses, farm animals and small animal cases
- Horses: antibiotics rarely enough, lavage used as minimum
| - Farm and severe small animal: lavage possible, often not cost effective in farm animals
84
Outline the use of arthroscopy in the treatment of septic arthritis
- Direct visualisation of joint
- Removal of fibrin
- Foreign material or articular fractures
- Used in chronic or complicated cases
- Ideally in every equine case
85
Outline the use of systemic antibiotics in the treatment of septic arthritis in small animals
- Broad spec
- C+S takes time, start before results available
- Amoxyclav common in small animals (penicillin + aminoglycoside in large)
- Start IV/IM admin, switch to oral after 5-7 days, total duration 2-4 weeks min.
86
Outline the use of local antibiotics in the treatment of septic arthritis in small and large animals
- Intra-synovial admin common in large animals
- High doses with low cost and toxicity achieved
- Gentamycin, amikacin, ceftiofur in horses
- Higher risk of nephrotoxicity in dogs
- PMMA beads useful in chronic/difficult cases
87
Outline the post-operative care in cases of septic arthritis in small animals
- NSAIDs
- Rest, controlled exercise, physio
- Avoid intra-articular medication, esp. in early stages as will predispose to infection (esp. HAs, PsGAGs, corticosteroids)
88
Discuss the prognosis for septic arthritis in small animals
- Following systemic antibiotics only: 56% full clinical recovery, 32% persistent mild lameness, 12% poor response (consider lavage)
- Factors affecting outscome: duration, severity, multiple joints affected, concurrent problems (e.g. bacterial endocarditis)
89
Outline the general treatment of IMPA
- Treat/remove underlying cause or antigenic trigger
- Analgesia while managing primary disease
- Nutritional support where needed
90
Outline the treatment of type I IMPA
- No underlying cause therefore immunosuppressive treatment
- Single agent e.g pred
- Combination therapy may be needed in refractory cases/side effects e.g. pred + ciclosporin/azathioprine
- Newer single agent therapy e.g. mycophenolate, luflenomide
91
Outline the monitoring required when treating IMPA
- Clinical sings
- Physical examination findings, owner reports
- Follow up arthrocentesis
- Serum C reactive protein
92
Evaluate the use of serum C reactive protein for the monitoring of IMPA
- Good surrogate marker for synovial inflammation
- Good correlation with pain scores and joint cellularity
- Objective and non-invasive method to monitor cases
93
Discuss the prognosis for erosive and non-erosive IMPA
- Good for non-erosive, but may relapse
| - Poor for erosive, surgical salvage procedures often required, euthanasia is reasonable alternative
94
Compare the joints typically affected by IMPA and septic arthritis
- IMPA: smaller distal joints e.g. hocks, carpi, stifle
| - Septic: more proximal larger joints e.g. elbow
95
Compare the synovial fluid analysis of IMPA and septic arthritis
- IMPA: ~300 cells x10^9/l, <95% neutrophils, usually non-degenerate
- Septic: cell count variable but usually very high, most cells are degenerate neutrophils
96
Outline why septic arthritis may not also be demonstrable by bacteria on smears
Pathology is more to do with sensitive location of bacteria, rather than their number so may be a small load
97
What may help indicate that blood in synovial fluid following arthrocentesis is as a result of sampling?
- Blood streak in otherwise clear fluid
| - Sample starts clear then changes to bloody
98
Compare the findings on a smear for an iatrogenic/very acute haemoarthrosis vs a long standing one
- Iatrogenic/very acute: platelets present
| - Chronic: no platelets (clotted) , increased white cells, erythrophagocytosis, haemosiderin, haematoidin
99
How can bacteria be distinguished from artefacts on a synovial smear?
- Artefact of fluid not lying flat on slide leading to dotty granular background
- May resemble bacteria, but is pink and irregular vs bacteria which are blue and regular
100
Explain why neutrophils may be confused with lymphocytes in synovial smears
Slow drying leads to lobes of neutrophilic nucleus becoming folded, so may look similar to lymphocyte
