Equine Forelimb Flashcards
(95 cards)
1
Q
Name 9 of themain causes of forelimb lameness in horses (11)
A
- Foot pain
- Cellulitis / lymphangitis
- Pastern joint degenerative joint disease
- Fetlock DJD
- Splints
- Tendon and ligament injuries - covered previously
- Carpal DJD
- Synovial sepsis*
- Fractures*
- Tendon / ligament ruptures*
- Luxations*
2
Q
What fractures of the forelimb are common?
A
Second phalanx, first phalanx, sesmoids, metacarpus, splint bones, carpal bones, ulna, shoulder + stress fractures of long bones
3
Q
How does the aetiology affect the fracture type?
A
–Kick wounds -> bony prominences (splint bones, olecranon)
–Trauma / concussion (pastern, metacarpus) – usually but not exclusively racehorse
–Stress fractures (metacarpus, radius, humerus, scapula)
–Articular / subchondral bone disease (fetlock, carpus
4
Q
What is a common site of a fracture in horses?
A
Splint bone
5
Q
How do we treat a splint bone fracture?
A
–Many will heal with conservative treatment and do not require surgical removal
- Rest, bandaging and anti-inflammatories for closed fractures (4-6 weeks healing time)
- As above but plus antibiotics for open fractures – watch out for joint involvement
6
Q
What shouldbe avoided with splint bone fractures?
A
GA
7
Q
What can kick wounds in the splint bone cause?
A
Non-displaced cannon fracture
8
Q
How do ulna/olecranon fractures present?
A
–These can present as ‘dropped elbow’ similarly to radial paralysis as the triceps action is affected (insertion on olecranon, acts to extend elbow)
9
Q
What does a fracture description evaluate?
A
Degree of comminution, stability and articular involvement, and this determine whether internal fixation is required
10
Q
What is the prognosis of an ulna/olecranon fracture?
A
Fair to good
11
Q
What is the history of a horse with stress fractures?
A
- Intense training
- None – “incidental finding”
- None - spontaneous catastrophic fracture
- Subtle loss of performance
- Acute-onset lameness associated with work
12
Q
What are the clinical signs of a horse with stress fractures?
A
•Lameness
–Single or multiple limbs
–Variable severity
–Variable presentation
–Variable duration
•Absence of clinical findings in affected limb
- Localised inflammation
- Regional pain response to palpation/manipulation:
- Specific tests (tibial torsion test)
13
Q
How do you diagnose a stress fracture? (7)
A
- Diagnostic Anaesthesia
- Scintigraphy
- Radiography
- Ultrasonography
- Magnetic resonance imaging
- Computed tomography
- Screening tools (biochemical markers)
14
Q
How do we manage a stress fracture?
A
Modify exercise patterns
- Combination of load, repetition and inadequate recovery = Stress Fracture
- Essential feature of treatment is to break this cycle
- Change intensity,
- level,
- and/or type of exercise
- Value of grading system – tailor exercise
Ensure balanced nutrition
- Vitamin & mineral levels and ratios
–Calcium – 35g/day
–Phosphorus - 23g/day
Extracorporeal shock wave therapy
- Anecdotal evidence
- Variable scientific findings, difference between focused & radial therapy
Surgery
•Few indications
Therapeutics - Bisphosphonates
15
Q
Which joint do articular fractures affect?
A
Any joint
16
Q
What are the common joints affected by articular fractures?
A
Fetlock, sesamoid bones and carpus, esp racehorses
17
Q
How can you treat articular fractures?
A
- Remove small fragments
- Can stabilise (screw) larger fragments
- Treat joint inflammation
- Must recognise and treat these fractures to prevent ongoing cartilage and joint disease
18
Q
What is the most common site of synovial sepsis?
A
Distal limb (flexor tendon sheath, pastern joint, fetlock joint)
19
Q
What are the common lligament and tendon injuries causing forelib lameness? (4)
A
–SDFT (esp racehorse)
–ALDDFT (all types of work)
–Suspensory ligament (racehorse and performance horse)
–Annular ligament syndrome (all types)
20
Q
What are the less common tendon and ligament injuries causing forelimb injuries? (3)
A
–DDFT (pastern)
–Distal sesamoidean ligaments
–Bicipital tendon
21
Q
Where is common for luxations/subluxations in the FL?(3)
A
- Pastern
- Fetlock
- Shoulder
22
Q
Where is a common site of osteochondrosis in the FL? (4)
A
–Fetlock (common site)
–Carpus (rare)
–Elbow (rare)
–Shoulder
23
Q
Where are the common sites for subchondral bone cysts?
A
Fetlock
24
Q
Name 2 flexural deformities of the forelimb (3)
A
- DIP joint
- MCP joint
- Carpus
25
Name a common site for angular limb deformities (2)
* MCP joint
* Carpus
26
Suprascapular nerve:
A) What is it damaged?
B) What does it innervate?
C) What does damage cause?
A) Damaged by blunt trauma to point of shoulder
B) Innervates supraspinatus and infraspinatus muscles
C) Causes muscle atrophy and lateral luxation of shoulder joint
27
Radialnerve neuropathies:
A) What causes it?
B) What does it innervate?
C) What is the effect?
A) Post-anaesthetic neuropathy or caused by trauma
B) Innervates extensor of elbow, carpus and digit, and dorsal skin sensation
C) Animal cannot protract limb and Ulna fractures can present
28
What appearance does a hors with radial nerve paralysis have?
Dropped elbow
29
* You have been asked to examine a 9 year old Thoroughbred cross which was found in the field acutely lame and unable to weight bear on its right forelimb.
* The horse is sweating and distressed and reluctant to move. On observation, there is a wound over the right olecranon, and the right olecranon is dropped lower than the left.
* What are your two main differentials in this case, and how will you distinguish between them?
–Olecranon/humerus fracture
–Radial nerve injury
30
How can we distinguish between radial nerve paralysis and an olecranon fracture? How do we confirm?
* Distinguish by clinical signs consistent with a fracture (localised pain and crepitus) cf nerve damage (unable to protract limb or fix carpus +/- sensory deficits on dorsal aspect of limb and absence of pain
* Confirm on radiography
31
What radiographic views will you take of the elbow joint?
Mediolateral and craniocaudal
Can’t take 45o degree obliques so these answers would be wrong
Think about where you would place the plate and X-ray machine – you can only take these views in the orientation I have described – e.g. the machine has to be cranial and the plate behind the olecranon.
32
Describe this fracture
* Open
* Comminuted
* Articular
* Transverse
* Ulna fracture
* With a large triangular fragment
* Proximal displacement of olecranon
33
The owner wants to have the horse referred for internal fixation – how will you prepare this horse to travel to a referral centre? (4)
1. Balanced analgesia - NSAIDs (equipalazone, flunixin, meloxicam, ketoprofen, carprofen etc) +/- opioids (e.g. butorphanol, buprenorphine, pethidine, methadone, morphine)
2. Antibiotics, e.g. IV or IM penicillin and IV gentamicin (open fracture with articular involvement)
3. If possible, load and unload horse on a slope so that the incline on the ramp is minimised
4. Stabilisation during transport – you cannot splint this region, some horses may walk better with a dorsal splint to stabilise the carpus, some may be better without, cross-tie in box so can use ropes to stabilise, ensure partitions across so can lean on them. Ideally travel facing backwards, so if driver has to brake suddenly the horse is not forced to weight-bear on leg
34
Name 9 causes of forelimb (11)
* Foot pain
* Cellulitis / lymphangitis
* Pastern joint degenerative joint disease
* Fetlock DJD
* Splints
* Tendon and ligament injuries - covered previously
* Carpal DJD
* Synovial sepsis\*
* Fractures\*
* Tendon / ligament ruptures\*
* Luxations\*
35
How do you go about doing a physical exam to diagnose forelimb lameness?
1.Observation
–Conformation (look back at Year 1 notes)
–Assymmetry (foot size, musculature)
–Wear and shape of feet
2. Palpation
–Assymmetry
–Heat, swelling, pain
–Swellings (bony, soft tissue, synovial)
3. Range of movement
–Joint range of movement
–Adhesions between soft tissues
36
What are the contra-indications of using nerve blocks? (4)
* Unstable limbs
* Suspected fractures
* Severe soft tissue injuries (such as DDFT ruptures)
* Risk of infection
* Current infection at injection sites, such as mud fever
* Where you cannot perform technique
37
Name 4 perineural anaesthetic techniques (6)
* Palmar digital nerve block
* Abaxial sesamoid nerve block
* Low four point (fetlock and below)
* High four point (metacarpal region and below)
* Lateral palmar nerve block (proximal suspensory ligament)
* Median and ulna nerve block (carpus and below)
38
Radial nerve:
A) What is it an extensor of? (3)
B) What is the function?
A) Extensors of elbow, carpus and digits
B) Skin sensation on craniolateral aspect of limb not dorsal digit
39
Median nerve:
A) What is it flexors of? (2)
B) What is the function?
A) Flexors of carpus and digit
B) Skin sensation on palmar aspect and dorsal digit
40
Ulna nerve:
A) What is it flexors of? (2)
B) What is the function?
A) Carpus and digit
B) Caudal aspect of forearm, lateral and dorsal digit
41
Label the black, green and pink nerve
Black Radial nerve
Green: Ulnar nerve
Pink: Median nerve
42
Label the nerve block and what it does
1. Palmar digital nerves in pastern region (palmar digital nerve block)
2. Palmar digital nerves on abaxial (away from midline) surface of proximal sesamoid bones (abaxial sesamoid nerve block)
43
Label the nerve blocks and what they do
3. Palmar metacarpal and palmar nerves in distal metacarpus (Low 4 point)
4. Palmar metacarpal and palmar nerves in proximal metacarpus (High 4 point)
44
Label the nerve blocks and what they do
1. Palmar digital nerves in pastern region (palmar digital nerve block)
* Removes sensation to palmar foot
2. Palmar digital nerves on abaxial surface of proximal sesamoid bones (abaxial sesamoid nerve block)
* Removes sensation to foot, pastern and palmar fetlock
45
Label the nerve blocks and what they do
3. Palmar metacarpal and palmar nerves in distal metacarpus (Low 4 point)
* Removes sensation to fetlock and below
4. Palmar metacarpal and palmar nerves in proximal metacarpus (High 4 point)
* Removes sensation to metacarpal region and below
46
Name 8 intra-articular anaesthesia sites (10)
–Distal interphalangeal joint
–Navicular bursa (you cant tell you’re in the right place without radiograph or contrast)
–Digital flexor tendon sheath
–Pastern joint
–Fetlock joint
–Midcarpal joint (communicates with carpometacarpal)
–Antebrachiocarpal joint
–Elbow joint
–Shoulder joint
–Bicipital bursa
47
When is radiography the first line of diagnostics? (3)
–Suspected fracture
–Suspected bone lesions
–Joint pain
48
What are the equine standard radiography views?
–4 views of each joint (LM, DLPMO, DMPLO, DP)
–Additional views of carpus and fetlock (racehorse)
–Elbow and shoulder (LM and CrCa)
49
When is ultrasound the first line of diagnostics?
For suspected soft tissue lesions (e.g. tendonitis, bursal swellings)
50
Where is gamma scintigraphy used for first line diagnostics?
Suspect fracture
51
When is arthrocentesis used for first line diagnostics?
Suspect joint sepsis
52
When is MRI used in forelimb lameness?
–Used for some difficult soft tissue injuries, e.g. prox suspensory desmitis
–Really good for foot stuff
53
When is CT used in diagnosing forelimb lameness?
Complicated fractured / bone lesions e.g. bone cyst
54
Define cellulitis
Inflammation of subcutaneous tissues (+/- infection)
55
Why might cellulitis happen and where may it be on the limb?
–Site of bacterial entry may be a wound, skin infection (e.g. Mud fever) or deeper infection
–Cellulitis may be localised or spread throughout limb
56
Name clinical signs of cellulitis (5)
–Heat, pain, swelling
–Usually diffuse swelling, can have localised abscess as well
–+/- pyrexia
–Varying degree of lameness
–Elevated white cell count
57
What is the approach to cellulitis?
1. Identify underlying cause
2. Rule out complicating factors (fractures, synovial sepsis, osteomyelitis) exp. if not clearing up
3. Treat underlying cause (including establishing drainage for pockets of infection)
4. Antibiotics and anti-inflammatories
58
What type of antibiotics are used for cellulits?
–Systemic antibiotics required due to spread of infection through tissues
–Penicillin, cephalosporins and potentiated sulphonamides
59
Define lymphangitis
Inflammation of lymphatic system of limb
60
What causing a build up of fluid in the lim with lymphagitis?
Impaired lymph drainage
61
What may tirgger lympangiitis?
Be triggered by infection, and once affected, horses may become predisposed to problem
62
What are the clinical signs of lymphangitis? (6)
–Hindlimbs more common than forelimbs
–Bilateral or unilateral
–Diffuse soft tissue swelling
–Prominent lymphatics
–Can progress to serum oozing through skin
–May have abrasions / site of infection
63
How do we treat lymphangitis? (3)
1. Identify and treat underlying cause
2. Antibiotics and steroids (dexamethasone IM followed by oral prednisolone)
3. Physical therapy (cold hosing, bandaging, walking exercise)
Treat aggressively – affected horses are predisposed to recurrence, and some may develop chronic limb swelling
Steroids – if we know its lympangitis not infection
64
What are the three less common causes of forelimb lameness? But should be on your differentials!!!!!!!!!!!!!!!
* Purpura haemorrhagica
* Equine viral arteritis
* Hypoproteinaemia / fluid overload / cardiac failure
65
What is Purpura haemorrhagica?
–immune-mediated vasculitis following infection
–Rare sequela to Strangles
66
What happens if you suspecy equine viral arteritis? What are the other signs (apart from lamenes)
–Reportable disease (repro disease)
–Other signs = swelling of periorbital region and genitalia
67
What areas are affected by hypoproteinaemia/fluid overload/cardiac failure?
All dependent areas affected - limbs, ventral abdomen and muzzle
68
Pasterndegnerative joint disease:
A) Before clinical signs, what may the disease be?
B) What may advanced disease have?
C) What may the cause be?
D) Where is chronic disease more likely?
Sorry there are lots of questions here.. was just the best way to link them.
A) Advanced
B) Have palpable bony swelling (make sure bone is articular, non-articular new bone is not clinically significant)
C) Have inciting cause (sepsis, fracture, bone cysts / OCD) – OCD is the main one, probably will have had a bony problem in the past
D) horses with repeated concussion / turning forces – barrel racing horse
69
What confirms the site of pain in forelimb lameness?
Intra-articular
70
Discuss this radiograph
New bone and osteophyte dorsal P2 and distal P1
71
Discuss this radiograph
Dorsopalmar – osteophyte formation
72
How can we treat pastern lameness (7)
–Mild cases (no radiographic changes) -\> intra-articular medication / anti-inflammatories. Hyaluronic acid - £150+, steroids - £2
–Once radiographic changes are present, disease will continue to progress
–Can manage lameness with NSAIDs (takes a long time to fuse on own)
–Surgical arthrodesis best option (80% hindlimbs, and 60% forelimbs athletically sound\*)
–Arthrodesis also an option for fractures and luxations (low motion joints)
–Low motion – can ride as long as there is pain relief.
–Rarely – joint will fuse on its own
73
What are the 4 main causes of fetlock disease?
–Developmental (OCD and bone cysts)
–Trauma / repetitive injury (older horses going on to develop JD)
–Articular fragments
–Major fractures that extend to joint
74
Discuss this and what the plan would be
* DP view articular proximal phalangeal fracture
* Will have swelling
* Non displaced – need 4 views!
* Needs a screw
* Cant work it
75
Discuss this and what the plan would be
* LM view osteochondral fragment of dorsoproximal P1 and proximal sesamoid bone
* Next – need to radiograph the other side!! Can then arthroscopy
76
What is this?
Fetlock Luxation
77
How can you diagnose fetlock disease? (4)
–History and palpation (fractures, joint effusions)
–Nerve blocks (NOT SUSPECTED FRACTURES)
* ABSNB – does not affect dorsal aspect
* Low 4 point – blocks whole joint
* Intra-articular – confirms joint involvement
–Radiography usually first line diagnostics for most diseases
–May require specialised obliques for some conditions
78
What do you do for:
A) Articular fragments?
B) Large fragments?
C) OCD lesions?
A) Remove
B) Stabilise
C) Remove/debride
79
What do you do for:
A) Bone cyst?
B) Subchondral bone disease?
C) Synovitis?
D) Chronic OA?
A) Debride
B) Rest
C) Medicate
D) Anti-inflammatories and analgesia
80
What are the splint bones?
2nd and 4th metacarpal and metatarsal bones are ‘splint bones’
81
What is meant by the term "slints" and what is it thought to be caused by?
–The term ‘splints’ is used to describe bony enlargement of this region
–Thought to be caused by trauma and subperiosteal haemorrhage
82
What are the clinical signs of splints (5)
–Usually seen in younger horses starting or increasing work
–Forelimb more common than hindlimb
–2nd metacarpal more common than 4th
–Some, but not all cause lameness
–‘Bench knee’ conformation may predispose
83
Name 3 things found on physical exam with splints (5)
–Heat, pain, swelling around proximal splint bone
–Soft tissue or bony swelling
84
How can you diagnose splints? (3)
–Usually diagnosed on clinical signs
–These are common and the bony swellings persist, therefore you will see old chronic injuries which are not clinically significant
–Can confirm on radiography, or use nerve blocks to confirm site of pain
85
Name 3 ways of treating splints (4)
–Anti-inflammatories and reduce / stop work until lameness settles – bute
–Bony swelling will persist (although will remodel and usually become smaller if caught in the acute phase)
–Swellings a cosmetic problem – cold hose, stop and cute
–Rarely, new bone formation impinges on suspensory ligament and requires surgical removal
86
Name4 clinical signs of osteoarthiritis of the carpus (5)
–Lameness
–Joint effusion (which joint is affected?)
–Bony swelling (peri-articular, physeal)
–Reduced range of movement (know your normals!)
–Pain on flexion (flexion tests)
87
What is osteoarthiritis often secondary to?
Other problems
88
How can you diagnose carpal joint disease?
–Joint effusion and pain on palpation -\> radiography
–Suspected fracture / sepsis -\> radiography
89
What does this show?
Radiocarpal joint effusion
90
When localising signs, which carpal nerve blocks can we treat as one?
Middle carpal and carpometacarpal always communicate
91
When doing nerve blocks of the carpus which do we have to treat as seperate?
Middle carpal and antebrachiocarpal rarely communicate
92
How do you treat carpal disease? (5)
–Remove articular fragments\*
–Stabilise large fragments\*
–Rest horses with subchondral bone disease
–Medicate synovitis (intra-articular meds)
–Anti-inflammatories and analgesia for chronic OA
93
The midcarpal and antebrachiocarpal joints are high motion joints, what happens if there are radiographic signs of OA?
Poor prognosis
94
In general:
A) What if there is a small bone fragment?
B) What if there is a big bone fragment?
A) Take it out
B) Mend it
95
Where is the fracture? Which treatment is most appropriate?
Antebrachial carpal joint – chip
Small – take it out
If it was a slab fracture – screw and stablise
