Exam 3: Lecture 17: Surgery of the Carpus+ Metacarpus and Phalanges Flashcards
(89 cards)
1
Q
Define palmigrade stance
A
occurs when the foot is positioned such that palmar surface of metacarpus contacts the ground
2
Q
Define valgus position
A
movement of foot in an outward deviation
3
Q
Define Varus position
A
Movement of food in an inwards deviation
4
Q
What does this image show?
A
Palmigrade stance
- dropped carpus
5
Q
How would you define carpal fractures in companion animals
A
rare
6
Q
Why are carpal fracture often disabling
A
because the carpal joint serves as a major weight bearing function
7
Q
Carap fractures without treatment leads to joint incongruity and development of OA leading to?
A
severe lameness
8
Q
What is the most frequently diagnosed fracture of the carpal bones in companion animals
A
Radial Carpal Bone Fractures
9
Q
Radial Carpal Bone Fractures may involve chronic lameness without history of _______
- may occur bilaterally
A
trauma
10
Q
Three common fracture patterns in Radial Carpal Bone Fractures
- speculated these fractures are a result of incomplete ossification of which bone
A
radial carpal bone
11
Q
Which breed of dogs are most common to have chronic radial carpal bone fractures
A
Boxers
sporting breeds
12
Q
Which breed of dogs does Accessory carpal bone fractures occur in
- Rare in companion animals
A
racing greyhounds
sled dogs
13
Q
Most Accessory carpal bone fractures occur in which leg?
- counterclockwise direction of racing
A
right leg
14
Q
Accessory carpal bone fractures are considered ______ injuries
- because they occur at tendinous or ligamentous insertions + are classified according to site of injury on Accessory carpal bone
A
Avulsion
15
Q
How would an animal present with Acute fractures of the carpus
A
- NWB lameness
- placing weight in limb cause carpus to collapse in palmigrade stance
16
Q
Hiw would an animal present with chronic radial carpal bone fracture
A
- weight bearing lameness (which may be intermittent)
- reduced carpal range of motion
- soft tissue swelling
17
Q
DI for carpal bone fractures are often painful and require ______ or general anesthesia for proper positioning to obtain quality radiographs
A
sedation
18
Q
Which radiographic views are sufficient in making a diagnosis for carpal bone fractures
A
- dorsoplamar
- medial lateral
- oblique projections
19
Q
Bilateral carpal radiographs and/or CT are helpful for diagnosing _____ radial carpal bone fractures
A
occult
20
Q
Fractures of the carpus must be differentiated from what other issue because these both may occur with other fractures
A
differentiated from ligamentous injury
21
Q
Is mediacal or conservative management indicated for carpal fractures
A
no
22
Q
what structure in the forelimb is a major weight bearing structure
A
radial carpal bone
23
Q
The radial carpal bone is in congruity with the articualr surface of the distal ______ which is necessary for optimal long term function
A
radius
24
Q
In animals with radial carpal bone fractures small chip fragments that cannot be stabilized must be?
A
removed
25
In animals with radial carpal bone fractures what must we do with large fractures
anatomically reduced + rigidity stabilized with lag screws or a combination of lag screws + K-wire
26
Dogs with chronic radial carpal bone fracture, severly comminuted fractures, OA, luxation, bone loss or infection. These problems are best treated with?
carpal arthrodesis
27
Patients with comminuted fractures of carpus may have open wounds. What should be done during pre-op management
- wounds cleaned + protected from further damaged + contamination
- mason metasplint or bivalve splint (applied for patient comfort + protect soft tissue from further contamination or injury induced by bone fracture
- Analgesics provided to post-traumatic animals
28
How would you define the bone structure of the carpus
composed of proximal and distal row of carpal bones
29
Which area of the carpus articulates primarly with the radius and serves as a major weight bearing area in the joint
Radial carpal bone
30
What does this image show?
reduction of radial carpal bone fracture with lag screw
31
The most common injury of the carpus is?
hyperextension injury
- trauma
- immune mediated
- level of injury varies (radiocarpal, inter carpal and carpometacarpal)
32
What does this image show?
hyperextension of the carpus
33
How would you define the presentation of this animal with a carpus injury?
- weight bearing or NWB lameness
- swelling + pain on palpation
34
What type of radiographs would be beneficial for this animal?
Stress views
- lateral and dorsoplantar
= determine severity + level of injury
= palmar ligaments + radial or ulnar collateral ligaments
35
How would you described conservative treatment (splinting) for carpal hyperextension?
rarely successful
36
What is the best treatment for carpal hyperextension
arthrodesis
37
How would you describe the treatment pancarpal or partial carpal arthrodesis in animals with carpal hyperextension
- remove cartilage
- autogenous cancellous bone graft
- rigid fixation
38
When would you use partial carpal arthrodesis in animals with carpal hyperextension
when radiocarpal joint is normal
- T-plate
- fuse middle carpal, intercarpal and carpometacarpal joints
39
What is the success rate for partial carpal arthrodesis in animals with carpal hyperextension
50%
40
What is the success rate of pancarpal arthrodesis in animals with carpal hyperextension
70%
41
Which techniques are appropiate for intercarpal and carpometacarpal joints
partial carpal and pancarpal arthrodesis
42
Post-op care and assessment for dogs with carpal fractures include?
- post-op radiographs
- pain management
- coaptation with soft padded bandage controls bleeding
- **coaptation with splint for up to 6 weeks (indicated for most dogs)
- activity restricted to leash walking + physical rehabilitation until the fracture is healing
- short leash walks used initially (help maintain strength joint mobility)
- distance walked gradually increases
- passive flextion and extension of arpus
- **screws for reconstruction of radial carpal bone not removed unless they cause a problem**
43
Complication of radial fractures include?
DJD
- may occur after articular fractures
- may be severe if anatomical reduction and rigid fixation are not achieved
Delayed union + nonunion
44
What is the prognosis for carpal fractures
- fair to good return to function
- depends on
= degree of articular cartilage damage
= wheather articular surface can be reconstructed
45
What is the prognosis for carpal arthrodesis
- fair to partial
- good for pancarpal arthrodesis
46
Young puppies in a variety of breeds are prone to carpal laxity, why so?
- carpal hyperextenion
- carpal hyperflexion
- carpal flexural deformities
47
What is the etiology of carpal laxity syndrome
theories
- over or under supplemented diet
- concrete surfaces with no exercise
48
Carpal laxity syndrome can be seen in dogs 5-27 weeks, but is there a male or female disposition?
yes! Males 2:1
49
Treatment for Carpal laxity syndrome includes?
- appropriate diet
- controlled exercise
(flooring with good traction)
- recovery 1-4 weeks
- residual deformities rare
- treatment is conservative
50
What does this image show?
Carpal laxity syndrome
51
Define sesamoid bones
small, round or oblong bones founds adjacent to metacarpophalangeal joints
52
What species is Metacarpal bone fractures common in?
dogs
cats
53
Which injury may result from direct blow or force to the paw or from hyperextension injuries
Metacarpal bone fractures
54
Complete Metacarpal bone fractures in which dog breed results of fatigue or relatively normal bone being loaded beyond its yield strain
greyhounds
55
How are Metacarpal bone fractures classified?
location
- base or proximal end of the bone, shaft, or diaphysis; head or distal end of the bone
56
Sesamoids
- fractures / fragmentation
= unclear in literature if the same
= racing _____ and _____
= proposed causes: trauma, congenital, DJD, or vascular
= lameness + pain on palpation
greyhounds and rottweilers
57
How many palmar sesamoid bones per metacarpophalangeal joint
- numbered 1-8 beginning on medial side
2
58
Sesamoid fractures occur after excessive tension on which tendons?
digital flexor tendons
59
Which sesamoid bone are most often affected due to excessive tension on the digital flexor tendons?
sesamoid bones 2 and 7 of the forelimb
60
Most sesamoid fractures on the paw cause _____
- sesamoid fractures cause less obvious lameness
NWBL
61
What does the arrows on the image show?
fragments of sesamoid 2 and 7
62
What type of treatment for sesamoid fractures show better outcomes than surgery
- 4-8 weeks of rest +/- splinting or bandage
conservative therapy
63
Proximal fragements of sesamoid are removed is causing ______ lameness
chronic
64
What does this image show?
dog with sesamoid fracture
= may have a history of acute lameness that subsided but recurred with exercise
65
Luxations of metacarpophalangeal joints or interphalanageal joints typically occur in what type/breed of dogs?
- working dogs
- racing greyhounds
66
What type of treatment yields better results than closed reduction + splintage in animals with Luxations of metacarpophalangeal joints or interphalanageal joints
- because chronic instability leads to DJD + less than optimal function
early surgical repair
67
What detailed radiographic views are needed for animals with Luxations of metacarpophalangeal joints or interphalanageal joints
- dorsopalmar + mediolateral views extending from carpus to ends of digits
- oblique views with digits spread
- a lateral view with affected digit pulled cranially (using tape or gauze)
68
How are stress radiographs important
show joint instability
69
T/F: Fractures of the phalanges occur less frequently, but they are handled similarly to metacarpal bone fractures
true
70
How are Acute Luxations in working or racing dogs is best treated?
- open reduction
- suturing of joint capsule and collateral ligaments
71
What is the best way to treat chronic luxations of the 2nd and 5th toes
amputation
72
_______ of metacarpophalangeal and interphalangeal joint results in good function + pain relief
Arthrodesis
73
Fixation systems applicable for phalangeal fractures / luxations include?
(name 3)
- orthopedic wire
- IM pine
- plates + screws
74
Digit masses are typically neoplastic
- PE and orthopedic exam: pain and swelling
- radiographs: osteolysis and soft tissue swelling
- fine needle aspiration for cytology
- 61% malignant
- what is the recommendation for digit issues
ampuation
75
What does this image show?
suggested skin incision lines + osteotomy lines for proximal + distal digit amputation
76
Which digits are weight bearing
3 and 4
77
Amputation of which digits results in mechanical lameness and decreases function
3 and 4
78
More ____ the digit amputation the better prognosis
distal
79
For digit amputation make _____ skin incision
- paralleing long axis around the digit
- starting proximodorsally + ending on palmar surface
elliptical
80
If you are amputating at interphalangeal joints disarticulate the joint with sharp dissection, preserving which structure?
preserve pad
81
Remove the ______ for metacarpophalangeal joint amputation
sesamoid bones
82
For digit amputation, resect the distal end of remaining proximal bones because it more cosmetric, but some surgeons omit this step, why?
more painful than cutting through joint
83
During digit amputation Resecting the distal end of the remaining proximal bone is important to do for ________
- involved with or in close proximity to joint
neoplasia!!
84
During digit amputation resect the distal end of remaining proximal bone. Make a _______ _____ line for interphalangeal joints of 3rd and 4th metacarpal bones
transverse osteotomy
85
During digit amputation resect the distal end of remaining proximal bone. Angle osteotomy towards mildine for which metacarpal bones
2nd and 5th
86
After a digit amputation is performed, what should be done to the soft tissue/skin to obtain cosmetic closure
suture closed
87
What procedure does the following define?
- **expose joint**
- **remove articular cartilage** (rongeurs or high speed bur)
-**contour surfaces**
(obtain good contact at functional angle)
- **temporarily hold bones in position**
(driving small k-wire from dorsal surface of each bone across joit surface
- **contour a small plate** (2.0) to dorsal surface of the bones
- **attach plate** using atleast one lag screw across joint surface
- **K-wire and tension band** in small dogs or cats when rapid healing is anticipated
Digit arthrodesis
88
What does A show from the Arthrodesis of proximal interphalangeal joint
plate and lag screws
89
What does B show from the Arthrodesis of proximal interphalangeal joint
K-wires and tension band
