Exam 2: Lecture 11: Surgery of the Tarsus, Metatarsus and Phalanges Flashcards
T/F: Tarsal fracture will never cause a loss of weight bearing support?
FALSE!
- MAY can loss of wt-bearing support
Define plantigrade stance
when the for positioned so plantar surface of clacaneous contact the ground
Define Valgus position
an outward movement
Define Varus position
an inward position
What does the following image show?
Plantigrade stance
- in this image AKA “Dropped Hock” - when the calcaneous is in contact with the ground
Are tarsal fractures common in companion animals?
no
Tarsal fractures are often disabling because?
tarsal joint serves a major weight bearing function
What if you do not treat tarsal fractures?
- joint incongruity + development of osteoarthritis
Joint incongruity and development of osteoarthritis can lead to?
severe lameness
Fractures of the tarsus are most in?
- working breed dogs
- rare in companion animals
(except fractured calcaneus)
Calcaneal fractures are distracted by pull of which muscles
- prevents bone contact between fragments + interferes with healing
gastrcnemius muscle
What is important to keep in mind with treatment of calcaneal fractures?
- treatment methods must resist tensile forces
Which species do talar neck fractures/ condylar fractures occur in and occasionally occur in?
- occur in cats
- occasionally occur in dogs
For optimal outcomes with talar neck fracturs / condylar neck fractrues what must occus?
Anatomic reduction + rigid fixation
Why is reconstruction difficult for talar neck fracturs / condylar neck fractrues
- small size of trochlea
- degree of comminution
If reconstruction is not feasible for talar neck fracturs / condylar neck fractrues, what primary procedure is performed?
Primary arthodesis
What breed are fractures of the central tarsal bone common in?
- common in greyhounds
- rarely seen in companion animals
How are fractures of the central tarsal bone graded?
according to fracture type and degree of fragment displacement
When are buttress effects of central tarsal bones lost?
fractures of 4th tarsal bone + calcaneus
What is the main treatment for fractures of the central tarsal bone?
repair with one or more small lag screws
Physical exams findings of animals with Acute fractures of the Tarsus include?
- NWB lameness
- Attempts to place wght on limb
- can cause tarsus collapse in plantigrade stance
What may happen when an animal with acute fractues of the tarsus attemps to place weight on that limb?
cause tarsus collapse in plantigrade stance
What may be seen on a PE in a pt with a fractured calacaneus
- may walk pantigrade on limb
- may be non-wght bearing
- pain, swelling, and crepitus present
- varus or valgus deviation of foot usually present
When getting DI for pt with tarsus, metatarsus or phalanges what is best to keep in mind?
They might be painful
- require sedation or general anesthesia for proper positioning for quality radiographs
Radiographs (DI) should be takes in what 3 positions to usually make a sufficient diagnosis
- dorsoplantar
- medial-lateral
- oblique projections
Fractures of tarsus differentiated from _____ injury
- may occur concurrently with fractures
ligamentous injury
What fracture type is differentiated from lacerations or rupture of Achilles tendon?
Calcaneal fractures
What type of injury does the following define?
- open wound
- soft tissue swelling around area PROXIMAL to calcaneal tuberosity
Acute laceration to Achilles tendon
What type of injury does the following describe?
- swelling CAUDAL to tarsus
- CREPITATION elicited on palpation
fractures of calcaneus
What do you say to medical management of tarsal fractures?
just say no
Is medical or conservative management needed for tarsal fractures?
not indicated
What is the surgical treatment for calcaneal fractures
pull gastrocenemius muscle restricted with tension band / wire / lag screws/ plate
What is the surgical treatment for articular fractures of talus
anatomically reduced + rigidity stabilized for optimal outcome
What procedure would be done in talar fractures that are not feasible
Arthrodesis of tarsocrural joint can be considered
What 2 thing are important to remeber preoperatively before going straight to surgery?
- examine for concurrent injury
- stabilize if necessary before surgery
patients with comminuted fractures of tarsus may present with what type of wounds
open
If patients with comminuted fractures of tarsus present with open wounds, what would you do?
- clean and protect from further damage + contamination
- mason metasplint or bivalve cast applied for comfort + protect soft tissue from injury by bone fragments
- analgesics provided to posttraumatic animals
What is the largest of the tarsal bones?
calcaneus
Distal half of the calcaneus have two facets and two processes. What do they articulate with to form a stable joint?
Articulate with the talus to form a stable joint
What forms the prominence for insertion of the Achilles tendon?
Tuber calcaneus
What is the second largest of the tarsal bones
Talus
Which bone articules proximally with the tibia, fibula and central tarsal bone?
talus
The body of the talus is divided into 2 parts. The medial and lateral trochleae articulate with which 2 bones proximally
tibia
fibula
The body of the talus is divided into 2 parts. What does the base articulate with?
central tarsal bone distally
Side of the trochleae articulate with medial and lateral?
malleoli
Transverse calcaneal fractures can be stabilized with?
Tension band wire or plate
Oblique or slab calcaneal fractures can be stabilized with?
lag screws
What does the following image show?
stabilization of calcaneal fractures using tension band wire
What does the following image show?
stabilization of calcaneal fractures using plate and screws
What does the following image show?
stabilization of calcaneal fractures using lag screws
What type of fracture is described in this image and how would it be stabilized?
transverse calcaneal fracture stabilized with tension band wire
What type of fracture is described in this image and how would it be stabilized?
Transverse calcaneal fracture stabilized with plate and screws
What type of fracture is described in this image and how would it be stabilized?
Olique or slab fractures stabilized with lag screws
Fractures of articular surface of talus can be stabilized with?
diverging K-wire or lag screws
What does the following image show?
Stabilization of talus fractures
- stabilized with diverging K-wire or lag screws
Which of the following fits the description?
- lag screw angled from caudal medial surface of head of talus into trochlea of talus
A
Which of the following fits the description?
- Screw placed from caudal medial base of talus into calcaneus
B + C
What should be done after surgery to evaluate fracture reduction and implant location
radiographs
What can be done post op for bleeding and swelling?
Coaptation with soft padded bandage
How long should coaptation with split be on for most dogs
up to 6 weeks for most dogs
Why should activity be restricted to leash walking + PT until the fracture is healed?
Short leash walks initially helps maintain stength + joint mobility
- distance can be gradually be increased
What is the benefit of passive flexion - extension of tarsus?
- maintains joint motion
- enhance patient comfot
- improve synovial fluid nutrients to cartilage
Pins for tension band stabilization of calcaneal fractures may cause?
irritation of soft tissue
- removed after healing if needed
Screws for reconstruction of talus are removed when?
Not removed unless they cause problem
- they do not typically cause problems
What disease may occur after articular fractures
- may be severe if anatomical reduction + rigid fracture fixation not achieved
degenerative joint disease
If the calcaneal fracture is not adeqately stabilized what can occur?
- from constant tensile stress on fracture line from pull of gastrocnemius muscle
delayed union or nonunion
What is the prognosis for calcaneal fractures
excellent for return to normal activity
What is the prognosis for tarsal fractures
fair to good return to function
What does prognosis depend on with tarsal fractures
- degree of articular cartilage damage
- wheather articular surface can be reconstructed
What species are metatarsal bone fractures common in?
dogs
cats
What is the normal cause for metatarsal bone fractures?
direct blow / force or hyperextension injuries
Complete metatarsal fractures in GREYHOUNDS can be cause by?
- result of fatigue
- normal bone loaded beyond its yield strain
How are metatarsal fractures classified?
according to location
What are the two locations that metatarsal fractures are classified?
- base or proximal end of bone, shaft, or diaphysis
- head or distal end of bone
Why is early surgical repair better than closed reduction and splintage?
chronic instability can lead to DJD + less optimal function
- BUT depends heavilty on condition (splinting may be appropiate)
Avulsion fractures of base metacarpal / metatarsal occur most often on which two digits?
2nd + 5th bones (digits)
Why do avulsion fractures of base occur most often on 2nd and 5th metacarpal / metatarsal bones?
ligamentous insertions
Phalangeal fractures occur similarly in dogs and cats, but what is the difference
fragments in cats are often smaller and more difficult to secure
Luxations of metacarpophalangeal joints or interphalangeal joints occur mostly in?
working dogs or racing greyhounds
Early surgical repair for luxations is better than closed reduction and splintages because?
chronic instability leads to DJD + less than optimal function
Radiographs for metacarpal / metatarsal fractures include?
- dorsoplantar + mediolateral views extending from tarsus ends to ends of digits
- Oblique views with digits spread
- lateral view with affected digit pulled cranially with tape or gauze may be needed to isolate individal bones
When are stress radiographs needed for metacarpal / metatarsal fractures?
may need to displace digit to show joint instability
Medical treatment of animals with metatarsal fractures include?
- anaglesics for post-traumatic pain
- conservative treatment with fiberglass bivalve cast or metasplint
When would conservative treatment be needed in animals with metatarsal fractures
- closed non-displaced metatarsal diaphysis fractures of 1 or 2 bones
- especially 2nd and 5th bones (non-weight bearing digits)
What type of medical management would be needed in the following
- cats with comminuted nonreducible fractures
- most phalangeal fractures + acute sesamoid bone fractures
coaptation
Cast or splints are not removed until radiographic evidence fracture bridged with bone. How long can this take
usually 4 to 8 weeks
What type of surgical treatment is needed for
- metatarsal fractures in athletic or racing dogs
- for optimal return to racing
- anatomic reduction + rigid stabilization
- plates + screws
When should plate fixation be done as a surgical treatment in animals with metatarsal fractures?
When FAS is low or when atletic function is desired
What type of fixation is shown for digit 2
bridging plate
- used to span + support comminuted fracture
What type of fixation is shown for digit 3 and 4
Compression plates
- applied to transverse fractures
What type of fixation is shown for digit 5
Lag screw compression
- with oblique line protected by neutralization plate
Large avulsed fragments from base of which digits generally require open reduction + internal fixation
- due to liagentous insertion cause gragment distraction
2nd and 5th metatarsal
What type of surgical treatment is used to counteract pull of adjacent ligaments or compress oblique fractures
Lag screws
How many metatarsal bone fractures are normally treated with a splint or cast?
- unaffected bones form an internal splint to prevent deformity
1 or 2
How many metatarsal bone fractures are normally treated with internal fixation
3 or 4
Large displaced avulsion fractures are treated with?
lag screws
Splint of bivalve cast applied after internal fixation until?
radiographic evidence of bone healing is achieved
- same for metacarpal fractures
When would you use intramedullary (IM) pinning technique in animals with metatarsal / metacarpal fractures
- treatment of multiple transverse or short oblique fractures in patients with high FAS
How would you place IM pins in the metatarsal / metacarpal bones?
- slot made in distal metaphysis
- pin directed through slot (drive proximally across fracture line)
- pin seated in proximal metaphysis or metacarpal or metatarsal bone
What treatment would be used in an animal with a high FAS and multiple transverse or short oblique fractures
Intramedually (IM) pinning technique
Fractures of the phalanges are less frequent. They are handled similarly to metatarsal fractures and most often amenable to?
splinting
How would you treat animals with acute phalangeal luxations that are working or racing dogs?
treat with open reduction and suturing of joint capsule + collateral ligaments
How would you treat chronic luxations of 2nd an 5th toe
amputation
What procedure of metatarsophalangeal + interphalangeal joints results in good function + pain relief
arthrodesis
What are the 4 fixation systems applicable for metatarsal + phalangeal fractures?
- orthopedic wire
- IM pins
- external fixation
- Plates + screws
Fixation of metatarsal and phalangeal fractures are determined by what two points?
- FAS score
- fracture location
Which treatment options are available for animals with a FAS score of 0 to 3
- bridging plates
- external fixators
- lag screws for avulsion fractures
Which treatment options are available for animals with a FAS score of 4 t 7
- bone plates and screws
- IM pins
- lag screws for avulsion fractures
Which treatment options are available for animals with a FAS score of 8 to 10
- splint or cast
- IM pins
- Tension band wire for avulsion fractures
What does A in the image show
Connect fixations pins with acrylic bars
- provides rigid stabilization of comminuted fractures
fixation does not interfere with open wound treatment
What does B in the image show
Place pins in Type Ib configuration + connect with acrylic (at and angel)
Phalangeal fractures / luxations, digit masses (amputation), and digit amputation is preformed the same as?
as the forelimb
