11 Surgery of the Tarsus, Metatarsus, and Phalanges

Plantigrade stance

What is it called when the foot is positioned so the plantar surface of the calcaneus contacts the ground, often the result of a tarsal fracture?

Valgus position

What is it called when there is an "outward deviation" of something, sometimes the result of a tarsal fracture?

Varus position

What is it called when there is an "inward deviation" of something, sometimes the result of a tarsal fracture?

Plantigrade stance (dropped hock)

What position is this?

Tarsal joint is a MAJOR weight bearing function (which, without treatment, causes joint incongruity and osteoarthritis)

Overall, tarsal fractures are rare in companion animals. When they happen, why are tarsal fractures disabling?

Working dogs (typically only happens in companion animals if they have a fractured calcaneus)

Overall, tarsal fractures are rare in companion animals. What animal DO they occur in?

Racing greyhounds

What animal is fracture of the central tarsal bone common in?

One or more small lag screws

How do you repair fractures of the central tarsal bones in greyhounds?

Radiographs (often sedate)

What do you often need to do to diagnose tarsal or calcaneus fractures?

Dorsoplantar, medial lateral, and oblique

What kind of projections do you do to adequately diagnose tarsal or calcaneus fractures on radiograph?

Lacerations or ruptures of the Achilles tendon (typically see an open wound)

What do you have to differentiate calcaneal fractures from when you see a plantigrade stance?

FALSE NOT INDICATED

TRUE OR FALSE: Medical and conservative management is very common for tarsal fractures.

Calcaneal fracture

In order to correct this fracture, you need to resist the pull of gastrocnemius muscle with tension bands, lag screws, or plates

Calcaneus

What is the largest of the tarsal bones?

Tuber calcaneus

What is the insertion for the Achilles tendon?

Talus

What is the SECOND largest tarsal bone?

OVERALL: Stabilization of calcaneal fractures

LEFT: Tension band wire for transverse fractures

MIDDLE: plate for transverse fractures

RIGHT: lag screws for oblique/slab fractures

What is happening here? Describe each of the fractures and the treatment.

OVERALL: Stabilization of talus fractures

LEFT: diverging K wire

RIGHT: lag screws

BOTH are stabilizing fractures of articular surface

What is happening here? Describe each of the fractures and the treatment.

Stabilization of neck of talus

What is happening here, where a lag screw is placed from head of talus into trochlea of talus AND from caudal medial base of talus into calcaneus?

Coaptation with splint up to 6 weeks for most dogs

What do you have to think about for post-op care for stabilization of tarsus and calcaneus fractures?

Metatarsal and metacarpal

ALL of what kinds of fractures need to be splinted after internal fixation?

May irritate soft tissue (may be removed)

What kinds of problems might pins for tension band stabilization of calcaneal fractures cause?

Screws for reconstruction

Pins for tension band stabilization for calcaneal fractures may irritate soft tissue and be removed. What is NOT typically removed?

Gastrocnemius musc.

What muscle pulling may cause delayed union or nonunion for calcaneal fractures if not adequately stabilized?

From direct blow or force to paw or hyperextension injuries

What is often the cause of metatarsal bone fractures in companion animals?

Greyhounds (often from fatigue or loaded beyond yield strength)

What animals commonly experience complete metatarsal fractures? What often causes it?

According to location: base (proximal end) or head (distal end)

How do you classify metatarsal fractures?

EARLY SURGICAL REPAIR (because chronic instability would lead to DJD and less optimal function)

WHEN does surgical repair do BETTER than closed reduction for metatarsal and phalangeal fractures?

Most commonly avulsion fractures of the base occur on 2nd and 5th bones

Avulsion fractures of the base of the metacarpal/metatarsal bones occur WHERE most often?

Working dogs or racing greyhounds

What animals do luxation of the metacarpophalangeal joints or interphalangeal joints occur in?

RADIOGRAPHS: dorsoplantar and mediolateral, oblique, and lateral view

How do you diagnose luxations or fractures of the metacarpal/metatarsal bones? What views?

Conservative treatment with fiberglass bivalve cast or metasplint (for CLOSED nondisplaced metatarsal diaphyseal fractures of the 1st or 2nd bones)

How can you medically manage metatarsal fractures?

2nd and 5th

What are the dog and cat's nonweight bearing digits?

when they have comminutes nonreducible fractures OR for phalangeal fractures and acute sesamoid bone fractures

When can you use coaptation in metatarsal fractures in cats?

When there is radiographic evidence of fracture bridging of the bone occurring (normally 4-8 weeks)

When do you typically removed casts or splints of metatarsal fractures?

For optimal return to racing (use plates or screws)

Why do you surgically treat metatarsal fractures in athletic or racing dogs?

When FAS is low or athletic function is desired

Why would you use plate fixation for surgical treatment of metatarsal fractures?

To span or support comminuted fractures

On what type of fracture in the metacarpus/metatarsus do you typically use bridging plates?

Transverse fractures

On what type of fracture in the metacarpus/metatarsus do you typically apply compression plates?

Oblique fracture

On what type of fracture in the metacarpus/metatarsus do you typically apply lag screw compression protected by a neutralization plate?

Bridging plate for comminuted fracture

What type of fracture and fixation is being used in digit 2 (the second from the left digit, next to the "thumb")

Compression plates for transverse fractures

What type of fracture and fixation is being used in digits 3 and 4 (the second and third digits from the right)?

Lag screw compression and neutralization plate for oblique fracture line

What type of fracture and fixation is being used in digit 5 (the right most digit)?

Large avulsed fragments from base of 2nd and 5th metatarsals treated with open reduction and lag screw internal fixation

What is happening here and how do you surgically treat it?

Splint or cast (unaffected bones form an internal splint to prevent deformity)

How do you treat fractures of 1 or 2 metatarsal bones?

Internal fixation

How do you treat fractures of 3 or 4 metatarsal bones?

Lag screw

What should you do if there is a metatarsal with a large displaced avulsion fracture?

Until radiographic evidence of bone healing is achieve

HOW LONG do you apply splint or bivalve casts after internal fixation for metatarsal/metacarpal fractures? KNOW THIS

For high FAS patients with multiple transverse or short oblique fractures

Why do you do IM pins for metatarsal/metacarpal fractures?

IM pins

What is the treatment for these metacarpal/metatarsal fractures?

Splinting

How do you typically treat fractures of the phalanges?

Acute phalangeal luxation

Which kind of phalangeal injury do you treat with open reduction and suturing of the joint capsule and collateral ligaments?

Chronic luxation of the 2nd or 5th toe (because they're non weight bearing)

What kind of phalangeal injury do you treat with amputation?

Arthrodesis (fuses two or more bones)

What surgery has good functioning results for luxation of metatarsophalangeal and interphalangeal joints?

Lower FAS scores (like 0-3, or animals that are older and have a harder time healing, etc) need more rigid fixation like bridging plates, external fixators, or lag screws

Higher FAS scores (like 8-10, or animals that are younger and heal quickly, etc) need LESS rigid fixation like splints, IM pins, or tension bands

How do you know what types of fixations to use for metatarsal/phalangeal fractures?

External fixation with minimal type II (on left) or type Ib configuration (on right)

How can you provide rigid stabilization of comminuted metatarsal fractures or open wound fractures?