Diagnosis and Surgical Treatment

Metatarsal fractures involve the long bones of the hind paw between the hock and the toes. Injuries can range from a single relatively stable fracture to complex trauma involving several metatarsal bones, significant displacement and damage to the surrounding soft tissues. Because the metatarsal bones work together to support and distribute weight through the paw, disruption of several bones can result in considerable instability and abnormal alignment of the foot. Treatment depends on the number of bones affected, fracture location, degree of displacement, stability of the paw, soft tissue injury and the individual patient. Some fractures can be managed using external support and restricted exercise, while unstable or significantly displaced injuries may require surgical stabilisation. Surgical treatment aims to restore appropriate alignment of the paw, provide sufficient stability for bone healing and allow comfortable return to normal limb function.

When is surgery recommended?

Surgery is generally considered when a metatarsal fracture is unstable, significantly displaced, involves several important weight-bearing bones or cannot be maintained in satisfactory alignment using external support alone. Surgical treatment may also be recommended where there are very short fracture fragments, fractures close to a joint, substantial disruption of the paw or other features that make conventional splinting less likely to maintain satisfactory alignment. Not every metatarsal fracture requires an operation. Relatively stable and minimally displaced injuries can sometimes heal successfully using external coaptation and restricted activity. Current evidence supports assessing these fractures individually rather than applying one treatment to every patient.
Veterinary orthopaedic power handpiece used by Mainliacht Surgical
What signs might you notice?

Dogs and cats with metatarsal fractures may show:
• Sudden hindlimb lameness
• Reluctance or inability to bear weight
• Swelling of the paw
• Pain when the foot is handled
• Bruising
• Abnormal positioning of the toes
• Visible deformity of the paw
• Wounds following more severe trauma
The severity of lameness does not always indicate the complexity of the fracture, so radiographs are required to determine exactly which bones are affected.

How are metatarsal fractures diagnosed?

Diagnosis begins with examination of the injured limb, including assessment of pain, swelling, paw alignment, stability and the surrounding skin and soft tissues.
Radiographs are obtained in orthogonal projections to determine:
• Which metatarsal bones are fractured
• The location and configuration of each fracture
• The degree of displacement
• Alignment of the digits and paw
• Whether adjacent joints are involved
Where the injury follows major trauma, the patient is also assessed for other injuries before definitive fracture treatment is undertaken.

Do all metatarsal fractures require surgery?

No.
Stable fractures with little displacement may sometimes be treated using a splint or cast together with strict activity restriction.
Surgical stabilisation becomes more appropriate as displacement, instability and fracture complexity increase. Published evidence suggests external coaptation can produce good results in appropriately selected minimally displaced cases, while markedly displaced injuries are more likely to benefit from surgical restoration of alignment.

What are the metatarsal bones?

Dogs and cats normally have four principal weight-bearing metatarsal bones running parallel to one another within the hind paw.
Together they transfer load from the hock towards the digits during standing, walking and running. Although each bone is relatively small, the group functions as a unit and appropriate alignment is important for normal positioning of the toes and distribution of weight across the paw.
Trauma may fracture only one metatarsal or several bones simultaneously. When several adjacent bones are fractured, much of the normal internal support of the paw can be lost, creating considerable instability.

Surgical assessment of a dog's paw during metatarsal fracture repair

Plate and screw fixation

Selected metatarsal fractures can be stabilised using small bone plates and screws.
This can provide rigid fixation and accurate restoration of alignment, particularly where the fracture fragments are sufficiently large to accommodate implants.

K-Wire fixation

Small pins can be placed within the medullary cavity of selected metatarsal bones.
Pin fixation may be used alone in appropriate fractures or incorporated into a more complex fixation construct.

External skeletal fixation and combined constructs

External fixation can be particularly useful where fracture fragments are small, several metatarsals are involved or extensive implant placement directly over the fracture would be undesirable.
The fixation strategy can be adapted to the individual injury while minimising disruption of the surrounding tissues.

Spider construct used for metatarsal fracture repair in a dog

The Spider construct

For selected complex metatarsal and metacarpal fractures, a combined intramedullary and external fixation technique sometimes referred to as a Spider construct can be used.

Small K-wires are placed to engage the fractured bones and are incorporated into an external supporting construct. This allows several small bones or short fracture fragments to be stabilised together while maintaining the overall alignment of the paw.

The technique can be particularly useful where conventional plate fixation of each individual metatarsal would be difficult or unnecessarily invasive.

A published series involving 12 dogs and 19 cats described combined intramedullary and external skeletal fixation for metacarpal and metatarsal fractures, with all frames removed within ten weeks. The authors considered the technique particularly useful for fractures close to the joints, although complications such as pin-tract discharge, swelling and frame irritation can occur.

What happens after surgery?

After fixation has been completed, the stability and alignment of the paw are assessed and postoperative radiographs are obtained.
The patient is monitored during recovery and appropriate pain relief is provided.
Depending on the fracture configuration and fixation technique, additional padded support may be used during the early postoperative period.
Patients are normally discharged with detailed instructions covering activity restriction, medication, wound or pin-site monitoring and scheduled rechecks.

Post-operative care

Recovery at home is an important part of successful fracture treatment.

During the early healing period:

• Activity should be strictly restricted
• Exercise should be controlled and kept short
• Running and jumping should be prevented
• Dressings or external fixation components must be kept clean and dry
• The paw should be checked regularly for swelling or discomfort
• All prescribed medications should be given as directed

Patients are re-examined during recovery, and repeat radiographs are taken to assess fracture healing.

Where an external construct has been used, removal is planned once sufficient healing has occurred rather than according to a fixed date.

Risks and complications

All fracture repairs carry some risk.
Potential complications following metatarsal fracture surgery include:
• Swelling and bruising
• Wound complications
• Infection
• Pin-tract irritation or discharge
• Implant loosening or movement
• Loss of fracture alignment
• Delayed bone healing
• Non-union
• Bridging of adjacent metatarsal bones during healing
• Irritation caused by an external frame
• Need for additional surgery
Complications involving pin tracts and frame irritation are recognised with external fixation techniques, although published case series have also reported good long-term limb function following successful healing

Recovery and expected outcome

Recovery depends on the severity of the original injury, number of bones affected, patient age and fixation technique.

0–2 weeks

Strict activity restriction while early soft tissue and bone healing begins. Wounds, dressings and any external fixation components are monitored closely.

2–6 weeks

Controlled activity remains important. Clinical rechecks are performed and limb use should gradually improve as healing progresses.

6–10 weeks

Repeat radiographs are commonly used to assess progression of bone healing. External fixation may be removed when adequate healing has occurred.

Long term

Exercise is gradually increased once fracture healing has been confirmed. The aim is comfortable weight bearing and return to normal or near-normal function.

Long-term prognosis for metacarpal and metatarsal fractures is generally favourable, although greater displacement and instability are associated with increased complication risk. In one retrospective series of 100 dogs, persistent clinical lameness was uncommon at long-term reassessment. PubMed

 

Frequently Asked Questions

No. Some stable and minimally displaced fractures can be managed successfully using external support and restricted activity. Surgery is more commonly considered where the injury is unstable, significantly displaced or involves several bones.

The metatarsal bones lie immediately alongside one another and are frequently exposed to the same traumatic force. Significant trauma can therefore fracture several bones simultaneously.

Yes. External fixation components are temporary and are removed once sufficient fracture healing has occurred.

Many patients achieve very good long-term function following successful fracture healing. Outcome depends on the original severity of the injury, associated soft tissue damage and whether normal alignment and stability can be restored.

A Spider construct combines small pins used to stabilise the metatarsal bones with an external supporting construct. It can be useful for selected complex fractures where conventional fixation of each individual bone would be difficult.

Healing time varies between patients. Several weeks of restricted activity are usually required and repeat radiographs are used to determine when activity can safely increase.

Some controlled limb use may occur during recovery, but unrestricted exercise should be avoided until sufficient healing has been confirmed by the veterinary surgeon.

Robert Murray
Robert MurrayB.Sc (Hons) Biomed, DVM (Hons), MRCVS
Robert Murray is a small animal veterinary surgeon providing peripatetic orthopaedic and complex soft tissue surgical services to veterinary practices across the Midlands and wider UK.

Surgical Support for Veterinary Practices

Mainliacht provides peripatetic small animal surgical services to veterinary practices across the Midlands and wider UK. BOAS surgery and a range of orthopaedic and complex soft tissue procedures can be performed within the referring practice, with surgical equipment, instrumentation and postoperative information provided as required. Veterinary surgeons are welcome to discuss a case before referral.

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