Running Injuries

Fractures of the Fifth Metatarsal

Fractures of the fifth metatarsal are common especially at the proximal portion (the base of the metatarsal). They are also referred to as tuberosity avulsion fractures. The tuberosity is the bony prominence that protrudes at the base of the metatarsal. An avulsion fracture refers to an injury to the bone in a place where a tendon or ligament attaches to the bone. When an avulsion fracture occurs, the tendon or ligament pulls off a piece of the bone.

The patient will complain of pain at the base of the fifth metatarsal. Localized swelling and bruising may be present.

Non-displaced fractures are treated conservatively. Non-displaced fractures are cracks in the bone seen on x-ray, but with the bones remaining in their proper position and alignment. Most non-displaced fractures of the 5th metatarsal can be treated without surgery. However displaced and comminuted fractures require surgery. A comminuted fracture is where there is splintering of the bone ends. This results in a situation where exact reconstitution or reconstruction is difficult or impossible. This situation is usually caused in cases of direct trauma to the fifth metatarsal.

There are three types of 5th Metatarsal Fractures:

1. Tuberosity avulsion fractures
2. Fractures within 1.5 cm of the 5th metatarsal tuberosity are called Acute Jones Fracture
3. Stress Fractures

Associated Structures

It is important to understand which structures are involves especially when a sporting activity was a precursor to the fracture. Associated soft tissues that may be affected include the lateral band of the plantar fascia, peroneus brevis tendon and peroneus tertius tendon.

The lateral band of the plantar fascia inserts into the proximal tip of the fifth metatarsal. The peroneus brevis inserts in a fan like pattern across the proximal end of the metatarsal.

Tuberosity avulsion fractures

These are the most common fractures and usually heal well with conservative treatment. If the fracture is displaced or comminuted the treatment options may vary.

Symptoms

• Sudden onset of pain at the base of the fifth metatarsal.
• Often occurs due to a ankle sprain or twist.
• Tenderness and swelling at site.

X-Rays

• Fractures appear perpendicular to the long axis of the fifth metatarsal
• Radiolucency located at the proximal metaphyseal-diaphyseal junction (metatarsal head-neck junction).

Differential Diagnosis

• Apophysis
• Accessory ossicles

Treatment

For non displaced tuberosity fractures:

• Non weight bearing cast for 6-8 weeks.
• Ankle splints
• Walking casts or boots.
• After immobilization orthotics and silicone pads

For displaced fractures:

• Internal fixation or closed reduction and pinning surgery.

Acute Jones Fracture

A Jones fracture is located within 1.5 cm distal to tuberosity of 5th metatarsal. A Jones fracture occurs in the mid portion of the foot. Patients who sustain a Jones fracture have pain over this middle/outside area of their foot, swelling, and difficulty walking.

Symptoms

• Sudden pain at the base of the fifth metatarsal with difficulty putting any pressure on the foot
• May be substantial swelling at site.
• Occurs often when force is applied to the foot during plantar flexion (foot pointing down ward) i.e pivoting in football and basketball.

Treatment

Depends on the type of fracture, there are three types of Jones fractures:

Type 1

• Classified as a fracture line with sharp margins and no widening of the fracture. Minimal evidence of periosteal reaction to chronic stress. A periosteal reaction is the formation of new bone in response to injury.
• Non weight bearing cast for 6-8 weeks or walking boot.

Type 2

• Fracture line that involves both cortices with an associated periosteal bone. The fracture will have a widening fracture line and there will be evidence of intramedullary sclerosis.
• A non weight bearing cast may be on for longer than 8 weeks.
• In athletes these fractures are usually treated with screw fixation.

Type 3

• Widening fracture line with complete obliteration of the medullary canal (this is the cavity containing bone marrow in the long part of a metatarsal) at the fractures site.
• Treated with screw fixation
• Healing times are much longer in this type of injury and there is a higher risk of a re-fracture.

Stress Fractures

Symptoms

• Often occurs in younger patients and athletes.
• Dull pain and swelling at the base of the fifth metatarsal
• Symptoms may be intermittent and only occur during exercise until the pain increases.

Treatment

• Non eight bearing casting for up to 20 weeks may be necessary. However a non weight bearing cast for such a long period of time can result in muscle wasting.
• Surgery may be necessary for athletes and patients who are reluctant to remain in a cast for prolonged periods.

Dr Foot Recommends

The Aircast Walker

Click here to view the Aircast Walker

Aircast Walkers are used in the treatment of foot injuries or ankle injuries such as a ankle fracture and Metatarsal fractures.

High profile players such as Wayne Rooney, David Beckham and Steven Gerrard have all used Aircast Walkers successfully following a foot or ankle injury.

What are they?

The Aircast Walker features a lightweight removable plastic cast with a durable, semi-rigid shell which provides far greater protection compared to a conventional plaster cast.

The aircast shell is lined with four air cells for pneumatic support and increased comfort. These air cells can be custom inflated using the hand bulb for a 'total contact' fit. This unique method of compression supports the swollen ankle or foot, which helps to reduce swelling. For this reason, they are commonly used in the treatment of Metatarsal fractures and other conditions such as a broken ankle.

One of the main benefits of the Aircast Walker is that it is much lighter than a plaster cast and allows a greater level of mobility, making it much more comfortable and convenient to wear. This allows the patient to be active and back to work (depending on your profession).

The walkers rocker sole reduces pressures through the sole of the foot which allows earlier partial weight bearing. Controlled weight bearing as instructed by your doctor also greatly enhances healing and reduces rehabilitation time, allowing you to get back to your sport.

The other advantage of uses the Airast Walker compared to the plaster cast is that the patient can take the cast off and undergo physiotherapy and exercise to prevent stiffness and reduce healing times. You can also wash your feet which makes it a much more hygienic and convenient method of immobilization following a metatarsal fracture.

Who uses them?

Many elite athletes such as such as Wayne Rooney and David Beckham have used the Aircast Walkers following a foot or ankle injury but they can be used by anybody who has suffered from a metatarsal fracture or ankle injury.

Mend it like Beckham! - Significantly improve your recovery time and your quality of life following a metatarsal fracture.

Click here to view the Aircast Walker