When to Seek Treatment for Continued Pain of 5th Metatarsal Base Avulsion Fx After 8 Weeks

5th Metatarsal Fracture

What is the 5th Metatarsal Bone?

The 5th metatarsal bone is the long bone located on the outside of the foot.

It has a base (tuberosity) where the peroneus brevis tendon and lateral plantar fascia attach, a long shaft and a head where it meets the 5th toe.

Please see Foot - Anatomy and Imaging for more information on where this bone is in the foot.

• 

  5th metatarsal - location and shape

  Button

• 

  5th metatarsal - tendons

  Button

Types of 5th Metatarsal Fracture

• There are several types of 5th metatarsal fracture.
• They usually occur due to twisting injury.
  
• Most heal without complication but can take time.

Base (Tuberosity) Avulsion Fracture

• In an avulsion fracture, a piece of the bone is pulled off the main portion of the fifth metatarsal by the attaching plantar fascia or tendon.

• These are the most common 5th metatarsal fracture.
• They are a cause of persisting pain after what is thought to be an ankle sprain.

• Treatment is protection in a stiff sole shoe or low "moon-boot" until comfortable.
• Surgery is rarely required, unless the avulsed fragment is very displaced and not healing (see images below).

• 

  5th metatarsal - minor base avulsion

  Button

• 

  5th metatarsal - large base avulsion

  Button

• 

  5th metatarsal - unhealed base avulsion

  Button

Shaft, Head and Neck Fractures

• Neck and head fractures (uncommon).

• Shaft fracture ("dancer's fracture") - these spiral fractures look bad but heal without surgery (see images below). Surgery can actually make them heal slower.

• 

  5th metatarsal - fresh dancer's fracture

  Button

• 

  5th metatarsal - healed dancer's fracture

  Button

Jones Fracture

• This fracture occurs in an area between the base and shaft of the fifth metatarsal which has a limited blood supply and is under tension stress on standing (see image).

• This injury heals slower than a base avulsion fracture. It sometimes does not heal or re-fractures after healing. Surgery may be recommended early in active people.

Interesting fact: this fracture was described by Dr Robert Jones in his own foot back in 1902.

Stress Fracture of the 5th Metatarsal

• This stress fracture of the foot occurs in a similar location to the Jones fracture but develops over time rather than acutely from an injury (see image - note thicker "whiter" bone).

• People with high arched (cavo-varus and metatarsus adductus) feet are more likely to have this stress fracture.

• Healing is slow and re-fracture can occur. Surgery is usually recommended.

5th Metatarsal Jones and Stress Fracture - symptoms

People who sustain one of these fractures have:

• pain,
• swelling,
• tenderness,
• and bruising over the outer foot.
• Difficulty walking.

Stress fractures may have had a dull ache and mild swelling during and after exercise for several weeks before sudden pain developed.

5th Metatarsal Jones and Stress Fracture - diagnosis

If a foot injury stops you walking on it, you should seek medical attention as soon as possible for proper diagnosis and treatment.

The diagnosis of a Jones fracture involves:

• history of injury
• examination of the foot.

X-rays are always required and other imaging studies (MRI or bone scan) may be needed.

5th Metatarsal Jones and Stress Fracture - treatment

Initial treatment consists of:

• rest, ice, compression, and elevation (RICE) to help control pain and swelling
• a splint or "moon-boot"
• crutches to keep weight off the foot.

These fractures can heal with prolonged immobilisation and crutches (> six weeks).

Delayed healing and re-fracture also occur.

If there is an associated foot structural issue, this will need addressing with orthotics (insoles).

Surgical Treatment of 5th Metatarsal Jones and Stress Fractures

• Jones fracture surgery is recommended  when the fracture is not healing well or re-fracture occurs, and in active people or high-risk feet.



• Stress fractures of the 5th metatarsal usually require surgery .



Interesting fact:  Dr Beamond has fixed these fractures in members of the Adelaide Crows, Adelaide 36ers and Adelaide United clubs.

 

Surgery involves placing a screw within the 5th metatarsal to stabilise the bone and allow the fracture to heal ( see images below ). Occasionally a metal plate is required instead.

 

Bone graft is used when needed to stimulate healing. 

• 

  5th metatarsal stress fracture

  Button

• 

  5th metatarsal screw - inside bone

  Button

• 

  5th metatarsal screw - model

  Button

Surgery:

• is often Day Surgery
• requires a general anaesthetic in most people
• takes 30 minutes.

First 2 weeks:

• bandage
• "moon-boot" and crutches
• rest, elevation and ice (RICE)
• ankle and foot movements
• post-operative appointment.

Next 4 weeks:

• "moon-boot" to stand and walk
• exercise bike and pool-based activities
• post-operative appointment and X-ray.

Next 1 to 2 months:

• shoes
• return to sports specific training then sport
• post-operative appointment +/- X-ray.

Benefits and risks:

• 95% of people are helped by surgery
• 5% of people need more surgery
• <1% of people are made worse by surgery.

Consequences and complications:

• driving restrictions (2 to 8 weeks)
• scar numbness is common
• re-fracture if return to sport before 10 weeks
• screw or plate is NOT normally removed
• see General Information about Surgery.

hearnbeembigh.blogspot.com

Source: https://www.adelaideankle.com.au/5th-metatarsal-fracture

Share this post