Fractures of the 5th Metatarsal

I have a friend and colleague (a podiatrist) who has recently managed to fracture the base of her fifth metatarsal.  So I thought it would be useful to look fractures in this area and look at how they present, are diagnosed and are treated.

She has kindly sent me pictures of her foot prior to diagnosis of the fracture, in the walking boot and also the x-ray itself, which shows the area damaged.  She has also said she is happy for me to write about it here as a case study.

A fracture can simply be described as a break in the continuity of the bone.  They can result in damage across the whole of the bone, or part of the bone, such as in a Greenstick fracture.

Fractures to the metatarsal bones are one of the most common injuries to the foot with up to 70% involving the fifth metatarsal (Polzer et al, 2012), the metatarsal near to the outside edge of the foot.

Commonly an individual will present with pain to the foot sustained after a traumatic event such as an inversion injury to the ankle.  For the most part, this kind of injury will result in a sprain to the ligaments on the outside of the foot and ankle, although at times it can be more sinister.

Symptoms

The main symptoms that patients report following an injury is pain, swelling, bruising and inability to weight bear.  In some severe injuries a wound may be present over the site of injury and bone could be seen – in this case this is a serious emergency and a rapid trip to the Emergency Department (ED) is recommended!  

The symptoms above are not restricted to fractures; in fact many soft tissue injuries present with similar features.  An x-ray is the only way in the early stages that you can definitively identify a fracture.  So how do you find out who needs an x-ray and who doesn’t?

The Ottawa Ankle Rules (OAR)

The OAR is a simple test to examine who needs an x-ray in the ED.  After all x-rays use radiation so you don’t want to go and irradiate people recklessly.  

They were first used in 1992 to try to reduce the cost of radiology and also the time that patients spent waiting in the ED.  Tenderness in predefined locations with the inability to bear weight is considered a positive finding and an –x-ray is ordered.  The test is geared towards a high sensitivity – essentially this means that a negative result (i.e. no pain and can bear weight) means no x-ray thus saving time in the ED and financial resources for tests that may not be needed.

The use of the OAR may explain why in the past an individual had an injury but the doctor decided not to x-ray.

So I have a fracture?  What next?

The treatment will depend upon the location, severity and displacement (how lined-up it is) of the fracture, combined with the patient’s symptoms.   In the initial stages patients may be non-weight bearing in either a cast, walking boot or an elasticated bandage.  With regards to weight bearing, authors differ on their approach with some recommending complete non-weight bearing for 8 weeks (Hopton & Harris, 2010) while others suggested weight bearing as tolerated (Polzeret al, 2012).  The treatment offered might well depend upon the clinical experience of the individual coupled with the severity of the injury.

In the case of my colleague, she was initially treated with a plaster of Paris “backslab” which sits upon the back of the leg and the sole of the foot to protect the area from further injury.  This is a temporary cast and has been replaced with a removable boot that allows her to bear weight when ready.  It also allows her to keep the foot clean and maintain her hygiene; something that a plaster cast cannot allow.

Will I need an operation?

In some cases an operation may be needed but this is normally limited to severe fractures or those that fail to heal with conservative and functional measures.  Kerkhoffs et al (2011) looked at surgical treatment for avulsion fractures in athletes and non-athletes and found that those who had surgery healed quicker and returned to sports sooner.  Although they did say their treatment approach with a simple lined-up fracture was to use conservative and functional measures.

How long will it take to heal?

The research seems pretty consistent here and found that on average the fracture shows signs of healing on x-ray within 6-12 weeks.  

Summary

So it seems that fractures to the 5th metatarsal are common and if uncomplicated can be treated fairly simply with control of individual patient symptoms.  If all goes well, most will heal between 6-12 weeks.

I will try to keep you updated with my friend’s progress as she recovers from her injury.

Fractures in the acute stages are not something which we can deal at Walk other than recommending further examination; however, once healing has occurred and you return to your normal level of activity we can aid rehabilitation.  

Fractures and the immobilisation of the the foot and leg can lead to functional problems that we are well placed to treat using soft tissue and joint mobilisation.  Why not get in touch to find out more?

Tel: 01562 51 56 61
Mobile: 077 666 888 29
Email: contact@walkfootcare.co.uk

References:

POLZER H, POLZER S, MUTSCHLER W & PRALL WC (2012) Acute fractures of the proximal fifth metatarsal bone: Development of classification and treatment recommendations based on current evidence.  Injury. 43:1626-1632.

HOPTON BP & HARRIS NJ (2010) Fractures of the foot and ankle.  Orthopaedic Surgery: Lower Limb. 28(10): 502-507.

KERKHOFFS GM, VERSTEEGH VE, SIEREVELT IN, KLOEN P & VAN DIJK, CN (2012) Treatment of proximal metatarsal V fractures in athletes and non-athletes.  British Journal of Sports Medicine. 46:644-648.