Foot Bones Most at Risk
- David Tollafield
- Mar 11
- 6 min read
Updated: Apr 25
Metatarsal Bones and Other Foot Fractures
Unfortunately, not all bones heal the same way or are as prone to damage as others.
What causes a fracture or break? Are these always what they seem? When my wife broke a bone in her foot back in October 2021, no one was more surprised than me. This draws me to admit that fractures can be missed in their early stages, and some people can walk without knowing that a fracture has taken place.
A whistle-stop tour of the anatomy
The feet have 26 bones, which are either small or long. Long bones give the foot shape, width, and length.
Small bones are more like building bricks in the foot and shape the arch. The heel bone is a platform for the leg to sit on and is protected by a fat heel pad. The names given to bones are primarily Latin.
Bones are covered in an outer layer of a hard or compact bone called the cortex. The inside is made of spongy bone, which one might like to think of as ‘aero’ type – after the chocolate bar with air holes.
Inside the long bone is a medulla cavity in which marrow sits. Marrow contains fat and blood-producing cells, including white cells, which are used for immune response.
SHORT BONES vs LONG BONES
The short bones are the cuneiforms, navicular and cuboid; the long bones are the metatarsals and phalanges. The hind foot has large bones which form the heel and ankle.
The long bones are more likely to fracture than the short bones, but the extent of any bone injury depends on the force exerted, the speed of impact and the direction of that force.
Falls, sudden twists, constant foot pounding, and dropping heavy objects can all cause fractures. Patients can also sustain fractures in the small bones of the toes. It is usual to bind two toes together but avoid cutting off the blood flow by being too tight.
The mechanics of these fractures occur when twisting movements arise with the foot tipping over. When my wife fell backwards and twisted her foot going up some steps, the tendon on the outside of the foot added to the problem, causing pulling where the tendon was attached.
What else do we need to know?
Bones have growth sites called epiphyses. When males and females mature around adolescence, these growth sites stop growing and change from cartilage to bone; the gaps now disappear. Silent Witness, CSI, and other TV programmes investigating cold cases use the closure of growth sites to estimate age, as well as carbon dating. Fractures through open growth sites can cause longer-term problems for children and adults.
A Bit of Physics, Chemistry and Nutrition
Healthy bones are made up of calcium phosphate and a protein called collagen. The outside hard cortex can resist the stresses and strains of everyday life.
The long bones in the foot are slightly curved to give spring resistance and are triangular in cross-section, which makes them very strong. Walking keeps our bones healthy. We also need vitamin D for healthy bones, which means a healthy diet, often called a Mediterranean diet of oily fish, legumes, and fruit.
Evidence suggests that Vitamin D supplements will not prevent fractures, while exercise and diet are vital. Vitamin D is essential to absorb calcium, so some bowel complaints can affect this process.
Osteoporosis is helped by vitamin D supplements, where the main skeletal bones affected are the vertebrae and pelvis rather than the foot.
Sunlight is important for the healthy absorption of calcium. For the whole process to work, we need our liver and kidneys in good working order, which is important for absorbing vitamins correctly.
Post-menopausal conditions increase the risk of fractures in females. Age, or shall we call it physiological age associated with natural tissue ageing, makes fractures higher in older patients.
Which Bones Are Most at Risk from Fracture?
The longer the bone, the more prone to a crack or break. The second and fifth metatarsals bear the main brunt of injury. My wife sustained a 5th metatarsal fracture. There are two main types of fractures – simple and complex fractures. Let’s put these into context.
When is a fracture dangerous?
Falls in the elderly are more dramatic because blood loss in a big space like the thigh is life-threatening. Fortunately, the foot does not have the same concerns, but blood loss can still become infected if a significant clot forms. Massive swelling after injury needs emergency attention. For the most part, most of these types of fractures are fixable, but the ankle is more open to long-term damage as the leg bones connect to the talus.
Road traffic accidents (RTA), occupational accidents, and industrial accidents are far more complex for the foot. If the fracture is not easily put back into place or is badly displaced, intervention is required to avoid long-term damage, poor function, and long-term pain.
Least dangerous fractures
Simple fractures usually mean no displacement of the overall shape, as in complex open or complex closed fractures. However, let us move away from these types of fractures because this comes under moderate to significant trauma, which is the domain of the orthopaedic surgeon.
Stress fractures are usually the most common of all foot fractures. There is a difference between these and the previous types of fractures. First, a crack occurs, which may be partial or complete. In other words, the crack may not go all the way through. These need rest, some splinting if necessary, ice, and reduced weight-bearing. X-rays show a delay of 2-3 weeks, so an X-ray looks normal. Although scans are more sensitive earlier, they are not 100% reliable if taken too soon.
Scan imaging is more expensive than x-rays, and in the NHS (UK) such imaging has to be booked for an appointment, often delaying the diagnosis.
Stress fractures can arise around the neck of the metatarsals, often the second and third metatarsals, but any can be involved. They have also been called ‘March’ fractures, as they used to occur in soldiers on parade because they stamped everywhere as a repetitive low-grade force. As a result, the foot swells around the bone. The area is tender, and walking can be uncomfortable.
Displaced fractures can still be simple but are more than simply stress-induced and require more care. If two ends or pieces are reasonably aligned, even if a gap exists, this can be splinted in a walker boot. The diagram shows a displaced simple long spiral fracture of the fifth metatarsal shaft, which was left to heal without surgery.
Treatment included walker shoe splinting, rest and gentle motion, and non-weight bearing for eight weeks. This took 12 weeks to settle, with some symptoms occurring for a few months afterwards.
Complex closed-foot fractures
Chips and small avulsions
In many cases, small pieces are pulled away in foot bones and can be left, but these flakes of bone may require removal if symptoms persist. The ankle is a common place for flakes to chip off, especially around the outer ankle bones. In addition, the navicular and its bulbous inside, known as a tuberosity, can be pulled open. Because the tendon is crucial in the middle section of the foot, pain continues until management is undertaken. An avulsion is more severe because the tendon will keep pulling until the bone is stabilised, opening up the fracture site. (Navicular avulsion fracture).
Avascular fractures
An avulsion fracture occurs when a tendon pulls part of the bone away. It is common after ankle trauma and is shown in marine blue in the figure below. The other type of fracture is the Jones fracture, which can be slow to heal as it arises across an area that disturbs the bone blood supply.
In these diagrams, we can see different fracture types along the bone from the head to the base: stress fracture. Not all Jones’ fractures require surgical management. Jones fracture fixation (C/O Sussex fracture clinic)
Taking Action After a Suspected Injury
If suspected, fractures need assessment early. If you are concerned, use the NHS 111 services rather than going to A&E. However, serious life-threatening injuries require 999 emergencies.
Of course, we should avoid fractures altogether, but the fifth metatarsal does pose additional problems in the foot.
For readers who would like more details about the foot and common problems, the author has written the following text, which is available from Amazon books.
David is a former lecturer and consultant podiatric surgeon turned author and writes for Busypencilcase Communications & Publishing. Est. 2015
Thanks for reading ‘Which Bones are Most at Risk from Fracture?‘ by David R. Tollafield
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