What is it?
Flat foot, or pes planus, refers to loss of the arch of the foot. This can lead to the foot changing shape, and problems with walking comfortably. Many people have naturally flat feet, and if it is a long-standing condition and the same on both feet, it is often not a problem. If a flat foot develops in a what was previously a more normal-shaped foot, or a pre-existing flat foot starts to become painful, it may need investigating.
Why does it occur?
Flat foot can develop as a result of a variety of underlying conditions, and can occur in children and adults.
Flexible flat feet in children are normal, and will often correct as the arch develops at around the age of 10. A fixed flat foot in a child may be as a result of a tarsal coalition, which is an abnormal connection of two or more bones towards the back of the foot and in the heel.
Progressive flat feet in older people may be as a result of loss of function of the tibialis posterior tendon, which is the most central of all the leg muscles and key in lower leg stabilisation. Painful flat feet may also develop secondary to arthritis within the feet.
What are the symptoms?
Flat feet can lead to a variety of symptoms, including pain within the midfoot and on the inside border while walking or playing sports. Pain behind the medial aspect of the ankle bone with associated swelling can also lead to problems during physical activity. Progressive deformity of the foot can lead to rubbing of the bones in the foot on footwear, or tingling of the nerve on the inside of the foot.
How is it diagnosed?
Flat feet need careful clinical examination in order to pinpoint one of many potential underlying causes. X-rays may be used to look for arthritis or a bony coalition within the foot, and MRI scans may be required to look for any dysfunction of the tendons.
How is it treated?
If the foot is flat but flexible, simple insoles and physiotherapy may well prevent any worsening of the deformity, and improve symptoms. For progressively painful flat feet, where there is an underlying condition, surgery may be required.
The kind of surgery you have will very much depend on the underlying cause of the flat foot. In a rigid, painful flat foot, secondary to arthritis, reconstruction or foot fusion surgery may be required. If the flat foot is caused by an underlying problem with a tendon, then surgery to repair or reinforce the tendon may be a better option. In a bony coalition, sometimes it may be necessary to remove damaged tissue to reconstruct the flat foot.
Tibialis posterior tendon surgery
Brace and boot treatment
The One Orthopaedics team specialists
Consultant Orthopaedic Foot and Ankle Surgeon FRCS (Tr & Orth)