Posterior Tibial Tendon Dysfunction (Adult Flat Foot)

Posterior Tibial Tendon Dysfunction (PTTD) describes the damage to, and inflammation of, the posterior tibial tendon, one of the major supporting tendons of the foot that plays an important role in our ability to walk, holding up the arch and supporting the foot as we walk. As the name suggests, the posterior tibial tendon travels down the back of the tibia (shin bone) and crosses to the inside of the ankle, behind and below the bony bump (medial malleolus) to attach to multiple sites at the bottom of the foot. PTTD is often referred to as Adult Acquired Flatfoot as it is the most common cause of flat feet developed in adulthood. This is because damage to the tendon impairs its ability to support and stabilise the arch.  

What causes PTTD?

PTTD is an overuse condition, caused by overloading and straining the posterior tibial tendon past what it can safely handle, resulting in damage and inflammation. Contributing factors to the development of PTTD can include:
  • Pronated or rolled-in feet
  • Other biomechanical or alignment issues
  • Flat, unsupportive footwear
  • Hard surfaces
  • Physical activity such as running, long-distance walking, hiking and climbing stairs
  • Obesity
  • Conditions such as diabetes and hypertension
  • Previous injury to the ankle
  • Steroid injections

What are the symptoms?

PTTD often affects one foot, though can develop in both. Without effective management, the symptoms of PTTD tend to progressively worsen resulting in a partial or even complete tear of the tendon. PTTD can be characterised into 4 stages of progression. Symptoms of PTTD can include:
  • Pain and tenderness on the inside of the ankle
  • Swelling
  • Redness and warmth
  • Flattening of the arch
  • Pain exacerbated by activity
  • Pain on palpation of the inside of the ankle behind the bony bump (medial malleolus)

How is treated?

Early intervention is recommended to stop the progression of painful symptoms and further damage to the posterior tibial tendon. The PRICE principles (protection, rest, ice, compression and elevation) can be used initially to help reduce painful symptoms. Treatment then needs to focus on addressing the cause of the PTTD and may include:
  • Orthotics to support the posterior tibial tendon, support the arch, and correct any other biomechanical or alignment issues
  • Supportive footwear that stabilises the foot at the ankle and limits the foot rolling in and hence placing more strain on the posterior tibial tendon
  • Stretching and strengthening to address tight or weak supporting muscles
  • Strapping the ankle to reduce strain on the tendon
  • Activity modification to reduce the strain on the posterior tibial tendon while it heals
  • Where injury to the tendon is severe, such as a significant tear, a brace or cast may be required to completely off-load the tendon
If left untreated, symptoms can leave you with not only flat feet but the inflammation and damage of surrounding structures, particularly at the ankle, as well as conditions such as arthritis that can make daily activities like walking painful.