Adult Acquired Flatfoot Syndrome - Posterior Tibial Tendon Dysfunction
Posterior tibial tendon dysfunction (PTTD) is the leading cause of adults acquiring a flat foot with age. It is a progressive condition that can lead to secondary effects on other supporting structures within the foot including ligament, bones and joints and can affect either one or both feet.
Posterior tibial tendon dysfunction is now increasingly being termed as Adult Acquired Flatfoot Syndrome, due to recognition that other tissues such as ligaments and joints can also become affected by this problem, and that most people move towards a progressive collapse and flattening of their foot.
What is posterior tibial tendon dysfunction?
The posterior tibial tendon runs behind the inside bump on the ankle (the medial malleolus), across the instep, and attaches to the bottom of the foot. It has a very important role in holding up the inside part of the foot and preventing collapse.
Posterior tibial tendon dysfunction runs the gamut from initial strain and minor degeneration of the posterior tibial tendon, through to frank rupture and severe collapse of the hindfoot and ankle. It is now known that the problem is caused by a degenerative tendinosis rather than inflammation. Inflammation when it does occur is secondary.
How do we diagnose this problem?
There are some classic clinical features that make it obvious to a trained eye that there is a failure of the posterior tibial tendon to do its job effectively, even in the absence of any pain. When symptoms do occur, they can often cause fullness and swelling (oedema) on the inside of the ankle where the tendon resides, or even pain in other locations due to a gradual shift in forces as the foot begins to collapse. Often a simple test known as a 'single heel raise' will be used to check weakness in the muscle/tendon.
There are several 'stages'' that also assist in describing posterior tibial tendon dysfunction, which reflect the severity and progression of the condition. These run form Stage 0, to Stage 4.
An ultrasound scan, or MRI scan will usually confirm a diagnosis of posterior tibial tendon dysfunction – allowing the diseased tendon to be easily assessed for any tears or deterioration. As the condition progresses, more attention is often paid to the secondary effects on the local joints (such as the talo-navicular and subtalar joints) that are often inevitably affected by osteoarthritis.
Treatment for posterior tibial tendon dysfunction
Posterior tibial tendon dysfunction tends to be a slowly progressive condition, that can at best be stabilised - but never really cured.
Because there is a slow deterioration in the stability and strength of the tendon with age, the foot will usually slowly collapse without significant interventions.
Treatment is typically guided by what Stage the condition is in. However, generally common treatmetns will include:
- Use of custom foot orthoses in firm, supportive footwear
- Use of some form of ankle bracing for sports and other higher impact activities or work
- Stretching and strengthening exercises
- Use of anti-inflammatories or injections if there is significant acute pain
- Use of a removable cast walker to settle acute episodes of pain
In our experience, the choice of footwear is perhaps the most important and under-appreciated consideration of all.
People who can be open to our advice and recommendations for enclosed, lace-up footwear for the majority of their weight-bearing activities/work, tend to have a much better outcome. Unfortunately, most dress shoes and open sandals, both male and female, will often be insufficient to assist in stabilising this condition.
If there is slow worsening of the condition, then a more substantial form of bracing known as an ankle-foot orthosis, or ''Richie Brace is often recommended if surgery is not a possibility.
Surgery
Surgery is considered as a last resort, as this will often involve substantial work to often fuse one or more joints in the rear area of the foot to aid stability and reduce pain. Sometimes tendon transfer procedures are attempted, but these appear to often be insufficient to stabilise the foot long term without other bone procedures as well. These surgeries can involve a lengthy recovery and lots of rehabilitation, which can often take 12-18 months.
