Tibialis Posterior Dysfunction: Understanding and Treating “Adult Acquired Flatfoot”
Tibialis posterior dysfunction (TPD) is a common condition that affects the tendon supporting the arch of your foot. This tendon, the tibialis posterior, runs along the inside of your ankle and attaches to the bones on the inside of your foot.
It plays a crucial role in supporting your arch and enabling you to turn your foot inwards. When this tendon becomes damaged or weakened, it can lead to pain, instability, and even flatfoot deformity.
Symptoms: More Than Just a Pain in the Foot
TPD often develops gradually, with symptoms worsening over time. Here’s what to look out for:
- Pain and Swelling: Pain along the inside of your ankle and foot, especially when standing, walking, or exercising. You might also notice swelling in this area.
- Arch Flattening: A progressive flattening of your foot’s arch, making it more difficult to stand on your toes or perform activities that require pushing off the ground.
- Changes in Foot Position: Your foot may begin to turn outwards, giving the appearance of “too many toes” when viewed from behind.
- Stiffness and Weakness: Difficulty moving your foot inwards or upwards, accompanied by a feeling of weakness or instability in the ankle.
Causes: A Multifactorial Condition
While the exact cause of TPD isn’t always clear, several factors can contribute to its development:
- Overuse and Strain: Repetitive activities that place stress on the tibialis posterior tendon, such as prolonged standing, walking, or running, can lead to overuse injuries.
- Acute Injury: A sudden injury, like an ankle sprain, can damage the tendon.
- Biomechanical Factors: Flat feet, high arches, or other foot deformities can alter the mechanics of your foot and ankle, increasing stress on the tibialis posterior tendon.
- Systemic Conditions: Conditions like diabetes, rheumatoid arthritis, and hypertension can weaken tendons and increase the risk of TPD.
- Age and Gender: TPD is more common in women and older adults due to age-related tendon degeneration and hormonal changes.
Diagnosis: A Comprehensive Approach:
Diagnosing TPD involves a thorough evaluation, this will typically:
- Taking a thorough history: Discuss your symptoms, medical history, and any activities that may have contributed to your condition.
- Clinical Assessment: Assess your foot and ankle for pain, swelling, range of motion, and any deformities. Specific tests to evaluate the function of the tibialis posterior tendon.
- Gait Analysis: Looking at function is an essential part of the assessment
- Imaging Studies: this may include a range of modalities including X-rays can help visualise the bones and joints of your foot and ankle, while ultrasound or MRI scans can provide detailed images of the tibialis posterior tendon, helping to identify any tears or degeneration.
Evidence-Based Treatment
Research supports the effectiveness of both conservative and surgical treatments for TPD. A 2019 systematic review in the Journal of Foot and Ankle Research found strong evidence for the use of orthotics and bracing in early-stage TPD. Physiotherapy, particularly eccentric strengthening exercises, has also been shown to be beneficial.
Staging of TPD:
- Stage 1: Tenosynovitis (inflammation of the tendon and its sheath) with no deformity.
- Stage 2: Flexible flatfoot deformity, where the arch collapses when bearing weight but can be corrected when not bearing weight.
- Stage 3: Rigid flatfoot deformity, where the arch remains collapsed even when not bearing weight.
- Stage 4: Ankle arthritis in addition to flatfoot deformity.
Important Considerations:
- Early diagnosis is crucial: Early intervention with conservative treatments like orthotics, bracing, and physiotherapy can often prevent progression of the condition.
- Other conditions can mimic TPD: Conditions like plantar fasciitis, Achilles tendinopathy, and nerve entrapment can cause similar symptoms. A thorough evaluation is necessary to rule out other possibilities.
