Posterior Tibial Tendon Dysfunction (Adult Acquired Flatfoot)

Posterior tibial tendon dysfunction is a gradual flattening of the arch caused by failure of the main tendon that supports it, also called progressive collapsing foot deformity or adult acquired flatfoot. Early cases are usually managed well with orthoses and bracing.

Posterior tibial tendon dysfunction (PTTD) — also called progressive collapsing foot deformity or adult acquired flatfoot — occurs when the posterior tibial tendon, the main support of the arch, becomes inflamed, weakened or torn. The arch gradually flattens, and without support the deformity can progress and involve the ankle. It is more common in women, in people over 40, and with obesity, diabetes or hypertension.

Assessment is largely clinical, supported by weight-bearing X-rays and, where the tendon needs evaluating, ultrasound or MRI. An important early sign is difficulty rising onto the toes on one leg, and whether the foot is still flexible guides treatment.

Management is initially non-surgical and focuses on supporting the arch and offloading the tendon — orthoses, bracing, supportive footwear, calf stretching, activity modification and weight management — usually coordinated with podiatry and physiotherapy. A cortisone injection into the tendon is avoided because of rupture risk. Referral to a foot and ankle surgeon is appropriate when the deformity is progressing or pain is not settling, as reconstruction is complex and recovery prolonged.

Common symptoms

Pain and swelling along the inside of the foot and ankle
A flattening arch, often with the foot pointing outward
Weakness or pain when pushing off or standing on the toes
Later, pain on the outside of the ankle as the heel shifts

Evidence-informed treatment summary

How our treatment options may fit for Posterior Tibial Tendon Dysfunction (Adult Acquired Flatfoot)

The options below include the treatments offered at The Back Pain Doctor. Listing a treatment does not mean it is recommended for this condition. The evidence, likely benefit and role of each option are considered against the diagnosis, examination findings, imaging where appropriate, patient goals, risks, cost and alternatives.

Foundation

Diagnosis, education and progressive rehabilitation

This is the starting point for most musculoskeletal conditions.

The priority is to identify the likely pain generator, explain the condition clearly, modify aggravating load and build a realistic plan to restore strength, movement and confidence.

Condition-dependent

Focused / radial shockwave therapy

Evidence is condition-specific; it is not a universal pain treatment.

Shockwave is best framed as an adjunct where the diagnosis fits. It is generally more established for selected tendon and plantar heel pain presentations than for many joint or nerve conditions.

Selected cases

Platelet-rich plasma (PRP)

Evidence varies substantially by condition, tissue and preparation method.

PRP may be discussed in selected tendon or joint presentations. It should not be presented as a guaranteed regenerative treatment, and uncertainty, cost and alternatives should be discussed.

Symptom relief

Image-guided corticosteroid / local anaesthetic injection

Best used for specific inflammatory or irritable pain generators, usually for short-term relief.

An injection may help when a joint, bursa, tendon sheath or other defined structure is driving symptoms. It is not a cure and needs to be weighed against risks, recurrence and the need for rehabilitation.

Emerging adjunct

EMTT / magnetotransduction

Clinical evidence is still developing and guideline support is limited.

EMTT may be discussed as an adjunct in selected presentations, but should be presented with clear uncertainty and never as a replacement for diagnosis, load management or rehabilitation.

Selected cases

Prolotherapy

Evidence is condition-specific and generally less established than exercise-based care.

Prolotherapy may be considered in carefully selected chronic ligament, tendon or joint-related pain presentations, but it is not a first-line treatment.

Pain modulator

Trigger point / myofascial treatment

Most relevant when focal myofascial pain is a clear contributor.

Trigger point treatment may reduce pain from focal muscle spasm or myofascial tenderness. It should be paired with movement restoration, strength work and recurrence prevention.

Nerve-specific

Nerve-focused treatment / hydrodissection

Relevant only when the history and examination support nerve irritation or entrapment.

Nerve-focused treatment may be discussed when there is a plausible peripheral nerve pain generator. Progressive weakness, major neurological deficit or red flags require a different pathway.

This is general information only. Suitability is assessed individually. Treatments with limited or condition-dependent evidence may still be discussed, but only with clear explanation of uncertainty, expected benefit, risks, cost and alternatives. Red flags, progressive neurological symptoms or suspected serious pathology require a different pathway.

Frequently asked questions

How is it diagnosed?

Assessment is clinical, looking for tenderness along the tendon, a collapsing arch when standing, the "too many toes" sign, and difficulty with a single-leg heel raise. Weight-bearing X-rays assess alignment, and ultrasound or MRI can evaluate the tendon where needed.

Can it be treated without surgery?

Most people, especially early on, are managed without surgery — supportive footwear, orthoses, bracing, calf stretching, activity modification and weight management. Simple analgesia may help; a cortisone injection into the tendon is generally avoided because of the risk of rupture.

Why is early treatment important?

A flexible flatfoot is much easier to manage than a rigid, arthritic one. Recognising and supporting the foot early can relieve symptoms and may help delay or avoid surgery.

Ready for a clearer plan for your back or musculoskeletal pain?

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Your assessment focuses on understanding the likely source of your pain and the most appropriate non-surgical options for your diagnosis, with the aim of reducing pain and improving function.

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