Adult flatfoot is usually an acquired deformity caused by dysfunction of the tibialis posterior tendon. It often develops gradually and may follow a minor injury or period of overuse.
Symptoms:
• The earliest symptom is pain along the inner (medial) aspect of the ankle.
• If untreated, the condition progresses with:
• Extension of pain to the outer (lateral) side of the ankle
• Gradual collapse of the medial arch resulting in a flatfoot deformity
• In later stages, development of arthritis in the hindfoot joints, particularly the subtalar joint, and occasionally the ankle joint.
Investigations:
Weight-bearing X-rays and MRI scans help determine the stage of the disease, which guides treatment planning.
Early stages (tendon inflammation/dysfunction):
• Steroid with local anaesthetic injection or platelet-rich plasma (PRP) injection into the tendon sheath for pain relief.
• Medial arch supporting insoles
• Physiotherapy to strengthen supporting muscles and improve function
Advanced stages (deformity present):
Pain is often more prominent on the lateral side of the ankle due to impingement and joint overload. It may occur during walking and, in arthritic cases, even at rest.
Non-operative treatment with insoles and occasional injections may provide temporary relief, but definitive management usually requires surgery.
Surgical correction aims to restore alignment and function and typically includes:
• Realignment of the heel
• Restoration of the arch
• Tendon transfer
• Ligament reconstruction (as required)
Recovery:
After surgery, patients remain non-weight-bearing for approximately 4 weeks, followed by gradual protected weight-bearing.
Long-term use of medial arch-supporting insoles is recommended to maintain correction and reduce recurrence risk.
