Question
A 60 year old obese woman has medial ankle pain and a flattening foot. She cannot perform a single leg heel rise.
- What is the diagnosis and pathology?
- How is it classified?
- Outline management by stage.
Answer
Diagnosis and pathology
- Progressive collapsing foot deformity from tibialis posterior tendon dysfunction
- Degeneration in the hypovascular zone behind the medial malleolus
- Spring ligament and deltoid failure follow, with hindfoot valgus, forefoot abduction and midfoot collapse
- Too many toes sign and failure of the heel to invert on heel rise
Classification
- Johnson and Strom stages I to III, with Myerson adding stage IV ankle valgus
- Stage I tenosynovitis, stage II flexible flatfoot, stage III fixed hindfoot valgus, stage IV deltoid failure with ankle valgus
- 2020 consensus classification of progressive collapsing foot deformity describes each component separately
Management
- Stage I, boot immobilisation, orthoses and physiotherapy, with tenosynovectomy if needed
- Stage II, FDL transfer with medialising calcaneal osteotomy, plus lateral column lengthening, spring ligament repair or a Cotton osteotomy as needed
- Stage III, triple arthrodesis
- Stage IV, triple arthrodesis with deltoid reconstruction, or tibiotalocalcaneal fusion
Related pages
Author Contributions
Orthofracs team
Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.