What is a flat foot?
A flat foot is a decrease in the medial arch of your foot, which can be congenital or acquired. An acquired flat foot is called posterior tibial tendon dysfunction, which occurs over time as the posterior tibial tendon undergoes damage and decreases in function.
How to diagnose a flatfoot?
A flat foot can be diagnosed clinically and X-rays are done to help determine the severity of the flat foot. Clinical tests are done to assess the flexibility/rigidity (Classification: Johnson and Strom) of the deformity such as examining the range of motion/pain in joints and the integrity of the posterior tibial tendon (heel rise test). Some other ther clinical exams such as calcaneal inversion, windlass mechanism, silfverskiold exam are done. An MRI is often done to evaluate the integrity of the posterior tibial tendon, spring ligament, deltoid, and amount of arthritis in a joint.
How to treat a flatfoot?
Conservative treatment involves athletic supportive shoes, physical therapy, inserts, custom orthotics, and bracing.
Surgery can be done and must be tailored to the patient based on clinical exam and imaging results. Surgery involves bone cuts/fusions, tendon transfers/lengthening, and/or ligament repair. Some common procedures for a flexible flat foot are lateral column lengthening (evans), medial displacement calcaneal osteotomy (koutsogiannis), plantarflexory first ray procedure (lapidus/cotton), gastrocnemius recession (strayer/baumann), and FDL transfer. A rigid flatfoot is often treated with fusion of the subtalar and talonavicular joint with a gastrocrecession. Additionally, the ankle may develop arthritis/talar tilt in severe deformity which requires further advanced procedures such as tibiotalocalcaneal/pantalar fusion or total ankle replacement/deltoid reconstruction.
Video of evans, kouts, and cotton: https://www.youtube.com/watch?v=t0lRBj6YevQ