A Painful Flat foot occurs due to tearing of the the Tibialis Posterior Tendon and the ligaments of the foot associated with a flattened arch. Conservative measures often are inadequate and symptoms and severity progress.
Surgery aims to treat the torn tendon and reinforce the arch and alignment of the foot with a good outcome expected in 90% of cases.
Flat Foot Reconstruction
In most cases the tendon itself is repaired and needs to be strengthened by using another tendon, flexor digitorum longus (FDL). This tendon lies alongside tibialis posterior at the ankle and bends the small joints of the toes. Other tendons for the small toes compensate after it is transferred. The main ligament, the spring ligament is repaired and reinforced.
To improve the biomechanics the heel bone is moved towards the inside of the foot (calcaneal osteotomy) and held with one screw. This is done with a minimally invasive technique. Often a small screw, termed an arthroereisis screw is placed in the sinus tarsi which also supports the mechanical alignment.
In advanced cases stiffness or arthritis can develop. Reconstruction is not appropriate and a fusion of the joints of the hind foot and arch is performed. These joints (subtalar, talo-navicular, and calcaneo-cuboid) are joined together with screws and / or plates. This is known as a triple fusion. This is effective in pain relief, however the ankle loses its side to side and rotatory motion.
Post Operative Recovery
The recovery from tendon reconstruction or fusion surgery is lengthy. The ankle is in a cast for 6 weeks, followed by a CAM boot for 6 weeks, before a rehabilitation program as directed by your physiotherapist.
The risks and complications will be discussed with you. There is a small risk of wound issues, infection, numbness and deep vein thrombosis. Specific risks include progressive arthritis requiring further surgery or fusion. A proportion of patients require the screws to be removed as a day procedure after recovery at the 6 month stage.