Adult acquired flat foot
was first described in the late 1960s as something that
occurred after trauma, as a result of a tear to the tibial posterior tendon. However, by 1969 two doctors called Kettlekamp and Alexander described cases in which no trauma had taken place. They
referred to the condition as "tibial posterior tendon dysfunction" and this became known as the most common type of adult acquired flat foot.
The posterior tibial tendon, which connects the bones inside the foot to the calf, is responsible for supporting the foot during movement and holding up the arch. Gradual stretching and tearing of
the posterior tibial tendon can cause failure of the ligaments in the arch. Without support, the bones in the feet fall out of normal position, rolling the foot inward. The foot's arch will collapse
completely over time, resulting in adult acquired flatfoot. The ligaments and tendons holding up the arch can lose elasticity and strength as a result of aging. Obesity, diabetes, and hypertension
can increase the risk of developing this condition. Adult acquired flatfoot is seen more often in women than in men and in those 40 or older.
The first stage represents inflammation and symptoms originating from an irritated posterior tibial tendon, which is still functional. Stage two is characterized by a change in the alignment of the
foot noted on observation while standing (see above photos). The deformity is supple meaning the foot is freely movable and a ?normal? position can be restored by the examiner. Stage two is also
associated with the inability to perform a single-leg heel rise. The third stage is dysfunction of the posterior tibial tendon is a flatfoot deformity that becomes stiff because of arthritis.
Prolonged deformity causes irritation to the involved joints resulting in arthritis. The fourth phase is a flatfoot deformity either supple (stage two) or stiff (stage 3) with involvement of the
ankle joint. This occurs when the deltoid ligament, the major supporting structure on the inside of the ankle, fails to provide support. The ankle becomes unstable and will demonstrate a tilted
appearance on X-ray. Failure of the deltoid ligament results from an inward displacement of the weight bearing forces. When prolonged, this change can lead to ankle arthritis. The vast majority of
patients with acquired adult flatfoot deformity are stage 2 by the time they seek treatment from a physician.
Observe forefoot to hindfoot alignment. Do this with the patient sitting and the heel in neutral, and also with the patient standing. I like to put blocks under the forefoot with the heel in neutral
to see how much forefoot correction is necessary to help hold the hindfoot position. One last note is to check all joints for stiffness. In cases of prolonged PTTD or coalition, rigid deformity is
present and one must carefully check the joints of the midfoot and hindfoot for stiffness and arthritis in the surgical pre-planning.
Non surgical Treatment
Non-surgical treatment includes rest and reducing your activity until the pain improves. Orthotics or bracing help support the tendon to reduce its pull along the arch, thus reducing pain. In
moderate to severe cases, a below knee cast or walking boot may be needed to allow the tendon to rest completely and heal. Physical therapy is an integral part of the non-surgical treatment regimen
to reduce inflammation and pain. Anti-inflammatory medication is often used as well. Many times evaluation of your current shoes is necessary to ensure you are wearing appropriate shoe gear to
The indications for surgery are persistent pain and/or significant deformity. Sometimes the foot just feels weak and the assessment of deformity is best done by a foot and ankle specialist. If
surgery is appropriate, a combination of soft tissue and bony procedures may be considered to correct alignment and support the medial arch, taking strain off failing ligaments. Depending upon the
tissues involved and extent of deformity, the foot and ankle specialist will determine the necessary combination of procedures. Surgical procedures may include a medial slide calcaneal osteotomy to
correct position of the heel, a lateral column lengthening to correct position in the midfoot and a medial cuneiform osteotomy or first metatarsal-tarsal fusion to correct elevation of the medial
forefoot. The posterior tibial tendon may be reconstructed with a tendon transfer. In severe cases (stage III), the reconstruction may include fusion of the hind foot,, resulting in stiffness of the
hind foot but the desired pain relief. In the most severe stage (stage IV), the deltoid ligament on the inside of the ankle fails, resulting in the deformity in the ankle. This deformity over time
can result in arthritis in the ankle.