This condition is characterized by a progressive flattening or falling of the arch. It is often referred to as posterior tibial tendon dysfunction (PTTD) and is becoming a more commonly recognized foot problem. Since the condition develops over time, it is typically diagnosed in adulthood. It usually only develops in one foot although it can affect both. Since it is progressive, it is common for symptoms to worsen, especially when it is not treated early. The posterior tibial tendon attaches to the bones on the inside of your foot and is vital to the support structure within the foot. With PTTD, changes in the tendon impair its ability to function normally. The result is less support for the arch, which in turn causes it to fall or flatten. A flattening arch can cause the heel to shift out of alignment, the forefoot to rotate outward, the heel cord to tighten, and possible deformity of the foot. Common symptoms include pain along the inside of the ankle, swelling, an inward rolling of the ankle, pain that is worse with activity, and joint pain as arthritis sets in.
A person with flat feet has greater load placed on the posterior tibial tendon which is the main tendon unit supporting up the arch of the foot. Throughout life, aging leads to decreased strength of muscles, tendons and ligaments. The blood supply diminishes to tendons with aging as arteries narrow. Heavier, obese patients have more weight on the arch and have greater narrowing of arteries due to atherosclerosis. In some people, the posterior tibial tendon finally gives out or tears. This is not a sudden event in most cases. Rather, it is a slow, gradual stretching followed by inflammation and degeneration of the tendon. Once the posterior tibial tendon stretches, the ligaments of the arch stretch and tear. The bones of the arch then move out of position with body weight pressing down from above. The foot rotates inward at the ankle in a movement called pronation. The arch appears collapsed, and the heel bone is tilted to the inside. The deformity can progress until the foot literally dislocates outward from under the ankle joint.
Often, this condition is only present in one foot, but it can affect both. Adult acquired flatfoot symptoms vary, but can swelling of the foot’s inner side and aching heel and arch pain. Some patients experience no pain, but others may experience severe pain. Symptoms may increase during long periods of standing, resulting in fatigue. Symptoms may change over time as the condition worsens. The pain may move to the foot’s outer side, and some patients may develop arthritis in the ankle and foot.
The diagnosis of posterior tibial tendon dysfunction and AAFD is usually made from a combination of symptoms, physical exam and x-ray imaging. The location of pain, shape of the foot, flexibility of the hindfoot joints and gait all may help your physician make the diagnosis and also assess how advanced the problem is.
Non surgical Treatment
Flatfoot can be treated with a variety of methods, including modified shoes, orthotic devices, a brace or cast, anti-inflammatory medications or limited steroid injections, rest, ice, and physical therapy. In severe cases, surgery may be necessary.
Until recently, operative treatment was indicated for most patients with stage 2 deformities. However, with the use of potentially effective nonoperative management , operative treatment is now indicated for those patients that have failed nonoperative management. The principles of operative treatment of stage 2 deformities include transferring another tendon to help serve the role of the dysfunctional posterior tibial tendon (usually the flexor hallucis longus is transferred). Restoring the shape and alignment of the foot. This moves the weight bearing axis back to the center of the ankle. Changing the shape of the foot can be achieved by one or more of the following procedures. Cutting the heel bone and shifting it to the inside (Medializing calcaneal osteotomy). Lateral column lengthening restores the arch and overall alignment of the foot. Medial column stabilization. This stiffens the ray of the big toe to better support the arch. Lengthening of the Achilles tendon or Gastrocnemius. This will allow the ankle to move adequately once the alignment of the foot is corrected. Stage 3 acquired adult flatfoot deformity is treated operatively with a hindfoot fusion (arthrodesis). This is done with either a double or triple arthrodesis – fusion of two or three of the joints in hindfoot through which the deformity occurs. It is important when a hindfoot arthrodesis is performed that it be done in such a way that the underlying foot deformity is corrected first. Simply fusing the hindfoot joints in place is no longer acceptable.