Overview Adult acquired flatfoot deformity or posterior tibial tendon dysfunction is a gradual but progressive loss of ones arch. The posterior tibial muscle is a deep muscle in the back of the calf. It has a long tendon that extends from above the ankle and attaches into several sites around the arch of the foot. The muscle acts like a stirrup on the inside of the foot to help support the arch. The posterior tibial muscle stabilizes the arch and creates a rigid platform for walking and running. If the posterior tibial tendon becomes damaged or tears the arch loses its stability and as a result, collapses causing a flatfoot. Adult flatfoot deformity can occur in people of all ages and gender however, it occurs most commonly in sedentary middle aged to elderly females. There are several risk factors for posterior tibial tendon dysfunction that include: obesity, steroid use, systemic inflammatory diseases such as rheumatoid arthritis, trauma, being born with a low arch, and diabetes. It occurs most commonly in one foot however, it can occur in both feet especially in people with systemic diseases such as diabetes and rheumatoid arthritis. Causes Adult flatfoot typically occurs very gradually. If often develops in an obese person who already has somewhat flat feet. As the person ages, the tendons and ligaments that support the foot begin to lose their strength and elasticity. Symptoms Posterior tibial tendon insufficiency is divided into stages by most foot and ankle specialists. In stage I, there is pain along the posterior tibial tendon without deformity or collapse of the arch. The patient has the somewhat flat or normal-appearing foot they have always had. In stage II, deformity from the condition has started to occur, resulting in some collapse of the arch, which may or may not be noticeable. The patient may feel it as a weakness in the arch. Many patients initially present in stage II, as the ligament failure can occur at the same time as the tendon failure and therefore deformity can already be occurring as the tendon is becoming symptomatic. In stage III, the deformity has progressed to the extent where the foot becomes fixed (rigid) in its deformed position. Finally, in stage IV, deformity occurs at the ankle in addition to the deformity in the foot. Diagnosis Perform a structural assessment of the foot and ankle. Check the ankle for alignment and position. When it comes to patients with severe PTTD, the deltoid has failed, causing an instability of the ankle and possible valgus of the ankle. This is a rare and difficult problem to address. However, if one misses it, it can lead to dire consequences and potential surgical failure. Check the heel alignment and position of the heel both loaded and during varus/valgus stress. Compare range of motion of the heel to the normal contralateral limb. Check alignment of the midtarsal joint for collapse and lateral deviation. Noting the level of lateral deviation in comparison to the contralateral limb is critical for surgical planning. Check midfoot alignment of the naviculocuneiform joints and metatarsocuneiform joints both for sag and hypermobility. Non surgical Treatment The adult acquired flatfoot is best treated early. Accurate assessment by your doctor will determine which treatment is suitable for you. Reduce your level of activity and follow the RICE regime. R - rest as often as you are able. Refrain from activity that will worsen your condition, such as sports and walking. I - ice, apply to the affected area, ensure you protect the area from frostbite by applying a towel over the foot before using the ice pack. C - compression, a Tubigrip or elasticated support bandage may be applied to relieve symptoms and ease pain and discomfort. E - elevate the affected foot to reduce painful swelling. You will be prescribed pain relief in the form of non-steroidal antiinflammatory medications (if you do not suffer with allergies or are asthmatic). Immobilisation of your affected foot - this will involve you having a below the knee cast for four to eight weeks. In certain circumstances it is possible for you to have a removable boot instead of a cast. A member of the foot and ankle team will advise as to whether this option is suitable for you. Footwear is important - it is advisable to wear flat sturdy lace-up shoes, for example, trainers or boots. This will not only support your foot, but will also accommodate orthoses (shoe inserts). Surgical Treatment For those patients with PTTD that have severe deformity or have not improved with conservative treatments, surgery may be necessary to return them to daily activity. Surgery for PTTD may include repair of the diseased tendon and possible tendon transfer to a nearby healthy tendon, surgery on the surrounding bones or joints to prevent biomechanical abnormalities that may be a contributing factor or both.