Adult Aquired Flat Foot
Flatfoot deformity is a general term used to describe a person whose arches are slowly dropping to the ground, aka ?fallen arches.? Adult-acquired flatfoot deformity can be caused by several factors, but the most common is abnormal functioning of the posterior tibial tendon in the foot and ankle. The posterior tibial tendon is the primary tendon that supports the arch. If this tendon begins to elongate from a sustained, gradual stretch over a long period of time, then the arch will progressively decrease until full collapse of the arch is noted on standing. What makes this tendon elongated? Biomechanical instability of the foot such as over-pronation or an accessory bone at the insertion site of the tendon are the primary causes for posterior tibial tendon dysfunction.
Posterior tibial tendon dysfunction is the most common cause of acquired adult flatfoot. Sometimes this can be a result of specific trauma, but usually the tendon becomes injured from wear and tear over time. This is more prevalent in individuals with an inherited flat foot but excessive weight, age, and level of activity are also contributing factors.
Symptoms of pain may have developed gradually as result of overuse or they may be traced to one minor injury. Typically, the pain localizes to the inside (medial) aspect of the ankle, under the medial malleolus. However, some patients will also experience pain over the outside (lateral) aspect of the hindfoot because of the displacement of the calcaneus impinging with the lateral malleolus. This usually occurs later in the course of the condition. Patients may walk with a limp or in advanced cases be disabled due to pain. They may also have noticed worsening of their flatfoot deformity.
The diagnosis of tibialis posterior dysfunction is essentially clinical. However, plain radiographs of the foot and ankle are useful for assessing the degree of deformity and to confirm the presence or absence of degenerative changes in the subtalar and ankle articulations. The radiographs are also useful to exclude other causes of an acquired flatfoot deformity. The most useful radiographs are bilateral anteroposterior and lateral radiographs of the foot and a mortise (true anteroposterior) view of the ankle. All radiographs should be done with the patient standing. In most cases we see no role for magnetic resonance imaging or ultrasonography, as the diagnosis can be made clinically.
Non surgical Treatment
Because of the progressive nature of PTTD, early treatment is advised. If treated early enough, your symptoms may resolve without the need for surgery and progression of your condition can be arrested. In contrast, untreated PTTD could leave you with an extremely flat foot, painful arthritis in the foot and ankle, and increasing limitations on walking, running, or other activities. In many cases of PTTD, treatment can begin with non-surgical approaches that may include orthotic devices or bracing. To give your arch the support it needs, your foot and ankle surgeon may provide you with an ankle brace or a custom orthotic device that fits into the shoe. Immobilization. Sometimes a short-leg cast or boot is worn to immobilize the foot and allow the tendon to heal, or you may need to completely avoid all weight-bearing for a while. Physical therapy. Ultrasound therapy and exercises may help rehabilitate the tendon and muscle following immobilization. Medications. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, help reduce the pain and inflammation. Shoe modifications. Your foot and ankle surgeon may advise changes to make with your shoes and may provide special inserts designed to improve arch support.
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.