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.
Adult acquired flatfoot is often a complex disorder, with diverse symptoms and varying degrees of deformity and disability. There are several types of flatfoot, all of which have one characteristic in common-partial or total collapse (loss) of the arch. Other characteristics shared by most types of flatfoot include Toe drift, where the toes and front part of the foot point outward. The heel tilts toward the outside and the ankle appears to turn in. A short Achilles tendon or calf muscle, which causes the heel to lift off the ground earlier when walking and may act as a deforming force. In addition, other deformities such bunions and hammertoes can occur and cause pain in people with flexible flatfoot. Health problems such as rheumatoid arthritis, diabetes and obesity can increase the risk of developing flatfoot and may (or may not) make it more difficult to treat. This article provides a brief overview of the problems that can result in AAFD. Further details regarding the most common conditions that cause an acquired flatfoot and their treatment options are provided in separate articles. Links to those articles are provided.
As discussed above, many health conditions can create a painful flatfoot. Damage to the posterior tibial tendon is the most common cause of AAFD. The posterior tibial tendon is one of the most important tendons of the leg. It starts at a muscle in the calf, travels down the inside of the lower leg and attaches to the bones on the inside of the foot. The main function of this tendon is to hold up the arch and support your foot when you walk. If the tendon becomes inflamed or torn, the arch will slowly collapse. Women and people over 40 are more likely to develop problems with the posterior tibial tendon. Other risk factors include obesity, diabetes, and hypertension. Having flat feet since childhood increases the risk of developing a tear in the posterior tibial tendon. In addition, people who are involved in high impact sports, such as basketball, tennis, or soccer, may have tears of the tendon from repetitive use. Inflammatory arthritis, such as rheumatoid arthritis, can cause a painful flatfoot. This type of arthritis attacks not only the cartilage in the joints, but also the ligaments that support the foot. Inflammatory arthritis not only causes pain, but also causes the foot to change shape and become flat. The arthritis can affect the back of the foot or the middle of foot, both of which can result in a fallen arch.
Patients will usually describe their initial symptoms as “ankle pain”, as the PT Tendon becomes painful around the inside of the ankle joint. The pain will become more intense as the foot flattens out, due to the continued stretching and tearing of the PT Tendon. As the arches continue to fall, and pronation increases, the heel bone (Calcaneus) tilts into a position where it pinches against the ankle bone (Fibula), causing pain on both the inside and outside of the ankle. As the foot spends increased time in a flattened, or deformed position, Arthritis can begin to affect the joints of the foot, causing additional pain.
First, both feet should be examined with the patient standing and the entire lower extremity visible. The foot should be inspected from above as well as from behind the patient, as valgus angulation of the hindfoot is best appreciated when the foot is viewed from behind. Johnson described the so-called more-toes sign: with more advanced deformity and abduction of the forefoot, more of the lateral toes become visible when the foot is viewed from behind. The single-limb heel-rise test is an excellent determinant of the function of the posterior tibial tendon. The patient is asked to attempt to rise onto the ball of one foot while the other foot is suspended off the floor. Under normal circumstances, the posterior tibial muscle, which inverts and stabilizes the hindfoot, is activated as the patient begins to rise onto the forefoot. The gastrocnemius-soleus muscle group then elevates the calcaneus, and the heel-rise is accomplished. With dysfunction of the posterior tibial tendon, however, inversion of the heel is weak, and either the heel remains in valgus or the patient is unable to rise onto the forefoot. If the patient can do a single-limb heel-rise, the limb may be stressed further by asking the patient to perform this maneuver repetitively.
Non surgical Treatment
It is imperative that you seek treatment should you notice any symptoms of a falling arch or PTTD. Due to the progressive nature of this condition, your foot will have a much higher chance of staying strong and healthy with early treatment. When pain first appears, your doctor will evaluate your foot to confirm a flatfoot diagnosis and begin an appropriate treatment plan. This may involve rest, anti-inflammatory medications, shoe modifications, physical therapy, orthotics and a possible boot or brace. When treatment can be applied at the beginning, symptoms can most often be resolved without the need for surgery.
In cases of PTTD that have progressed substantially or have failed to improve with non-surgical treatment, surgery may be required. For some advanced cases, surgery may be the only option. Symptomatic flexible flatfoot conditions are common entities in both the adolescent and adult populations. Ligamentous laxity and equinus play a significant role in most adolescent deformities. Posterior tibial tendon dysfunction (PTTD) is the most common cause of adult acquired flatfoot. One should consider surgical treatment for patients who have failed nonoperative therapy and have advancing symptoms and deformities that significantly interfere with the functional demands of daily life. Isolated Joint Fusion. This technique is used for well reducible flat foot by limiting motion at one or two joints that are usually arthritic. The Evans Anterior Calcaneal Osteotomy. This is indicated for late stage II adult acquired flatfoot and the flexible adolescent flatfoot. This procedure will address midtarsal instability, restore the medial longitudinal arch and reduce mild hind foot valgus. The Posterior Calcaneal Displacement Osteotomy (PCDO). This technique is indicated for late stage I and early stage II PTTD with reducible Calcaneal valgus. This is often combined with a tendon transfer. A PCDO is also indicated as an adjunctive procedure in the surgical reconstruction of the severe flexible adolescent flatfoot. Soft tissue procedure. On their own these are not very effective but in conjunction with an osseous procedure, soft tissue procedures can produce good outcome. Common ones are tendon and capsular repair, tendon lengthening and transfer procedures. Flat foot correction requires lengthy post operative period and a lot of patience. Your foot may need surgery but you might simply not have the time or endurance to go through the rehab phase of this type of surgery. We will discuss these and type of procedures necessary for your surgery in length before we go further with any type of intervention.