Adult Aquired FlatFoot

Overview

Dysfunction of the tibialis posterior tendon is a common condition and a common cause of acquired flatfoot deformity in adults. Women older than 40 are most at risk. Patients present with pain and swelling of the medial hindfoot. Patients may also report a change in the shape of the foot or flattening of the foot. The foot develops a valgus heel (the heel rotates laterally when observed from behind), a flattened longitudinal arch, and an abducted forefoot. Conservative treatment includes non-steroidal anti-inflammatory drugs, rest, and immobilisation for acute inflammation; and orthoses to control the more chronic symptoms. Surgical treatment in the early stages is hindfoot osteotomy combined with tendon transfer. Arthrodesis of the hindfoot, and occasionally the ankle, is required in the surgical treatment of the later stages of tibialis posterior dysfunction.Acquired Flat Foot




Causes

There are multiple factors contributing to the development of this problem. Damage to the nerves, ligaments, and/or tendons of the foot can cause subluxation (partial dislocation) of the subtalar or talonavicular joints. Bone fracture is a possible cause. The resulting joint deformity from any of these problems can lead to adult-acquired flatfoot deformity. Dysfunction of the posterior tibial tendon has always been linked with adult-acquired flatfoot deformity (AAFD). The loss of active and passive pull of the tendon alters the normal biomechanics of the foot and ankle. The reasons for this can be many and varied as well. Diabetes, high blood pressure, and prolonged use of steroids are some of the more common causes of adult-acquired flatfoot deformity (AAFD) brought on by impairment of the posterior tibialis tendon. Overstretching or rupture of the tendon results in tendon and muscle imbalance in the foot leading to adult-acquired flatfoot deformity (AAFD). Rheumatoid arthritis is one of the more common causes. About half of all adults with this type of arthritis will develop adult flatfoot deformity over time. In such cases, the condition is gradual and progressive. Obesity has been linked with this condition. Loss of blood supply for any reason in the area of the posterior tibialis tendon is another factor. Other possible causes include bone fracture or dislocation, a torn or stretched tendon, or a neurologic condition causing weakness.




Symptoms

Symptoms are minor and may go unnoticed, Pain dominates, rather than deformity. Minor swelling may be visible along the course of the tendon. Pain and swelling along the course of the tendon. Visible decrease in arch height. Aduction of the forefoot on rearfoot. Subluxed tali and navicular joints. Deformation at this point is still flexible. Considerable deformity and weakness. Significant pain. Arthritic changes in the tarsal joints. Deformation at this point is rigid.




Diagnosis

Clinicians need to recognize the early stage of this syndrome which includes pain, swelling, tendonitis and disability. The musculoskeletal portion of the clinical exam can help determine the stage of the disease. It is important to palpate the posterior tibial tendon and test its muscle strength. This is tested by asking patient to plantarflex and invert the foot. Joint range of motion is should be assessed as well. Stiffness of the joints may indicate longstanding disease causing a rigid deformity. A weightbearing examination should be performed as well. A complete absence of the medial longitudinal arch is often seen. In later stages the head of the talus bone projects outward to the point of a large "lump" in the arch. Observing the patient's feet from behind shows a significant valgus rotation of the heel. From behind, the "too many toes" sign may be seen as well. This is when there is abducution of the forefoot in the transverse plane allowing the toes to be seen from behind. Dysfunction of the posterior tibial tendon can be assessed by asking the patient to stand on his/her toes on the affected foot. If they are unable to, this indicates the disease is in a more advanced stage with the tendon possibly completely ruptured.




Non surgical Treatment

Nonoperative therapy for posterior tibial tendon dysfunction has been shown to yield 67% good-to-excellent results in 49 patients with stage 2 and 3 deformities. A rigid UCBL orthosis with a medial forefoot post was used in nonobese patients with flexible heel deformities correctible to neutral and less than 10? of forefoot varus. A molded ankle foot orthosis was used in obese patients with fixed deformity and forefoot varus greater than 10?. Average length of orthotic use was 15 months. Four patients ultimately elected to have surgery. The authors concluded that orthotic management is successful in older low-demand patients and that surgical treatment can be reserved for those patients who fail nonoperative treatment.

Acquired Flat Foot




Surgical Treatment

Surgery is usually performed when non-surgical measures have failed. The goal of surgery is to eliminate pain, stop progression of the deformity and improve a patient?s mobility. More than one technique may be used, and surgery tends to include one or more of the following. The tendon is reconstructed or replaced using another tendon in the foot or ankle The name of the technique depends on the tendon used. Flexor digitorum longus (FDL) transfer. Flexor hallucis longus (FHL) transfer. Tibialis anterior transfer (Cobb procedure). Calcaneal osteotomy - the heel bone may be shifted to bring your heel back under your leg and the position fixed with a screw. Lengthening of the Achilles tendon if it is particularly tight. Repair one of the ligaments under your foot. If you smoke, your surgeon may refuse to operate unless you can refrain from smoking before and during the healing phase of your procedure. Research has proven that smoking delays bone healing significantly.

Write a comment

Comments: 0