Adult-acquired flatfoot or collapsed arch occurs because the large tendon on the inside of the ankle – the posterior tibial tendon – becomes stretched out and no longer supports the foot?s arch. In many cases, the condition worsens and and the tendon thickens, becoming painful, especially during activities. Flatfoot or collapsed arch is also known as posterior tibial tendon dysfunction. This condition is different than having flat feet since birth (known as congenital flatfoot), although sometimes these patients develop similar symptoms and require similar treatments.
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.
Some symptoms of adult acquired flat foot are pain along the inside of the foot and ankle, pain that increases with activity, and difficulty walking for long periods of time. You may experience difficulty standing, pain on the outside of the ankle, and bony bumps on the top of the foot and inside the foot. You may also have numbness and tingling of the feet and toes (may result from large bone spurs putting pressure on nerves), swelling, a large bump on the sole of the foot and/or an ulcer (in diabetic patients). Diabetic patients should wear a properly fitting diabetic shoe wear to prevent these complications from happening.
In diagnosing flatfoot, the foot & Ankle surgeon examines the foot and observes how it looks when you stand and sit. Weight bearing x-rays are used to determine the severity of the disorder. Advanced imaging, such as magnetic resonance imaging (MRI) and computed tomography (CAT or CT) scans may be used to assess different ligaments, tendons and joint/cartilage damage. The foot & Ankle Institute has three extremity MRI?s on site at our Des Plaines, Highland Park, and Lincoln Park locations. These extremity MRI?s only take about 30 minutes for the study and only requires the patient put their foot into a painless machine avoiding the uncomfortable Claustrophobia that some MRI devices create.
Non surgical Treatment
Nonoperative therapy for adult-acquired flatfoot is a reasonable treatment option that is likely to be beneficial for most patients. In this article, we describe the results of a retrospective cohort study that focused on nonoperative measures, including bracing, physical therapy, and anti-inflammatory medications, used to treat adult-acquired flatfoot in 64 consecutive patients. The results revealed the incidence of successful nonsurgical treatment to be 87.5% (56 of 64 patients), over the 27-month observation period. Overall, 78.12% of the patients with adult-acquired flatfoot were obese (body mass index [BMI] = 30), and 62.5% of the patients who failed nonsurgical therapy were obese; however, logistic regression failed to show that BMI was statistically significantly associated with the outcome of treatment. The use of any form of bracing was statistically significantly associated with successful nonsurgical treatment (fully adjusted OR = 19.8621, 95% CI 1.8774 to 210.134), whereas the presence of a split-tear of the tibialis posterior on magnetic resonance image scans was statistically significantly associated with failed nonsurgical treatment (fully adjusted OR = 0.016, 95% CI 0.0011 to 0.2347). The results of this investigation indicate that a systematic nonsurgical treatment approach to the treatment of the adult-acquired flatfoot deformity can be successful in most cases.
If conservative treatment fails to provide relief of pain and disability then surgery is considered. Numerous factors determine whether a patient is a surgical candidate. They include age, obesity, diabetes, vascular status, and the ability to be compliant with post-operative care. Surgery usually requires a prolonged period of nonweightbearing immobilization. Total recovery ranges from 3 months to one year. Clinical, x-ray, and MRI examination are all used to select the appropriate surgical procedure.