Rigid Flatfoot Deformities: Overview

Rigid Flatfoot Deformities: Overview

This video will provide an overview of rigid flatfoot deformities in adults. It is important to recognize that flatfoot deformities occur on a spectrum. Rigid deformities are a more advanced form of this condition. The various stages of flatfoot deformities have been a topic of debate in the field, and thus other names to describe the condition may be used, such as progressive collapsing foot deformity or posterior tibial tendon dysfunction.

A rigid flatfoot deformity is a late-stage flatfoot deformity in which the alignment in the foot cannot be moved into a normal position in an examination. In this condition, the flatfoot has progressed to a point in which there is also malalignment in multiple joints in the foot. In the most advanced stage of rigid flatfoot deformity, the ankle joint is also involved and misaligned. Arthritis may be present in the foot and ankle joints in rigid deformities.

Flatfoot deformities are common. Studies have shown the condition is present in approximately a quarter of the population. Flatfoot deformity is more common in women over 40 and those with diabetes and obesity. Patients with loss of sensation in the feet, those with arthritic conditions, and those with soft tissue laxity are at higher risk for this condition.

While some people can be born with flat feet, it can also occur over time and is most commonly the result of repetitive microtears to the posterior tibial tendon. This tendon arises from a muscle in the calf and passes by the medial, or inside ankle, where it finally attaches to the arch of the foot. This tendon helps support the arch and when damaged over time, support will be lost. While this tendon is most likely to contribute to this problem, there are other soft-tissue structures that can lead to the progressive changes seen. The alignment of the bones will also change, which contributes to the overall deformity.

Patients who have rigid flatfoot deformities that have progressed may not have the inner ankle and foot pain seen with flexible or earlier-stage deformities. Typically, the pain has now shifted to the outside ankle where there is pinching due to the shifted bones. Pain may also occur at rest. Patients may appreciate a visible deformity in the appearance of their foot or a loss of motion in the foot that may prohibit walking.

A thorough history of the patient's medical health will be completed to determine if they are at risk for this condition. In rigid flatfoot deformities, a patient will be unable to do a test called a single heel raise which is commonly assessed in this condition. A health care provider will also closely assess the mobility of the patient's foot and ankle to confirm the deformity will not move into a normal position. In more severe cases, a provider will look for wounds related to the abnormal pressure of the shifting bones.

X-rays will be ordered to assess the alignment of the bones in the feet to accurately stage the condition. A CT scan may be ordered ahead of any surgery to look closely at the bone changes. MRI or ultrasound may also be ordered to assess for inflammation around the soft tissues. Following a careful history, examination, and review of imaging, a health care provider will determine the best treatment options for the patient.