In this section Cypress Foot and Ankle expert Dr. Christopher Correa describes what a bunion is and discusses causes and treatments for bunions. What is a bunion? When most people think of bunions they think of a bump at the base of the big toe either on the side or on the top. Bumps that form on the top are typically due to arthritis and may or may not be associated with mal alignment of the big toe joint. When the bump forms on the side it is typically part of a tri-planar mal alignment of the big toe joint. While the “bump” is an integral part of the bunion in reality a bunion is a mechanical mal alignment of the big toe joint which causes the 1st metatarsal to deviate away from the foot and the big toe to encroach on the 2nd toe. This is better known as Hallux Abducto Valgus (HAV).
Understanding how Bunions form
As with most orthopedic deformities the symptoms of a bunion range from mild to severe and develop slowly over time. Not all bunions are painful or severe enough to require surgery however no bunion can be corrected without some kind of surgery. Magazines that sell braces or strapping methods that claim to “correct your bunion while you sleep” may temporarily correct the deformity while the device is applied to the foot but unfortunately do not provide any long-lasting correction. This is because they do not address the underlying issue of mid foot instability and muscular imbalance that lead to the deformity in the first place. You see, HAV is a dynamic deformity meaning it is one that develops during the gait cycle from excessive or "out of phase" muscle contractions caused when the body tries to stabilize an unstable mid foot. This instability may be inherent from the boney structure (congenital) or developed over time from factors such as poor shoe gear choice (high heels) and or tight calf muscles. These imbalances compound over time to create a slowly progressing deformity that can become quite severe and debilitating. That being said, not all bunions are painful. Some patients develop bunions and are able to alleviate their symptoms with orthotics and proper shoe gear for many years and never require surgery. Some of the nastiest bunions I have ever seen have been on 90 year or patients who have had their bunions for 4 decades or more and never bothered to have surgery. When asked why they typically reply with something to the effect of “As long as I wore wide shoes it never bothered me, so I left it alone”. In other cases, bunions continue to be painful in spite of conservative care. These patients typically complain of pain at the bump itself when wearing any kind of shoe, pain at the big toe joint with prolonged walking, tiredness, mid foot cramping at the medial arch from mid foot instability and even pain in the ball of the foot under the 2nd metatarsal head. To understand where this pain comes from let’s take a brief look at foot mechanics. Please use the below images for understanding the relevant anatomy.
Red box = 1st ray. Green box = 2nd ray
Red arrow hallux (Big toe), Blue arrow = 1st metatarsal head, Green arrow = 2nd metatarsal head
The foot is in essence a tri pod with a longitudinal and transverse arch. During stance and toe off phase of the gait cycle the foot goes from a relatively flattened position (pronated) to a higher arched position (supinated). During this process the mid foot locks and serves as a rigid lever to push off from propelling the body forward. In feet with mid foot instability resupination is difficult or absent in this phase and instead what happens is dorsiflexion or elevation of the 1st metatarsal and overloading of the 2nd metatarsal head. In an effort to stabilize the mid foot and prevent inappropriate dorsiflexion the muscles in the plantar arch fire longer and harder than normal leading to the gradual development of deformity both at the big to joint and the lesser digits. Typically, this is a slow process than develops over months to years however in special circumstances bunions can develop rather quickly. While most bunions do not tend to appear until the 4th or 5th decade of life, in some cases children can develop them at a young age.
Treatments for Bunions
As mentioned before, while treating HAV conservatively is possible there are no conservative methods to reversing bunion deformity. Pain that cannot be controlled with conservative methods then usually requires surgical intervention. Bunion surgery traditionally has fallen into 2 categories – mid foot or head procedures. Head procedures usually involve rebalancing of the ligamentous structures surrounding the metatarsal head combined with a distal osteotomy (bone cut) to shift the head of the metatarsal over. These procedures usually require a less intensive recovery but are primarily used in patients with less deformity and no mid foot instability. Moderate to severe bunions or bunions with excessive mid foot instability usually require a base procedure typically in the form of an arthrodesis (joint fusion) of the 1st tarsometatarsal joint located at the base of the 1st metatarsal. The recovery from this surgery is longer than a head procedure but allows for better alignment of the metatarsal and has a lower recurrence rate. Surgical planning is extremely nuanced and required an in-person evaluation of your feet and relevant imaging. If you are suffering from bunions give the experts at Select Foot and Ankle Specialists a call and take the first step towards recovery today!
