Hallux Valgus (Bunion Deformity)

What is it?

A bunion is essentially a shift of the toe bones into the improper position causing pain and loss of function. The deformity involves the big toe and the long bone behind the big toe, the 1st metatarsal. Over time, the 1st metatarsal will begin to move towards the other foot (medial) while the big toe will move out of joint towards the 2nd toe (lateral). Now that the end of the 1st metatarsal bone is sticking out, it will be under pressure from shoes and the ground. This constant pressure and friction will cause extra bone formation, leading to the bump that is seen on the side of the foot. The big toe will continue to shift towards the second toe causing an unbalanced big toe joint. Over time arthritis can develop in the joint due to the mal-positioned joint. A bunion deformity is always progressive. It will always get worse over time.

Causes:

Bunions are usually a genetic deformity. There is an imbalance of the muscles and the ligaments that are holding the 1st metatarsal in place. As this joint becomes weaker over time, the long metatarsal bone will begin to shift medially. The big toe is then under stress and begins to shift laterally under the pressure of the joint and shoes. Shoes with a tight and narrow toe box can help to create and make a bunion worse over time. High heeled shoes can also worsen and cause a bunion. Patients will a flat foot type (pronation) have a higher chance of having a bunion in the future.

Symptoms:

A bunion deformity does not always have to be associated with pain. Some patients have a very severe deformity and no pain, while others with a mild deformity have severe pain. Patients usually will have pain right over the bump with continued irritation and bruising to the bone from shoe gear and the ground forces. As the deformity progresses, pain will then be noticed in the joint itself when the big toe is moving. The big toe is very important during the gait cycle for pushing off the ground. With this imbalance of the joint there is a loss of the proper range of motion of the big toe joint leading to an inefficient gait. Over time arthritis will develop in the joint as the cartilage is scraped away each time the joint moves. The pain can be of different degrees depending on the degree of deformity, shoe gear, and activity level.

Diagnosis:

A clinical examination of the foot is done first. It is very important that the structure and biomechanics of the patient’s entire foot is examined. In order to identify the severity of the deformity, the stability of the joints around the bones involved is essential. The doctor will analyze the gait pattern of the patient. The doctor will identify if there is pain with joint movement and if the big toe can easily be re-located back into the joint. X-ray evaluation is essential in order to determine the degree of the bone shift and specific angles and the relationships between the bones.

Treatment:

Conservative treatments for bunions are limited. Wider shoe gear and accommodation for the deformity can be used to take the pressure off the area. Bracing and spacers are often used to brace the big toe back into position and can take some of the pressure of the big toe. However, this does not address the deformity and shift in the metatarsal bone. Furthermore, the bracing techniques are only work when used, once the brace is removed, the big toe will immediately go back into its deformed position. Custom molded Orthotics can take some pressure off the big toe and redistribute the forces of the ground through the rest of the foot. Orthotics can slow the progression of the deformity. There is no way to stop the progression or reverse the deformity without literally moving the bones back into the correct position and realigning the joint. This can only be accomplished through surgery.

The Foot and Ankle Institute has performed a great deal of research into the proper treatment of bunion deformities. Many years ago, it was thought that bunions were overgrowths of bone. Removal of the painful bunion or "bump" prominence resulted in improvement for only a short period of time and the bunion would return rapidly because the joint was not realigned. Now we know that in order to realign the joint, the first metatarsal must be repositioned and fixated in the proper position. This can be accomplished by two basic types of procedures. The Offset Austin and Lapidus bunionectomy are the ideal procedures as they limit the chance of the bunion deformity from returning.

The choice of the procedure to be performed will be dictated by the severity of the deformity.

Mild Bunion Deformity

Bunion Deformity	Basic Correction
X-ray of a mild bunion with small angle between first and second metatarsal and between the first metatarsal and the big toe.	Basic correction with screw fixation after the head of the bone has been shifted and the angle closed.

Severe Bunion Deformity

X-ray of a severe bunion with large angle between the first and second metatarsal and between the first metatarsal and the big toe.	Clinical photo of a severe bunion deformity.
Elevation of the 1st metatarsal is noted (Yellow line is ideal, while red is 1st metatarsal)	Picture showing instability at the first metatarsal cuneiform joint. Notice the first metatarsal higher than the lesser metatarsals.
Correction of a severe bunion at the first metatarsal cuneiform joint. The large angles are reduced and the instability permanently stabilized.	The first metatarsal is brought down to the ground for ideal alignment and added foot stability.

The underlying cause of severe bunions is thought to be at the medial cuneiform joint and not at the great toe joint. If there is looseness of the medial cuneiform joint, there is motion of the metatarsal allowing the metatarsal to move out of position resulting in a bunion. The metatarsal may also move up resulting in poor position on the ground and collapse of the arch.

The Foot and Ankle Institute Advantage

The most important part of bunion surgery is the proper procedure selection. This is done with a patient exam and x-rays of the foot that are done on your first visit. The proper procedure is selected based on how big the bunion is and how loose the bunion is. In simple cases, the Offset Austin allows for immediate weight in a boot and return to tennis shoes in 3 to 4 week. More complex cases including those requiring more stability are done with the Lapidus procedure. Although the recovery is slightly longer with the Lapidus procedure, there is no chance of the bunion coming back and foot stability is dramatically increased.

The surgery is done with the use of screws in both cases to allow rapid healing and less pain from bone movement. There is usually excellent motion of the toe with no limitations of activity or loss of foot function noted. The scars are closed with plastic surgery techniques to limit scarring and hidden on the side of the foot for better cosmetic healing. With excellent technique and proper procedure selection, bunion surgery can be both simple to recover from and highly successful with little to no pain.

Surgical Correction of A Mild Bunion Deformity

Pre-operative x-ray showing small angle between the first and second metatarsals and between the first metatarsal and the big toe.	Picture showing clinical appearance of a mild bunion.
Post-operative x-ray showing closed angle between the first and second metatarsals and between the first metatarsal and the big toe after bone cut and screw fixation.	Picture showing clinical appearance after surgical correction.

Surgical Correction of A Severe Bunion Deformity

The Foot and Ankle Institute is an international bunion referral center. We have operated on patients from all over the United States and many other countries. We pride ourselves on our constant research and technique advancements. The Foot and Ankle Institute is also a referral center for failed previous bunion surgeries and is internationally known for repair and salvage of poor bunion surgery outcomes.

X-ray of a severe bunion with a large angle between the first and second metatarsal and between the first metatarsal and the big toe.	Clinical photo of a severe bunion deformity.
Correction of a severe bunion at the first metatarsal cuneiform joint. The large angles are reduced and the instability permanently stabilized.	Picture showing clinical appearance after surgical correction.