Edited by Daniel Guss, MD, M.B.A.
A bunion (a.k.a Hallux Valgus) is a common foot condition associated with a prominent bump on the inside of the forefoot (see Figure 1). The word bunion originates from the Latin root for the word “turnip”. Bunions can lead to discomfort over the prominence, especially if patients wear tight fitting shoes. It is common for bunions to run in a family and gradually worsen over time. The vast majority of bunions can be managed successfully with basic non-operative treatment. Surgery is reserved for patients who have persistent symptoms in spite of appropriate non-operative treatment.
Figure 1 : Bunion Deformity
Clinical Presentation: Bunions
Patients with bunions will often describe pain over the prominent bump on the inside of their forefoot (the medial eminence). They may also experience pain under the ball of the foot near the base of the second toe. Symptoms can vary in severity, from none at all to severe discomfort aggravated by standing and walking. There is no direct correlation between the size of the bunion and the patient’s symptoms. Some patients with severe bunion deformities may have minimal symptoms, while patients with mild bunion deformities may have significant symptoms. Symptoms are often exacerbated by restrictive shoe wear, particularly shoes with a narrow toe box or an uncomfortable, stiff, toe box.
Patients with bunions often have a positive family history. It is common for patients to have a first-degree relative who has had a bunion, flatfoot deformity, or significant clawing of their lesser toes. This may be the biggest risk factor for developing a significant bunion deformity.
The primary anatomic cause of a bunion is that the bone on the inside of the forefoot at the base of the big toe (the first metatarsal) begins to drift and separate away from the bone of the midfoot at the base of second toe (the second metatarsals). This V-shaped separation pushes the great toe outwards creating a prominent bump known as a bunion deformity- on the inside of the foot. The bunion bump is often normal bone sticking out of the side of the foot, rather than a growth of new bone. Thickening of the tissues overlying the bony prominence can worsen the prominence. Over time, arthritis can also develop in the joint.
Bunion deformities can vary greatly in their extent and in the symptoms that they cause. Most commonly the symptoms are worsened by restrictive shoe wear, specifically shoes with a narrow toe box or very stiff, non-pliable material that cannot stretch over the bump.
Physical Examination: Bunions
Physical examination typically reveals a prominent bump on the inside of the forefoot. As the metatarsal, the midfoot bone, starts moving outwards, the big toe itself starts drifting inwards, combining to worsen this bump. Drifting of the big toe actually causes the big toe joint to “subluxate”, which means it moves out of place. In mild and moderate bunions, this joint may be repositioned back to a neutral position (reduced) on physical examination. With increased deformity or arthritic stiffness the big toe joint (the first MTP joint) cannot be fully straightened to a normal position. Patients may also have a skin callus at the base of their second toe in the sole of the forefoot because as the first toe drifts, the second toe carries more weight, and this can be an additional source of pain called metatarsalgia.
Imaging Studies: Bunions
If your surgeon is contemplating an operation, it is common to obtain weight-bearing x-rays of the foot. These x-rays are typically taken from the top (anteroposterior) (see Figure 2) and from the sides (lateral). Both of these x-ray views allow the operation of the big toe joint (first MTP joint) to be observed.
Figure 2 : X-ray showing bunion
The degree of big toe angulation can be measured on x-ray. Mild deformities are considered a big toe angulation of <20 degrees, moderate deformities from 20-40 degrees and in severe deformities the great toe angulation is greater than 40 degrees. It is important that the x-rays be obtained in a full weight-bearing position in order to adequately assess the alignment issues associated with the bunion deformity.
Non-Operative Treatment: Bunions
The initial treatment of a bunion should be non-operative. Symptoms can often be greatly improved with simple non-operative interventions. Non-operative treatment may include:
- Properly fitted shoes: Properly fitting comfort shoes with a wide non-constrictive toe box, especially one that is made out of a soft material such as leather, can be quite helpful in reducing the irritation over the prominent bunion. In some instances, it is helpful to have a shoemaker stretch the inside aspect of the shoe. Jamming a foot with a bunion into a constrictive shoe will likely lead to the development of uncomfortable symptoms.
- Bunion pads (bunion sleeve): Bunion pads may also be helpful in decreasing the symptoms associated with the bunion (Figure 3). These pads can be obtained at many drugstores. Essentially they serve to lessen the irritation over the medial prominence and, thereby, decrease the associated inflammation This should be combined with comfortable non-constrictive shoes.
- A toe spacer placed between the great toe and the second toe can help to straighten the bunion deformity and, thereby, decrease the irritation associated with the bunion. Toe spacers can be obtained at most drug stores or online.
- Soft shoe inserts: Over-the-counter accommodative orthotics may also help bunion symptoms. This product is particularly helpful if bunion symptoms include pain that is under the ball of the foot. Orthotics with a slight arch may be helpful for patients that have flat feet. These can be purchased at many sports stores, outdoors stores, or pharmacies.
- Bunion splints have often been used to treat the symptoms associated with hallux valgus. These splints are typically worn at night in an effort to reduce the bunion deformity. There is no evidence to suggest that these splints decrease the rate at which bunion deformities occur. There is also no evidence that clearly supports their effectiveness. Some patients, however, report good relief with the use of these splints.
Figure 3: Bunion Sleeve -soft material pads the prominent bunion
Operative Treatment: Bunions
Surgery should only be considered for bunions that are moderately to severely painful, and NOT for correction of the cosmetic appearance. The primary indication for operative intervention is pain that is not relieved by appropriate non-operative management. Although symptom-free bunions can slowly worsen or increase in size over time, surgical treatment is NOT recommended unless significant pain symptoms develop. The prolonged recovery time associated with most bunion operations, combined with the potential for complications means that patients should be thoughtful about considering bunion surgery.
There are many different procedures that have been described to correct bunions. The type of operation your foot surgeon recommends to correct your bunion should be dictated by the severity of your bunion deformity and the surgeon’s preference. There are well over 100 different bunion correction procedures described in the orthopaedic literature. However, the broad categories of bunion correction procedures are listed below, some of which link to a page where the surgery and recovery are described in detail.
- Removal of the prominence on the inside of the foot (medial eminence).
- Distal metatarsal osteotomy (chevron) with great toe soft-tissue tightening (medial capsular tightening and distal soft-tissue repair).
- Proximal metatarsal osteotomy Ludloff, Cresentic, SCARF, medial opening wedge) with with great toe soft-tissue tightening (medial capsular tightening and distal soft-tissue repair).
- Lapidus hallux valgus correction (first tarsometatarsal joint fusion) with distal soft tissue procedure.
- Great Toe Fusion (1st MTP joint arthrodesis).
- Akin osteotomy (Realignment bone cut at the base of the big toe)
- Removal of the medial eminence with suture stabilization of the first and second metatarsals
- Keller joint arthroplasty (removal of the proximal aspect of the proximal phalanx).
When to see an orthopaedic foot specialist
For most people, sufficient education combined with following the above non-operative treatment measures will result in good function with fewer symptoms. Reasons to seek consultation with an orthopaedic foot specialist include:
- Persistent bunion pain that does not improve with shoe modification and other non-operative measures.
- Worsening bunion deformities that begin to involve the second toe, altering its alignment or causing additional pain.
Edited November 17, 2016 (Previously edited by Jean Brilhault, MD)