Bunion surgery is performed to correct a painful bunion deformity, or to prevent or treat the development of arthritis of the big toe joint due to the abnormal position of the joint when a bunion is present. It can also be performed if the bunion is crossing over or under the second toe, leading to toe pain and deformity. A bunion is not simply a bump or bone enlargement on the side of the foot. It is actually a deformity of the way the bone behind the great toe is angled. This bone is angled too far outward, and needs to be repositioned for the bunion to be truly corrected. The most common way a bunion is corrected is by making a cut in the bone, moving the bone inward back towards the foot, and then securing it there while it heals in that position.
Bunion correction procedures generally fall into one of three categories. The most common category of procedure performed involves cutting and moving the bone near the top end. This is done on mild and moderate bunions, but it cannot correct severe bunions enough to be useful in those cases. Several different types of bone cut patterns have been innovated over the years, although by far and away the most common pattern is that of a 'V' shaped cut through the side of the bone neck, which then allows the bone head to slide over towards the foot, correcting the bunion deformity, The cut bone is then held together with permanent internal screws or temporary external wires until the bone heals, usually in six weeks. Due to the stability of the shape of this bone cut pattern, weight can be borne on the foot as long as it is protected in a medical walking boot.
The second category of procedure performed involves cutting and moving the bone along the bottom base of the bone. This procedure works well for severe bunions where the angle of the bone is very large. The only drawback is that this area is more unstable from a structural standpoint than the top end of the bone, and the recovery process requires more care and support. Numerous different types of bone cut patterns can be performed in this area, and can include removal or additions of bone wedges, 'Z' shaped bone cuts, or a semi-circular shaped bone cut pattern. A combination of internal screws, plates, or staples are used to keep the bone in place while it heals. Because of the general instability of this area, most patients are non-weight bearing in a cast and crutches during the six weeks of bone healing time.
The third category of procedure that is performed to correct a bunion is generally reserved for severe bunions with general bone hyperflexibility, although some surgeons prefer its use for a wider range of bunions. This procedure does not involve cutting the bone, but rather involves fusing the joint at the base of the bone after releasing it into the corrected position. This has the advantage of fixing the bunion at the apex of its deformity, and will stabilize a bone that is too hyper mobile, leading to more structural stability. The bones in this joint are held together using a combination of screws and plates, or simply with two screws, and the fusion can take six to eight weeks to complete. During this time, weight-bearing is usually prohibited, as excess motion of this site while it is still healing can lead to a failure of the fusion.
There is a fourth category of procedure performed to correct bunions. These procedures were performed commonly years ago, but were not found to correct the bunion over the long term because the angle of the bone is not changed. However, these procedures works well for minimal bunions in which there is only a small bump causing discomfort, or for older patients who are not expected to have a relatively easy time recovering from the usual bunion surgery. These procedures involve some type of bone removal, where either the bump is simply shaved flat, or the bone at the base of the toe is partially removed. The tissue surrounding the joint is rebalanced to help keep the toe straight. Recovery from these procedures do not require time for the bone to heal, and patients are able to return to shoes more quickly. While the level of bunion correction is much lower in these procedures compared with the above three categories, bunion symptoms can be relieved in those who otherwise could not have traditional surgery.