Bunion Surgery: Should You Perform A Lateral Release?
Yes. Neal Blitz, DPM says the lateral release is a common component of bunion surgery as it aids in bunion correction and assists with reduction of the intermetatarsal angle when surgeons combine this procedure with structural realignment of the first metatarsal.
Bunion surgery is a common part of nearly all foot surgery practices and many surgeons have a strong opinion on whether a lateral release is necessary. We have all performed numerous bunion surgeries and have been exposed to various techniques for bunion correction. However, the lateral release seems to be common to a vast majority of all of these procedures.
McBride popularized the lateral release in the earlier part of the century as an isolated soft tissue procedure to correct hallux valgus. Since the procedure did not correct the structural deformity, surgeons performed the procedure with fibular sesamoidectomy and/or adductor transfer in an attempt to maximize the soft tissue correction. However, it became apparent that overzealous work within the interspace may promote a muscular imbalance, resulting in hallux varus.
It is obvious that a bunion, for the most part, is a problem in which the first metatarsal deviates from its native position, resulting in a subluxation/deviation of the first metatarsophalangeal joint (MPJ). Therefore, surgical correction is geared toward restoring an anatomic relationship of the first metatarsal with the entire foot as well as restoring the alignment of the big toe joint. Depending on the severity of the bunion, the surgeon may restore this relationship through varying metatarsal osteotomies and/or fusion of the first metatarsocuneiform joint.
The lateral release is an ancillary procedure that facilitates this relocation of the first metatarsal. Remember that the osseous reconstruction is what drives the success of the correction.
The literature and textbooks are clearly filled with articles that utilize variations of a lateral soft tissue release as part of a bunion surgery operation, whether it is a metatarsal osteotomy and/or a Lapidus bunionectomy. We should remember that the surgeon may even perform the lateral release as an isolated procedure although this does not seem to be common practice today unless the deformity is indeed minimal.
The purpose of the lateral release is simple and, in my opinion, serves two very important purposes. The release eliminates the pull of the adductor muscle on the hallux and releases the soft tissue contracture of the lateral first MPJ capsule. The first addresses a potential cause of the bunion and the second addresses an effect of the bunion.
Removing the adductor tendon from its insertion on the phalanx (and sesamoid) eliminates a deforming force that pulls the big toe laterally. Whether one believes that the adductor musculature is a deforming force or not in the etiology of bunions is irrelevant. In the muscular imbalance tug of war between the adductor and abductor of the big toe joint, the adductor clearly has won. Restoring the balance of power by releasing/removing the adductor tendon altogether has some theoretic merit. However, in clinical practice, the adductor attachments can reform so this release may not be so permanent.
Releasing the lateral sesamoid ligament and lateral capsule contracture is important with larger bunions and longstanding bunions. For these patients, logic would suggest that the lateral side of the joint complex is tightened and/or contracted whereas the medial side is loosened and/or attenuated. Though this has not been proven scientifically with a bunion per se, we understand that, in general, dislocated or subluxed joints develop soft tissue contractures.