Emerging Insights On Fixation For Austin/Chevron Bunionectomies
Drawing from the literature as well as their clinical experience, these authors review the evolution of fixation options for Austin/Chevron bunionectomies. In addition to exploring the pros and cons of resorbable implants, they assess the advantages of allografts and offer key surgical insights.
The Austin/Chevron bunionectomy for the distal first metatarsal has long been a popular and stable procedure for the treatment of mild to moderate hallux valgus since Gill and colleagues first described it in 1976.1 In the 1980s, Austin popularized the bunionectomy, which became the desired procedure for the treatment of mild to moderate hallux valgus deformities.2
Although surgeons had historically performed the distal Chevron bunionectomy successfully without the use of fixation, many surgeons now prefer to utilize some form of rigid fixation to reduce the likelihood of displacement of the osteotomy site with possible malunion.1 Austin initially advocated manual compression of the distal metaphyseal osteotomy augmented by bandage, splintage and, at times, rigid casting.2 However, many surgeons faced inconsistent results including osteotomy subluxation, dislocation, nonunion, iatrogenic distal fragment fractures and many more.
Small and colleagues reported an 8 percent increase of displacement at the osteotomy site for distal Chevron bunionectomies without the use of fixation.3 This concern lead to the popularization of internal fixation as an adjunct to ensure stability of the osteotomy.
Since the introduction of the Austin bunionectomy, surgeons have employed numerous methods and materials for stabilization and fixation. Studies have found fixation with Kirschner wires provide adequate stability.4 Use of one or more K-wires appeared to decrease the incidence of many of the previously mentioned complications. However, such fixation can prove to be unpleasant for the patient with increased risks.
K-wires tend to cause pain in the surrounding skin as well as unwanted skin traction. They also may provide a conduit for the introduction of bacteria to the operative site. The wires also limit early range of motion at the metatarsophalangeal joint (MPJ) due to the irritation of the skin and associated pain with the tethering effect of the protruding wires during the motion of the joint.1 In addition to the potential for pin migration, another disadvantage is that patients must take extra care to avoid “bumping” or catching the wires on a multitude of surrounding obstacles.3
In order to avoid some of the disadvantages and complications of utilizing K-wires, many surgeons began to insert the K-wire and bury it in the subperiosteal layer, either indicating they would remove the K-wire at a later date, requiring an additional procedure, or that they would not remove it at all.
K-wires may be the least expensive of all implants for fixation but the low cost may not justify the minimal degree of compression and the long list of potential risks and complications.