Retrospective Analysis of the Akin Osteotomy

Abstract

Hallux abductovalgus is one of the most common deformities addressed by foot and ankle surgeons. Surgically, it can be approached using a wide variety of procedures. After performing the first metatarsal osteotomy, the final step is often to realign the great toe in a rectus position. This is performed with an osteotomy of the proximal phalanx. The Akin osteotomy is a medially based closing wedge osteotomy of the proximal phalanx. When executing the osteotomy, the goal is not only to correct abduction, but also to keep the lateral cortex intact, which allows it to act as an additional point of fixation. However, the lateral cortex can be iatrogenically compromised during surgery or in the postoperative period. We investigated the frequency of disruption of the lateral cortex, osteotomy displacement, healing time, and the need for surgical revision associated with the Akin procedure. A total of 132 patients who had undergone Akin osteotomy were included in the present retrospective study. Intraoperative fluoroscopy showed the lateral cortex was compromised in 47 (35.6%) patients and remained intact for 85 (64.4%) patients. Of the 47 (35.6%) patients with lateral cortex disruption intraoperatively, 9 (19.1%) experienced displacement during the postoperative period, of whom, 3 (6.38%) required surgical revision. Although intact during surgery, the other 6 (4.55%) patients sustained lateral cortex fractures postoperatively, 2 (33.3%) of whom required surgical revision. A statistically significant difference was found between the integrity of the lateral cortical hinge and the healing time of the osteotomy. All the osteotomies with displacement postoperatively were noted to have lateral cortex failure, either during surgery or during the follow-up period.

Progressive Akin Osteotomy

“…Maybe, an oblique oriented osteotomy reduces the chance of hinge failure, as it was suggested by Boberg et al 4 But a perpendicular oriented osteotomy to the long axis of the proximal phalanx achieves a greater degree of correction and more stable fixation. Douthett et al 3 reported 47 intraoperative lateral cortex phalanx disruptions in 132 patients, and 88.6% of the osteotomies were perpen-dicular to the longitudinal axis of the phalanx. Additional fixation is often required when a lateral cortex disruption happens.…”

“…2 The most common complication associated to this procedure is the intraoperative fracture of the lateral cortex of the proximal phalanx. 3 This can occur due to excessive weakening of this cortex by the saw oscillation, or to resection of a large bone wedge. Lateral hinge fracture causes, despite osteosynthesis, osteotomy instability with the consequent risk of secondary displacement.…”

Minimally Invasive vs Open Akin Osteotomy

“…1,5,26 Intraoperative fracture of the lateral cortex is a frequently reported side effect (25.9%-36.5%), which is discussed controversially to cause a secondary loss of correction and delayed bone healing in up to 6.8%. 6,11 Several devices (heat-sensitive memory staples, bicortical screws, locking plates, K-wires, sutures) were proven to provide a stable fixation of the osteotomy. 4,17,20,22 There is no consensus about which fixation method provides the best clinical outcome.…”

Hallux Valgus

“…It is important to keep the lateral cortex integrity intact; otherwise, there is a risk of destabilization of the osteotomy. 25…”

“…It is important to keep the lateral cortex integrity intact; otherwise, there is a risk of destabilization of the osteotomy. 25 Distal metatarsal osteotomies Distal chevron osteotomy. The distal chevron osteotomy is indicated in mild to moderate hallux valgus deformity.…”