Key Pearls For An Alternative Approach To The Akin Osteotomy

The Akin osteotomy for hallux valgus surgery has undergone much scrutiny since it was initially described in 1925. The osteotomy is not routinely performed as a separate procedure as it has been shown to provide unsatisfactory correction unless it is coupled with more proximal correction that narrows the first and second intermetatarsal angle.13

Other indications for the Akin osteotomy include hallux valgus interphalangeus or situations in which residual valgus causes increased pressure of the second toe. The main contraindication of the Akin procedure is when the metatarsophalangeal joint is subluxed.14

When beginning the procedure, one would expose the medial cortex of the proximal phalanx of the great toe in a longitudinal fashion. This can be a continuation of the incision used in the exposure of the medial aspect of the first metatarsophalangeal joint. Carefully continue a dissection around the dorsal and plantar surface of the mid-phalanx and use retractors to protect the flexor and extensor tendons. Utilize a microsagittal saw to remove a small wedge of bone from the proximal phalanx 2 to 3 mm distal to the articular surface. Typically, the wedge is 3 to 4 mm at the medial cortex.

In order to maintain stability, take care not to penetrate the lateral cortex. However, if it is inadvertently released, one can still achieve stability. Then close the osteotomy site and hold it temporarily with a 0.045-inch Kirschner wire until placing secure fixation. Use a second 0.045-inch Kirschner wire to drill the proximal cortex but do not carry it through the distal cortex to allow adequate fixation of the tapered, threaded pin. The pin has variable threads that engage the proximal and distal cortices differently to cause compression of the two fragments. It is important to measure the width of the bone to be compressed so one can use the appropriate thread length to provide the proper compression. The pin comes in three different lengths.

Then insert the NexFix Compression Pin with the wire driver across the osteotomy site. It may be necessary to use a small bone clamp during the insertion of the pin so one does not push away the far cortex. One would use intraoperative fluoroscopy to assist with the proper depth of the insertion and take care not to over-penetrate the far cortex. Doing so may decrease the holding power of the tapered, threaded pin.
One may insert the pins from proximal medial to distal lateral or in the reverse direction, depending on surgeon preference. However, we feel that starting proximally decreases the exposure necessary. Cut the pins flush to the bone and leave them permanently or with 1 mm of the pin protruding for removal. If removal is necessary, an awl and a grasper are included in the set for over drilling the cortex and grasping the pin. One can achieve closure with interrupted, nonabsorbable skin sutures.