Can An Adjunctive Akin Give You That Perfection You Are Looking For In Bunion Surgeries?
There are some procedures that unfairly get a “bad” reputation. This is usually due to overuse or prior misuse. The Akin procedure is one such procedure and many have used the term “cheater Akin.” This is a case in which a practitioner incorrectly uses the procedure for bunion correction. This procedure is designed for correcting the hallux interphalangeus deformity only, not any deformity proximal to the metatarsophalangeal joint.
I have been in practice long enough now that I have seen cases several years out. More often than not, I am disappointed with bunion surgeries I have performed in which I did not use an Akin in conjunction with another procedure, such as an Austin or Lapidus. Typically, the patient is satisfied but as a surgeon, I think you should be a bit of a perfectionist. I am disappointed by anything less than perfectly straight. Our task in bunion surgery is to fully correct the deformity.
If you carefully evaluate the hallux in bunion deformities, there is often an interphalangeus deformity. I also consider this as an intraoperative fine-tuning procedure, similar to a shim in a door or window. I am a firm believer in working proximal to distal in any type of foot surgery with multiple procedures. Therefore, I will do the primary procedure and load the foot to evaluate and decide whether to perform an Akin procedure.
Here are some tips to make the Akin procedure more reproducible.
Use a long, oblique osteotomy that goes from the distal medial metaphyseal-diaphyseal junction for the base to the proximal lateral metaphyseal-diaphyseal junction for the apex. I remove a very small wedge (less than 2 mm) and only take the wedge approximately halfway across. Then I like to feather the remaining half of the osteotomy to close it. It is crucial to leave a lateral cortex. This will serve as a second point of fixation preventing rotation.
I then temporarily fixate the osteotomy with a guide pin from a 3.0 mm cannulated screw set. I like the Synthes set and use a partially threaded guide wire. This wire must be bicortical and one can verify this with fluoroscopy or direct visualization. Direct the pin from the proximal to the medial aspect of the proximal phalanx perpendicular to the osteotomy.
Proceed to under-drill and countersink the proximal cortex. Angle the phalanx in this area and bear in mind that the proximal portion of the screw hole requires slightly more countersinking. Take care to countersink enough to get the screw head past this portion of the cortex but not so much that the head does not purchase. After measuring the pin for the length of the screw, insert the screw. The screw must be bicortical and is most often a short-thread length pattern.
If you carefully evaluate your bunion surgeries clinically and radiographically both preoperatively and postoperatively, you may discover that the Akin procedure provides the small degree of correction necessary for perfection.
Best wishes and stay diligent.