Is The Miami Phalangeal Osteotomy A Viable Alternative To The Akin Osteotomy?

Author(s): 
Michael M. Cohen, DPM, FACFAS

   The indications for the Miami phalangeal osteotomy are identical to the Akin procedure. The Miami osteotomy also addresses the distal articular set and the hallux interphalangeal angles. I find it especially useful when addressing crossover or second toe impingement problems, and when correcting bunion deformities in patients with a pronated foot and a high metatarsal adductus component. In these patients, it is well recognized that lasting correction is a challenge despite a well-executed operation with proper intermetatarsal angle restoration. In this situation, both the Akin and Miami phalangeal osteotomies provide an enhanced cosmetic outcome, theoretically providing a longer lasting result.

   The Miami phalangeal osteotomy has additional inherent uses. It is an excellent procedure to use when addressing failed hallux valgus surgery requiring correction of angular malalignment of an Akin osteotomy. The procedure allows realignment of the phalanx without the need to shorten the phalanx further by extracting an additional wedge of bone. Other potential uses include the ability to slide the phalanx proximally as an adjunctive procedure to elevate the distal fragment when treating hallux limitus or distract distally to lengthen and plantarflex the phalanx if it has been shortened with a previous osteotomy.

A Step-By-Step Guide To The Surgical Technique

Through a medial or dorsomedial approach, reflect the capsule with minimal to no dissection over the medial phalanx. Perform all the proximal osteotomies. Direct attention to the base of the proximal phalanx and identify the dorsal phalangeal tubercle just distal and central to the articular surface. This represents the attachment of the extensor capsularis tendon.

   Using a saw, perform a straight through and through osteotomy at approximately 25 to 30 degrees to the longitudinal bisection. Aim for the tip of the toe and stay parallel to the nail plate. It is best to make the osteotomy as long as possible and at a gradual angle, exiting as distal as possible and just proximal to the interphalangeal joint. Rotate the toe medially and fixate the osteotomy provisionally with a K-wire (usually 0.062 inch) directed dorsal to plantar when the correction appears satisfactory.

   One may use intraoperative fluoroscopy to confirm the reduction. If the correction is inadequate, retract the K-wire and reinsert it after dialing in the proper correction. When you are satisfied with the correction, place a parallel drill guide over the K-wire and fixate the osteotomy with one or two mini fragment screws. The 0.062-inch K-wire hole makes a perfect sized drill hole for a 2.0 mm screw and one may use this for a second screw if necessary.

   However, be sure not to place the screw too proximal near the edge of the shelf to avoid fracturing through it. Countersinking will help avoid this problem, particularly if one is using a 2.7 mm screw. Use the intact periosteal capsular structures as this will allow you to perform a sound plication.

Examining The Efficacy Of The Miami Phalangeal Osteotomy

A study focused on 36 oblique proximal phalangeal osteotomies performed in 32 patients with an average age of 49.9 years.5 At a follow-up of three to 21 months, angular correction ranged from 7 to 22 degrees and the hallux interphalangeal angle was corrected to within 5 degrees of neutral. There were no nonunions or delayed unions, no hardware loosening and only one patient had a mild loss of correction. The time to achieve healing ranged from four to eight weeks. No bone callus or osteoarthritis occurred.

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