Pertinent Pearls On Fifth Metatarsal Osteotomies
Remember, when choosing this procedure, you can only shift the capital fragment a small amount. Therefore, adequate space medial to the head of the fifth metatarsal is necessary for the head to displace appropriately. Another thing to take into consideration is that because this osteotomy is slightly distal to the metaphyseal-diaphyseal junction, the healing potential will not be as optimal. Also, these osteotomies do not lend themselves well to internal fixation.9,10
Oblique osteotomy. Since its original description in 1975, surgeons have used the oblique osteotomy extensively for tailor’s bunion correction.9,12 Various authors have described a variety of modifications to this procedure and numerous studies validate its effectiveness.9,12
The senior author has found that the oblique osteotomy (Helal) is a procedure that lends itself to a wide range of angular deformities. One can manipulate the obliquity of the cut to account for the amount of desired correction. By increasing the obliquity of the osteotomy, not only does one get the amount of correction desired but one can also usually avoid a proximal procedure.
It should be noted that the amount of medial shift obtained is also proportional to the amount that the metatarsal will shorten. The senior author has not found this to be a problem long-term. The amount of shortening clinically is typically not significant and patients do not seem to be very concerned with it. However, if you are planning on combining the oblique osteotomy with an additional fifth digit arthroplasty, this becomes more relevant. As always, this is something to review with the patient on the informed surgical consent.
Surgeons can certainly combine the distal osteotomies with a lateral exostectomy but this is not always needed. In any case, always perform the exostectomy last so one can appropriately decide if it is in fact necessary.9,10,11,15
Fixation for oblique osteotomies can occur with a variety of screws and/or Kirschner wires. The senior author’s personal preference for the distal oblique osteotomy is typically a single screw (2.0 cortical) or a 0.062 mm K-wire. When utilizing the Kirschner wire, the senior author will drive it from proximal lateral to distal medial. Although this may seem technically unconventional (as it is generally not recommended to fixate from least stable to most stable), it is easier to perform and allows one to see that the K-wire is not entering the joint.
Regardless of the choice of fixation or even the specific osteotomy, the distal procedures typically lend themselves to immediate “heel” weightbearing.1,9,10,15 Again, this is important as the possibility of immediate weightbearing means patients are not intimidated by circumstances that may interfere too much with their day-to-day lives.
Navigating Proximal Osteotomies
Proximal osteotomies. These osteotomies will allow for the greatest degree of correction. However, they are technically difficult and one must select them only in appropriate scenarios. Historically, surgeons considered these procedures as less favorable options due to the delicate blood supply to the base of the fifth metatarsal as well as the instability of the osteotomies themselves.1,15 The deformities well suited for this type of procedure include those with a significantly increased fourth-fifth intermetatarsal angle and splay foot deformities.9,10 Gerbert’s indications included a non-arthritic joint in the presence of a deformity that involved the entire metatarsal.16