The closing base wedge osteotomy (CBWO) has long been a favorite for the severe bunion deformity in podiatric surgical history, especially throughout the 1970s and 1980s. Has the once sacred procedure become extinct? Is this procedure still a viable option for the severe bunion deformity? Do the potential complications move this procedure to the back of the bus when it comes to treating the severe bunion deformity?
In my opinion, the answer to all of these questions is yes.
It has been 20 years since I graduated from the Scholl College of Podiatric Medicine and I have never done a CBWO in my podiatric life. I did an extensive amount of surgery in my residency and fellowship programs, and I currently have a busy surgical practice. I have never thought highly of the CBWO or somewhere along the line I would have given it a try.
I do not think it is just me either. How about you? You do not see much about the CBWO in the literature anymore. I do not know of any of my colleagues who do the CBWO anymore. These factors point me to thinking of the CBWO as an extinct procedure.
Summarizing The Arguments Against The CBWO
When examining a severe bunion deformit, the apex of the deformity is at the metatarsocuneiform joint (MCJ), not the metatarsal base. Why then is it a good idea to operate distal to the apex of the deformity? I submit that it is not and therefore the Lapidus arthrodesis is a superior choice for the severe bunion deformity with or without metatarsus primus elevatus. When it comes to the hypermobile first ray bunion deformity, the effectiveness of the Lapidus arthrodesis is well documented.
There is no reliable method to evaluate hypermobility clinically. Kevin Kirby, DPM, has stated in the Precision Intricast newsletters that the term “hypermobile first ray” is better termed “decreased first ray dorsiflexion stiffness.” This terminology takes into account both the amount of motion and the loading force required to produce the motion about the first ray deformation.
A foot with decreased first ray dorsiflexion stiffness and a pronated subtalar joint results in significantly increased ground reactive forces at the second metatarsal head in comparison to the first metatarsal head. This leads to increased subtalar pronation. Arthrodesis of the first metatarsocuneiform joint increases the first ray dorsiflexion stiffness. This increase equalizes the ground reactive forces of the first and second metatarsal heads in the pronated foot. This stabilization subsequently decreases subtalar pronation.
The severe bunion with normal first ray dorsiflexion stiffness is more debatable. The debate is really more one-sided when considering the true apex of the deformity. This transverse plane instability occurs at the metatarsocuneiform joint. This is not an actual bowing of the base or midshaft of the first metatarsal. When it comes to correcting deformities, how often do we perform this correction at the level of the deformity? Why not move the entire ray into a corrected position instead of part of the ray? Which correction is going to have more long-term predictability?
I do think the Lapidus procedure has a high learning curve to do it correctly and this, in turn, scares some away from this procedure. I also think your training and when you were trained play factors in this decision process. If you have been trained primarily in CBWO, you are probably going to lean toward this procedure. I think both procedures have comparative complications but different specific complications. I think the postoperative courses for both are similar. Neither one of these factors should influence the decision process.
Helpful Tips On The Lapidus Procedure
I would like to share some tips to make the Lapidus procedure slightly easier to perform. First, completely release the first MCJ to visualize the joint adequately. I like to use a sagittal saw with a 38-blade to plane off the cuneiform side. This is where the transverse plane correction should originate. Bone resection on both sides of the joint should be minimal and just behind the subchondral bone plate. I also remove the flare off the lateral aspect of the base of the first metatarsal. This allows one to place the first ray in a fully corrected position.
I subsequently place the first ray into a corrected position in both planes and “feather” the fusion site with the saw. I like to utilize two 4.0 cortical screws as described by Sigvard Hansen Jr., MD. Postoperatively, I have the patient non-weightbearing for four weeks, partial weightbearing for two weeks and full weightbearing in a cast boot for four weeks.
So what do you think? Is the CBWO past its prime?