Is The First MPJ Arthrodesis Underutilized For Severe Bunion Deformities?

I admit that I am a perfectionist—almost to a fault. This is a good thing if you are a surgeon but if you are trying to organize your bookshelf or your digital pictures, it is tedious. I expect perfect results when I do surgery while also striving for perfection in my everyday life.

I have found it particularly difficult to obtain consistently excellent results for certain podiatric conditions. One of these conditions is the severe hallux abducto valgus deformity. In my 22 years of practice, I have tried practically every procedure applicable for this deformity with the exception of the closing base wedge (see my prior blog about this obsolete procedure at https://tinyurl.com/cxmmqqn ). The results were consistently not up to my critical expectations postoperatively.

I would first like to take a moment to recommend that you perform a critical analysis of all your surgical outcomes. This will make you a better surgeon. Learn from your good and bad outcomes equally. We all have bad outcomes. If someone tells you otherwise, he or she is lying. Look for procedures that yield consistently excellent results in your hands as you build your surgical armamentarium.

In regard to the severe bunion deformity, I usually take one of two surgical routes. I base my choice on the age, sex and shoe type of the patient. If the patient is a young male or a young or middle-aged female who wears high heels or dress shoes, I most often opt for a Lapidus, McBride and Akin approach. If the patient is an older female or middle-aged woman who does not wear dress shoes or high heels, or a middle-aged or older male, I typically choose a first metatarsophalangeal joint (MPJ) arthrodesis. This is the procedure I would like to discuss.

The first MPJ arthrodesis is my favorite procedure. If I could only perform one procedure for the rest of my career, it would be the first MPJ arthrodesis. I like this technique because it is as consistent as a surgical procedure possibly can be. This surgery has been around since Clutton described it in 1894.1 Its concepts have remained the same for more than 100 years. The evolution of fixation has taken the first MPJ arthrodesis to the pinnacle of consistency in the foot surgery world.

What are severe bunion patients looking for? They want correction of their deformity and/or reduction of their pain. Those are the only reasons they are having surgery. I have seen failures of all types over the years with the Z, Mau, Ludloff, closing base wedge, opening base wedge and crescentic osteotomies. I can take blame for some of the failures and for others, I can attribute fault to other surgeons. In these cases, there was a failure to reach objective goals, which most often led to an unhappy patient. The first MPJ arthrodesis has never led me down the dreaded path of inconsistency unless it has been my surgical error. Again, this is where critical postoperative analysis leads surgeons to more consistent results.

With the severe bunion deformity, there is often a hypermobile first ray, severely increased intermetatarsal and hallux abductus angles. The first MPJ arthrodesis closes down the intermetatarsal angle by converting the retrograde force of the hallux onto the metatarsal from a deforming force to a corrective force. The procedure corrects the hallux abductus angle by reducing the MPJ. One plantarflexes the first ray by dorsiflexing the hallux on the metatarsal, thereby stabilizing the first ray.

I use locking plates for fixation. I then proceed to position the hallux in 5 to 10 degrees of dorsiflexion, parallel to the second digit in neutral position with no frontal plane rotation. I tend to put the toe in much less abduction than the literature recommends. Most patients really dislike their first and second digits crowded together. Another significant benefit to the first MPJ arthrodesis is the postoperative healing course. I allow protected weightbearing in a cast brace for seven weeks and then transition the patient into a gym shoe.

In general, foot surgeons often underutilize this procedure. They significantly underutilize it when dealing with severe bunions. Arthritic changes of the joint are not the sole indication for this procedure. Severe deformity is an indication as well. You may want to consider this option for patients with severe bunion deformities as the consistent results will satisfy both you and your patients.

Best wishes and stay diligent.

Reference
1. Clutton HH. The treatment of hallux valgus. St. Thomas Rep. 1894;22:1.