Why I Prefer First MPJ Implants To Being A ‘Fusion Guy’

Ron Raducanu DPM FACFAS

I’m not a first MPJ “Fusion Guy.” To be truthful, I have not done one primary first metatarsophalangeal joint fusion throughout my whole career. I have done some redos but not one primary first MPJ fusion has crossed my OR table so far. I don’t think one ever will as a primary procedure choice for hallux limitus, regardless of the stage or age of the patient. The fusions I have seen or had to redo for others just did not do well for a variety of reasons. I think the current technology for first MPJ implant arthroplasties are great in comparison to what has been available in the past. I have seen tremendous outcomes.

I talk to many “Fusion Guys” who believe that at a certain point, fusion is the only way to go. Many of them go the route of a cheilectomy as some of the more recent literature suggests but I really am not convinced.1,2 Neither are McNeil and colleagues in their most recent study.3 They claim further studies are required to really conclude which procedure is best and which is most appropriate in which circumstances.

When I lecture about the technique I use (disclaimer: I am a paid lecturer for Arthrosurface and use the HemiCap DF implant), people often ask me about what results I get. I generally reply that my patients are very pleased with the outcome of the procedure.

This is when things get a little dicey. Inevitably someone listening will ask how much improvement in range of motion I get and I reply that I get more range of motion postoperatively than I did preoperatively. When people ask me what the numerical value of my improvement is, I tell the audience that I really have no idea as my ultimate goal is not only the satisfaction of my patient, but also the pain-free range of motion my patient needs for everyday activities.

This is when the tirade starts. They tell me I am a quack. They tell me I have no business on the podium, etc. The fact of the matter is that I have done the procedure many times and I have satisfied patients.

When things finally settle down and I can get a word in, I ask the audience to explain to me what happens to the sesamoid apparatus during the time the joint has a very limited range of motion and we all agree that the apparatus can get “frozen.”

I then ask the audience what happens to the sesamoid apparatus if I introduce a severe increase in range of motion all at once. Now I have their attention. It stands to reason that if I really crank that range of motion right away, once the patient gets active again (I get my patients back in shoes within two weeks of the procedure), they will have almost immediate pain at the sesamoid apparatus. This does occur on occasion but is generally very manageable and only happens in certain shoes and when their intensity of activity is great.

People then tell me I should be more aggressive with my sesamoid release with a McGlamry elevator if I am not getting the range of motion I want on the table. The question then becomes: is the range of motion you get on the table any indication of the range of motion you will get when the patient becomes ambulatory again? We all intuitively know the answer to that question is absolutely not. I also profess that I am not sure whether I am doing damage to the sesamoid apparatus when scooping with the McGlamry elevator. Do you?

Of the people who continually ask me about fusions, they claim that it is somewhat because of the potential arthritic process of the sesamoids that leads them in the direction of a fusion right off the bat. Here is where I get confused.

You are not fusing the sesamoids but the first MPJ, right? Well, even with a fusion in place, the flexor hallucis longus and brevis still fire and are slightly moving the sesamoids, aren’t they? If the sesamoids are moving, then there will be pain if the sesamoids are arthritic and a first MPJ fusion does not really address that. The fusion is not locking the sesamoids in place and even if the sesamoids move a little, there will still be pain, won’t there? Of the first MPJ fusions I have seen, most surgeons do not remove the sesamoids. I was trained to leave them there.

The other thing I don’t get is why we don’t try implants first. In the past with the Silastic implant, the defect was large and it was difficult to use bone grafts and such if a conversion to a fusion is necessary. That is pretty cut and dry. With the current options though, there is plenty of bone left over to convert to a fusion down the road if necessary. The Silastic implants had a limited lifespan, necessitating a quick replacement in the active individual. With the latest generation of implants, it is likely the implant will outlive the patient.

I hear from residents nationwide who are just not exposed to first MPJ implants enough to be comfortable doing them in practice. We need to shift this paradigm, folks. Basically what I am hearing is that they either perform cheilectomies or fusions regardless of age, activity levels and stage of deformity. I might be hearing from only select residents but I am hearing much the same things from the attendings in the audiences I lecture to.

Obviously, I am a huge advocate of the first MPJ implant and have had tremendous success with the procedure in my short 11 years out of residency so far. I really think with the new crop of implants available today, it is at least worth another look for my various “Fusion Guy” colleagues.

I am also sure many of you reading this will tell yourselves, “He’s a paid lecturer! Of course, he is writing this blog and telling us all to switch over!” Rightfully so. Take what I say with a giant grain of salt. Better yet, give it a go and decide for yourself.

References
1. Waizy H, Czardybon MA, Stukenborg-Colsman C, et al. Mid- and long-term results of the joint preserving therapy of hallux rigidus. Arch Orthop Trauma Surg. 2010 Feb;130(2):165-70.
2. Bussewitz BW, Dyment MM, Hyer CF. Intermediate-term results following first metatarsal cheilectomy. Foot Ankle Spec. 2013 Jun;6(3):191-5.
3. McNeil DS, Baumhauer JF, Glazebrook MA. Evidence-based analysis of the efficacy for operative treatment of hallux rigidus. Foot Ankle Int. 2013; 34(1):15-32.

Comments

The cheilectomy vs. fusion choice is one often presented by our orthopedic colleagues who may not offer the broad range of surgical choices for hallux rigidus more common in podiatry. Cheilectomies can increase range of motion but need to be used cautiously when there is inadequate cartilage quantity and quality at the first MPJ to support the additional motion.

There are a number of papers that support the success of first MPJ fusion but how is success measured? Usually by a pain-free joint. There are other parameters to consider beyond a lack of joint pain. The longer-term pathomechanical sequelae of first MPJ fusion may be more challenging to measure. Some issues I have seen related to mechanical changes include shifting of pressure, in propulsive phase, to the lesser metatarsals, increased lateral ankle instability due to the lateral shift in propulsion and an increase in hip pain, specifically ITB type pain as the leg may not fully internally rotate to allow propulsion off the first MPJ.

That is just my experience but feel that we need carefully study the biomechanical effects of of such surgical procedures.

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