Special Considerations for Hallux Valgus in the Military Population

Hallux valgus is one the most common conditions we see as podiatrists. We have become so accustomed to painful presentations of bunions; but in our young, military population, that isn’t always the case.

In the military, I find it very surprising how many soldiers will present with another condition, were referred simply because their primary care thought they should get it looked at, or want to get it documented for the VA (Veterans Affairs) prior to getting out of the military.

Why is that? Because patients are young, and their bunions haven’t progressed? Is there a magic intermetatarsal angle that makes bunions painful? Or, is it more related to the hallux abductus angle or sesamoid position? Is there even a correlation between symptoms and radiographic findings? Is it possible that in the military we simply see patients with clinically mild deformities with minimal symptoms? Or, does size of the deformity simply not matter? These are all questions that many of us ponder and will be addressed within this column.

Demographics and Findings of Patients With Hallux Valgus in a Military Population

Over the past 6 years at Ft. Leonard Wood, I have been reviewing all the standing foot X-rays and cataloging findings. I specifically have focused on first MTPJ conditions with hallux valgus being 53% of those cases. As one starts to weed out all the dependents and retirees, the number of trainees and active-duty military with hallux valgus starts to become much more manageable. Over the past 6 years, 316 total cases of hallux valgus had weight-bearing images, and only 222 involved active duty military, with the majority evaluated by myself and my colleagues. Only one-eighth of those patients required surgery.

Why so few? Well, first of all, Ft. Leonard Wood is the largest training base in the military and thus we see a large percentage of trainees on whom we can’t operate until they have completed training. So, very often trainees with a symptomatic bunion, have two options: medical discharge or push through training. So, the majority of bunion surgery performed at our hospital are likely individuals presenting with years of nagging pain. I personally have done more bunion surgery on male soldiers than females, which seems to be directly opposite of the demographics I’ve observed of the average foot surgeon in private practice. There are simply more men than women in the US military.       

Posing Key Questions Regarding Bunion Presentations in the Military

So, what concerns do most patients with bunions actually present with? In my experience it is actually plantar fasciitis, metatarsalgia, or, believe it or not, ingrown nails (lateral border of the hallux). It is simply a rarity for a soldier to simply complain of bunion pain until they have been in the military a few years. In addition, it is even less common to have someone complain of sesamoid pain.  

Next, are we simply seeing only mild-to-moderate deformities (see Figure 1) because so many of our military trainees are under 25 years old and the majority of our active duty personnel are under 40? First of all, of the 222 cases I shared above, 92 were female and 130 male. Regarding the size of the deformity, I measured every weight-bearing AP view, including: intermetatarsal (IM) angle, hallux abductus (HA) angle and sesamoid positions, comparing by gender. Some interesting numbers emerged. The averages are listed in Table 1 and illustrated in Figure 2.  

Men and women in this sample averaged the exact same numbers for IM angle (12 degrees), HA angle (24 degrees) and sesamoid position.¹ Extreme values did exist, with the highest IM being 20 degrees in both men and women. The highest HA was 40 degrees in both men and women. Those are certainly severe deformities. The highest sesamoid position was 6 and no one had a position lower than 3. There were several individuals with increased proximal articular set angle (PASA), distal articular set angle (DASA) and hallux interphalangeal angle (HIA) deformities as shown in Figure 3, Figure 4 and Figure 5. There were 4 males and 4 females with metatarsus adductus and one male with a skewfoot. Based on the numbers, we saw some fairly significant, but asymptomatic, deformities. The Weil Institute concluded “radiographic angles were not well correlated with patient-centered outcomes in hallux valgus surgery.”² While that doesn’t resolve why so many present without bunion pain, it surely leads us to question whether the size of the deformity correlates to symptoms. The Weil Institute published another article concluding that, “It would appear that radiographic severity of bunion deformity is not well correlated with symptom level and/or disability.”³  

Although reviewing X-rays and educating patients is worthwhile, I’ve noticed colleagues outside of podiatry seem to evaluate bunions by size, not symptoms. We’ve all likely seen presentations that do not correlate with deformity size.

So, we know that faulty biomechanics likely leads military personnel to present with other symptomatic pathologies, even if their bunions are asymptomatic. However, what makes some of these individuals eventually develop bunion pain? I have no clue, but we have seen this trend throughout my career.  

Next, should one fix the bunion if the patient has other foot and ankle conditions? I see two sides to this question: age and activity level. My answer will change based on demographics and equating the military as professional athletes. So, if I have a soldier with flat feet and significant bunions that I feel impact his flat feet, I will advise that soldier that he/she should address the bunion now along with the flat foot. Conversely, I will convince that Marine that has a painful bunion to fix his flatfoot at the same time. On the other hand, I may not go that route with a sedentary 55 year old. Address only what hurts. I am sure many of you will ponder which route to take.

The Author’s Thoughts on Choosing the Best Surgical Approach

In my experience, I prefer to tailor my surgical procedures to the needs of the patient, and do not take a rote algorithmic approach. In 30 years of X-ray evaluations, I haven’t done more than five Akin procedures per year. Akins were designed to correct a deformity of the hallux. If there is no deformity, there is no need for an Akin. Amongst the 222 cases I shared above, only 14 patients had a significant DASA and only 6 patients had a HIA over 15 degrees. So, if I operated on each and every one of those 222 cases, I would expect to perform maybe 5–10 Akins. As we look at the IM and HA angles of these patients, we clearly have an average of IM angle of 12 degrees and HA angle of 24 degrees. Based on that average, we could address this simply with a chevron bunionectomy. As the IM angle increases, I will see my selection expand to a Kalish. As the deformity starts approaching 15 degrees, depending on metatarsal length, I will start opting towards a Lapidus. I rarely do closing wedge osteotomies anymore. Only on rare occasions with a short first metatarsal will I utilize an opening wedge osteotomy. Ignoring PASA simply befuddles me, as I will do as many Reverdin-style osteotomies as I need to address PASA. I find failure to do so will simply lead to the hallux drifting back into valgus. I have no worries about combining a proximal procedure with a Reverdin.    

Surgical results amongst the military can be problematic simply because of the demands placed upon them. Regardless of the procedure, athletes and the military put any surgery to the test. Fournier and colleagues reported in his study of civilian athletes that 80% returned to sports.⁴ Unangst reported similar numbers as Saxena for return to running rates.¹ Contrast that with Schroeder’s report from a large military base that saw only 28% of all their bunion surgeries returned to full duty within 1 year of their surgery.⁵ That seems like a dismal number, but when the majority of their patients were assigned to combat units, it makes a lot more sense.

Lastly, what about a first MTPJ fusion? It is not only appropriate for severe deformities, but I find it is so much more predictable and manageable for revision bunions. 

In Conclusion

The moral of the story is that we have to tailor our surgery to each and every patient. We all need to be competent in managing distal, shaft, and proximal procedures, along with fusions. Even today, when I discuss bunion surgery with my own residents, I stress that if you are doing the same procedure daily, then you might as well not be ordering X-rays or even measuring angles. The same could be said for the trends in procedures. Nelson performed a review of all the Lapidus procedures performed within the military from 2014-2021, which of course included all my cases, finding that there was a significant increase in the number of these procedures performed in the military, especially after 2017 with the introduction of newer techniques.⁶ As we have seen in the civilian sector, Lapidus interventions have become very popular and frankly, a lot easier to do with the jigs. Not every patient needs a Lapidus, though. I have stretched the indications for this procedure of the years, including IM angles of 13-14 degrees. I have done well over a 1500 Lapidus corrections in my career; however, I have never used a jig system.

I’ve also noted a lot of interest in MIS (minimal incision surgery) bunionectomies recently. Like anything, it has a place and a role to play for all of us in the future. There is a considerable learning curve and shouldn’t be considered an option for all bunions, following my theme of tailored surgical selection. I personally reserve MIS for cases that I would typically do a chevron or a proximal osteotomy on. Predictably, I see MIS Lapidus is also now trending. In order to assure long-term success, especially in the military population, surgeons must carefully examine X-rays, measure key angles and choose interventions that support the data and associated biomechanics.

Dr. Spitalny is a Staff Podiatrist at GLWACH, Ft. Leonard Wood, Missouri and Adjunct Faculty SSM Depaul Podiatry Residency in St. Louis, Missouri.

References

1.     Unangst AM, Ryan PM. Return to run rates following hallux valgus correction: A retrospective comparison of metatarsal shaft osteotomies versus the modified Lapidus procedure. Foot Ankle Surg. 2021;27(8):892-896.
2.    Matthews M, Klein E, Youssef A, et al. Correlation of radiographic measurements with patient-centered outcomes in hallux valgus surgery. Foot Ankle Int. 2018;39(12):1416-1422.
3.     Matthews M, Klein E, Acciani A, et al. Correlation of preoperative radiographic severity with disability and symptom severity in hallux valgus. Foot Ankle Int. 2019;40(8):923-928.
4.     Fournier M, Saxena A, Maffulli N. Hallux valgus surgery in the athlete: current evidence. J Foot Ankle Surg. 2019;58(4):641-643.
5.     Schroeder P, Nicholes M, Baynes T, Huh J, Dowd T. What proportion of active-duty servicemembers functionally improve at 1 year post hallux valgus correction? Clin Orthop Relat Res. 2022; 480(11):2174–9.
6.     Nelson DA, Huh J, Clifton DR, Edgeworth DB, Shell D, Choi YS, Deuster PA. Rates of Lapidus procedures in the US military before and after the advent of and advocacy for tri-plane Lapidus corrective surgery. J Foot Ankle Surg. 2022 Aug 28;S1067-2516(22)00238-1.