Maintaining Perspective On The Debate Of Open Versus Minimal Incision Bunion Surgery

There has a been a small uptick in the number of lectures, industry events and articles that have been published on minimally invasive, percutaneous or minimal incision approaches to the foot and ankle. Rather than delve into what is right or wrong per se, I’d like to provide a little narrative behind the storyline and why the thought process works in some but not all cases.

As we know, hallux valgus is nearly an art form. We are all trained on various open approaches. “Dialing in” the correction on intra-operative radiographs can be challenging. During my training, I only read about failures of minimally invasive approaches and often received advice to “never go down that path.” However, after critical evaluation of my own work, I am intrigued about how minimal incision approaches may fit into my practice. Am I able to dial in that correction with these approaches? Is it useful for those with diabetes? Can I accomplish the goals of pain reduction and improved functionality? Ultimately, will my patients benefit from this approach?

Minimally invasive approaches have been around since the 1940s with Morton Polokoff, DPM, starting to perform “subdermal surgery.” Minimally invasive techniques were subsequently popularized by Stephen Isham, DPM in the late 1980s and 1990s as he developed more techniques and began lecturing on his “Reverdin-Isham” operation.¹ This was an intra-articular oblique and incomplete osteotomy of the first metatarsal head and proximal phalanx. Results were satisfactory for mild to moderate hallux valgus.² 

Over time, surgeon pioneers, typically outside the United States, started to broaden the indications and push the limits on techniques. This involved transverse osteotomies and percutaneous fixation, screw fixation, metatarsal osteotomies and even calcaneal osteotomies. As a country, we are starting to realize the potential of minimal incision approaches and how we can use them in an everyday setting. But first, we need to know our goals and limitations.  

The goal of hallux valgus correction is to restore alignment of the great toe and first metatarsal complex, including the sesamoids. Authors continue to show us time and time again that restoration of the sesamoid alignment is crucial.³ In a great article from 2018, Kim and Young showed us that the relationship of the sesamoids and the first metatarsal can be categorized into four categories.⁴ These categories are based on sesamoid subluxation and metatarsal rotation greater than 16 degrees. The most severe being complete sesamoid dislocation and over 16 degrees of metatarsal rotation. Employing weightbearing computerized tomography (CT) to assess this relationship, these study authors maintained that we should perform a lateral release only 70 percent of the time for hallux valgus repair.4 Kim and Young also found that the first metatarsal rotates into valgus approximately 87 percent of the time by greater than 16 degrees. 

The art of hallux valgus surgery is turning into a scientific cookbook, which in my mind is a great thing. As our understanding of the small world of the foot and ankle continues to evolve, we are driven by the technology at our fingertips that helps us improve the treatment of pathologies we see every day.

Historically, open bunionectomies have been a mainstay in our operating rooms and surgery centers, but there has been a transition to a “less invasive,” more “scientific” approach. From my perspective, there has to be a good meeting point between the two approaches. Some believe you cannot accomplish the ultimate goal of hallux valgus correction (reduction of the sesamoid complex in the frontal plane) with minimally invasive approaches. The objective of frontal plane rotation (when necessary) of either the metatarsal or sesamoids is achievable if the metatarsal osteotomy is transverse. Surgeons can reduce some sesamoid-first metatarsal complexes with a straight lateral translation (approximately seven to 11 degrees of correction) about 12 percent of the time.^5,6 One should critically assess the sesamoid reduction in each phase of the process, both on an anteroposterior view and sesamoid axial view radiographically. Weightbearing CT scans are highly valuable as well.

Trends in the world of hallux valgus correction will always wax and wane.  Approaches will fall in and out of favor based on cost, training, and appeal. Minimally invasive approaches can work if surgeons perform them correctly.  

I prefer a minimal incision approach (transverse osteotomy) for mild hallux valgus deformities and proximal rotational midfoot fusions with or without a lateral release for moderate to severe deformities. Do not put blinders on and think that an open distal translational osteotomy is the only way to get adequate sesamoid reduction and a happy patient.

Dr. McAlister is a fellowship-trained foot and ankle surgeon. He is in private practice and founder of the Phoenix Foot and Ankle Institute. (www.phoenixfai.com) He can be reached at jeff.mcalister@phoenixfai.com.

References

1. Isham S. The Reverdin-Isham procedure for the correction of hallux abducto valgus. A distal metatarsal osteotomy procedure. Clin Podiatr Med Surg. 1991;8(1):81-94. 
2. Malagelada F, Sahirad C, Dalmau-Pastor M, et al. Minimally invasive surgery for hallux valgus: a systematic review of current surgical techniques. Int Orthop. 2018;43(3):625–37. 
3. Shibuya N, Kyprios EM, Panchani PN, Martin LR, Thorud JC, Jupiter DC. Factors associated with early loss of hallux valgus correction. J Foot Ankle Surg. 2018;57:236–240. 
4. Kim JS, Young KW. Sesamoid position in hallux valgus in relation to the coronal rotation of the first metatarsal. Foot Ankle Clin. 2018;23(2):219–230. 
5. Lamo-Espinosa JM, Florez B, Villas C, et al. The relationship between the sesamoid complex and the first metatarsal after hallux valgus surgery without lateral soft-tissue release: a prospective study. J Foot Ankle Surg. 2015;54:1111–1115. 
6. Ramdass R, Meyr AJ. The multiplanar effect of first metatarsal osteotomy on sesamoid position. J Foot Ankle Surg. 2010;49:63–67.