Point-Counterpoint: Is The Lapidus Bunionectomy Overrated?

While acknowledging the benefits of the Lapidus bunionectomy for patients with severe hallux valgus, this author argues the Lapidus is otherwise overutilized and cites concerns with delayed weightbearing, non-union and destroying a functioning joint.

By Adam Landsman, DPM, PhD

Writing an article on the negative aspects of one of the most popular bunionectomy procedures is certainly going to get me ridiculed by many of my colleagues.

However, as my number of years in practice grows, I have earned the privilege of skepticism when new procedures emerge (or rather resurge). It is hard to believe that over 20 years ago, I was in the midst of debating the relative merits of the oblique closing base wedge osteotomy. My article on internal fixation techniques for this procedure won the prestigious William J. Stickel Award from the Journal of the American Podiatric Medical Association, and proved that surgeons could achieve stable internal fixation for this inherently unstable osteotomy.

So what happened to the closing base wedge osteotomy? Well, it is still around and still in use by many foot surgeons who have skillfully learned how to sidestep the shortcomings of the procedure to achieve outstanding results. However, most of us have abandoned the base wedge osteotomy for a variety of reasons: excessive shortening, technical difficulty, failed union, transfer lesions and the need for prolonged non-weightbearing and/or rigid boots. Hmm, sound familiar?

If you took a poll of your colleagues and asked them if they still performed base wedge osteotomies, most would probably say that they do not, but many are performing the Lapidus bunionectomy. Accordingly, let us take a critical look at the Lapidus procedure and try to understand the reasons why surgeons frown upon the base wedge osteotomy, but embrace the Lapidus bunionectomy.
 

Understanding The Impact Of Arthrodesis Within The Lapidus Procedure

One immediate difference that comes to mind between the Lapidus bunionectomy and the closing base wedge osteotomy is that the Lapidus procedure incorporates an arthrodesis in order to correct deformity whereas one performs a closing base wedge osteotomy in an extracapsular manner. This is not a trivial difference. When we fuse a joint, the patient loses motion and, more importantly, the position of that joint is locked for eternity. If we fuse the joint in a suboptimal position, that is a much more difficult problem to fix.
Some may argue this is an advantage of the Lapidus procedure because you can eliminate hypermobility.

We could debate all day long if all of those patients who get Lapidus bunionectomies actually have hypermobility but I would suggest the real issue is instability at the metatarsophalangeal joint (MPJ) and not the metatarsocuneiform joint. So why fuse a joint that is not painful or functioning abnormally?

Arthrodesis at the base of the first metatarsal can be technically difficult. By definition, it requires shortening of the metatarsal so a compensatory plantarflexion is almost always required to eliminate the risk of transfer lesions. The more proximal you work in the foot, the longer the lever arm is from the hallux. Accordingly, one must be more precise with his or her cuts.

As with any arthrodesis, non-unions, delayed unions and malunions are more common than extra-capsular osteotomies. New fixation techniques and a better understanding of the mechanical load vectors involved will minimize but not eliminate this problem, provided the bones have enough time to actually heal. You cannot beat mother nature. The Lapidus procedure is an intrinsically unstable osteotomy that will take time to heal.

A Few Points To Consider With Metatarsal Rotation And Triplane Correction

It is apparent to all experienced surgeons that the more proximal an osteotomy is, the greater the amount of angular correction that one can achieve. This is simple physics.

Furthermore, there appear to be real benefits to derotation of the first metatarsal in order to facilitate realignment of the tendons, particularly the flexor hallucis brevis and sesamoid apparatus. The triplane correction of the Lapidus bunionectomy is one of its most significant benefits. It also requires a great deal of surgical skill to get optimal positioning and lock that mobile, counter-rotated bone just right. As a result, the Lapidus procedure is one of the least forgiving procedures we do. Due to the difficulty in achieving proper alignment and stability, I have found that overcorrection, overshortening and plantarflexion are much more common with the Lapidus bunionectomy.

It has also been suggested that one great benefit of the Lapidus procedure is the ability to rotate the metatarsal in the frontal plane to realign the sesamoids. The work by Dayton and colleagues reminded us all to check the sesamoid axial views.^1-3

But the ability to counter-rotate is not unique to the Lapidus bunionectomy. One can also modify midshaft and distal head procedures to achieve counter-rotation. Medial reefing of sesamoids, along with lateral soft tissue releases, can also reduce the deforming rotational force, provided that the base of the metatarsal has not already been fused. Dayton and colleagues addressed this issue directly and found that isolated soft tissue releases were not adequate, but rotation of the metatarsal is a response to dynamic mechanical forces as well.² In addition, soft tissue realignment certainly plays a role in the correction, regardless of the mechanism by which one repositions the bones.

What is undisputed is that the derotational aspect of the Lapidus bunionectomy is permanent because the joint has been destroyed. Certainly, there are patients who benefit from this added stability but not every elevated intermetatarsal angle is simply a response to hypermobility or frontal plane rotation.  

Exploring Different Perceptions Of What Constitutes Immediate Post-Op Weightbearing

In debates with my colleagues, I frequently hear about minimal immediate postoperative disability as a reason for doing the Lapidus procedure. I think my definition of immediate weightbearing after surgery is completely different from theirs. The scarf bunionectomy, Austin bunionectomy and Reverdin bunionectomy are three examples of procedures in which there is clearly intrinsic stability. Surgeons can position the cuts in a way that compresses the osteotomy with standing, unlike the Lapidus bunionectomy, which has a natural tendency toward plantar gapping when loaded.

The difference is significant. When I perform the scarf bunionectomy, patients walk out of the hospital in a surgical shoe and normally switch to an athletic shoe in one week. That is what I mean by postoperative weightbearing.

My Lapidus-loving colleagues will typically place their postoperative patient in a fixed ankle boot for a month and many of these patients utilize crutches and remain partially non-weightbearing for several weeks. This can also lead to joint stiffness at the first MPJ from delayed range of motion.

Is There An Elevated Risk Of Scarring With The Lapidus Procedure?

Although there have been reports of minimally invasive Lapidus bunionectomies, the vast majority of these procedures require a proximal first metatarsal medial cuneiform incision. Furthermore, most of the time, this incision continues distally to the first MPJ. Alternatively, there may be a second distal incision.
In either case, there is usually substantially more dissection and associated scarring with the Lapidus procedure. Although the risk of infections following foot surgery is relatively low, the small risk is amplified with the Lapidus bunionectomy.

In Conclusion

I should make it clear that I am not anti-Lapidus but I do think it has become a grossly overused procedure. In my experience, the Lapidus bunionectomy is an excellent choice for the patient who has good bone density with significant deformity including markedly elevated first intermetatarsal angles (i.e. 18 degrees or more), frontal plane deformity (visible rotation on sesamoid axial radiographs), and/or flexible pes planus deformity. This patient should also have no illusions about immediate weightbearing and should be able to live with the fact that he or she will not be able to return to an athletic style shoe for at least one month.

Consequently, I rarely choose to treat my patients with a Lapidus bunionectomy. In my opinion, it requires too much post-op disability, too much dissection, too much expensive hardware and is exceptionally unforgiving as bunionectomies go. I am also disheartened by the higher rate of failed unions at the metatarsocuneiform joint and extended recovery. I am also concerned about the irreversible destruction of a functioning joint and the risk of shortening and malpositioning of the first metatarsal.

The Lapidus bunionectomy is a fine procedure but it is increasingly perceived  as a “one-size-fits-all” solution, which it is not. This is a powerful procedure that surgeons should reserve for patients with severe deformity. Unfortunately, I believe it is frequently used inappropriately and therefore is overrated.

Dr. Landsman is the Chief of the Division of Podiatric Surgery at Cambridge Health Alliance. He is an Assistant Professor of Surgery at Harvard Medical School.

References
1.    DiDomenico LA, Fahim R, Rollandini J, Thomas ZM. Correction of frontal plane rotation of sesamoid apparatus during Lapidus procedure: a novel approach. J Foot Ankle Surg. 2014; 53(2):248–251.
2.    Dayton P, Feilmeier M, Kauwe M, Hirschi J. Relationship of frontal plane rotation of first metatarsal to proximal articular set angle and hallux alignment in patients undergoing tarsal metatarsal arthrodesis for hallux abducto valgus: a case series and critical review of the literature. J Foot Ankle Surg. 2013; 52(3):348–354.
3.    Dayton P, Kauwe M, Feilmeier M. Is our current paradigm for evaluation and management of the bunion deformity flawed? A discussion of procedure philosophy relative to anatomy. J Foot Ankle Surg. 2015;54(1):102-11.

Questioning the conventional factors that go into procedure selection, this author emphasizes a stronger anatomical understanding of bunion correction and advocates triplane realignment for consistently reproducible outcomes.  

By Paul Dayton, DPM, MS, FACFAS

As for all procedures, the goals for bunion surgery are complete correction, consistent correction and durable correction. This is what our patients expect when they agree to surgery.

The question at hand and the basis of this argument is, which procedure can deliver on these goals? There are a plethora of studies indicating less than favorable results after metatarsal osteotomy even though it is the most popular option.^1–7

Let’s face it. Bunion surgery has a bad reputation among patients and providers. We warn our patients of significant potential complications as a priority during our discussions and both providers and patients shy away from surgery because we don’t have confidence in the consistency of our traditional methods.

Why then would the Lapidus procedure be any better? The answer is not in the execution of the procedure but in the philosophic and anatomic differences between the concepts of osteotomy and triplane tarsometatarsal fusion. Regardless of configuration or location in the first metatarsal, osteotomy makes a new deformity in the normally straight first metatarsal. This is the first issue with osteotomy philosophy.

How Bunion Correction Has Evolved

In 2015, we wrote “Of the over 100 procedures that have been proposed to treat hallux valgus or the ‘bunion’ deformity, the majority focus on correction through metatarsal osteotomies at various levels combined with soft tissue balancing procedures at the first (metatarsophalangeal) joint. This paradigm of metatarsal osteotomy and soft tissue balancing is so commonplace that any argument for a fundamental change to the approach becomes uncomfortable and seems unwarranted to most foot and ankle surgeons. However, the simple fact that there are so many procedures, so many modifications, and such high complications can be interpreted as a failure of our basic paradigm of metatarsal osteotomy and soft tissue balancing.”⁸

Although there has been some movement to better understand the basic anatomy and what we are seeing on the two-dimensional AP radiograph, we are still debating the Lapidus procedure based on how it fits into the spectrum of osteotomy procedures. The fact is my personal concept of tarsometatarsal arthrodesis, which I employ for every non-degenerative bunion, takes into consideration a truer understanding of the deformity and is not limited by arbitrary indications such as large intermetatarsal angles and “hypermobility.” I firmly believe, based on research findings and experience, we should treat all deformities at the anatomic apex and we must correct all planar components of the deformity in every case.

So, is this the “Lapidus procedure” or another debate altogether? In reality, this is not a debate over individual procedures. It is a debate over anatomic understanding and philosophy. The reasons to choose a tricorrectional tarsometatarsal arthrodesis procedure are not based on intermetatarsal angle, hallux abductovalgus and hypermobility. The reasons are that it corrects all bunions at the anatomic apex at a location where triplane realignment is consistently and completely obtainable. The current multi-osteotomy mindset that surgeons learn and practice drives the search for yet more procedures and modifications in an attempt to reduce complications and recurrence when, in fact, it may be our most basic evaluation system that is incorrect and driving these complications.

Emphasizing Triplane Realignment

Additionally, the thinking is it is the fusion of the tarsometatarsal that can reduce recurrence. We know, however, that a full-blown recurrence is possible even with a solid arthrodesis at the tarsometatarsal. This highlights another misconception: that range of motion and functional instability occur exclusively at the tarsometatarsal. We know that the normal range of motion of the first ray occurs at the naviculocuneiform and intercuneiform joints to a much greater degree than the tarsometatarsal.

Many surgeons, including myself, now believe that it is triplane realignment that results in a balanced soft tissue envelope at the first metatarsophalangeal joint (MPJ) and first ray, and it is this fact that reduces recurrence, not the fusion of the tarsometatarsal.

As my colleagues and I wrote previously, “If one examines the multitude of metatarsal osteotomy designs, it is clear that the correction provided is limited to the transverse or sagittal planes regardless of the geometry of the cut, the fixation selected, or the associated soft tissue balancing. Although broadly accepted, this multiprocedural approach based on severity algorithms overlooks the most important component of any deformity, which is the primary level of the deformity. The metatarsal in a bunion is not deformed. Rather, the structure of the forefoot deviates from normal anatomy in multiple planes at the level of the first (tarsometatarsal and metatarsophalangeal joints). The traditional approach to surgery (osteotomy) does not always correct this primary deformity; instead, metatarsal osteotomies create a new deformity of the metatarsal itself.”⁹  

It has been several years since we wrote this and my conviction has only strengthened based on emerging information and personal experience.^10–12 We need to change our basic premise of procedure selection to one based on three-dimensional functional anatomy, not two-dimensional angles measured on an AP radiograph.

While we can continue the debate by reviewing a variety of case series and cohort studies to try to determine which philosophy is best, the observation bias that exists in all of these studies renders them useless to answer the question.  

The current convention for measuring the preoperative intermetatarsal angle is an angular comparison of the mid-diaphysis line of the first and second metatarsals. The method of measurement changes after the procedure and we measure from the midpoint of the first MPJ surface and the center of the tarsometatarsal joint.

Although this is conventional as part of our current scheme to measure the pre-op intermetatarsal angle, we should abandon it for the simple reason that it produces misleading conclusions regarding the true correction provided by metatarsal corrective procedures by vastly overestimating correction of all the AP radiographic angles. Studies that report results based on this convention are simply inaccurate.¹³ If one analyzes the mid-diaphyseal intermetatarsal angle, in many cases following metatarsal osteotomy, the true intermetatarsal angle actually increases while center of joint measurements suggest a decrease. Additionally, the forefoot is not narrowed in a majority of cases following osteotomy, indicating a lack of true deformity correction.

Current Concepts On Sesamoid Position And Frontal Plane Rotation

We also must recognize that frontal plane rotation of the first metatarsal exists in a bunion deformity. This frontal plane component has a significant and dramatic effect on the alignment of the first MPJ, including the sesamoids. Researchers have studied the position of the metatarsal in a bunion deformity and noted a consistent pronation or valgus position.^14,15 Other authors have recently observed the importance of reducing the valgus (pronated) frontal plane component of the metatarsal in the deformity and the effect that this derotation can have on MPJ and sesamoid alignment.^16,17 We cannot clinically visualize frontal plane position of the metatarsal in a bunion deformity. However, just because we cannot see it clinically does not mean that it does not exist.

Maintenance of sesamoid position is one factor that can illustrate the shortcomings of an osteotomy. If the pronated or valgus metatarsal is the primary reason for perceived deviation of the sesamoids, what is really taking place with transverse plane translational osteotomies that produce alignment of the sesamoids immediately post-procedure?

In the case of a sliding osteotomy that corrects the intermetatarsal angle but cannot produce varus (supination) rotation to correct frontal plane position of the metatarsal, pulling of the sesamoids medial to the median crista through capsulorrhaphy has created the perception that the sesamoids are correctly positioned under the metatarsal on the AP radiograph when, in fact, they are not. Though the immediate post-op sesamoid position looks correct on the AP radiograph, the sesamoids are not in their anatomic grooves and long-term maintenance is not predictable as the sesamoids drift laterally on the pronated metatarsal head. Deforming forces from the hallux proximal to the metatarsal—because of the lateral position of the sesamoids and tendons as described by Mortier and coworkers—can result in recurrence of the hallux abductovalgus and the increased intermetatarsal angle.¹

So we use capsular balancing to offset the lack of true deformity correction and, in my experience, this does not stand the test of time. If pronation is present, making the sesamoids look subluxed on the AP radiograph, then it is supinatory derotation, not capsular balancing maneuvers, that is needed to “balance the soft tissues.” With triplane tarsometatarsal joint correction, we rarely have to do any significant capsular balancing to get and maintain complete sesamoid reduction.

The fact is, common and popular metatarsal osteotomy procedures do not address the primary level of the deformity, nor do they address the deformity in all three planes. Instead, these popular procedures focus correction on a non-deformed metatarsal and actually create a new deformity in the previously straight but deviated metatarsal.

Final Thoughts

So, is the Lapidus bunionectomy the answer? Going by traditional indications and execution, my answer would be no.

My personal philosophy is to treat a bunion deformity as we do other deformities by addressing the apex of the deformity and addressing all planar components. We will learn more in the coming years about the long-term results of the triplane tarsometatarsal arthrodesis. Personally, after 10-plus years of performing this technique exclusively for non-degenerative bunions, I have no plans of returning to my roots of two-dimensional radiographic evaluation and the frustration of selecting from dozens of osteotomies that in reality are all the same flawed philosophy.

Dr. Dayton is affiliated with the Foot and Ankle Center of the Iowa/Midwest Bunion Center in Ankeny, Iowa. Dr. Dayton is a Fellow of the American College of Foot and Ankle Surgeons.

Dr. Dayton has been performing triplane tarsometatarsal arthrodesis exclusively for non-degenerative bunions since 2009. He has disclosed that he has worked as a consultant and design team surgeon with Treace Medical Concepts, Inc. since 2014.

References
1.    Mortier JP, Bernard JL, Maestro M. Axial rotation of the first metatarsal head in a normal population and hallux valgus patients. Orthop Traumatol Surg Res. 2012; 98(6):677-683.
2.    Tanaka Y, Takakura Y, Sugimoto K, Kumai T, Sakamoto T, Kadono. Precise anatomic configuration changes in the first ray of the hallux valgus foot. Foot Ankle Int. 2000; 21(8):651-656.
3.    Chi TD, Davitt J, Younger A, Holt S, and Sangeorzan BJ. Intra- and inter-observer reliability of the distal metatarsal articular angle in adult hallux valgus. Foot Ankle Int. 2002; 23(8):722-726.
4.    King DM, Toolan BC. Associated deformities and hypermobility in hallux valgus: an investigation with weightbearing radiographs. Foot Ankle Int. 2004; 25(4):251-255.
5.    Scranton PE, Rutkowski R. Anatomic variations in the first ray- part 1: anatomic aspects related to bunion surgery. Clin Orthop Rel Res. 1980; 151:244-255.
6.    Grode SE, McCarthy DJ. The anatomic implications of hallux abducto valgus: a cryomicrotomic study. J Am Pod Med Assoc. 1980; 70(11):539-551.
7.    Eustace S, Obyrne J, Stack J, Stephens MM. Radiographic features that enable the assessment of first metatarsal rotation: the role of pronation in hallux valgus. Skeletal Radiol. 1993; 22(3):153-6.
8.    Dayton P, Merrell K, and Feilmeier M. Is our current paradigm for evaluation and management of the bunion deformity flawed? A discussion of procedure philosophy relative to anatomy. J Foot Ankle Surg. 2015;54(1):102-11.
9.    Dayton P, Feilmeier M, Kauwe M, Hirschi J. Relationship of frontal plane rotation of first metatarsal to proximal articular set angle and hallux alignment in patients undergoing tarsal metatarsal arthrodesis for hallux abducto valgus: a case series and critical review of the literature. J Foot Ankle Surg. 2013; 52(3):384-354.
10.    DiDomenico LA, Fahim R, Rollandini J, Thomas ZM. Correction of frontal plane rotation of sesamoid apparatus during lapidus procedure: a novel approach. J Foot Ankle Surg. 2014; 53(2):248-251.
11.    Okuda R, Yasuda T, Jotoku T, Shima H. Proximal abduction-supination osteotomy of the first metatarsal for adolescent hallux valgus: a preliminary report. J Orthop Sci. 2013; 18(3):419-425.
12.    Dayton P, Feilmeier M, Hirschi J, Kauwe M, Kauwe JS. Observed changes in radiographic measurements of the first ray after frontal plane rotation of the first metatarsal in a cadaveric foot model. J Foot Ankle Surg. 2014;53(3):274-278.
13.    Dayton P, Feilmeier M, Lenz R. Clinical and surgical implications of first ray triplane deformity. In Dayton P (ed.) Evidence-Based Bunion Surgery: A Critical Examination of Current and Emerging Concepts and Techniques. Springer International, Switzerland, 2018, pp. 73–90.
14    Judge MS, LaPointe S, Yu GV, Shook JE, Taylor R. The effect of hallux abducto valgus surgery on the sesamoid apparatus position. J Am Pod Med Assoc. 1999; 89(11-12):551-559.
15.    Ramdass R, Meyr AJ. The multiplanar effect of first metatarsal osteotomy on sesamoid position. J Foot Ankle Surg. 2010; 49(1):63-67.
16.    Okuda R, Kinoshita M, Yasuda T, Jotoku T, Kitano N, Shima H. Postoperative incomplete reduction of the sesamoids as a risk factor for the reccurence of hallux valgus. J Bone Joint Surg. 2009; 91(7):1637-1645.
17.    Okuda R, Kinoshita M, Toshito Y, Jotoku T, Kitano N, Shima H. The shape of the lateral edge of the first metatarsal head as a risk factor for recurrence of hallux valgus. J Bone Joint Surg. 2007; 89(10):2163-2172.

Additional References
18.    Talbot KD, Saltzman CL. Assessing sesamoid subluxation: how good is the AP radiograph? Foot Ankle Int. 1998; 19(8):547-554.
19.    Dayton P, Kauwe M, Feilmeier M. Clarification of the anatomic definition of the bunion deformity. J Foot Ankle Surg. 2014; 53(2):160-163.
20.    Robinson AHN, Cullen NP, Chhaya NC, Sri-Ram K, Lunch A. Variation of the distal metatarsal articular angle with axial rotation and inclination of the first metatarsal. Foot Ankle Int. 2006; 27(12):1036-1040.
21.    Lee KM, Ahn S, Chung CY, Sunk KH, Park MS. Reliability and relationship of radiographic measurements in hallux valgus. Clin Orthop Relat Res. 2012; 470:2613-2621.
22.    Meyr AJ, Myers A, Pontious J. Descriptive quantitative analysis of hallux abductovalgus transverse plane radiographic parameters. J Foot Ankle Surg. 2014; 53(4):397-404.
23.    Kuwano T, Nagamine R, Sakaki K, Urabe K, Iwamoto Y. New radiographic analysis of sesamoid rotation in hallux valgus comparison with conventional evaluation methods. Foot Ankle Int. 2002; 23(9):811-817.