Addressing Common Complications Of The Lapidus Bunionectomy

Although the Lapidus bunionectomy has a proven track record for the treatment of hallux valgus, complications can occur. This author provides a guide to rectifying such post-op events as non-union, malunion, excessive shortening and bunion recurrence.

The Lapidus bunionectomy is probably the go-to bunion surgery method for treating large and/or recurrent bunions, but the procedure is not without its pitfalls.^1-11 Even when experienced surgeons perform the Lapidus procedure, things can go wrong and it is important to understand what possible complications exist and how to manage them successfully. While there have been tremendous advances with the Lapidus bunionectomy during the past decade that have allowed surgeons to minimize postoperative problems, it is impossible to completely eliminate complications altogether.  

While these are dozens of mishaps that can be classified as complications after Lapidus bunion surgery, I would like to discuss the more common complications that can occur. The good news is that when one identifies these Lapidus complications and manages them properly, the end result may be satisfactory. While there is no cookie cutter approach to every complication, I would like to provide a framework (or playbook) on what has been successful in my hands as I approach two decades of performing the Lapidus bunionectomy.  

Key Pearls On Fighting Post-Op Infection
Infections occur with any surgery and the Lapidus bunionectomy is not an exception. Superficial infection is one of the more common occurrences after the Lapidus procedure. Deeper infections that involve bone and/or hardware are much more uncommon, but you should always keep this possibility in the back of your mind. It is important to recognize infections early and initiate treatment, even if it requires “going back in” shortly after the index operation.  

Acute infections typically present a few days after surgery and may present with symptoms such as increased pain, warmth, fevers, chills and/or night sweats. When you suspect possible infection, examine the patient for this even if it is prior to your standard first postoperative visit. Useful lab work to obtain includes complete blood cell (CBC) count, Chem 7, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Demarcating erythema with a felt tip marker is helpful to evaluate progress. Superficial infections usually involve focal erythema around the incision and/or around areas of increased swelling. Oral antibiotics usually resolve the infection.  

Consider intravenous antibiotics for patients with a bright erythema and cellulitis. Incision and drainage may be required when erythema does not respond to oral or intravenous antibiotics as this suggests a deeper infection. Overt areas of fluctuance can be concerning for abscess and/or hematoma. Dehiscence may require more immediate action for incision and drainage. Subacute or chronic infections may present weeks or months after the index operation.   

Any infection where hardware is involved is concerning because surgeons often need to remove infected hardware. Removing hardware prior to bone healing at approximately six weeks jeopardizes the capability for fusion. Generally speaking, removing infected hardware trumps the need to keep hardware for the sake of the fusion. In some cases, hardware can remain in place in the presence of deep infection based on the clinical situation and the surgeon’s experience in managing this scenario. Generally speaking, surgeons should remove grossly purulent hardware. A rule of thumb is that when hardware is infected, so is the bone. Accordingly, one should perform bone debridement when it is clinically necessary.  

Surgically managing the postoperative infection after a Lapidus bunionectomy may involve at least two stages depending on the extent of the infection. The first procedure is to wash out the foot, obtain cultures and assess the infection. If infection is limited and the hardware is not purulent, subsequent treatment may involve intravenous or oral antibiotics depending on the clinical scenario. If the hardware is purulent with obvious infection, one can remove the hardware at this first stage or in a few days once culture results return. The surgeons may place antibiotic beads or a block at this stage as well, depending on the extent of the infection. The second operation involves a second washout, placement/exchange of antibiotic beads/block and the possible use of external fixation. Depending on the timeframe from the index operation to the infection, there may be a partial fusion and placing external fixation is not always necessary. Long-term antibiotics are recommended for osteomyelitis.

Emerging Insights On Post-Lapidus Non-Unions
The word “non-union” is strongly associated with the Lapidus bunionectomy, due to early inexperience with the procedure. Of course, non-unions can occur as the Lapidus procedure involves a bone fusion but the frequency of non-union is not the issue it used to be. The incidence is now acceptably low enough that one can dismiss the notion of a strong association of non-unions with the Lapidus bunionectomy.  

The non-union rate after Lapidus bunionectomy can be up to 10 percent, depending on the fixation method and postoperative weightbearing protocols.⁸ More recent studies have illustrated non-union rates lower than 10 percent.^4,12-14 Non-union is more likely to occur from inadequate joint preparation and poor fixation. We used to blame postoperative weightbearing for non-unions but several early weightbearing studies have debunked that myth.^4,12,14,15

An important point to make with non-union and Lapidus is that a radiographic non-union is a completely acceptable result. A radiographic non-union is one in which the bones are not mended on X-rays and the patient is asymptomatic. Early Lapidus studies included radiographic asymptomatic non-union as part of their calculation for non-union rate, thereby inflating their non-union rate upwards of one out of four cases, which also contributes to this Lapidus non-union stigma. Clinical experience has also taught me that delayed unions and non-union after Lapidus bunionectomy can eventually mend over time so there is no rush to treat X-rays as long as the patient is symptom-free. For patients whose X-rays show lucency and sclerosis at the fusion site three months after the index operation, one should consider the use of a pulsed electromagnetic field bone stimulator.

Surgeons can revise symptomatic non-unions as early as six to nine months after the index operation depending on the clinical scenario. The most important point when planning a non-union revision is to figure out why the patient developed the non-union in the first place so you can avoid the same pitfalls. Smokers have a high risk for non-union for the index operation and the revision so one should initiate smoking cessation counseling with patients. Non-union can be more common in obese patients as the excessive weight can supersede the hardware’s ability to hold the segment stable.

With non-union surgery, there is often existing hardware that may or may not be broken. Obviously, one needs to remove existing hardware at the same time as the planned revision. It is good medicine to remove existing hardware (when possible) as new hardware may be a different metal, potentially causing an electrical current between the metals.  

Surgeons should consider the previous fixation construct of the index operation and likely not repeat it. If crossed screws were part of the index procedure, the revision may be better served with a plate. If a plate was part of the index operation, then one may want to consider crossed screws or a completely different plating system for the revision procedure. Sometimes crossed screws and a plate have a place. One may consider external fixation as well, especially when the medial cuneiform has significant bone loss. The take-home point for fixation is that the new fixation should be more stable than what one used for the index surgery.  

There are two ways that I handle non-unions. The first is to take down the entire joint and the other is to perform a spanning autologous bone block graft. Preoperative computed tomography is helpful to assess the extent of the non-union. Partial unions may lend themselves to placing a spanning bone block graft but this scenario is much less frequent. When you need to address the entire non-union, resect the non-union to good bleeding, healing bone, so much so that you should expect some additional bone loss and shortening of the first ray segment. It is important to keep in mind the length of the first ray during this process and not completely disrupt the metatarsal parabola. Often the treatment for non-union requires a bone block graft to maintain the length of the first ray. The heel bone is a great source for bicortical bone, which is excellent for this scenario. Allograft is also usually needed to augment the bone defect.  

How To Fix Excessive Shortening
Shortening is expected to occur with all Lapidus procedures due to the resection of the first tarsometatarsal joint and should be no more than 0.5 cm. The surgeon can combat this shortening by inferiorly translating the first metatarsal or plantarflexing the first metatarsal during the surgery to obtain first metatarsal head presence on the ball of the foot. Over-shortening of the first metatarsal may result in sub-second metatarsal head metatarsalgia and/or loss of hallux purchase with or without flexion of the hallux interphalangeal joint.  

Surgeons should be mindful of the metatarsal head parabola and sub-second metatarsal symptoms preoperatively. For patients who have sub-second metatarsal head callus with pain and a first ray that is already short by 0.5 cm, one should consider concomitant second metatarsal shortening. I have found patients tolerate about a 0.5 cm differential between the first and second metatarsal. A differential over 1 cm can become problematic. One way to control shortening intraoperatively is to avoid use of the saw to remove the joint cartilage as more bone loss is possible with this technique. I prefer the curettage method and if the joint requires molding, one can use the sagittal saw to feather the joint under irrigation.    

The surgical treatment for excessive shortening involves restoring the parabola, which can involve bringing the first ray out to length and/or shortening the second metatarsal. One can lengthen the first ray with callus distraction or a bone graft, and I have found the latter to be a better option.

One can insert a bone graft into the previous fusion site (yes, you need to take down the fusion). Again, the calcaneus is a good source for this bone block graft. Surgeons can achieve first ray lengthening of 1 to 2 cm but approximately 1 cm in length is what is commonly needed for most of these revision cases. Acute lengthening may stress the neurovascular structures so one should proceed with caution. Also, significant lengthening may jam the first metatarsophalangeal joint (MPJ) and this should be a consideration when lengthening occurs intraoperatively. Fixation involves a long plate that spans the graft with at least two points of fixation proximal and distal to the graft site. It is important to have stable fixation.

Addressing Bunion Recurrence
Recurrence after Lapidus bunionectomy is uncommon since the procedure involves correction at the apex of the deformity. There are two causes of recurrence to consider with the Lapidus procedure. The first cause is from untreated hypermobility and the second is hallux abduction/valgus. It is not uncommon for the hallux to drift laterally. This is not a recurrence but rather a functional positioning of the hallux. In these cases, the patient is concerned that the bunion may be coming back but X-rays often demonstrate otherwise with a corrected intermetatarsal angle.

Untreated hypermobility, especially in the transverse plane, can cause the intermetatarsal angle to splay back open after surgery. I previously described the intraoperative hypermobility test to identify and treat this during the index operation rather than waiting for this to present itself as a recurrent bunion.^17,18 Recurrence due to intraoperative hypermobility generally requires additional fusion procedures.¹⁹ Hypermobility after existing first tarsometatarsal joint fusion can originate from the first intercuneiform joint and/or the naviculocuneiform joint. Radiographs and the clinical exam can help pinpoint the source. Additional fusion of the intercuneiform joint of the first metatarsal base to the second metatarsal base may be indicated.  

When Malunion Occurs
Depending on the plane with which the fusion site was set, there are a host of problems that can occur from malunion. A dorsal bunion and hallux limitus are the result when the first metatarsal has healed in an elevated position. These patients may also experience sub-second metatarsal transfer metatarsalgia. Improper alignment of the first metatarsal in the transverse plane may result in a persistent bunion that presents immediately after the index operation. Overcorrection of the intermetatarsal angle may result in a hallux varus. Overly plantarflexing the first metatarsal may cause sub-first metatarsal sesamoiditis with callosities.  

Surgically correcting Lapidus malunions is usually straightforward and involves opening wedge osteotomies or closing wedge osteotomies through the fusion site. Treat an elevated first ray with a dorsal opening wedge osteotomy at the fusion site. Surgeons can correct an undercorrected intermetatarsal angle with a medial opening wedge osteotomy. Closing wedge osteotomies may be appropriate but may create unwanted shortening. Accordingly, it is important to consider the clinical scenario when designing your osteotomies. A negative intermetatarsal angle along with hallux varus may respond to treatment near the metatarsal head (rather than the base) through a reverse Austin-type osteotomy.  

In Conclusion
When it comes to Lapidus complications, the best way to treat the complications is not to have them in the first place. Of course, it is impossible to be complication-free but when complications arise, it is best to identify them quickly and initiate proper treatment.

Dr. Blitz, the creator of the Bunionplasty^® procedure, is in private practice in both Midtown Manhattan, New York and Beverly Hills, Calif. He is board-certified by the American Board of Foot and Ankle Surgery, and is a Fellow of the American College of Foot and Ankle Surgeons. To learn more about minimally invasive bunion surgery, visit www.bunionplasty.com.

To learn more about bunion surgery by Dr. Blitz, please visit www.DrNealBlitz.com .

References

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2.     Lapidus PW. A quarter century of experience with the operative correction of the metatarsus varus in hallux valgus. Bull Hosp Joint Dis Orthop Inst. 1956; 17(2):404.
3.     Lapidus PW. The author’s bunion operation from 1931 to 1959. Clin Orthop. 1960; 16:119-35.
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8.     Sangeorzan BJ, Hansen ST Jr. Modified Lapidus procedure for hallux valgus. Foot Ankle. 1989;9(6):262-6.
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11.     Catanzariti AR, Mendicino RW, Lee MS, Gallina MR. The modified Lapidus arthrodesis: a retrospective analysis. J Foot Ankle Surg. 1999;38(5):322-32.
12.     Lamm BM, Wynes J. Immediate weightbearing after Lapidus arthrodesis with external fixation. J Foot Ankle Surg. 2014;53(5):577-83.
13.     Patel S, Ford LA, Etcheverry J, Rush SM, Hamilton GA. Modified lapidus arthrodesis: rate of nonunion in 227 cases. J Foot Ankle Surg. 2004;43(1):37-42.
14.     King CM, Richey J, Patel S, Collman DR. Modified lapidus arthrodesis with crossed screw fixation: early weightbearing in 136 patients. J Foot Ankle Surg. 2015;54(1):69-75.
15.     Blitz NM. Early weightbearing of the Lapidus bunionectomy: is it feasible? Clin Podiatr Med Surg. 2012;29(3):367-81.
16.     Gutteck N, Wohlrab D, Zeh A, Radetzki F, Delank KS, Lebek S. Immediate fullweightbearing after tarsometatarsal arthrodesis for hallux valgus correction--Does it increase the complication rate? Foot Ankle Surg. 2015;21(3):198-201.
17.     Blitz NM. Use of the first ray splay test to assess transverse plane instability before first metatarsocuneiform fusion. J Foot Ankle Surg. 2006;45(6):441-3; author reply 443.
18.     Fleming JJ, Kwaadu KY, Brinkley JC, Ozuzu Y. Intraoperative evaluation of medial intercuneiform instability after Lapidus arthrodesis: intercuneiform hook test. J Foot Ankle Surg. 2015;54(3):464-72.
19.     Galli MM, McAlister JE, Berlet GC, Hyer CF. Enhanced Lapidus arthrodesis: crossed screw technique with middle cuneiform fixation further reduces sagittal mobility. J Foot Ankle Surg. 2015;54(3):437-40.

Editor’s note: For related articles, see “Performing Revision Surgery Following The Lapidus Bunionectomy,” the November 2013 DPM Blog by Allen Jacobs, DPM, FACFAS, or “Emerging Concepts With Post-Lapidus Bunionectomy Weightbearing” in the September 2012 issue of Podiatry Today.