Essential Insights On Crossover Hammertoe Repair

Crossover toe deformity can be a technical challenge for surgeons as well as a challenge in addressing the preconceived expectations of patients. With this in mind, this author provides practical surgical pearls, discusses the plantar versus dorsal approach debate in regard to plantar plate repair and offers keys to minimize complication risk.

The crossover toe deformity is a hammertoe variant that involves biplanar malalignment (sagittal and transverse) affecting both the metatarsophalangeal joint (MPJ) and the proximal interphalangeal joint, which typically occurs with the second toe overlapping the hallux.^1-6

This deformity most commonly affects women over 50 years of age.⁴ Although the crossover toe deformity is considered a “toe” deformity, much of the pathology exists at the level of the MPJ. Part of the pathology associated with the crossover toe typically involves ligamentous attenuation and/or tearing of the plantar plate and lateral collateral ligament of the MPJ.⁵ Several other forefoot deformities may exist concomitantly including, but not limited to, hallux valgus, hallux rigidus, hallux interphalangeus, abnormal metatarsal cascade, adjacent lesser toe contracture and adjacent lesser toe transverse plane deformity.

One should consider initial conservative treatments, including wide/deep toe box shoes, taping, splinting, padding and orthotics among other options. Despite conservative efforts, frequently crossover toe deformities progress and pain persists, resulting in a discussion of surgical options.

Keys To An Effective Surgical Consult

The goals of crossover toe correction should include decreased pain, improved function, getting the second toe to purchase the ground in stance and attaining toe position conducive with use of off-the-shelf shoe gear.

When initiating a discussion for the correction of crossover toe deformity, it is imperative to manage patient expectations appropriately. Second MPJ pathology is difficult to treat and the patient and surgeon should acknowledge that the second toe may never be “normal.” A crossover toe, by definition, is non-functional and does not appropriately purchase the ground. When considering surgery, bear in mind that the crossover toe has, in many cases, maintained this abnormal posture for years. If the patient expects the toe to function as if it were never deformed, the likelihood of dissatisfaction increases. It is the full responsibility of the surgeon to honestly describe the expected result of a successful outcome.

With appropriate procedure selection and properly performed surgery, the surgeon can achieve the aforementioned goals. However, there is often some residual stiffness and/or swelling that may occur with the toe, and last up to or beyond one year.^7-8 At the time of the surgical discussion, it is also necessary to evaluate the patient and associated imaging properly to determine what concomitant pathologies require simultaneous attention, including the first MPJ and adjacent lesser toe pathology.

If hallux pathology (e.g. hallux valgus) is present, address the first MPJ first to allow appropriate room for correction of the second toe deformity. Additionally, a detailed vascular examination is necessary to assess for the risk of vascular embarrassment following complete correction of the second toe position as the deformed toe is often chronically dislocated. If there is preoperative concern for the heightened post-op risk of an ischemic toe, I recommend consultation with a vascular specialist. For some patients (e.g. elderly, those with low functional demand) in whom vascular disease or severe deformity is present, one can consider offering amputation as a primary treatment option to the patient with a more predictable result than reconstruction.

Addressing Debates Over Plantar Plate Repair And Optimal Fixation For Hammertoe Deformities

Currently, there remains a discussion regarding the management of the plantar plate and the most optimal surgical approach. There are commercially available systems to fully address plantar plate pathology from a dorsal approach while some surgeons maintain a direct plantar approach is the preferred method.^7-9

In my experience, surgeons can adequately address the plantar plate from a direct plantar approach that avoids a dorsal incision that crosses the MPJ, thus reducing the risk of a dorsal contracture. This approach often supplements the crossover toe repair. In a recent study from our Orthopedic Foot and Ankle Center, my colleagues and I demonstrated, via validated outcome measures, significant improvements in pain, disability and activity limitation when employing a direct plantar approach to plantar plate repair in 76 patients.⁷

Additionally, debate continues for the most appropriate proximal interphalangeal joint fusion hardware for hammertoe (including crossover toe) deformity. Internal implants are increasingly popular for proximal interphalangeal joint fusion as the selection of medical devices in this arena continues to grow due to the decreased risk of infection and decreased rate of non-union. Historically, Kirschner wires were the gold standard for hammertoe correction fixation. In addition to factors such as low cost and ease of use, many surgeons continue to employ Kirschner wires secondary to the ability to traverse fixation across multiple joint levels (proximal interphalangeal joint and MPJ). Regardless of the instrumentation the surgeons uses to correct crossover toe deformity, it is imperative to address both the soft tissue and osseous components of the deformity fully as well as concomitant adjacent deformities.

A Practical Guide To The Surgical Approach

My initial approach for crossover toe correction is to address the first ray deformities present. Pay particular attention to transverse plane deformity within the hallux itself (i.e. hallux interphalangeus) in addition to possible hallux valgus or hallux rigidus deformities to ensure proper spacing exists to realign the second toe once you have properly aligned the first ray. Proceed to evaluate the lateral toes (i.e. third, fourth and fifth). If there is medial deviation of these digits, address these deformities next. This may require a proximal interphalangeal fusion, a proximal interphalangeal joint arthroplasty and/or dorsal-medial MPJ capsulotomy with lateral MPJ capsulorrhaphy.

After aligning the adjacent digits, focus attention on the second ray. I prefer a multi-incisional approach and limiting the risk of postoperative dorsal MPJ contracture (i.e. floating toe). Begin with a linear incision at the level of the distal metatarsal to the MPJ. I intentionally make this incision slightly proximal so the incision does not completely cross the MPJ, again with an effort to reduce the risk of dorsal contracture postoperatively. One can perform tenotomy on the extensor tendon or lengthen the tendon through the proximal portion of this incision if necessary. I perform a dorsal and medial capsulotomy at the second MPJ with complete release of the medial aspect of the MPJ.

If I encounter an elongated second metatarsal, I perform a shortening osteotomy through the same dorsal incision, using the Weil technique. I find it necessary over 75 percent of the time to perform a shortening osteotomy when addressing a crossover toe. Often, I will medially translate the capital fragment of the osteotomy 2 to 3 mm to aid in balancing (i.e. lateralize) the force vectors of the flexor and extensor tendons for improved transverse plane alignment.⁹

I fixate the osteotomy with a single snap-off screw. If employing a single point of fixation, one should ensure that iatrogenic rotational deformity of the metatarsal head does not induce a new deformity. A second point of fixation is an option at the surgeon’s discretion. After completing and fixating the osteotomy, perform a lateral MPJ capsulorrhaphy using a polyglactin 910 suture (Vicryl Rapide, Ethicon). Of note, following the osteotomy but prior to fixation, one may evaluate the plantar plate from a dorsal approach and employ commercially available plantar plate instrumentation to repair an identified tear per the technique guide. However, this is not my preferred technique.

Additionally, one can consider a flexor to extensor tendon transfer as an alternative or supplement to direct plantar plate repair.^10-14 Also, authors have proposed the use of the extensor digitorum brevis tendon transfer to aid in the correction of multiplanar deformity of the second toe and MPJ with a study citing highly satisfied or moderately satisfied results in nine of 11 patients.¹⁰ However, I do not personally have experience with this technique.

Directing your attention to the digit, make two transverse, semi-elliptical converging incisions about the proximal interphalangeal joint. Enter the proximal interphalangeal joint through a tenotomy of the extensor tendon and release the collateral ligaments prior to bony resection.Resect the head of the proximal phalanx and base of the middle phalanx. (Alternately, the surgeon may opt to just resect the head of the proximal phalanx if he or she is performing an arthroplasty.) Of note, when using a proximal interphalangeal joint fusion implant, a separate longitudinal incision may be preferable (rather than the aforementioned proximal interphalangeal joint incision) for ease of insertion of the implant. However, as I previously stated, I prefer not to make this continuous to the dorsal MPJ capsulotomy incision.

If one is addressing the plantar plate as well, direct attention to the plantar second MPJ. Make a 4 cm longitudinal linear incision directly under the second MPJ, deepening dissection to the flexor tendons with subsequent retraction of the flexor tendons. Take care not to over-dissect the plantar tissues while deepening the incision as this can result in atrophy and increased scarring of the plantar metatarsal pad.

Of note, with crossover toe deformities, medial displacement of the flexor tendons is common. The plantar plate is most often torn or attenuated at the plantar lateral aspect of the plate, just proximal to the distal attachment to the proximal phalanx base. Debride and excise the degenerated tissues associated with the tear. I have found that a wedge type resection (medial apex) of the affected plantar plate tissues aids in proper realignment of the MPJ and reefing of the attenuated tissues. One can also assess the lateral collateral ligament of the MPJ and reinforce it as needed.

When repairing the plantar plate, I most commonly fixate the proximal interphalangeal joint with an 0.062-inch Kirschner wire. After debriding the plantar plate tissues and preparing them for repair, complete the proximal interphalangeal joint stabilization and hold the toe in the corrected position at the MPJ with slight plantarflexion. Then advance the K-wire across the MPJ to stabilize the repair. Take care not to displace or rotate the metatarsal osteotomy.

After stabilizing the second MPJ, repair the plantar plate tissues with “0” polyglactin 910 suture, using a pants-over-vest technique (typically, one places the sutures prior to delivering the wire fixation, tying the sutures after stabilizing the MPJ in corrected position). Then relocate the flexor tendons in a central position if they are medially displaced. If selecting a proximal interphalangeal joint implant, rather than a K-wire, to fixate the toe fusion, my preference is to use a small suture anchor with braided non-absorbable suture at the plantar base of the proximal phalanx for the plantar plate repair to provide additional stability in lieu of rigid temporary fixation across the MPJ. Doing so helps prevent undesired attenuation in the early postoperative period. Then close the incisions in the preferred method.

What You Should Know About Postoperative Management

My patients maintain strict non-weightbearing in a posterior splint for one week with subsequent protected heel weightbearing in a pneumatic walking boot. If a Kirschner wire is present, the patient continues wearing the boot until wire removal, typically at six weeks. If one uses a proximal interphalangeal joint implant instead, use a looped elastic toe splint with a plantar pad (or similar device) to aid in stabilization of the second MPJ with protected heel weightbearing in a pneumatic walking boot at one week postoperative.

Regardless of the approach, postoperatively, the patient should continue to use the digital splint until at least three months after surgery. Return to normal shoe gear is typically four to six weeks, depending on the concomitant procedures and fixation the surgeon has employed.

Ensuring A Proactive Approach To Minimizing Complication Risk

Several complications and pitfalls can occur with crossover hammertoe surgery, resulting in limited patient satisfaction. One commonly associated complication is the floating toe. Judicious incision planning and proper technique can help limit the likelihood of this complication. Recurrence of transverse plane malalignment may also occur. Non-union at the proximal interphalangeal joint fusion site can occur but is typically not of clinical significance.

The most concerning complication that can present is vascular embarrassment of the second toe secondary to the acute realignment of a chronically dislocated toe and the associated vasospasm. In regard to the direct plantar plate repair via a plantar approach, some commonly believe the plantar scar results in predictable pain and discourage this approach. However, in my experience, this heals predictably and most often without hypertrophy if one ensures proper incision placement. In the same aforementioned study from the Orthopedic Foot and Ankle Center, we found plantar wound problems in 4.2 percent of our cohort (six of 144) following plantar plate repair from retrospective clinical data.⁷

In Conclusion

The crossover toe is a complex multiplanar variant of the hammertoe that can be difficult to treat and test the surgeon’s armamentarium. However, by maintaining a systematic and thorough approach while focusing not only on the second ray, but also the concomitant and adjacent deformities, one can achieve successful results with decreased pain and improved function. In order to maintain patient satisfaction, it is imperative for the preoperative discussion to address both the concerns of the patient and surgeon, and for the two parties to mutually agree that the realistic intended goals of the surgery match the patient’s expectations.

Dr. Prissel is a fellowship-trained foot and ankle surgeon who is in private practice at the Orthopedic Foot and Ankle Center in Westerville, Ohio. He is an Associate of the American College of Foot and Ankle Surgeons.

References

1.     Graziano TA. Correction of crossover second toe deformity. Clin Podiatr Med Surg. 1996;13(2):269-78.
2.     Johnson JB, Price TW 4th. Crossover second toe deformity: etiology and treatment. J Foot Surg. 1989;28(5):417-20.
3.     Coughlin MJ. Crossover second toe deformity. Foot Ankle. 1987;8(1):29-39.
4.     Kaz AJ, Coughlin MJ. Crossover second toe: demographics, etiology, and radiographic assessment. Foot Ankle Int. 2007;28(12):1223-37.
5.     Coughlin MJ, Schutt SA, Hirose CB, et al. Metatarsophalangeal joint pathology in crossover second toe deformity: a cadaveric study. Foot Ankle Int. 2012;33(2):133-40.
6.     Doty JF, Coughlin MJ, Weil L Jr., Nery C. Etiology and management of lesser toe metatarsophalangeal joint instability. Foot Ankle Clin. 2014;19(3):385-405.
7.     Prissel MA, Hyer CF, Donovan JK, Quisno AL. Plantar plate repair via direct plantar approach: an outcomes analysis. Poster, American College of Foot and Ankle Surgeons Annual Scientific Conference 2016, Austin, TX, 11-14 February 2016. Available at https://www.acfas.org/Education-and-Professional-Development/Annual-Scientific-Conference/Posters/ACFAS-Online-Posters/?format=Scientific&classification=Forefoot+Reconstruction .
8.     Klein EE, Weil L Jr, Baker J, Baca J, Arbuckle K, Fleischer A. Intermediate term clinical and patient reported outcome measures of the dorsal approach plantar plate repair. Poster, American College of Foot and Ankle Surgeons Annual Scientific Conference 2016, Austin, TX, 11-14 February 2016. Available at https://www.acfas.org/Education-and-Professional-Development/Annual-Scientific-Conference/Posters/ACFAS-Online-Posters/?format=Scientific&classification=Forefoot+Reconstruction .
9.     Watson TS, Reid DY, Frerichs TL. Dorsal approach for plantar plate repair with weil osteotomy: operative technique. Foot Ankle Int. 2014;35(7):730-9.
10.     Klinge SA, McClure P, Fellars T, DiGiovanni CW. Modification of the Weil/Maceira metatarsal osteotomy for coronal plane malalignment during crossover toe correction: case series. Foot Ankle Int. 2014;35(6):584-591.
11.     Ellis SJ, Young E, Endo Y, et al. Correction of multiplanar deformity of the second toe with metatarsophalangeal release and extensor brevis reconstruction. Foot Ankle Int. 2013;34(6):792-9.
12.     Lui TH. Correction of crossover deformity of second toe by combined plantar plate tenodesis and extensor digitorum brevis transfer: a minimally invasive approach. Arch Orthop Trauma Surg. 2011;131(9):1247-52.
13.     Hobizal KB, Wukich DK, Manway J. Extensor digitorum brevis transfer technique to correct multiplanar deformity of the lesser digits. Foot Ankle Spec. 2016;9(3):252-7.
14.     Myerson MS, Jung HG. The role of toe flexor-to-extensor transfer in correcting metatarsophalangeal joint instability of the second toe. Foot Ankle Int. 2005;26(9):675-9.
15.     Haddad SL, Sabbagh RC, Resch S, et al. Results of flexor-to-extensor and extensor brevis tendon transfer for correction of the crossover second toe deformity. Foot Ankle Int. 1999;20(12):781-8.

For further reading, see “A Closer Look At Tendon Transfers For Crossover Hammertoe” in the June 2014 issue of Podiatry Today, “Correcting The Crossover Toe With Direct Plantar Plate Repair” in the January 2014 issue or “Emerging Concepts In Treating Second Crossover Toe Deformity” in the October 2009 issue.