Pertinent Pearls On Conservative Management Of Lisfranc Injuries

This author presents an orthotic solution for a 67-year-old, who presented with pain following a fifth metatarsal base fracture.

On March 18, 2016, I had the opportunity to examine a formerly active, otherwise essentially healthy 67-year-old female psychologist who presented to me with a chief concern of persistent left midfoot and lateral ankle pain following immobilization for a left fifth metatarsal base fracture sustained on September 1, 2015.

Initial treatment by her orthopedic surgeon consisted of crutch-assisted, non-weightbearing ambulation for four weeks followed by four weeks of weightbearing in a short-leg fracture shoe. Afterward, the patient attempted to ambulate in Merrell wedge clogs but experienced increasing discomfort in the midfoot region, specifically at the base of the fourth metatarsal. The discomfort persisted and the patient received sequential triamcinolone acetonide 40 mg injections that failed to provide definitive relief.

Magnetic resonance images (MRIs) revealed normal fifth metatarsal base fracture healing with a secondary finding of inflammation at the fourth metatarsal base. At the time of my exam, the patient experienced periodic swelling at the site, resulting in difficulty fitting into conventional footwear. There is no pain upon arising but the discomfort increases with increasing periods of weightbearing, and is especially severe during the propulsive phase of gait. The lateral ankle pain varies with the type and amount of activity she performs, and she characterizes it as a dull ache.

The patient’s medical and surgical histories are notable for a history of bilateral hallux abducto valgus repair by an orthopedic surgeon with screw fixation, bilateral knee arthroscopic repair of meniscal disorders, right hip replacement and bilateral foot cramping.

What The Physical Examination Revealed

The vascular and neurologic parameters were within normal ranges. Physical examination of the area of chief concern revealed marked tenderness at the third, fourth and fifth tarsometatarsal articulations with profound discomfort upon forceful eversion of the forefoot while inverting the rearfoot. No visible inflammation was present. Neither fifth metatarsal base palpation nor palpation with third, fourth or fifth metatarsal shaft loading elicited tenderness. Palpation of the sinus tarsi reproduced the lateral ankle discomfort with a Visual Analogue Scale pain rating of 8.5/10. There was a normal range of pain-free plantarflexion and inversion as well as ankle dorsiflexion.

Bilateral weightbearing AP and lateral radiographs as well as a medial oblique view of the left foot failed to reveal evidence of fracture or overt derangement in the areas of chief concern. There was an essentially healed fracture of the base of the left fifth metatarsal.

Key Insights On Diagnosis And Treatment

I diagnosed the patient with a Lisfranc strain of the left foot and a lateral talocrucral compression syndrome of the left foot. These conditions are secondary to or aggravated by compensatory pathomechanical function to avoid fracture site stresses, and compensation for inherent structural deficiencies such as:

• collapsed cavus bilaterally;

• partially compensated rearfoot varus bilaterally;

• partially compensated forefoot varus bilaterally;

• partially compensated forefoot equinus bilaterally;

• ligamentous laxity;

• limited right hip external rotation;

• hallux extensis bilaterally;

• genu recurvatum bilaterally;

• limb length discrepancy (short right limb);

• hallux abducto valgus bilaterally; and/or

• hammertoe deformity of the second through fifth proximal interphalangeal joints bilaterally.

The patient immediately discontinued wearing the cast walker and returned to stable sneaker footwear. I injected dexamethasone PO₄/Marcaine into the lateral Lisfranc segment. I applied a Campbell’s type rest strap to the affected foot and placed a compression anklet over the strap. I removed a lift that the patient was wearing in the left cast walker. One week later, the patient reported a 90 percent comfort level and stated she had not walked that well in months.

At the time of this second visit, I took a neutral subtalar joint plaster impression cast for the prescription of foot orthoses. A computerized gait examination via the F-Scan system (Tekscan) documented pedal dysfunction and asymmetry.

What You Should Know About Lisfranc Injuries

Trauma to the tarsometatarsal articulation, known as a Lisfranc injury, is not the most common type injury to the foot but is present more often than one would suspect. Lisfranc injuries encompass a broad range of soft tissue and bony injures to this site, varying in their degree of severity. If left unrecognized or treated inappropriately, Lisfranc injuries may lead to a loss of transverse as well as longitudinal arch stability, secondary osteoarthritis and long-term disability. The risk of untoward complications increases with delayed diagnosis and misdirected management.¹

The Lisfranc joint is named after the French Napoleonic surgeon and gynecologist who performed an amputation at this site.² The Lisfranc articulation forms the transverse metatarsal arch with the stable second metatarsal base acting as the “keystone.” Ligamentous support, especially from the oblique interosseous ligament (also referred to as the Lisfranc ligament), courses from the medial malleolus to the base of the second metatarsal, and is the strongest supporting structure of the tarsometatarsal joint complex.³ A characteristic radiographic finding of a bone “fleck” at the base of the second metatarsal indicates rupture of this ligament.¹

Acute Lisfranc injuries comprise 0.1 to 0.45 percent of all lower extremity fractures and dislocations, but up to 20 percent go undiagnosed or improperly diagnosed at the time of initial assessment.^4,5

Classically, this injury may occur as a result of a high-energy mechanism such as an auto accident or a fall from a height with the end result more likely to be fracture-dislocation. Low-energy induced Lisfranc injuries tend to be primarily ligamentous in nature although one should not overlook the possibility of fracture. Many of these injuries occur with the foot plantarflexed and an axial load driven into it, similar to what occurs when one misses a downward step. Lisfranc injuries also occur in field sports when the athlete plants the foot with the support limb internally rotating and driving forward while an untoward abductory force is introduced across the tarsometatarsal articulation. In either case, injuries may be bony, soft tissue or combination of both. Since soft tissue injuries are not apparent radiographically, one may initially overlook the Lisfranc diagnosis.

One may confirm the diagnosis by thorough history taking, physical examination, radiographs and, if necessary, MRI. Physical examination should include inspection for ecchymosis, global or localized edema, and range of motion. Widening between the first and second metatarsal or the second metatarsal and internal cuneiform usually indicates Lisfranc ligament damage.¹ In some cases, weightbearing and/or stress abduction radiographs under local anesthesia may be necessary.

Management may be conservative or surgical depending upon the degree of involvement. However, in all cases, one should identify and neutralize precipitating, perpetuating or aggravating abductory forces. 

Lisfranc injuries need not be acute or severe to produce symptomatology. In fact, they may be precipitated by repetitive, low-energy level microtraumatic insults over a long period of time. In this patient, due to the prolonged (six months) and persistent antalgic gait adjustments that occurred in an attempt to avoid pressure on the fractured fifth metatarsal base and the accompanying medial displacement of body weight, the injury accentuated and aggravated compensation for existing structural pathology via forefoot varus and forefoot equinus. These additional forces resulted in chronic abduction and dorsiflexory forces through the forefoot, thereby repeatedly stressing the lateral segment of Lisfranc articulation.

Prior local triamcinolone acetonide injections did not provide definitive relief since the underlying pathomechanics went unidentified and unaddressed. Coupled with the fact that the patient had been wearing a recommended 3/8-inch heel raise on the injured side in spite of the fact that current clinical findings pointed to a longer extremity on that side, perhaps accentuated by or as a sequela of her right hip replacement, it is no wonder that the patient was not getting better faster. To date, the patient is asymptomatic, wears orthoses and has returned to all pre-injury fitness activities.

Dr. D’Amico is a Professor and Past Chairman in the Division of Orthopedics at the New York College of Podiatric Medicine. He is a Diplomate of the American Board of Podiatric Medicine, and a Fellow of the American Academy of Foot and Ankle Pediatrics. Dr. D’Amico is in private practice in New York City.

References

1. Della Rocca GJ, Sangeorzan BJ. Navicular and midfoot injuries. In: DiGiovanni C, Greisberg J (eds): Core Knowledge in Orthopedics Foot and Ankle. Elsevier Mosby, St. Louis, 2007, pp. 306–309.

2. Lisfranc J. Nouvelle methode operatoire pour l’amputation partiellle du pied dans son articulation tarso-metatarsienne. Paris L’Imprimerie de Feuquery. 1815; 1.

3. Solan MC, Mormon CT, Miyamoto RG, et al. Ligamentous restraint of the second tarsometatarsal joint: a biomechanical evaluation. Foot Ankle Int. 2001; 22(8):637–41.

4. Court-Brown CM, Caesar B. Epidemiology of adult fractures: A review. Injury. 2006; 37(8):691–7.

5. Trevino SG, Kodros S. Controversies in tarsometatarsal injuries. Orthop Clin North Am. 1995; 26(2):229–38.