A Closer Look At The Open And Screw Fixation Approach To The Lisfranc’s Injury
It is widely agreed that the Lisfranc’s fracture/dislocation are significant injuries that have the potential to cause major morbidity in the short-term and even more so in the long-term. Though it is not entirely clear what aspect of these injuries result in the long-term problems (pain), they seem to be related to midfoot arthrosis and/or a resultant structural deformity.
In a highly referenced consecutive series study, Artnz, Veith and Hansen assessed 41 tarsometatasal joint fracture/dislocations in patients who underwent open reduction internal fixation (ORIF) with AO screws.1 They concluded that “the development of post-traumatic arthritis was directly related to the damage to the articular surfaces or to inadequate reduction, or to both.”
Accordingly, most surgeons recommend surgical intervention when patients present with such an injury and meet the surgical criteria for the use of internal fixation. The purpose of the fixation is simple. We seek to stabilize the midfoot in as near to anatomic alignment until the ligaments and fractures heal. This process takes six to eight weeks.
When it comes to Lisfranc’s injuries, it is important to recognize that surgeons perform no direct ligamentous repair and allow the ligaments to heal secondarily. The ligaments will heal in the position where the osseous structures are, so it is extremely important to achieve anatomic alignment.
In a retrospective study by Kuo and colleagues, researchers evaluated the outcome over a seven-year period after open reduction and internal fixation of Lisfranc’s injuries.2 They identified that a “major determinant to good outcome was anatomical reduction (p = 0.05)” in 48 patients with an average follow-up of 52 months.
Pertinent Insights On Optimal Incisions
I have found that the best way to obtain an anatomic alignment is to directly visualize each involved tarsometatarsal joint. Two incisions allow for direct visualization of the first, second and third tarsometatarsal joints, which are mostly affected with these injuries. The clinical exam is helpful to “piano key” each tarsometatarsal joint and physicians should correlate this with a stress test for subtle injuries. It is much less common for the fourth and fifth tarsometatarsal joints to be involved.
A dorsomedial incision provides access to the first tarsometatarsal joint and an incision over the third tarsometatarsal joint allows access to the second and third tarsometatarsal joints. Indeed, an open approach has the potential for wound-related complications but providing adequate space between the incisions markedly reduces this potential problem. This is especially the case in patients without medical comorbidities that could lead to failure. Smoking, diabetes and/or immunopathy are indeed clinical situations in which the surgeon may consider limited incisional and/or percutaneous approaches, based on “biology” alone.
Why Screw Fixation Is The Best Option For Stability
While there are several fixation options for the surgeon to choose from, I have found screw fixation to be the most reliable in terms of providing a stable construct that keeps the alignment in place during the healing process.
There are several forces acting on the midfoot that may promote fixation failure and migration, which may lead to loss of fixation and malalignment. First, all tendon insertions that cross the Lisfranc’s ligament have a theoretical potential to introduce a rotational component resulting in malalignment (an occurence that is intuitively more likely with K-wires). Second, premature weightbearing may introduce a cantilever effect on the midfoot and cause gapping plantarly on the tensile side of the foot. Loss of correction after the index operation may result in arthrosis and structural deformity.
The construct for screw fixation of Lisfranc’s injuries involves placing a screw across each tarsometatarsal joint. However, most surgeons only fixate the first three tarsometatarsal joints with screws. When it comes to involvement of the fourth and fifth tarsometatarsal joints, surgeons tend to fixate these with K-wires. The reasons for this are beyond the scope of this blog but are related to the differences in the medial and lateral columns of the foot.
One would place the screws from dorsal-distal to proximal-plantar (see Figure 1). A single screw typically suffices. In some cases, I have used two screws across the first tarsometatarsal joint and this is a clinical decision. I do not perform a lag technique and I have found that cortical screws are ideal. It is helpful to stabilize the tarsometatarsal joint with a temporary K-wire prior to placing a screw. This temporary K-wire limits the potential for rotatory malignment when one inserts the screw. Since the surgeon places the screws from distal to proximal, one should place the temporary fixation from proximal to distal as this avoids congestion on the metatarsal base when placing the screw. Intra-operative fluoroscopy is helpful to confirm that the visual alignment corresponds with the radiographic alignment. One should correct any disparities.
Surgeons should insert the Lisfranc’s screw last. Much importance is placed on “re-creating” the ever so important Lisfranc’s ligament between the second metatarsal base and the medial cuneiform. One would place the Lisfranc’s screw from the medial cuneiform into the second metatarsal base. Though the idea of this screw is to bring these two osseus components together, I recommend achieving this with clamp rather than relying on a lag technique or screw (see Figure 2).
With a clamp, the surgeon can “dial in” the exact position of the first and second rays, and verify the position on intra-operative imaging. Given that the medial cortical surface of the medial cuneiform is shallow (thin), a washer may prevent the head of the screw from sinking into the bone and lead to a loss of stability.
Optimally, one should insert the screw is into the cortical diaphyseal bone of the second metatarsal shaft. This is why a cortical pitch screw is advantageous. I prefer the screw to purchase both cortices of the second metatarsal shaft and be slightly “proud” on the lateral aspect of the second metatarsal shaft. In this scenario, I think two cortices provide more stability than one cortice. If there is a screw break postoperatively, the surgeon should be able to remove the screw from the prominent tip.
Screw fixation is not without its limitations. Some suggest that the placement of the screws across the joints may be promoting arthrosis in the first place. Indeed there is validity to that argument. However, bear in mind that in many cases, these injuries are associated with injury damaged articular surfaces and are inherently predisposed to arthrosis. Therefore, it becomes equally important to prevent malalignment and fixation failure. Screws seem to be capable of providing a more stable construct than K-wires. This does not mean that screws are incapable of fatigue, especially in the non-adherent patient (see Figure 3).
There is indeed an emphasis on the Lisfranc’s screw. Figure 4 demonstrates an example of widening between the first and second metatarsals when one has not placed a Lisfranc’s screw. In this example, diastasis occurred three months after the index operation. The signs of Lisfranc’s ligament disruption may be subtle and it is important to perform a stress test following suspicious fracture patterns.
In summary, I believe it is important to provide both anatomic reduction and a stable construct during the acute and sub-acute healing process after Lisfranc’s fracture/dislocation repair. While other methods of fixation may achieve these goals, I find screw fixation to be the most reliable technique and it provides a stable construct in comparison to K-wires. Nonetheless, Lisfranc’s fractures/dislocations can be devastating injuries. In some cases, a poor long-term result may be inevitable despite fixation methods and even when one has achieved anatomic reduction.
1. Arntz CT, Veith RG, Hansen ST Jr. Fractures and fracture-dislocations
of the tarsometatarsal joint. J Bone Joint Surg Am. 70(2):173-81, 1988.
2. Kuo RS, Tejwani NC, Digiovanni CW, Holt SK, Benirschke SK, Hansen ST Jr, Sangeorzan BJ. Outcome after open reduction and internal fixation of Lisfranc joint injuries. J Bone Joint Surg Am. 82-A(11):1609-18, 2000.