Intermetatarsal Reduction Screw: A Novel Closed Reduction Technique for Isolated Lateral and Divergent Lisfranc Injuries of the Foot

Lisfranc injuries denote a heterogenous group of injuries that involve tarsometatarsal dislocations or fracture dislocations. In general, the outcome of closed reduction is considered inferior to that of an open reduction in these injuries.1 In contrast, the open reduction has its own share of complications. These injuries are usually associated with severe swelling of the foot and poor soft tissue conditions. Wound complications and infection are the most commonly reported complications. Other complications of open reduction include deep peroneal neuropathy and contracture of the extensor hallucis longus tendon.2 We report a novel closed reduction technique followed by temporary internal fixation for isolated lateral and divergent varieties of Lisfranc injuries.

TECHNIQUE

This reduction technique is relevant only to isolated lateral and divergent varieties—to be precise—types B2 (partial incongruity with lateral dislocation), C1, and C2 (divergent pattern with partial or total displacement respectively) of the Myerson classification.3 We perform surgery within 24 hours of injury whenever feasible. Fixation with K-wires alone has shown to have high failure rates; hence, we perform our fixation with transarticular screws.

The patient is operated in the supine position with a support under the ipsilateral thigh to maintain the knee in 90-degree flexion, which helps us to take fluoroscopic images (anterior-posterior, lateral, and oblique views) with least manipulation of the foot. Reduction and fixation proceed from the medial column to the lateral direction. The prerequisite to apply this technique is an intact or well reduced and fixed medial column.

The first tarsometatarsal joint (if dislocated as in C1 and C2 types) is aligned by reducing the medial border of the medial cuneiform to the medial border of the first metatarsal. The joint is held reduced with a provisional K-wire, and then fixed with the 4-mm cannulated cancellous screw passing from the first metatarsal to the medial cuneiform. Once the medial column is stabilized, we proceed directly to reduce the rest of the foot toward the first ray at the tarsometatarsal joints. (The above-mentioned step is not needed in B2 fractures where the medial column is already intact.) Abduction stress views of the forefoot are taken. If the gap between the first and second metatarsal bases is >2 mm, then we proceed with our intermetatarsal screw-assisted reduction.

The first step involves the application of a 1.5-mm K-wire from the shaft of the first metatarsal to that of the second metatarsal, the direction being parallel to the first metatarsal base. With image intensification, it is made sure that the second metatarsal is not displaced in dorsal or plantar directions. A stab incision is applied at the entry and the first and second metatarsals drilled over this K-wire with a cannulated drill. The K-wire is removed and a 4-mm cannulated cancellous screw (with washer) is applied over the 1-mm guidewire. This screw is tightened to get compression of the diastasis to <2 mm. The intermetatarsal reduction screw acts by pulling the intermediate (articulations of second and third metatarsals) and lateral (articulations of fourth and fifth metatarsals) columns toward the medial column, restoring all tarsometatarsal articulations.

Once this reduction is attained, the Lisfranc joint is stabilized with a 4-mm cannulated cancellous screw (with washer) passing from the medial cuneiform to the base of the second metatarsal. This stabilizing screw was placed in the line of the interosseous Lisfranc ligament. The 2 converging screws’ fixation into the second metatarsal gives good stability, reducing the chances of loss of reduction and implant failure during rehabilitation. After this, the tarsometatarsal articulations of the third metatarsal and lateral column (fourth and fifth metatarsals) are to be assessed and fixed with K-wires if there is instability (especially in Myerson C2 injuries). We do not prefer rigid fixation in these joints as they are relatively dynamic. At the end of the surgery, congruent reduction of the Lisfranc joint is ensured by the alignment of the medial border of the second metatarsal in line with the medial border of the middle cuneiform. Step by step demonstration of our technique in a case of Myerson C1 Lisfranc dislocation is illustrated in Figure 1A–E.

F1FIGURE 1:

Stepwise illustration of reduction and fixation of a case of Myerson C1 Lisfranc dislocation (shaded metatarsals indicate the dislocated ones; unshaded metatarsals indicate the ones that are congruently reduced). A, Injury pattern showing divergence. B, After reduction of the medial column and fixation with a single screw. C, Application of intermetatarsal reduction screw. D, Achievement of reduction of Lisfranc joint with an intermetatarsal screw. E, Stabilization screw applied across the Lisfranc joint.

The ankle and foot are immobilized in a below-knee cast for a period of 6 weeks and the patient is kept non–weight-bearing. After 6 weeks, the cast is removed and the ankle mobilized, but the patient is kept non–weight-bearing for another 6 weeks. All screws (intermetatarsal screw, Lisfranc joint stabilization screw, and first ray stabilization screw and lateral K-wires, if present) are removed electively between 3 and 6 months from surgery.

EXPECTED OUTCOME

Lisfranc injuries can be difficult to diagnose and reduce. If not reduced congruently, this injury can lead to chronic pain, arthritis, and significant disability. The classic treatment involves open reduction and fixation. Once anatomic exposure is achieved, bone clamps are used to reduce the dislocation (with or without fracture) and keep them reduced for definite fixation with wires or screws. These clamps come in the way of optimum screw placement and aggravate the pre-existing soft tissue damage.4 Though closed reduction techniques like Chinese finger traps and second ray axial traction are described, they do not work consistently and many a time, they are supplementary to open reduction, reducing the extent of open dissection.4

The technique that we have described predictably reduces the divergence between first and second rays, stably holds the reduction, and does not come in the way of application of definite reduction screws. As close the intermetatarsal reduction screw is to the metatarsal base, the more effective is the compression. But the presence of the first ray stabilization screw and the trajectory of the future Lisfranc stabilization screw determine the entry point of the intermetatarsal reduction screw. The objective is to maintain a safe distance between the screw heads of the first ray screw and intermetatarsal reduction screw and the tips of the intermetatarsal screw and the Lisfranc stabilization screw. In isolated Myerson B2 dislocations, we could place the intermetatarsal reduction screw as close as 1.5 cm to the first tarsometatarsal joint. In the presence first ray screw or the Lisfranc stabilization screw planned to exit more distally, the placement of the reduction screw was more distal, but within 3 cm from the first tarsometatarsal joint. Our choice of screw size (4 mm) was on the basis of availability. Depending on the size of the foot, smaller cannulated screws (3.5 or 3 mm with washers) can also be used in this technique to achieve the same objectives. The only situation where this technique can fail is when there is entrapment of any tendon. If so, the entrapped soft tissue may be released with small incision and dissection.

Wilppula5 has described a classification system to grade the quality of reduction of Lisfranc joints in postoperative radiographs. The good anatomic reduction is described as a good total shape of the foot, with <5 mm diastasis between the first and second metatarsal bases. The reduction is graded fair when the diastasis is between 6 and 9 mm and poor when the diastasis is ≥10 mm. Till date, we have performed this reduction technique in 8 cases and we could achieve good to fair clinicoradiological results in all 8 cases (Table 1 and Fig. 2A–C). Though the technique looks promising, our sample size and follow-up are not enough to make far-reaching conclusions.

TABLE 1 - Demographic, Clinical, Injury, Treatment, and Follow-up Characteristics of Patients Treated by the Authors Using This Technique Patient Number Age (y)* Myerson Type Quality of Reduction as per Criteria of Wilppula Additional Joints That Needed Fixation Duration of Follow-Up (mo) AOFAS Score (Mid Foot) at Last Follow-Up 1 44 C1 Fair First TMT joint 47 70 2 36 C1 Good First, third, fourth TMT joint 46 80 3 46 B2 Good None 28 86 4 51 B2 Good None 28 70 5 28 C2 Fair First and fifth TMT joints 26 68 6 25 B2 Good None 20 76 7 33 B2 Good None 13 84 8 31 B2 Good None 12 82

*All patients were male individuals.

AOFAS indicates American Orthopedic Foot and Ankle Society; TMT, tarsometatarsal.


F2FIGURE 2:

A, Preoperative radiographs of a 31-year-old male patient with Myerson type B2 Lisfranc fracture dislocation of the left foot. B, Immediate postoperative radiographs demonstrating the intermetatarsal reduction screw (A) and stabilization screw (B). C, Radiographs after removal of screws showing maintenance of congruent reduction.

Controversy exists as to the timing and need for hardware removal in these injuries.1 As described by previous authors, we prefer temporary internal fixation to permanent internal fixation or partial arthrodesis.1 We believe that routine hardware removal is essential to restore normal tarsometatarsal motion. Retaining the hardware reduces this motion and increases the chances of implant breakage leading to challenges in removal. We routinely removed all hardware between 3 and 6 months of surgery assuming that the benefits outweigh the risks. For the same reason, we prolonged the non–weight-bearing time to 3 months, giving chance to complete bony and soft tissue healing, which otherwise could lead to medial arch collapse, especially so if there is no supporting implant.

COMPLICATIONS

We did not face any complications specific to this technique, probably because we routinely removed the screws. If screws are retained, then complications related to screw bending and breakage are likely. All patients returned to the preinjury level of activity and none of our patients had significant pain or arthritic changes on available follow-up.

We conclude that this novel intermetatarsal screw-assisted reduction technique is worth attempting in all cases of isolated lateral and divergent Lisfranc injuries.

REFERENCES 1. Abbasian MR, Paradies F, Weber M, et al. Temporary internal fixation for ligamentous and osseous Lisfranc injuries: outcome and technical tip. Foot Ankle Int. 2015;36:976–983. 2. Cochran G, Renninger C, Tompane T, et al. Primary arthrodesis versus open reduction and internal fixation for low-energy Lisfranc injuries in a young athletic population. Foot Ankle Int. 2017;38:957–963. 3. Myerson MS, Fisher RT, Burgess AR, et al. Fracture-dislocations of the tarsometatarsal joints: end results correlated with pathology and treatment. Foot Ankle. 1986;6:225–242. 4. Southerland CC, Charles C, Caroline E, et al. Reduction of Lisfranc dislocations using second ray axial traction. Conference proceedings 2016; 147-151. 5. Wilppula E. Tarsometatarsal fracture-dislocation. Acta Orthop Scand. 1973;44:335–345.

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