What Is Lisfranc Injury?
A lisfranc joint is situated on top of the foot where metatarsal bones (bridge to toe) connect the rest of the foot. The severity of a Lisfranc injury can vary widely from a simple injury involving one midfoot joint to a complex trauma involving many midfoot joints and broken bones. It is a condition characterized by disruption between the articulation of the medial cuneiform and the base of the second metatarsal of the foot.
What Are the Different Lisfranc Joint Complexes?
Mainly the Lisfranc joint complex is a combination of:
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Tarsometatarsal (TMT) joint or Lisfranc joint articulation.
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Intertarsal (these joints are situated between the tarsal bone of the foot) articulation.
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Intermetatarsal articulation (these joints are formed between the metatarsal bone of the foot).
The Lisfranc joint complex has a relatively rigid medial column (1st, 2nd, 3rd tarsometatarsal joints) and mobile lateral column (4th and 5th TMT joints).
What Is the Role of Lisfranc Ligament?
It is the most important stabilizer of the second metatarsal of the foot. It is an interosseous ligament that goes from medial cuneiform to the base of the second metatarsal and helps maintain the midfoot arch.
This ligament is tightened with pronation and abduction of the forefoot. Other ligaments around the Lisfranc Ligament are:
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Plantar Tarsometatarsal Ligaments: Between medial cuneiform and second and third metatarsal and the Lisfranc ligament give transverse stability.
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Dorsal Tarsometatarsal Ligaments: Between dorsal ligaments are weaker. Therefore bony displacement often occurs on the dorsal side.
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Intermetatarsal Ligaments: Between second to fifth metatarsal bases. The first and second metatarsals are not connected by a ligament.
What Are the Causes of Lisfranc Injury?
It is one of the most common injuries of the foot. This injury is caused due to following reasons:
Indirect Injury: The TMT joint disruption results from indirect rotational force and axial load applied to the hyper plantar flexed forefoot. The abduction moment applied to the forefoot displaces the second to fourth metatarsals dorsally. In addition, low-energy injuries may result in a sprain of the ligament due to twisting or spinning the ankle accidentally, for example, ballet dancers, athletic injuries, horse riding, etc.
Direct Injury: Direct crush injury leads to disruption of the articulation. High-energy injuries results in complete ligament disruption or osseo-ligamentous disruption of the complex. Causes are commonly motor vehicle accident and fall from height.
What Are the Symptoms of Lisfranc Injury?
The symptoms of this condition include:
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The patient presents with swelling (quite significant and may even mask bony deformity) in the midfoot.
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Severe pain in the forefoot.
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Unable to bear weight.
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Tenderness over the tarsometatarsal joint.
How Is Lisfranc Injury Diagnosed?
Certain imaging tests such as X-ray and CT (computed tomography) scan helps in diagnosing the condition.
- X-ray: This imaging test uses high electromagnetic waves to get a clear picture of the affected bones. On taking an X-ray, it may show different findings, such as:
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AP (anterioposterior) View: Malalignment of the medial border of the middle cuneiform aligns with the medial border of the second metatarsal diagnostic of Lisfranc injury.
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Internal Oblique view: Malalignment of the medial border of the lateral cuneiform aligns with the medial edge of the base of the 3rd metatarsal. Likewise, malalignment of the cuboid's medial edge aligns with the medial edge of the 4th metatarsal.
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Lateral View: Non-weight bearing X-ray shows dorsal displacement of the base of the first or second metatarsal.
CT Scan:
CT plays an important role in looking at the widening of the joint spaces. It can also detect associated fractures, confirm the diagnosis, and help to formulate the surgical plan.
How Is Lisfranc Injury Treated?
There are two methods through which Lisfranc injury is treated, operative and non-operative.
1. Non-operative Method: This method is done when an individual has nondisplaced or minimally displaced foot, less than two mm (millimeter) displacement of the tarsometatarsal joint in any plane, and patient with surgical contraindications like poor medical status, Charcot joint, or vascular disease.
In such conditions, the foot is placed below the knee splint, and when swelling is reduced, a cast is applied for eight weeks. This helps in minimizing the movement of the foot and hence helps faster healing.
2. Operative Method: This method is opted when the displacement of the tarsometatarsal joint is more than two mm.
ORIF (open reduction and internal fixation) is the standard of care with screw fixation of the medial column with a 3.5 mm CC (cannulated cancellous). Screw and temporary fixation of the lateral column with K (Kirschner) wire. The K wire is stiff, which helps in healing the bone faster.
Screw fixation is more stable than K wire fixation. The lateral column (4th and 5th metatarsal) can be reduced and fixed to a cuboid with K wire.
What Are the Protocols After the Treatment?
Some of the protocols that need to be taken care of after postoperative management include:
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The foot is immobilized in a non-weight-bearing cast for six weeks, so progressive weight-bearing is allowed after six weeks only.
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The cast can be removed only when there is no pain while lifting any weight. If the lateral column is fixed with K wire, then the wire should be removed only after six to eight weeks.
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The screw should be removed after three to six months.
What Are the Possible Complications of the Postoperative Method?:
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Post-Traumatic Arthritis - It means that the joints of the foot may get inflamed, but it is reversible and heals after a few months.
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Compartment Syndrome - If swelling persists. It is a condition in which the pressure around the muscle rises, which can limit blood and oxygen flow in the body.
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Nonunion and Malunion - Nonunion is a condition in which the bone does not heal after the fracture and takes 9 to 12 months to heal the fracture. Malunion is a condition in which the bone heals in an abnormal position.
Conclusion:
Lisfranc Injury is very notorious and may be more complicated than it appears. But it shows symptoms just after the injury, making it easy to diagnose. In most cases, surgical intervention is not needed, and the bone heals just by giving a cast and proper rest. Consult an orthopedic specialist immediately for better results.
