Introduction

Lisfranc injuries refer to the damage of the bones in the Lisfranc joint, which is located in the midfoot, essentially in the middle of the feet. This condition can vary between mild to severe, depending on the injury, and the types of injuries include dislocation of the joint, fractures, sprains and widening of the joint.¹ Common mechanisms that cause Lisfranc injuries are twisting injuries or high-impact trauma, which is typically a result of sports activities, vehicle crashes and falls.² It is a very uncommon condition; however, it is important to accurately diagnose this condition because a missed diagnosis can lead to serious health complications such as chronic pain, midfoot instability and arthritis. Nevertheless, there is a wide range of clinical examination techniques for healthcare professionals in suspected Lisfranc injuries, which will help diagnose the condition.

Understanding the lisfranc joint complex

The Lisfranc joint refers to the tarsometatarsal joints of the foot, and the basic anatomy is made of the medial cuneiform bones, the cuboid bone and the metatarsal base.³ The Lisfranc ligament structure plays a key role in maintaining the arch and stability of the midfoot and the connection between the midfoot and forefoot. 

The Lisfranc joint complex is essential for stabilising the foot and plays a key role in bearing body weight during movements like walking. There are five long metatarsal bones that connect to the toes, the tarsal bones, which are below the metatarsal bones, specifically the three cuneiform bones and the cuboid, which forms the arch of the foot.⁴ The most important ligament in the anatomy of the foot is the Lisfranc ligament because it acts like a strong anchor, keeping the midfoot bones connected to the forefoot, leading the feet to be aligned and stable. If there are any injuries to these ligaments, it can lead to pain and swelling. In more severe cases, these symptoms in the foot can give instability when walking and make it difficult to perform sports activities. 

Patient history: the first clue

When it comes to Lisfranc injuries, patient history is crucial in the decision of examination and aids in diagnosis. Furthermore, it is useful for healthcare professionals to understand the mechanism of the injury, like how the injury may have occurred and why. The onset and location of pain is also important; the pain is usually located in the midfoot area, which could also be accompanied by swelling, bruising and numbness.

Patients who are affected with Lisfranc injuries have their ability to bear weight questioned, which can then be used to decide if weight-bearing or non-weight-bearing radiography techniques will be used.⁵ If the patient cannot stand up and put weight on the foot, then the non-weight-bearing technique can be used for initial assessment. Nevertheless, the history of how the injury occurred is important to decide if the injury is caused by a low-energy trauma or a high-energy trauma. For example, low-energy trauma incidents that could injure the Lisfranc joint are sprains and twisting injuries that can be caused by motorcycle incidents or sporting incidents.⁶

Physical examination techniques

Inspection

Inspecting the site of the injury is important for suspected Lisfranc injuries to determine the potential diagnosis. In particular, swelling and pain at the midfoot that lasts more than five days can be a sign of Lisfranc injury.⁷ Moreover, these symptoms can cause altered foot movement and abnormalities in the foot alignment, which can also be visually inspected. Swelling and tenderness can be visible most commonly in the tarsometatarsal joints, and widening of the foot may also be seen.

Palpation

Palpation across the tarsometatarsal (TMT) joints is also commonly seen as a sign of a Lisfranc injury. Localised tenderness along the dorsal (top) surface of the midfoot can be visible, which is an indication of disruption in the Lisfranc ligament or associated fractures.⁸ Plantar tenderness on the bottom of the midfoot is rare but can also be seen, which is a specific sign of ligamentous injury. Plantar tenderness can be rare but is useful in diagnosing Lisfranc injury, especially when X-rays appear normal.

Range of motion 

Motion of the foot is assessed to see if there are any abnormalities, and this is then compared with the unaffected foot. Motion includes passive and active movement of the affected foot to see if there is restriction or pain associated; however, this can not always be a sign of Lisfranc injuries, so it is always better to take imaging tests alongside examination.

Special tests for lisfranc injury

Alongside physical examination, there are specific tests that are used to accurately diagnose Lisfranc injuries. An example of this would be the piano key test, which is a test that involves force applied to the midfoot area to see if the patient experiences any pain or motion. If yes, then this would be a positive test indicating a suspected Lisfranc injury.⁹ Similarly, the drawer test, also known as the midfoot shift test, is another type of test that involves controlled force application to the midfoot to assess stability and movement of the ligaments. 

Other clinical assessments include the single limb heel rise, which is used in a variety of health conditions. This test involves the patient raising their heel repeatedly on an apparatus whilst standing on land, to observe if there is balance of the midfoot.¹⁰ Test performance can vary from individual to individual. There are many limitations to this test as performance can be dependent on individuals who are older in age, have a disability or other health conditions. 

Role of imaging 

Other than physical and clinical assessments, imaging techniques such as X-rays, computed tomography (CT) and magnetic resonance imaging (MRI) scans are regularly used for suspected Lisfranc injuries. As there is often misdiagnosis with most Lisfranc injuries, conventional radiography can be a promising assessment technique. Techniques such as weight-bearing and manual stress radiography, CT, MRI and ultrasonography are sometimes unavailable due to emergency cases. Therefore, radiography remains the most accessible and commonly used imaging method as it is convenient and cost-effective.¹¹ Although radiography is used more commonly, CT scans are better for imaging the bone alignment and fractures clearly, and MRIs are better for assessing ligament integrity. 

In cases where there is availability of MRI then it is preferred over any other imaging technique as MRI has demonstrated good ability to evaluate ligament integrity, correctly classifying 90% of Lisfranc joint complex injuries in comparison to other techniques.¹² MRI findings have been proven to show strong accuracy compared to radiography,  in such cases, recommending surgery or other treatment plans. 

FAQs 

What is the clinical test for lisfranc injury?

Special tests, such as the key piano test,s can be performed. 

How to assess lisfranc injury?

Patient history is taken, then physical examination and further clinical tests are performed. 

What is the best imaging for lisfranc?

Although there are various imaging techniques used for Lisfranc, MRI would be the best option. 

Is there always bruising with a lisfranc injury?

Bruising may occur at the midfoot, but it is not always the case. 

What to do with a lisfranc injury?

The foot can be put in a cast, or in severe cases, surgery may be required. 

Can lisfranc be misdiagnosed?

 Lisfranc injuries are often misdiagnosed with other conditions 

What sport is lisfranc injury most common in?

These injuries are more common in high-impact sports like football and basketball. 

Summary 

Lisfranc injuries are rare and often misdiagnosed; therefore, they require careful clinical evaluation. The first steps of clinical evaluation involve taking a patient's history in depth to find out the cause behind the injury. Physical examination will then reveal more about the injury; however, it is not always enough. Further special testing for Lisfranc, such as the key piano test, can be used to clinically diagnose the condition. Imaging tests can be used for definitive diagnosis as they are a clinical standard and will assess the injury in more depth, which will allow health care professionals to plan for treatment. Early recognition and diagnosis are important in Lisfranc injuries as they prevent long-term health complications.