The First Tarsometatarsal Joint in Lisfranc Injuries

Classification in 157 patients with Lisfranc injuries using three-dimensional fracture lines and heat map

BACKGROUND

Recently Lisfranc fractures have increased due to increased high-energy injuries from various causes. However, due to incomplete traditional classification, the pattern and distribution of fractures cannot be analyzed in three dimensions. This study examines a novel fracture pattern based on the fracture line and heat map for Lisfranc injuries.

METHODS

We retrospectively analyzed data from CT scans of 157 patients diagnosed with Lisfranc injuries. We extracted the CT data of a healthy adult and created a standard foot model. We performed 3D reconstruction using patients' CT images and superimposed the fracture model onto the standard model for drawing fracture lines. Subsequently, we converted the fracture lines into a heat map for visualization.

RESULTS

The novel classification identifies high-density fracture sites within the tarsometatarsal joint, predominantly localized in the medial and lateral columns. The fracture lines not involving the TMT joint are mainly located in the medial aspect of the first metatarsal trunk and the fifth metatarsal trunk. Additionally, we develop an assessment protocol for Lisfranc injury that incorporates ligament injury, displacement, and fracture.

CONCLUSION

The new classification accurately identifies the different types of fractures in Lisfranc injuries, enabling clinicians to more fully and accurately understand their patients' injuries and assisting them in efficiently making sound decisions to avoid diagnostic delays that can negatively impact postoperative outcomes.

Comparison of diagnostic performance of X‑ray, CT and MRI in patients with surgically confirmed subtle Lisfranc injuries

The present study aimed to compare the diagnostic performance of three imaging tests: X-ray, computed tomography (CT) and magnetic resonance imaging (MRI), for subtle Lisfranc injuries and three anatomical subtype injuries. The non-weight-bearing X-ray, CT and MRI imaging results of patients with subtle Lisfranc injuries from September 2013 to March 2022 were retrospectively reviewed. Subtle Lisfranc injuries and three anatomical subtypes (first, second and cuneiform rays) were diagnosed based on the surgical reports. The diagnostic performance of X-ray, CT and MRI was compared. The sensitivity (Sn), specificity (Sp), positive predictive value, negative predictive value, area under the receiver operating characteristic curve (AUC) and κ coefficient were reported. A total of 31 patients were included in the study. The correct diagnosis was made in 48.4% (15/31), 87.1% (27/31) and 96.8% (30/31) of patients by X-ray, CT and MRI, respectively. A total of 54 different anatomical injuries were found intraoperatively in all patients, with MRI and CT having high agreement (Sn, 72.2 and 87.0%; κ, 0.69 and 0.78, respectively) and X-ray having a low agreement (Sn, 29.6%; κ, 0.26) with the surgical findings. Regarding the first-ray injuries, CT had the highest Sn (76.9%), Sp (100%) and AUC (0.885) in diagnosing subtle Lisfranc injuries. MRI showed the best Sn (88.5 and 93.3%, respectively) and AUC (0.942 and 0.904, respectively) in both second and cuneiform rays. In conclusion, non-weight-bearing X-rays had poor diagnostic accuracy for subtle Lisfranc injuries and their subtypes. CT was superior to X-rays and MRI in diagnosing first-ray injuries. Although not significantly different from CT in terms of overall diagnosis, MRI was superior to X-ray and CT in diagnosing second and cuneiform-ray injuries.

Management of Lisfranc Injuries: A Critical Analysis Review

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There is a spectrum of midtarsal injuries, ranging from mild midfoot sprains to complex Lisfranc fracture-dislocations.

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Use of appropriate imaging can reduce patient morbidity, by reducing the number of missed diagnoses and, conversely, avoiding overtreatment. Weight-bearing radiographs are of great value when investigating the so-called subtle Lisfranc injury.

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Regardless of the operative strategy, anatomical reduction and stable fixation is a prerequisite for a satisfactory outcome in the management of displaced injuries.

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Fixation device removal is less frequently reported after primary arthrodesis compared with open reduction and internal fixation based on 6 published meta-analyses. However, the indications for further surgery are often unclear, and the evidence of the included studies is of typically low quality. Further high-quality prospective randomized trials with robust cost-effectiveness analyses are required in this area.

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We have proposed an investigation and treatment algorithm based on the current literature and clinical experience of our trauma center.