Introduction:
Diagnosing subtle Lisfranc injuries (SLIs) presents a significant challenge in clinical practice. While weightbearing (WB) radiographs are commonly used, they often miss approximately 20% of SLIs during initial assessments. Computed tomography (CT) scans have been suggested as a potential alternative, yet clear diagnostic guidelines remain undefined. This study aimed to evaluate and compare the effectiveness of measurement techniques using both radiographs and bilateral foot CT scans to improve SLI diagnosis and guide surgical decision-making.
Methods:
We conducted a retrospective analysis of patients diagnosed with SLIs between January 2014 and January 2020. Measurements were taken from bilateral WB radiographs, focusing on the distances between the medial cuneiform and second metatarsal base (C1M2), and the first and second metatarsal bases (M1M2). Bilateral foot CT scans were also performed, and C1M2 distances were examined on axial and coronal planes (top, middle, and base). A surgical indication was defined as diastasis greater than 1 mm on CT scans. Clinical outcomes were assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) score at the final follow-up. Intraobserver and interobserver reliability were also rigorously evaluated.
Key Findings:
Our review included thirty patients with SLIs. Twenty-four patients underwent surgical fixation (Group A), while six were treated conservatively (Group B). A side-to-side difference (STSD) greater than 1 mm in C1M2 distances on radiographs demonstrated a sensitivity of 91.7% and a specificity of 66.7%. In contrast, M1M2 distances showed lower sensitivity (54.2%) and specificity (16.7%). Analysis of STSDs across all points on CT scans proved informative in distinguishing between both groups (P ≤ 0.038). Notably, clinical outcomes, as measured by AOFAS scores, showed no significant difference between the surgical and conservative treatment groups (P = 0.631). Reliability assessments indicated good to very good intraclass and interclass correlation coefficients, with the exception of STSD of WB M1M2 distance and the coronal top plane on CT scans.
Conclusion:
This study highlights the significant efficiency and reliability of bilateral foot CT scans in both the diagnosis and treatment planning for subtle Lisfranc injuries. When Comparing Feet using radiographic measurements, the STSD of WB C1M2 distance was found to be more sensitive than the STSD of WB M1M2 distance for SLI detection. These findings suggest that CT scans offer a superior diagnostic tool for SLIs, potentially leading to more accurate diagnoses and informed treatment strategies.
Level of evidence: Case control study; III.
