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

Abstract

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.

Keywords: X-ray; computed tomography; imaging diagnosis; magnetic resonance imaging; subtle Lisfranc injury; tarsometatarsal joint.

Figure 1

(A) X-ray anterior-posterior view showing that the alignment of the second metatarsal bone and the middle cuneiform bone was lost. The basal space of the first and second metatarsals was significantly widened. (B) Small fracture of the medial cuneiform bone can be seen on the axial CT (red circle). (C) Small avulsion fracture of the middle cuneiform bone can be seen on the axial CT (yellow circle).

Figure 2

(A) The Lisfranc ligament injury (red circle) can be seen on the MRI transverse section T2 image. (B) MRI coronal T2 image shows prominent bone marrow edema in the middle cuneiform bone (green circle). (C) The second metatarsal basal bone marrow edema can be seen on the MRI transverse section T2 image. The Lisfranc ligament is not visible (blue circle).

Figure 3

Intraoperative findings of the subtle Lisfranc injury. (A) Rupture of the dorsal ligament and instability of the first tarsometatarsal joint was classified as a first-ray injury. (B) Rupture of the Lisfranc ligament and the dorsal ligament of the second tarsometatarsal joint was classified as a second-ray injury. (C) The first and (D) second tarsometatarsal joint gaps further widened during the intraoperative stress test.

Figure 4

ROC curves for X-ray, CT and MRI examinations. ROC, receiver operating characteristic.

Figure 5

Number of cases correctly detected by X-ray, CT and MRI examinations in each subtype of subtle Lisfranc injury.