Foot & Ankle Service, Department of Orthopaedic Surgery, Emory University Hospital, Atlanta, GA, USA.
Department of Orthopaedic Surgery, Emory University Hospital, Atlanta, GA, USA.
Foot Ankle Int. 2024 Oct;45(10):1145-1155. doi: 10.1177/10711007241266844. Epub 2024 Jul 30.
Early detection of Lisfranc injury is critical for improving clinical outcomes, but diagnosing subtle injury can be difficult. Weightbearing computed tomography (WBCT) allows evaluation of such injuries in 3 dimensions (3D) under physiologic load. This study aimed to assess the utility of 1-, 2-, and 3-dimensional measurements on WBCT to diagnose subtle injury in isolated ligamentous Lisfranc injuries.
Ten cadaveric specimens underwent WBCT evaluation of the Lisfranc joint complex in the intact state and subsequently with sequential sectioning of the dorsal Lisfranc ligament and interosseous Lisfranc ligament (IOL) to create subtle Lisfranc injury, and finally after transectioning of plantar Lisfranc ligament (PLL) to create the injury conditions for complete ligamentous Lisfranc injury. Measurements under static vertical tibial load of 80 kg were performed on WBCT images including (1) Lisfranc joint (medial cuneiform-base of second metatarsal) volume, (2) Lisfranc joint area, (3) C1-C2 intercuneiform area, (4) C1-M2 distance, (5) C1-C2 distance, (6) M1-M2 intermetatarsal distance, (7) first tarsometatarsal (TMT1) alignment, (8) second tarsometatarsal (TMT2) alignment, (9) TMT1 dorsal step-off distance, and (10) TMT2 dorsal step-off distance.
In the subtle Lisfranc injury state, Lisfranc joint volume and area, C1-M2 distance, and M1-M2 distance measurements on WBCT significantly increased, when compared with the intact state ( values .001 to .014). Additionally, Lisfranc joint volume and area, C1-M2 distance, M1-M2 distance, TMT2 alignment, and TMT2 dorsal step-off measurements were increased in the complete Lisfranc injury state. Of all measurements, C1-M2 distance had the largest area under the curve (AUC) of 0.96 (sensitivity = 90%; specificity = 90%), followed by Lisfranc volume (AUC = 0.90; sensitivity = 80%; specificity = 80%) and Lisfranc area (AUC = 0.89; sensitivity = 80%; specificity = 100%).
In a cadaveric model we found that WBCT scan can increase the diagnostic accuracy for subtle Lisfranc injury. Among the measurements, C1-M2 distance exhibited the highest level of accuracy. The 2D joint area and 3D joint volume also proved to be accurate, with 3D volume measurements of the Lisfranc joint displaying the most significant absolute difference between the intact state and increasing severity of Lisfranc injury. These findings suggest that 2D joint area and 3D joint volume may have potential as supplementary measurements to more accurately diagnose subtle Lisfranc injuries.
WBCT may help surgeons detect subtle Lisfranc injuries.
早期发现跖跗关节损伤对于改善临床预后至关重要，但细微损伤的诊断可能较为困难。负重位 CT（weightbearing computed tomography，WBCT）可在生理负荷下对 3 维（3D）的此类损伤进行评估。本研究旨在评估 1 维、2 维和 3 维测量在 WBCT 诊断孤立性韧带性跖跗关节损伤中的应用价值。
10 具尸体标本先在完整状态下接受 WBCT 评估，然后通过切开背侧跖跗关节韧带和骨间跖跗关节韧带（interosseous Lisfranc ligament，IOL）造成细微跖跗关节损伤，最后通过切断足底跖跗关节韧带（plantar Lisfranc ligament， PLL）造成完全韧带性跖跗关节损伤。在静态垂直胫骨负荷 80kg 下，在 WBCT 图像上进行以下测量：（1）跖跗关节（内侧楔骨-第 2 跖骨基底）容积；（2）跖跗关节面积；（3）C1-C2 间楔骨区；（4）C1-M2 距离；（5）C1-C2 距离；（6）M1-M2 跖骨间距离；（7）第 1 跖骨骰骨关节（first tarsometatarsal，TMT1）对线；（8）第 2 跖骨骰骨关节（second tarsometatarsal，TMT2）对线；（9）TMT1 背侧台阶距离；（10）TMT2 背侧台阶距离。
在细微跖跗关节损伤状态下，与完整状态相比，WBCT 上的跖跗关节容积和面积、C1-M2 距离和 M1-M2 距离明显增加（ 值.001 至.014）。此外，在完全跖跗关节损伤状态下，跖跗关节容积和面积、C1-M2 距离、M1-M2 距离、TMT2 对线和 TMT2 背侧台阶测量值增加。在所有测量中，C1-M2 距离的曲线下面积（area under the curve，AUC）最大，为 0.96（敏感性为 90%，特异性为 90%），其次是跖跗关节容积（AUC 为 0.90；敏感性为 80%，特异性为 80%）和跖跗关节面积（AUC 为 0.89；敏感性为 80%，特异性为 100%）。
在尸体模型中，我们发现 WBCT 扫描可提高对细微跖跗关节损伤的诊断准确性。在这些测量中，C1-M2 距离的准确性最高。2D 关节面积和 3D 关节容积也表现出较高的准确性，其中跖跗关节的 3D 容积测量在完整状态和跖跗关节损伤严重程度增加之间的差异最大。这些发现表明，2D 关节面积和 3D 关节容积可能具有作为补充测量手段，以更准确地诊断细微跖跗关节损伤的潜力。
WBCT 可能有助于外科医生发现细微的跖跗关节损伤。
