Department of Orthopaedic Surgery, Catholic Kwandong University College of Medicine, Seo-gu, Incheon, Republic of Korea.
Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul, Republic of Korea.
Arthroscopy. 2018 Mar;34(3):866-871. doi: 10.1016/j.arthro.2017.09.014. Epub 2017 Nov 22.
To show the effectiveness of magnetic resonance imaging (MRI) for the detection of tram track lesions in the ankle compared with ankle arthroscopy.
We retrospectively assessed all patients who underwent arthroscopic ankle surgery between January 2013 and July 2015. Patients with anterior impingement spurs were included, but those with an osteochondral lesion or arthritis were excluded. Anterior ankle bony spurs on preoperative weight-bearing radiographs were scored using an impingement classification system. The 3.0-tesla MRIs were reviewed for tram track lesions (defined as focal high signal intensity along the talar dome cartilage surface on coronal views) and compared with arthroscopic findings. The cartilage defect grade at arthroscopy was stratified according to the International Cartilage Repair Society (ICRS) grading system.
Overall, 175 ankles in 170 patients were evaluated. Tram track lesions were identified on MRI in 14 ankles (8.0%) and at arthroscopy in 16 ankles (9.1%). The overall sensitivity of MRI for the detection of tram track lesions was 87.5% and the specificity was 100%. On plain weight-bearing radiographs, of the 16 patients with confirmed tram track lesions on arthroscopy, 4 patients had grade 1, 2 had grade 2, and 10 had grade 3 impingement spurs. Under the ICRS grading system, 4 patients had grade II, 4 had grade III, and 8 had grade IV cartilage defects at arthroscopy. On MRI, 2 patients had grade II (50% of arthroscopy), 4 had grade III (100% of arthroscopy), and 8 had grade IV defects (100% of arthroscopy). The impingement spur grade showed no significant correlation with the arthroscopic ICRS grade of the tram track lesion (P = .609).
Tram track lesions can be confidently detected on MRI with high sensitivity and specificity. The impingement spur grade did not correlate with the severity of cartilage injury of the talar dome.
Level III, diagnostic evaluation study.
展示磁共振成像（MRI）在检测踝关节 tram track 病变方面的有效性，与踝关节镜检查相比。
我们回顾性评估了 2013 年 1 月至 2015 年 7 月期间接受关节镜踝关节手术的所有患者。纳入有前撞击骨刺的患者，但排除有骨软骨损伤或关节炎的患者。术前负重位 X 线片上的前踝骨赘采用撞击分类系统进行评分。对 3.0T MRI 进行 tram track 病变（定义为冠状位上距骨穹窿软骨表面的局灶性高信号强度）评估，并与关节镜检查结果进行比较。关节镜下软骨缺损分级采用国际软骨修复学会（ICRS）分级系统。
共有 170 例患者的 175 个踝关节进行了评估。MRI 显示 14 个踝关节（8.0%）有 tram track 病变，关节镜检查显示 16 个踝关节（9.1%）有 tram track 病变。MRI 检测 tram track 病变的总敏感性为 87.5%，特异性为 100%。在常规负重 X 线片上，16 例经关节镜证实有 tram track 病变的患者中，4 例为 1 级，2 例为 2 级，10 例为 3 级撞击骨刺。根据 ICRS 分级系统，关节镜检查有 4 例为 II 级，4 例为 III 级，8 例为 IV 级软骨缺损。MRI 上，2 例为 II 级（关节镜检查的 50%），4 例为 III 级（关节镜检查的 100%），8 例为 IV 级缺损（关节镜检查的 100%）。撞击骨刺分级与关节镜 tram track 病变的 ICRS 分级无显著相关性（P=0.609）。
MRI 可高度敏感和特异性地检测 tram track 病变。撞击骨刺分级与距骨穹窿软骨损伤的严重程度无关。
III 级，诊断评估研究。
