Gatlin Coley C, Matheny Lauren M, Ho Charles P, Johnson Nicholas S, Clanton Thomas O
The Steadman Philippon Research Institute, Vail, CO, USA.
The Steadman Philippon Research Institute, Vail, CO, USA
Foot Ankle Int. 2015 Mar;36(3):288-92. doi: 10.1177/1071100714553469. Epub 2014 Sep 24.
Talar chondral defects can be a source of persistent ankle pain and disability. If untreated, there is an increased risk of osteoarthritis. The purpose of our study was to determine diagnostic accuracy of 3T MRI in detecting Outerbridge grades 3 and 4 articular cartilage lesions of the talus in a clinical setting, utilizing a standardized clinical MRI protocol.
Patients who had a 3T ankle MRI and subsequent ankle surgery, by a single surgeon, were included in this study. MRI exams were performed 180 days or less before surgery. Seventy-nine ankles in 78 patients (mean age of 42.3 years) were included in this study. Mean body mass index was 26.3. A standard clinical MRI exam was performed on a 3T MRI scanner. Mean days from MRI to surgery was 39 days. All MRI exams were read and findings recorded by a musculoskeletal radiologist. Arthroscopic examination was performed by a single orthopaedic surgeon. Detailed arthroscopic findings and demographic data were collected prospectively and stored in a data registry. Of the 78 patients, 31 (39.2%) reported previous ankle surgery. Pain was the primary reason for seeking medical attention as reported by 95% of patients, followed by instability in 44% and loss of function with 42%.
Prevalence of Outerbridge grade 3 and 4 talar articular cartilage defects identified at arthroscopy was 17.7%. The 3T MRI demonstrated a sensitivity of 0.714, specificity of 0.738, positive predictive value of 0.370, and negative predictive value of 0.923.
Sensitivity and specificity levels were acceptable for detection of grades 3 and 4 articular cartilage defects of the talar dome using 3T MRI. The high negative predictive value may be beneficial in preoperative planning. While these values are acceptable, a high index of suspicion should be maintained in the appropriate clinical setting.
距骨软骨损伤可能是踝关节持续疼痛和功能障碍的一个原因。若不治疗，患骨关节炎的风险会增加。我们研究的目的是在临床环境中，利用标准化临床MRI方案，确定3T MRI检测距骨Outerbridge 3级和4级关节软骨损伤的诊断准确性。
本研究纳入了由同一位外科医生进行3T踝关节MRI检查及后续踝关节手术的患者。MRI检查在手术前180天或更短时间内进行。本研究纳入了78例患者的79个踝关节（平均年龄42.3岁）。平均体重指数为26.3。在3T MRI扫描仪上进行标准临床MRI检查。从MRI检查到手术的平均天数为39天。所有MRI检查均由一位肌肉骨骼放射科医生解读并记录结果。由一位骨科医生进行关节镜检查。前瞻性收集详细关节镜检查结果和人口统计学数据，并存储在数据登记处。78例患者中，31例（39.2%）报告曾有过踝关节手术。95%的患者报告疼痛是就医的主要原因，其次是44%的患者存在踝关节不稳，42%的患者存在功能丧失。
关节镜检查发现的距骨Outerbridge 3级和4级关节软骨损伤的患病率为17.7%。3T MRI显示灵敏度为0.714，特异度为0.738，阳性预测值为0.370，阴性预测值为0.923。
对于使用3T MRI检测距骨穹窿3级和4级关节软骨损伤，灵敏度和特异度水平是可接受的。高阴性预测值可能有助于术前规划。虽然这些值是可接受的，但在适当的临床环境中应保持高度怀疑。
