An Increased Lateral Femoral Condyle Ratio Is an Important Risk Factor for a Medial Meniscus Ramp Lesion Including Red-Red Zone Tear

The Clinical Application of Machine Learning Models for Risk Analysis of Ramp Lesions in Anterior Cruciate Ligament Injuries

“…27,32,63 In this study, as demonstrated by a bump in the machine learning model, an increased medial meniscal slope was found as a risk factor for ramp lesions, consistent with the study findings of Song et al 53 The results of this study were also consistent with those of previous studies. 31,32,38,43 A medial tibial slope .5.5°was found to be a significant risk factor for ramp lesions in this study. Briefly, accompanying an increased LFC ratio, increased anterior and rotatory laxity occurred initially, confirmed by the greater side-to-side laxity and high-grade pivot shift in this study.…”

“…However, LFC anatomy was also suggested as a secondary risk factor for ACL failure because of no significant differences in the LFC ratio between primary and ancillary ACL reconstruction in a study by Grassi et al, 20 although it was significant in the multiple ACL failure group. Although the association between ramp lesions in ACL injuries and an increased LFC ratio has been discussed recently, 31 the lack of literature hampers the establishment of an association between LFC ratio and ramp lesions. In our study, an increased LFC ratio was found to be a significant risk factor for ramp lesions (OR, 378.418 [95% CI, 1.356-105564.8]; P = .035), and the cut-off value was found to be >71.3% (AUC: 0.571; sensitivity: 24.1%; specificity: 89.6%; P < .033), although its effect on the machine learning model was limited (Figure 2A).…”

“…48,52 The LFC ratio was measured on plain radiography using the method described by Pfeiffer et al 45,46 (Figure 2). 31 The mechanical axis angle (hip-knee-ankle) was evaluated using full-length weightbearing radiographs.…”

“…The predictive factors were age, BMI, sex, time from injury to surgery (≥3 or <3 months), bone contusions, presence of Segond fractures, presence of MCL injuries, pivot-shift grade (high vs low), LFC ratio, injury mechanism (contact vs noncontact), presence of varus knee alignment (>6° or ≤6°), amount of anterior translation on stress radiography, and medial/lateral tibial and meniscal slopes on MRI. 31,32 The receiver operating characteristic (ROC) curve and area under the curve (AUC) were plotted to identify the cut-off radiographic measurements for ramp lesions with the maximum point of the Youden index, which indicated the farthest point from the reference line in ROC curves. The sensitivity, specificity, positive predictive value, and negative predictive value were also calculated using ROC analysis.…”

“…Bone morphology and clinical findings around the knee have been considered central risk factors for an ACL injury and failure of ACL reconstruction. ‖ Several findings, including lateral and medial tibial slopes, 19,32,43 meniscal slope, 32,53 tibial plateau and femoral condyle morphology, 13,19,44,46,58,61 varus knee alignment, 8,27,32 bone contusions, 27,32,63 increased lateral femoral condyle (LFC) ratio (ie, deeper posterior LFC), 13,31,45,46,61 have been investigated in multiple radiographic or MRI studies as potential risk factors of an ACL injury or ACL reconstruction failure as well as of meniscal injuries. Although these factors have been associated with meniscal tears or ACL injuries in many previous studies, they remain difficult to detect preoperatively.…”