Radiographic Identification of the Anterior and Posterior Root Attachments of the Medial and Lateral Menisci

Abstract

Background: Anatomic root placement is necessary to restore native meniscal function during meniscal root repair. Radiographic guidelines for anatomic root placement are essential to improve the accuracy and consistency of anatomic root repair and to optimize outcomes after surgery. Purpose: To define quantitative radiographic guidelines for identification of the anterior and posterior root attachments of the medial and lateral menisci on anteroposterior (AP) and lateral radiographic views. Study Design: Descriptive laboratory study. Methods: The anterior and posterior roots of the medial and lateral menisci were identified in 12 human cadaveric specimens (average age, 51.3 years; age range, 39-65 years) and labeled using 2-mm radiopaque spheres. True AP and lateral radiographs were obtained, and 2 raters independently measured blinded radiographs in relation to pertinent landmarks and radiographic reference lines. Results: On AP radiographs, the anteromedial and posteromedial roots were, on average, 31.9 ± 5.0 mm and 36.3 ± 3.5 mm lateral to the edge of the medial tibial plateau, respectively. The anterolateral and posterolateral roots were, on average, 37.9 ± 5.2 mm and 39.3 ± 3.8 mm medial to the edge of the lateral tibial plateau, respectively. On lateral radiographs, the anteromedial and anterolateral roots were, on average, 4.8 ± 3.7 mm and 20.5 ± 4.3 mm posterior to the anterior margin of the tibial plateau, respectively. The posteromedial and posterolateral roots were, on average, 18.0 ± 2.8 mm and 19.8 ± 3.5 mm anterior to the posterior margin of the tibial plateau, respectively. The intrarater and interrater intraclass correlation coefficients (ICCs) were >0.958, demonstrating excellent reliability. Conclusion: The meniscal root attachment sites were quantitatively and reproducibly defined with respect to anatomic landmarks and superimposed radiographic reference lines. The high ICCs indicate that the measured radiographic relationships are a consistent means for evaluating meniscal root positions. Clinical Relevance: This study demonstrated consistent and reproducible radiographic guidelines for the location of the meniscal roots. These measurements may be used to assess root positions on intraoperative fluoroscopy and postoperative radiographs.