The Reproducibility of Radiographic Measurement of Medial Meniscus Horn Position

Purpose: The objective of this investigation was to evaluate the possibility of locating and reproducing the tibial insertion areas of the anterior and posterior horns of the medial meniscus on preoperative radiographs according to an established method for the lateral meniscus. Methods: In 20 tibia heads, we prepared anterior and posterior horn insertions and marked their circumference with radiopaque steel balls of 1.6 mm in diameter. Standardized anteroposterior and lateral radiographs were made. On these radiographs, different landmarks were defined, their distances measured (tibial width and depth, distance from lateral tibia border to meniscus insertion midpoint, distance from anterior tibia border to meniscus insertion midpoint, distance from anterior and lateral tibia border to medial intercondylar spine), and ratios determined. Results: The anterior horn midpoint is located at 57.3% ± 2.7% of tibial width and 12.0% ± 1.0% of tibial depth, and the posterior horn midpoint is located at 56.5% ± 1.6% of tibial width and 81.6% ± 3.4% of tibial depth. The statistical analysis of these measures showed a precise and constant positioning of the medial meniscus insertions on the tibia plateau. We also found constant topographic relations to the medial intercondylar spine. Conclusions: The midpoints of both insertion areas of the medial meniscus have constant positions at 57.3% and 56.5% of tibial width and at 12.0% and 81.6% of tibial depth for the anterior and posterior horn, respectively. They can precisely and reproducibly be defined on radiographs. Clinical Relevance: We have developed a technique for precise radiographic tibial horn determination, exact placement of the tibial tunnels, and thus reconstruction of meniscus insertion anatomy in medial meniscus transplantation.