Sonography of the medial and lateral tendons and ligaments of the knee: the use of bony landmarks as an easy method for identification

OBJECTIVE: Our purpose was to describe the use of bony landmarks in the evaluation of the medial and lateral ligaments and tendons of the knee on sonography and to evaluate the value of this approach in healthy volunteers. MATERIALS AND METHODS: Anatomic slices obtained in cadaveric specimens were inspected for the presence of bony landmarks on the medial and lateral aspects of the knee. Then sonography was performed on 40 knees of 20 healthy volunteers by two musculoskeletal radiologists who independently rated the visualization of bony landmarks and adjacent ligaments and tendons on a 5-point grading scale. RESULTS: Bony landmarks on the lateral aspect of the knee include Gerdy's tubercle on the tibia and the sulcus for the popliteal tendon on the femur. Landmarks on the medial aspect of the knee include the medial epicondyle on the femur and the sulcus for the semimembranosus tendon on the tibia. Visualization of all landmarks was rated in the good to excellent range, and agreement between observers ranged from 92.5% to 100%. CONCLUSION: Bony landmarks can be identified in healthy adults on the medial and lateral aspects of the knee and may serve as reference points for identification of most medial and lateral tendons and ligaments.