Hirtler Lena, Schreiner Markus, Röhrich Sebastian, Kandathil Sam A, Kainberger Franz
Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria.
Department of Orthopedics and Trauma-Surgery, Medical University of Vienna, Vienna, Austria.
Ann Anat. 2025 Apr;259:152388. doi: 10.1016/j.aanat.2025.152388. Epub 2025 Jan 28.
The intercondylar space is defined as the topographic area walled by the intercondylar notch (IN) and encasing the central ligaments of the knee joint. As the anterior cruciate ligament (ACL) is not only impinged against the roof but also against the lateral wall of the IN, information concerning changes to the IN during the progression of osteoarthritis could be potentially relevant in predicting the future risk for ACL-rupture and -degeneration and ensure preventive measures as early as possible. Therefore, the purpose of this study was to evaluate the influence of osteoarthritis on osseous notch morphology.
Image data was retrieved from the Osteoarthritis Initiative. Patients were subdivided into five groups according to the severity of osteoarthritis following the Kellgren and Lawrence classification. 415 patients were selected randomly to ensure equally large groups. Osseous structures were measured in coronal and axial planes in MRI. At the level of the popliteal groove and on the level of the joint line, the width of the lateral and medial femoral condyle, the notch width (NW) as well as the total width of the distal femur were measured. The notch width index (NWI) as ratio between the NW and the total width of the distal femur was calculated. Three shapes (A-shape, Inverse-U-shape and Ω-shape) of the IN were differentiated.
The morphology of the IN is directly influenced by the development of osteoarthritis. Especially the Ω-shape is characteristic for more severe cases of osteoarthritis (p < 0.001). Measurements were also significantly influenced by the imaging plane and the level of measurements (both p < 0.001).
The results of this study reflect significant changes to the intercondylar space in increasing grades of osteoarthritis. Additionally, the recommendation on the location of measurements of the IN should be revised, as especially the measurements on the level of the joint line in coronal plane MRI are a more reliable and objective indicator for the diagnosis of IN stenosis and therefore of changes to the intercondylar space, which always influences the health of the ligaments housed. At the level of the popliteal groove a NWI< 0.25 and NW< 19 mm and at the level of the joint line a NWI< 0.17 and a NW< 14 mm should be interpreted as severe notch stenosis and a definitive risk factor for ACL rupture.
髁间间隙被定义为由髁间切迹（IN）围成并包含膝关节中央韧带的地形区域。由于前交叉韧带（ACL）不仅会撞击到IN的顶部，还会撞击到其侧壁，因此有关骨关节炎进展过程中IN变化的信息可能与预测ACL断裂和退变的未来风险相关，并确保尽早采取预防措施。因此，本研究的目的是评估骨关节炎对骨性切迹形态的影响。
从骨关节炎倡议组织获取图像数据。根据Kellgren和Lawrence分类法，将患者根据骨关节炎的严重程度分为五组。随机选择415名患者以确保各组人数相同。在MRI的冠状面和轴位面上测量骨性结构。在腘窝沟水平和关节线水平，测量股骨内外侧髁的宽度、切迹宽度（NW）以及股骨远端的总宽度。计算切迹宽度指数（NWI），即NW与股骨远端总宽度的比值。区分了IN的三种形状（A形、倒U形和Ω形）。
IN的形态直接受骨关节炎发展的影响。尤其是Ω形是更严重骨关节炎病例的特征（p < 0.001）。测量结果也受成像平面和测量水平的显著影响（两者p < 0.001）。
本研究结果反映了随着骨关节炎等级增加髁间间隙的显著变化。此外，关于IN测量位置的建议应予以修订，因为特别是冠状面MRI关节线水平的测量对于诊断IN狭窄以及髁间间隙变化是更可靠和客观的指标，而髁间间隙变化始终会影响其中韧带的健康。在腘窝沟水平，NWI < 0.25且NW < 19 mm，在关节线水平，NWI < 0.17且NW < 14 mm应被解释为严重切迹狭窄以及ACL断裂的明确危险因素。
