The Steadman Clinic, Vail, Colorado, USA.
Oslo Sports Trauma Research Center, Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo, Norway.
Am J Sports Med. 2019 Feb;47(2):372-378. doi: 10.1177/0363546518814258. Epub 2018 Dec 7.
Meniscal ramp lesions have been defined as a tear of the peripheral attachment of the posterior horn of the medial meniscus (PHMM) at the meniscocapsular junction or an injury to the meniscotibial attachment. Precise anatomic descriptions of these structures are limited in the current literature.
To quantitatively and qualitatively describe the PHMM and posteromedial capsule anatomy pertaining to the location of a meniscal ramp lesion with reference to surgically relevant landmarks.
Descriptive laboratory study.
Fourteen male nonpaired fresh-frozen cadavers were used. The locations of the posteromedial meniscocapsular and meniscotibial attachments were identified. Measurements to surgically relevant landmarks were performed with a coordinate measuring system. To further analyze the posteromedial meniscocapsular and meniscotibial attachments, hematoxylin and eosin and alcian blue staining were conducted on a separate sample of 10 nonpaired specimens.
The posterior meniscocapsular attachment had a mean ± SD length of 20.2 ± 6.0 mm and attached posteroinferiorly to the PHMM at a mean depth of 36.4% of the total posterior meniscal height. The posterior meniscotibial ligament attached on the PHMM 16.5 mm posterior and 7.7 mm medial to the center of the posterior medial meniscal root attachment. The meniscotibial ligament tibial attachment was 5.9 ± 1.3 mm inferior to the articular cartilage margin of the posterior medial tibial plateau. The posterior meniscocapsular attachment converged with the meniscotibial ligament at the most posterior point of the meniscocapsular junction in all specimens. Histological staining of the meniscocapsular and meniscotibial ligament PHMM attachments showed similar structure, cell density, and fiber directionality, with no qualitative difference in the makeup of their collagen matrices across all specimens.
The anatomy of the area where a medial meniscal ramp tear occurs revealed that the 2 posterior meniscal attachments merged at a common attachment on the PHMM. Histological analysis validated a shared attachment point of the meniscocapsular and meniscotibial attachments of the PHMM.
The findings of this study provide the anatomic foundation for an improved understanding of the meniscocapsular and meniscotibial attachments of the PHMM, which may help provide a more precise definition of a meniscal ramp lesion.
半月板斜坡损伤被定义为内侧半月板后角（PHMM）在半月板囊结合处的外周附着处的撕裂或半月板胫骨附着处的损伤。目前文献中对这些结构的精确解剖描述有限。
定量和定性描述 PHMM 和后内侧囊解剖结构，以参考与手术相关的解剖标志，确定半月板斜坡损伤的位置。
描述性实验室研究。
使用 14 个男性非配对新鲜冷冻尸体。确定后内侧半月板囊和半月板胫骨附着处的位置。使用坐标测量系统对与手术相关的解剖标志进行测量。为了进一步分析后内侧半月板囊和半月板胫骨附着处，对 10 个非配对标本的单独样本进行了苏木精和伊红及阿利新蓝染色。
后半月板囊附着处的平均长度为 20.2 ± 6.0 毫米，后下方附着于 PHMM，深度为整个后半月板高度的 36.4%。后半月板胫骨韧带附着于 PHMM 后 16.5 毫米和内侧 7.7 毫米，位于后内侧半月板根附着中心的后方。半月板胫骨韧带胫骨附着处位于后内侧胫骨平台关节软骨缘下方 5.9 ± 1.3 毫米处。所有标本的后半月板囊附着处均在后半月板囊结合处的最后方与半月板胫骨韧带会聚。所有标本的半月板囊和半月板胫骨韧带 PHMM 附着处的组织学染色显示出相似的结构、细胞密度和纤维方向性，其胶原基质的组成没有明显差异。
内侧半月板斜坡撕裂发生区域的解剖结构显示，2 个后半月板附着处在后半月板 PHMM 的共同附着处融合。组织学分析验证了 PHMM 后半月板囊和半月板胫骨附着处的共同附着点。
本研究的发现为更好地理解 PHMM 的半月板囊和半月板胫骨附着处提供了解剖学基础，这可能有助于更精确地定义半月板斜坡损伤。
