## 4 Discussion  
While there exists a reasonable understanding of the microstructure of the menisci, to the best of our knowledge, this study represents the third attempt to quantify degenerative changes in the menisci of individuals with osteoarthritis using light microscopy. Other studies have investigated meniscus structure by electron microscopy. Previous investigations of meniscus structure also have relied on histological staining and polarized light microscopy [27; 28; 29]. Moreover, this study also constitutes another attempt to explore the use of the Bonar score in meniscus pathology. Our study affirms a positive correlation when considering the presence of degeneration in the medial and lateral menisci of osteoarthritis knees. Another significant finding in our study was the application of the adapted Bonar scoring system, specifically designed for tendinous connective tissue. To our knowledge, this study is one of a series of studies to explore the use of the Bonar score in meniscus pathology [24]. But it is the second to apply the Bonar score comprehensively to assess the entire meniscus structure, along with modifications based on the work of [PERSON] et al. In our previous study we also used the Bonar score system in quantifying the pathological changes in meniscal tissue. We quantified the effect of nicotine on meniscal tissue, using the Bonar scoring system, and its modification, in microscopic examination [30]. That was our first attempt to explore the use of the Bonar score in meniscus pathology. Moreover, [PERSON] et al. also used the Bonar score in meniscus root pathology [24]. On the other hand, [PERSON] et al. developed their own grading-based, histopathological system. They added a main criterion, surface, and also evaluated the cellularity, collagen organization, and matrix staining (ground substance), before excluding the tenocytes and vascularity criteria [18]. The original Bonar scoring system is the most commonly employed established scale used to assess microscopic alterations in tendinous tissue [20; 21; 22; 31; 32]. The classical Bonar scoring system evaluates four main variables: cell morphology, accumulation of ground-substance elements, neovascularization, and collagen architecture [20]. Several researchers have adapted the classical Bonar score by incorporating additional variables to enhance diagnostic and microscopic evaluation. The most common modification involved adding a cellularity variable, based on local fibroblast counting [23; 33; 34; 35; 36]. Some studies also considered the morphology of intratendinous adipocytes [33; 37] and the presence of calcifications as additional variables [33; 37]. In our study, we adapted the Bonar quantitative scoring system, originally intended for tendons, to assess meniscal histology. Additionally, we opted to use the modified Bonar score. This score includes a reversal of attributes related to neovascularization. [PERSON] et al. modified the Bonar scoring system with respect to the neovascularization process. They highlighted that, while new vessel formation can signify tissue regeneration and healing, it is well documented in advanced tendinopathies and considered a pathological phenomenon [38]. Regarding meniscal vascularity, numerous authors have explored this aspect in a macroscopic manner. Full vascularization occurs shortly after birth, and in mature menisci, blood vessels and nerves are confined to the peripheral 10-25% of the tissue. Contrarily, vascularization in the meniscus is approximately 10-30% at 10 years of age [6]. Some studies have reported a decrease in blood vessel counts with increasing age [39], and the presence of blood supply to tissue has been linked to healing and repair [9]. Additionally, [PERSON] et al. suggested that the pediatric population exhibits greater intrinsic healing capacity for tears in what is traditionally considered the avascular zone of the meniscus, possibly due to vascularity extending beyond the generally accepted boundaries established in adult studies [40]. On the other hand, [PERSON] et al.