Abnormal subchondral bone remodeling and its association with articular cartilage degradation in knees of type 2 diabetes patients

Type 2 diabetes （T2D） is associated with systemic abnormal bone remodeling and bone loss. Meanwhile, abnormal subchondral bone remodeling induces cartilage degradation, resulting in osteoarthritis （OA）. Accordingly, we investigated alterations in subchondral bone remodeling, microstructure and strength in knees from T2D patients and their association with cartilage degradation. Tibial plateaus were collected from knee OA patients undergoing total knee arthroplasty and divided into non-diabetic （n---70） and diabetes （n = 51） groups. Tibial plateaus were also collected from cadaver donors （n = 20） and used as controls. Subchondral bone microstructure was assessed using micro-computed tomography. Bone strength was evaluated by micro-finite-element analysis. Cartilage degradation was estimated using histology. The expression of tartrate-resistant acidic phosphatase （TRAP）, osterix, and osteocalcin were calculated using immunohistochemistry. Osteoarthritis Research Society International （OARSI） scores of lateral tibial plateau did not differ between non-diabetic and diabetes groups, while higher OARSI scores on medial side were detected in diabetes group. Lower bone volume fraction and trabecular number and higher structure model index were found on both sides in diabetes group. These microstructural alterations translated into lower elastic modulus in diabetes group. Moreover, diabetes group had a larger number of TRAP~ osteoclasts and lower number of Osterix~ osteoprogenitors and Osteocalcin~ osteoblasts. T2D knees are characterized by abnormal subchondral bone remodeling and microstructural and mechanical impairments, which were associated with exacerbated cartilage degradation. In regions with intact cartilage the underlying bone still had abnormal remodeling in diabetes group, suggesting that abnormal bone remodeling may contribute to the early pathogenesis of T2D-associated knee OA.

MRI findings in injured articular cartilage of the knee correlated with surgical findings

Background There is a strong need for quick noninvasive diagnostic technique that can give a valid estimate of the status of the cartilage reliably, discriminating intact cartilage from various grades of impaired cartilage. The goal of this study was to assess the incidence of knee cartilage injuries and compare the accuracy of two-dimension spin echo （2D SE） and fast spin echo （FSE） （conventional MRI）, three-dimensional spoiled gradient echo （3D SPGR）, three-dimensional fast imaging employing steady state acquisition （3D FIESTA） MR imaging sequences with surgical examination of the articular cartilage. Methods One hundred and thirty-eight knees with history of knee trauma received conventional MRI, 3D SPGR and 3D FIESTA MRI examination before surgery, and surgical examination of articular cartilage was used as reference standard. A modified version of the Noyes classification system was applied for the evaluation of the lateral femoral condyle （LFC）, medial femoral condyle （MFC）, lateral tibial plateau （LTP）, medial tibial plateau （MTP）, trochlea and patella. The incidence and distributions of different injured grades at different articular surfaces of knee were assessed. A series of assessment indeces of 3D SPGR, 3D FIESTA, and the combination of the conventional MRI and 3D SPGR imaging were calculated. Results The incidence of cartilage defects （grade 2 to 4） was 22% （183/828）, according to surgical examination. Grade 3 and 4 lesions were absent at the medial tibial plateau. The rates of exact match between the grading results of different MRI procedures and surgical examination were 49% of 3D SPGR, 61% of 3D FIESTA, and 82% of the combination of 3D SPGR and conventional MRI. Also, the combination of 3D SPGR and conventional MR imaging provided the highest sensitivity, specificity, accuracy, positive and negative predictive values, at 71%, 97%, 90%, 90% and 90%, respectively. Conclusions For all the articular surfaces of the traumatic knees, about one fifth （22%） were cartilage defects. Both 3D SPGR and 3D FIESTA imaging performed similarly in detecting cartilage lesions of the knee. The increased accuracy in chondral assessment can be achieved by combining 3D SPGR and conventional MRI within a reasonable time.

Cells from Cow Knee Joints Used to Grow New Cartilage Tissue in Laboratory

In an effort to develop a method for cartilage tissue engineering,researchers successfully used cartilage cells from cow knee joints.By creating a successful method with conditions conducive to growing healthy cartilage tissue,the findings could help lead to a new treatment cure for osteoarthritis using stem cell-based tissue engineering.Articular cartilage is tissue that is found on all the joint surfaces in the body.Since the tissue