Anterior cruciate ligament resection and medial meniscectomy result in multifocal cartilage degenerations

Damage to the meniscus and the anterior cruciate ligament alters the pattern of loading in the knee joint and frequently leads to cartilage degeneration and osteoarthritis. This study aimed to evaluate the area of greatest impact after traumatic osteoarthritic induction at the knee joint in sheep model. Osteoarthritis was induced unilaterally at the right hind knee of six sheep by surgical resection of the anterior cruciate ligament and medial meniscus. After 3 weeks recovery period, sheep were exercised once daily by running a 100 meters distance on a hard surface for 3 weeks. Gross and histological assessments were done. Six regions examined were; the patella, patella femoral groove, medial femoral condyle, lateral femoral condyle, medial tibia plateau and lateral tibia plateau. Their mean International Cartilage Repair Society grading was: 2.5±0.42, 3.3±0.17, 2.25±0.38, 1.33±0.25, 2±0.37 and 1.5±0.22 respectively. The control from all samples scored zero at the above regions. The lesions at various regions were significantly higher compared to the control (p < 0.05). Patella femoral groove was significantly higher compare to all other regions except for Patella. Lateral femoral condyle was the least (p < 0.05). Histological staining revealed defined osteoarthritic changes. Total excision of medial meniscus and anterior cruciate ligament followed by exercise regime induced osteoarthritis in the affected knee joint. The changes in pattern of degeneration, affected patella femoral groove the most; followed by the patella and medial femoral condyle, then medial tibia plateau, lateral tibia plateau and lastly the lateral femoral condyle

Improved functional recovery of osteoarthritic knee joint after treatment with chondrogenically induced multipotent cells

The aim of this study was to quantify the functional improvements of osteoarthritic (OA) knee joints after treatment with chondrogenically induced pluripotent stem cells. OA was induced in the right knee joints by the resection of the anterior cruciate ligament and medial meniscus. Nine sheep were divided equally into 3 groups. Two treatment groups received either autologous chondrogenically induced adipose-derived stem cells (ADSCs) or bone marrow stem cells (BMSCs), while the control group received basal medium. Electromyography evaluations (EMGs) were conducted at week 0 (pre-OA), 8 (post-OA) and 24 (post-treatment), and compared to ascertain recovery in joint function. Multifocal subchondral lesions were developed after OA inductions and the treatment groups demonstrated the presence of regenerated neocartilages, evidenced by the presence of PKH26 tracking dye. Post-treatment EMGs showed that the controls retained significant reductions in amplitude compared to the pre-OA values, whereas ADSCs and BMSCs samples had no further significant reductions in amplitude post treatments (p<0.05). ADSCs and BMSCs treated knee joints had structural regeneration of cartilage; confirmed by PKH26 dye. The EMG analysis provided evidence of functional recovery associated to the structural regenerations

Improved functional assessment of osteoarthritic knee joint after chondrogenically induced cell treatment

Objectives: Our previous studies on osteoarthritis (OA) revealed positive outcome after chondrogenically induced cells treatment. Presently, the functional improvements of these treated OA knee joints were quantified followed by evaluation of the mechanical properties of the engineered cartilages. Methods: Baseline electromyogram (EMGs) were conducted at week 0 (pre-OA), on the locomotory muscles of nine un-castrated male sheep (Siamese long tail cross) divided into controls, adipose-derived stem cells (ADSCs) and bone marrow stem cells (BMSCs), before OA inductions. Subsequent recordings were performed at week 7 and week 31 which were post-OA and post-treatments. Afterwards, the compression tests of the regenerated cartilage were performed. Results: Post-treatment EMG analysis revealed that the control sheep retained significant reductions in amplitudes at the right medial gluteus, vastus lateralis and bicep femoris, whereas BMSCs and ADSCs samples had no further significant reductions (P < 0.05). Grossly and histologically, the treated knee joints demonstrated the presence of regenerated neo cartilages evidenced by the fluorescence of PKH26 tracker. Based on the International Cartilage Repair Society scores (ICRS), they had significantly lower grades than the controls (P < 0.05). The compression moduli of the native cartilages and the engineered cartilages differed significantly at the tibia plateau, patella femoral groove and the patella; whereas at the medial femoral condyle, they had similar moduli of 0.69 MPa and 0.40-0.64 MPa respectively. Their compression strengths at all four regions were within ±10 MPa. Conclusion: The tissue engineered cartilages provided evidence of functional recoveries associated to the structural regenerations, and their mechanical properties were comparable with the native cartilage