Replacement of the medial tibial plateau by a metallic implant in a goat model

Abstract

The purposes of the present study were to explore the surgical possibilities for replacement of the medial tibial plateau by a metallic implant in a large animal model and to examine the implications for the opposing cartilage. In six goats, the medial tibial plateau of the right knee was replaced by a cobalt-chromium implant, using polymethylmethacrylate bone cement for fixation. The unoperated left knee served as a control. At 26 weeks after surgery, the animals were killed, and the joints evaluated macroscopically. Cartilage quality was analyzed macroscopically and histologically. Glycosaminoglycan content, synthesis, and release were measured in tissue and medium. All animals were able to move and load the knees without any limitations. Macroscopic articular evaluation scores showed worsening 26 weeks after inserting the implant (p < 0.05). Macroscopic and histologic scores showed more cartilage degeneration of the opposing medial femoral condyle in the experimental knee compared to the control knee (p < 0.05). Higher glycosaminoglycan synthesis was measured at the medial femoral condyle cartilage in the experimental knees (p < 0.05). This study shows that the medial tibial plateau can be successfully replaced by a cobalt-chromium implant in a large animal model. However, considerable femoral cartilage degeneration of the medial femoral condyle was induced, suggesting that care must be taken introducing hemiarthroplasty devices in a human clinical setting for the treatment of postmeniscectomy cartilage degeneration of the medial tibial plateau. ß

Establishing a live cartilage-on-cartilage interface for tribological testing

“…First, there was an increased release of both GAG and HYP for MoC articulation, which is in line with the other studies with simple motion[25] or animal models[34,41]. When compared to other in vitro wear systems utilizing physiological loads[61], the wear profiles of mechanically loaded CoC and FSC were similar.…”

“…For the MoC tests, the metal counterface is a cobalt chromium head (32 mm diameter), which was selected due to its clinical role in hemiarthroplasty and its research role in in vitro wear testing[34,40,41]. After removal of tissue from the joint, all samples underwent a five-day preculture in culture media with daily changes and replenishing…”

Biological Reconstruction of the Osteochondral Unit After Failed Focal Resurfacing of a Chondral Defect in the Knee

“…17 These implants have also been tested against conventional microfracture treatment of focal cartilage defects in which less degenerative changes in the opposing medial tibial plateau were found in the resurfacing group in a large animal model after 6 months. 8 Degenerative changes of the opposing cartilage were also seen when implants were placed in the medial tibial plateau, 7 while reduced degenerative changes were observed when compared with untreated osteochondral defects in large animal models. 13 Of note, the entire subchondral bone plate at the base of the cartilage defect is lost if the focal implant is placed into the subchondral bone, and a significant defect of the subarticular spongiosa results.…”

Application of induced pluripotent stem cells for cartilage regeneration in CLAWN miniature pig osteochondral replacement model

“…This animal model is adopted to mimic clinical situations in which replacement of tibial plateau with osteochondral implant is desirable, instead of creating joint defect in patellar groove as studied in animal experiments [8] , [9] , [14] . For example, meniscectomy causes cartilage degeneration which appears earlier in the tibial plateau than the femoral condyle [46] . Tibial plateau fractures result in damages in the cartilage of the tibial side, which also causes cartilage degeneration of the femoral condyle [47] .…”