پيوند غضروفي استخوايي اتوژن به روش موزاييك پلاستي

Mosaicplasty in femoral chondylar defect (An animal study)

Background: Autogenous osteochondral grafting of articular defect in weight - bearing surface of large joints proved to be a proper biomechanical and physiological solution for localized full thickness defects. Objectives: To study the gross and histopafhological results of mosaicplasty in an animal model (sheepʹs medial femoral condyle), evaluating the factors of defect and graft size, Assessing the effect of fixation with only cancellous bone impaction between graft cloumns, and early free post operative motion. Methods: fourteen medium sized sheep were the subject of the study. Cylindrical osteochondral grafts of 4mm and 6mm diameter and lcm length from the periphery of the medial femoral condyles at patellofemoral joint were used to fill corresponding 5 millimeter and 15 millimeter diameter cylindrical defects of 1cm depth at weight bearing surface of medial femoral condyles. The Spaces between the grafts were packed with cancellous bone with double gloved thumb. The sheep were free for activities and weight bearing after the operation. Two of the 14 sheep died. All the sheep were sacrified after 4 months and their knees collected as specimens for further gross and histopathogical studies. Result: A^ grafted defects except one healed with smooth cartiulage. The qualify of cartilage were evaluated by histopafhological criteria, rating the cellular morphology, surface regularity, structural intesrity and thickess of cartilage, bounding to adjacent normal cartilage and clustering. Twenty - three out of 24 specimen showed excellent or good result, that is a success rate of 95.8%. Conclusion: Mosaicplasty, autogenous osteochondral grafting in this animal study was effective and successful even in larger defects of 15- millimeter diameter. Cancellous bone cementing between the cylindrical grafts, respecting the normal convexity of the femoral condyle insertion of obliquely - harvested grafts at the periphery of the defects and freedom of motion and activity were all helpful in obtaining the good result 4 months after graft implantation.