Bone Abstracts

Objective: Growth plate injury can lead the development of angular deformities and limb length discrepancies in growing children. Current several treatments can’t regenerate the damaged cartilage adequately. In this study, we investigated the feasibility of the transplantation of cylindrical costal osteochondral graft to establish a new regenerative treatment for growth arrest.

Methods: An experimental model of partial growth plate injury was created by resecting the medial part of the proximal tibial growth plate in male six-week-old New Zealand White rabbits. The rabbits were divided into three groups: control (no transplantation), bone wax transplantation (current treatment), costal osteochondral graft. The angular deformities of the tibia and bony bridge were analyzed using radiographs and μCT, and the repair of the injured growth plate cartilage and bony bridge formation were histologically evaluated at four and eight weeks post-operatively.

Results: The mean MTPA was 69.9°(59.0° to 84.0°) at four weeks, and 50.3°(37.0° to 65.9°) at eight weeks post-operatively in the control group, 79.8°(70.0° to 90.0°) at four weeks, and 62.0°(56.0° to 69.0°) at eight weeks post-operatively in the bone wax group, 81.7°(74.0° to 92.7°) at four weeks and 68.8°(64.2° to 74.3°) at eight weeks post-operatively in the osteochondral graft group. In the control group, bony bridge replaced injured growth plate. In the bone wax group, some cases showed disappearance of transplanted bone wax and replacement with a bony bridge and few chondrocyte-like cells were seen at eight weeks post-operatively. In the osteochondral graft group, the growth plate were thickened, continuous and proliferative and prehypertrophic chondrocytes-like cells were newly formed at the site of growth plate injury and the cells took on a columnar arrangement like normal physis at eight weeks post-operatively.

Conclusion: Cylindorical costal cartilage graft transplantation can prevent the formation of a bone bridge and promote the regeneration of injured growth plate.

Disclosure: The authors declared no competing interests.