Chondrocyte allograft transplantation for damaged growth plate reconstruction

The growth plate is responsible for longitudinal bone growth. The problem of repair of damaged growth plate in children has never been adequately solved. The purpose of this study is to investigate the ability of the cultured chondrocyte for the prevention of bony bridge and repairment of damaged growth plate. Chondrocytes were obtained from the new born canine epiphyseal plate and was cultured in high density. Fourteen days later they formed micromass easily removable from the culture flask. Twenty dogs were divided into two groups; in group I, the medial proximal tibial growth plate was destroyed and then cultured chondrocytes were transplanted into the defect, and in group II, the medial proximal tibial growth plate was left in destroyed state. Each left leg was remained as a control. The growth pattern was observed radiographically and histologically until 16 weeks after graft. 4 weeks after the operation, the angular deformity had been observed, and 31 degrees of angulation was noted at the 16th week in group II, while there was less than 8 degrees of angulation and nearly normal growth in most of dogs of group I (8 of 10 dogs). The other 2 dogs had shown 20 degrees angulation. In group II, there was definite bony bridge on the medical proximal growth plate. In group I, initially, the cultured chondrocyte remained as a amorphous cartilagenous mass, but as time progressed, amorphous cartilagenous mass had formed cartilagenous matrix which was proved by Safranin-O staining. Although this study showed the role of cultured chondrocyte as a method of preventation of bony bridge formation and possibility to repair of growth plate, further studies should be done to prove the reconstruction of the growth plate.

Metal Debris Induced Osteolysis after Cementless Total Hip Arthroplasty: One case report / 대한정형외과학회잡지

The titanium alloy Ti-6A1-4V is widely used for joint implantation. In spite of its favorable characteristics, titanium alloy can be particularly susceptible to wear, thus generating metallic debris that can lead to aseptic loosening of the implant. We report a case of osteolysis by metal debris after cementless total hip arthroplasty.

Chemonucleolysis using Chondroitinase ABC: An Expreimental Study / 대한정형외과학회잡지

Chymopapain and collagenase are well known chemonucleolytic agents for lumbar disc herniation. However, these enzymes have serious problems occasionally, such as severe neurotoxicity or anaphylaxis even fatal to patients. Chondroitinase ABC, a metabolic product of Proteus vulgaris, has a specific action on the proteoglycans of the nucleus pulposus, but rarely no effect on the intrathecal nerve tissues of vessels. Seventy eight rabbit lumbar discs were evaluated radiographically and histologically after injection of chondroitinase ABC 40U/ml per disc and compared with buffer injected group and nonigected control group. There was considerable disc space narrowing of the chondroitinase ABC injected group which was verified radiographically and histologically(p < 0.01). A zone of Safranin 0 depletion was present in the ventral anulus fibrosus adjacent to the nucleus pulposus in all treated discs, indicating proteoglycan loss. On electron microscopic findings there were collapse of chondrocytes and notochordal cells. All of these findings are corresponding to the evidence that chondroitinase ABC may be another chemonucleolytic agent by decreasing disc volume and thereby decompressing spinal cord or nerve roots. All histologic effects of chondroitinase ABC were confined to intervertebral disc tissues. Chondroitinase ABC deserves to be a study object for the alternative of chemonucleolysis.