Pennock Andrew T, Robertson Catherine M, Wagner Ferdinand, Harwood Frederick L, Bugbee William D, Amiel David
Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA, USA.
Am J Sports Med. 2006 Apr;34(4):586-91. doi: 10.1177/0363546505281815. Epub 2005 Dec 28.
Osteochondral allografts currently are hypothermically stored for a minimum of 14 days to a maximum of 28 days before surgical implantation, making storage conditions increasingly important. Previous studies have suggested that graft deterioration during storage may result from degradative factors and residual marrow elements in the subchondral bone.
Allografts stored with large bone-to-cartilage ratios will be compromised after prolonged storage compared with grafts with minimal bone.
Controlled laboratory study.
Osteochondral plugs were harvested from 16 fresh human femoral condyles and randomly assigned to 1 of 3 groups based on bone-to-cartilage ratios: 1:1, 5:1, or 10:1. These ratios were considered on the basis that the 1:1 ratio is the minimum bone necessary to press-fit an allograft and 10:1 is the present ratio used by tissue banks for allograft storage. After 14 and 28 days of storage at 4 degrees C, the specimens were assessed for viability and viable cell density using confocal microscopy, proteoglycan synthesis by (35)SO4 incorporation, and glycosaminoglycan content.
All grafts underwent a significant decline in viable cell density, proteoglycan synthesis, and chondrocyte viability (particularly in the superficial region) after 14 days of storage, but no differences were observed between the 1:1, 5:1, or 10:1 ratio groups at either day 14 or day 28. In addition, no significant difference was noted in the glycosaminoglycan content in any of the groups.
Osteochondral allografts stored with a 10:1 bone-to-cartilage ratio, similar to tissue-banking ratios, performed no worse than allografts stored with minimal bone, suggesting that the bone-to-cartilage ratio plays little to no role in the degradation of allografts during prolonged storage.
As the practice of osteochondral allograft resurfacing becomes more commonplace, it is important that surgeons understand the factors that affect graft quality.
目前，骨软骨异体移植在手术植入前需在低温下储存至少14天，最长28天，因此储存条件愈发重要。先前的研究表明，储存期间移植物的退化可能是由降解因素和软骨下骨中的残留骨髓成分导致的。
与骨量最少的移植物相比，骨与软骨比例大的异体移植物在长期储存后会受到损害。
对照实验室研究。
从16个新鲜的人类股骨髁采集骨软骨栓，并根据骨与软骨比例随机分为3组中的1组：1:1、5:1或10:1。设定这些比例的依据是，1:1的比例是压配异体移植物所需的最小骨量，而10:1是组织库用于异体移植物储存的当前比例。在4℃储存14天和28天后，使用共聚焦显微镜评估标本的活力和活细胞密度，通过（35）SO4掺入法评估蛋白聚糖合成，并测定糖胺聚糖含量。
储存14天后，所有移植物的活细胞密度、蛋白聚糖合成和软骨细胞活力（尤其是在表层区域）均显著下降，但在第14天或第28天，1:1、5:1或10:1比例组之间未观察到差异。此外，任何一组的糖胺聚糖含量均无显著差异。
与组织库的比例相似，以10:1的骨与软骨比例储存的骨软骨异体移植物，其表现并不比骨量最少的移植物差，这表明骨与软骨比例在异体移植物长期储存期间的降解中几乎不起作用。
随着骨软骨异体移植表面置换术的应用越来越普遍，外科医生了解影响移植物质量的因素非常重要。
