Scanty integration of osteochondral allografts cryopreserved at low temperatures with dimethyl sulfoxide

Knee Surg Sports Traumatol Arthrosc DOI 10.1007/s00167-010-1317-8

EXPERIMENTAL STUDY

Scanty integration of osteochondral allografts cryopreserved at low temperatures with dimethyl sulfoxide
Francisco Forriol • Umile Giuseppe Longo • Eduardo Alvarez • Stefano Campi Purificacion Ripalda • Carla Rabitti • Nicola Maffulli • Vincenzo Denaro
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Received: 21 November 2009 / Accepted: 21 October2010 Ó Springer-Verlag 2010

Abstract Purpose To compare the integration of osteochondral allografts cryopreserved at different temperatures and different concentrations of dimethyl sulfoxide in an in vivo sheep animal model. Methods Thirty-six adult sheep were randomly allocated to 6 groups of allograft osteochondral transplantation. Six osteochondral cylinders were stored for 6 weeks at-80°C; 6 at -80°C with 10% dimethyl sulfoxide (DMSO); 6 at -80°C with 10% DMSO for 90 min; 6 at -186°C; 6 at -186°C with 10% DMSO; 6 at -186°C for 90 min. After transplantation, all animals were euthanized at 6 months. Harvested specimens underwent gross morphologic and histologic evaluation.

Results We found no statistically significant differences when comparing the gross cartilage morphology andhistopathologic scores of each group. The Mankin and OARSI scores and the modified Wakitani and OARSI scores showed a good correlation grade. The Mankin and modified Wakitani scores showed a fair correlation grade. Conclusion The cryopreservation protocols adopted in the present study provided scanty integration in an in vivo sheep model of osteochondral allograft transplantation. Therefore, their usein the clinical practice is discouraged. Keywords Osteochondral allograft Á Cartilage Á OARSI Á ICRS Á Sports Á Sheep

Introduction
F. Forriol Research Unit FREMAP Hospital, Madrid, Spain U. G. Longo Á S. Campi Á V. Denaro Department of Orthopaedic and Trauma Surgery, Campus Biomedico University, Via Alvaro del Portillo, 200, 00128 Trigoria, Rome, Italy E. Alvarez Á P. Ripalda Laboratory ofOrthopaedic Research, Department of Orthopaedic Surgery, Pamplona, Spain C. Rabitti Department of Anatomical Pathology, Campus Biomedico University, Via Alvaro del Portillo, 200, 00128 Trigoria, Rome, Italy N. Maffulli (&) Barts and The London School of Medicine and Dentistry, Mile End Hospital, Centre for Sports and Exercise Medicine, Queen Mary University of London, 275 Bancroft Road, London E14DG, UK e-mail: n.maffulli@qmul.ac.uk

The management of chondral and osteochondral defects in weightbearing regions of the knee is challenging [14, 34]. Articular cartilage has limited capacity for regeneration, and the difficulties are magnified in the case of full-thickness cartilage defects [5, 13, 32, 46, 47]. Osteochondral autograft transfer procedures involve taking cylindrical grafts fromareas of decreased weight bearing in the knee and transferring them to accurately prepared recipient defect sites [37, 38, 40]. These techniques have the advantages of ready availability of donor cartilage and use of native hyaline cartilage containing active, mature chondrocytes [6, 28, 53]. There is a lack of consistency in the published literature on long-term followup of these patients to allowdefinitive conclusions on the effectiveness of osteochondral autograft transplantation [15, 17, 21–23, 35, 36, 48, 50, 62]. Furthermore, concerns exist on the morbidity that ensues at the donor cartilage harvest sites [33].

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There have been some controversies regarding the most effective storage method of the osteochondral graft. The chondrocytesviability and the cartilage biomechanical properties are much better when using a fresh chondral or an osteochondral graft. However, chondrocyte viability at the time of implantation continues to be in question, as it does not seem to be related to clinical outcomes [2, 20]. After freezing, cell viability is low despite low cellularity (3–10% of the cartilage volume of the tissue). Adding...