Metabolic responses of osteochondral allografts to re‐warming

Abstract

Symptomatic chondral and osteochondral defects affect a large and growing number of patients. A safe and effective surgical treatment for large articular defects is osteochondral allograft (OCA) transplantation. One of the major causes of failure for OCA transplantation is loss of essential chondrocyte viability during the preservation and storage period. It is also possible that metabolic responses of the OCA when transitioning from storage temperature to body temperature may contribute to mechanisms causing failure. The present study was designed to compare MOPS SM -preserved OCAs to those stored using the current standard of care (SOC) method with respect to metabolic responses when rewarmed for transplantation to and maintenance at body temperature (37˚C). It was theorized that grafts stored using the MOPS SM protocol would maintain significantly higher chondrocyte viability and produce significantly lower levels of inflammatory mediators and degradative enzymes, and significantly higher levels of chemokines compared to grafts stored using the SOC protocol. Left over SOC and MOPS SM -stored OCA tissues were collected after surgery, and cartilage explants were cultured for 6 days. Media was analyzed for biomarkers using commercially available assays. Cartilage from SOC grafts released significantly higher levels of PGE2, MMP-1, MMP-2, and MMP-13, and significantly lower levels of IL-8 and Groa, compared to cartilage from MOPS SM -stored grafts. Clinical significance: These data suggest that OCAs stored using the MOPS SM protocol have potentially less detrimental initial inflammatory and degradative responses to re-warming for transplantation compared to OCAs stored using the current tissue bank protocols. ß

Effects of Compliance With Procedure-Specific Postoperative Rehabilitation Protocols on Initial Outcomes After Osteochondral and Meniscal Allograft Transplantation in the Knee

“…It is clear that pre-, intra-, and postoperative management strategies are vital to continuing to improve outcomes after osteochondral and/or meniscal allograft transplantation surgery. After a shift in practice based on the validation and availability of MOPS grafts, 3,4,25–27 preimplantation treatment of OCA bone with autogenous bone marrow aspirate concentrate, 1,19,24 and modifications to OCA cutting and fixation techniques, 19,20 primary allograft transplantations performed at our center were associated with a 1- to 3-year combined revision and failure rate of 13.2% based on the data from the present study. In addition, revision allograft transplantation cases, which were all performed with these same graft preservation and implantation protocols, were associated with a 72% success rate.…”

“…Based on preclinical and clinical evidence 1,3,4,19,21,24–27,29 as well as our training and experience, procedure-specific postoperative management protocols were developed for the first full year after surgery for each major variation of osteochondral and/or meniscal allograft transplantation surgery in the knee performed at our institution (Appendices 1-5, available as supplemental material). Once these protocols were implemented, they were prescribed to each patient undergoing allograft transplantation in the knee.…”

Clinical Application of the Basic Science of Articular Cartilage Pathology and Treatment

“…3,[115][116][117][118] Key factors that influence these impediments include OCA chondrocyte viability at time of transplantation, surgical im-plantation techniques, patient immune responses, and patient compliance with prescribed postoperative rehabilitation protocols. 3,[116][117][118][119][120][121][122][123][124][125][126][127] Donor chondrocyte viability is critical to OCA transplantation success and has recently been addressed with a novel tissue preservation system. 3,[116][117][118][119]123,128 OCA bone integration rates have been improved by preimplantation graft preparation techniques, use of autogenous bone marrow aspirate concentrate, improved implantation and fixation methods, and in-depth patient education and monitoring for postoperative rehabilitation protocols.…”

“…Recent studies suggest that when the limiting factors for success are comprehensively addressed by using OCAs with high-chondrocyte viability, improved graft preparation, implantation, and fixation techniques, and comprehensive patient education and management protocols, OCA transplantation can be a consistently successful cartilage restoration technique for large contained or uncontained chondral and osteochondral single surface, multisurface, and bipolar defects in the knee. 3,[117][118][119]121,123,124,129,131,132,139 However, limitations for OCA transplantation in the knee remain such that the slight possibility for disease transmission, the lack of consistent success in treating global degenerative knee OA or immune-mediated arthritis, and accurate revision and success rates must be clearly communicated to patients who are considering this treatment option. 70,115,116,127,128,140,141…”

Comparison of meniscal allograft transplantation techniques using a preclinical canine model

“…10,[18][19][20][21] In an attempt to mitigate these complications, our group has developed and validated a method for preservation of fresh, viable menisci that complies with the United States Food and Drug Administration (FDA) classification of a human cell and tissue product under Section 361 of the Public Health Services Act, as well as techniques for reconstruction or preservation of the menisco-tibial ligament and combined transplantation with fresh tibial osteochondral allograft (OCA). [22][23][24][25][26][27] While safety and initial efficacy for this approach have been documented, comprehensive comparative data are necessary in order to directly compare the currently available MAT techniques. 26,27 Therefore, the objective of the present study was to assess the functional outcomes after MAT when performed using three different clinically-relevant methods in a preclinical canine model.…”