PURPOSE: The purpose of this study was to determine the effects of a multi-drug injectate containing morphine, ropivacaine, epinephrine, and ketorolac, commonly referred to as the "Orthococktail", on cartilage tissue viability and metabolic responses using an established in vitro model.METHODS: With IRB approval and informed patient consent, tissues normally discarded after total knee arthroplasty (TKA) were recovered. Full-thickness cartilage explants (n = 72, Outerbridge grade 1-3) were created and bisected. Paired explant halves were treated with either 1 mL of the Orthococktail or 1 mL of saline and cultured for eight hours at 37°C with 0.5 mL of the treatment being removed and replaced with tissue culture media every hour. Explants were cultured for 6 days and media were changed and collected on days 3 and 6. After day 6, tissues were processed for cell viability, weighed, and processed for histologic grading. Outcomes measures were compared for significant differences between treated and untreated samples using paired t-Tests.RESULTS: There were no significant differences in cartilage viability between control and Orthococktail-treated samples across a spectrum of cartilage pathologies. Orthococktail treatment consistently resulted in a significant decrease in the release of PGE2, MCP-1, MMP-7, and MMP-8 on day 3 of culture, and PGE2, MMP-3, MMP-7, and MMP-8 on day 6 of culture, compared to saline controls.CONCLUSION: The results of the present study indicate that an "Orthococktail" injection composed of morphine, ropivacaine, epinephrine, and ketorolac is associated with a transient decrease in degradative and inflammatory mediators produced by more severely affected articular cartilage that may mitigate peri-operative joint pain such that post-operative narcotic drug use could be reduced.CLINICAL RELEVANCE: The Orthococktail solution used in this study may be a safe intra-operative intra-articular injection option for patients undergoing joint arthroplasty and other joint preservation surgical procedures.
View details for DOI 10.1016/j.arthro.2021.12.019
View details for PubMedID 34952188