Biomechanical Analysis of Osteochondral Autograft Insertion Pressures
Dr. R. Cole Beavis
29 slide(s) – 00:07:10 – English – 2009-07-05
The findings of our study examining the biomechanical analysis of 3 different osteochondral autograft instrumentation systems.
Purpose: To evaluate the insertion forces required to seat osteochondral plug grafts and the accuracy of plug harvest and seating using three unique instrumentation systems. Our hypothesis was that the systems would have different insertion forces. Method: The COR (Depuy-Mitek), Mosaicplasty (Smith & Nephew) and OATS (Arthrex.) Instrumentation systems and recommended surgical techniques were used to harvest, transfer, and implant grafts. To simulate the in-vivo surgical setting, multiple-impacts with a mallet were applied to the instruments. Ten tests each were performed for all systems in both rigid polyurethane foam blocks and porcine femur models. Plug length after harvest and final graft position were manually measured. Insertion forces were recorded using a load cell (Omega Engineering) affixed to the insertion tamp. The area under the force curve recorded by the transducer for each blow was then summed to yield the total force required to seat each graft. Means and standard deviations were then calculated and Tukey's test was used to determine significant differences between the means. Results: The COR system demonstrated significantly lower mean insertion forces in both polyurethane foam blocks and porcine models when compared with the OATS and Mosaicplasty systems. Graft harvest with Mosiacplasty led to greater harvest length inconsistency than with other systems tested. OATS grafts were more likely to be left proud. Conclusion: The COR system produced significantly lower insertion forces during graft insertion. COR and OATS yielded consistent harvest lengths. The majority of OATS grafts were left proud which would require additional impaction force to fully seat the graft.