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.

Purpose: New high-strength sutures demonstrate high failure loads, but may be more likely to slip compared with polyester sutures. The purpose of this study was to determine the knot security and ultimate failure load of 8 common sutures tied with 6 arthroscopic knots. The hypothesis was that knots tied using high-strength sutures would not slip and demonstrate greater tensile strengths than polyester suture.

Method: Eight different sutures (Ethibond, FiberWire, ForceFiber, Hi-Fi, MagnumWire, Maxbraid, Ortho-cord and Ultrabraid) were tied with 6 arthroscopic knots (Duncan, Revo, San Diego, SMC, Tennessee and Weston.) Knots were backed up with 4 reversed half-hitches on alternating posts. Each suture-knot combination was tied 10 times for a total of 480 knots tested. Cyclic testing was performed followed by loading to failure. Mode of failure, ultimate failure load and force during slippage was recorded.

Results: FiberWire demonstrated the highest failure load (259.70N+/−85.81) and Ethibond the lowest (143.92N+/−16.56) (p< 0.05). Knots tied with Ethibond slipped 22.4% of the time compared with 31.7%–40.0% for high-strength sutures. Frequent slippage occurred with Duncan loops (97.5%) and Weston knots (86.3%) while the SMC (1.3%) and Revo knots (3.6%) rarely slipped (p< 0.05). Mean failure loads were highest for the Revo (280.99N +/− 57.01) and SMC knots (274.89N +/−57.90) compared with all others (p< 0.05).

Conclusion: Our results demonstrate that knots tied with Ethibond were least likely to slip and yielded a more consistent (narrow standard deviation) but overall lower ultimate tensile strength than all of the high strength sutures. Early slippage of some knots tied with high-strength suture was responsible for greater variability with some failing at sub-maximal loads. The Duncan loop and Weston knots were the most likely to slip.