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Introduction:Cadaveric Evaluation of the MAKO Multi Compartmental KneeKinematics*Gokce Yildirim - NYU Hospital for Joint Diseases - New York, USAPeter Walker - - New York, USAMichael Conditt - MAKO Surgical Corp. - Boerne, USASharon Horowitz - MAKO Surgical Corp. - Fort Lauderdale, USAIvan Madrid - NYU Hospital for Joint Diseases - New York, USA*Email: gokce.yildirim@med.nyu.eduThe MAKO Surgical Rio Robotic Arm utilizes the pre-op CT images to plan positioning of theuni-condylar and patella-femoral components in order to achieve the most desirable kinematicsfor the knee joint. We hypothesize that the anatomic matching surfaces and the cruciateretaining design of the Restoris knee will best replicate normal knee kinematics. We tested thehealthy cadaveric knee versus the MAKO knee and the most common TKR designs in order toevaluate and compare the kinematic properties.Methods:Six healthy male left knees were dissected to leave only the knee capsule and the quadricepstendon intact. The femur and the tibia were cut 20cm from the joint line and potted with cementinto a metal housing. The knee was attached to a crouching machine capable of moving theknee joint though its normal human kinematics from extension to maximum flexion, validatedin previous studies. Forces applied to the quadriceps tendon allowed the knee to flex and extendphysiologically, and springs attached to the posterior were substituted as the hamstrings at arate of half the force exerted by the quadriceps as shown in the literature. Three dimensionalvisual targets attached to the bones were tracked by computer software capable of recreating thepositions of the bones in any given flexion angle. A cruciate retaining and posterior stabilizedTKR design were chosen to represent the TKRs most commonly available in the market today.The intact knee, MAKO implanted knee, CR and PS TKR designs were tested in sequence onthe same specimens. The computer software analyzed the normal distance between the bonesurfaces and plotted the locations of contact which could then be quantitatively compared foreach given scenario [Fig. 1].Results:Our results showed that the MAKO knee kinematics resembled the normal knee kinematicsthroughout the knee flexion range. The TKR designs altered the kinematics of the knee wherethe internal rotation of the tibia was no longer observed with the increasing flexion angle, whilethe femoral roll back in high flexion was only replicated by the post of the PS design and not bythe CR design.Conclusions:Anatomic restoration of the joint surfaces and retention of the cruciate ligaments maintainednormal kinematics, which is expected to be an advantage in obtaining improved clinical results.FiguresFigure 1file:///E|/ISTA2010-Abstracts.htm[12/7/2011 3:15:47 PM]