Freeze clamping musculo-tendinous junctions for in vitro simulation of joint mechanics.

Incorporation of physiologic muscle tensions to simulate normal in vivo joint loading in cadaveric biomechanical studies has been a challenging problem, especially about the knee, foot, and shoulder. Simulation of muscle contraction requires attachment of tension producing devices to musculotendinous units. To this end, we modified the 'cryo-jaw' device, first described by Riemersma and Schamhardt (1982, J. Biomechanics 15, 619-620) to couple linear actuators to fresh cadaver tendons. These clamps were used in the simulation of 11 different muscles in laboratory investigations of shoulder, elbow, knee, and foot function. The clamps were able to transmit repetitively 3500 N of quadriceps force in eight knees and 2000 N of Achilles force in 11 feet. Overall success rate was 95%.