Metacarpophalangeal joint mechanics after 3 different silicone arthroplasties.

Purpose: This study was performed to compare metacarpophalangeal (MCP) joint mechanics after arthroplasty with 3 currently available silicone implants and to determine how postarthroplasty mechanics compares with the mechanics of the intact joint.

Methods: Planar 2-dimensional kinematic analysis was performed using digitized radiographs on 10 isolated fingers harvested from 5 fresh-frozen human cadavers. Radiopaque markers were affixed to the metacarpals and proximal phalanges, sewn to the flexor and extensor tendons, and placed into the stems and hinges of the implants.

Strain-rate sensitivity of the rabbit MCL diminishes at traumatic loading rates.

This study was performed to determine whether the viscoelastic behavior of ligaments persists at high rates of loading, such as those associated with sports-related trauma or motor vehicle accidents. Medial collateral ligaments (MCLs) from 22 skeletally mature New Zealand White rabbits were tensile tested quasi-statically and via two impact conditions at displacement rates of 0.17 mm/s (n=22), 640+/-160 mm/s (n=10) and 2500+/-270 mm/s (n=12) (corresponding to strain rates of approximately 1.