Evaluation of the Separation Force for Various Artificial Hip Bearings

Separation of the hip joint after total hip arthroplasty (THA) has been documented using video fluoroscopy during various activities such as gait and abduction type movements. It has been proposed that larger-diameter bearings provide greater inherent joint stability than smaller ones. In addition, large-diameter bearings tend to develop a fluid film between the surfaces that may induce a “suction” effect because of surface tension that may keep the bearing surfaces in contact during periods of unloading or light distractive motion.