J024051 人工股関節カップー臼蓋間の術中固定性評価システム([J024-05]骨の臨床評価・解析)

Abstract

Quantitative evaluation of the fixation of acetabular component(cup) in pelvis is important for the clinical fixation of total hip arthroplasty(THA). The cup stability is mainly caused by the compressive stress from the inserted acetabulum, in the case of press-fit type THA. Direct measurements of the compressive stress acting between the trial cup and bone is expected to be useful for evaluation of initial stability during operation of THA. In this study, we proposed a measurement system of contact pressure distribution between the cup and the reamed acetabulum by means of a thin and flexible contact pressure sensing system. The pressure sensor unit with 78|im thickness was sealed with a polyimide film, and attached at the outer surface of the trial cup of 50mm diameter. Three bone models were drilled by hemispherical reamers 50mm, 51mm and 52mm in diameter, respectively. The contact pressure distributions were measured when the trial cup was manually inserted into the bone model. The contact pressure was measured as larger values in the acetabulum with 50mm diameter than in the 51mm and 52mm diameter. The sensing system could obviously show the differences of fixation conditions as the differences of pressure distributions with quantitative values. The system is expected to use in the intraoperative evaluation of stability during THA operations.