High cathepsin B activity in arthroplasty interface membranes. A histochemical study of 9 loose cemented total hip...

We studied biopsies of interface membranes of 9 aseptically loosened total hip prostheses. The morphologic resemblance of the cement-facing surface of the membranes to synovial tissue of arthritic joints, as noticed by others, was confirmed by histochemical techniques. High cathepsin B activity was found in the bone-facing surface of the membranes. Since this enzyme also plays an important role in tissue destruction of arthritic joints, further similarities in the mechanisms of tissue breakdown in arthritis and aseptic loosening of cemented hip prostheses may be conjectured.