HIGH CATHEPSIN-B ACTIVITY IN ARTHROPLASTY INTERFACE MEMBRANES - A HISTOCHEMICAL-STUDY OF 9 LOOSE CEMENTED TOTAL HIP PROSTHESES

We studied biopsies of interface membranes of 9 aseptically loosened t otal hip prostheses. The morphologic resemblance of the cement-facing surface of the membranes to synovial tissue of arthritic joints, as no ticed by others, was confirmed by histochemical techniques. High cathe psin 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 prosthese s may be conjectured.