Total joint replacement: both a miracle and a disappointment.

Abstract

Total joint arthroplasty has become a successful therapy for patients with debilitating arthritis of the major weight-bearing joints. However, by current standards, the life of a total joint implant is approximately 10 to 15 years. Older, more sedentary patients enjoy greater and longer-term success than younger, active patients. Eventually, most implants fail because of component loosening. Currently, efforts to obtain longer-term implant stability are focused on achieving bone growth into the implanted components. A new process of plasma-spraying hydroxyapatite--an entirely biocompatible, bioceramic material--onto porous, titanium alloy components promotes bone ingrowth into the components resulting in implant fixation, which is superior to current methods of cemented or cementless fixation. Early results suggest that hydroxyapatite-bioingrowth fixation may be the start of a new era in joint implant surgery.