Gene therapy and cement injection for the treatment of hip prosthesis loosening in elderly patients

Abstract

Approximately one million total hip replacement operations are performed worldwide annually, mostly for osteoarthritis and rheumatoid arthritis. A major complication in total hip arthroplasties is loosening of the prosthesis leading to pain and walking difficulties and a higher risk for dislocations and pathological fractures.11 Within ten years of primary hip replacement 7-13 percent of patients need revision surgery due to loosening of the implant.16 The number of revision surgeries in elderly patients is likely to increase considerably in the next decades, due to the tendency to insert orthopaedic implants at younger ages and the longer life expectancy of patients. Revision surgery has a high complication rate in elderly patients1,20,23,25 and is associated with less improvement in social outcome, compared to primary hip arthroplasty in patients of all ages.24 Many studies have focused on the relatively good technical outcome of revision hip arthroplasty in patients of all ages. However, the impact on the patient__s life, especially in elderly patients has been underemphasised. This thesis was set up to develop and analyse an alternative treatment for hip prosthesis loosening. We used a gene-directed enzyme-prodrug therapy to kill and remove interface tissue, after which we injected bone cement around the prosthesis percutaneously under CT- and fluoroscopy guidance.