Clinical results of the Harris-Galante cup implanted from 1986 to 1991

Abstract

In the period 1986–1991, we performed 370 consecutive total hip arthroplasties (THA) using the Harris-Galante porus coated prosthesis. The characteristics of this component are: a fiber-mesh coating in pure Ti alloy that stimulates osteoinduction, a process of fusion of fiber-mesh to the metal back that reduces potential damage to the microstructure of the fibers with consequently less resistance to fatigue and a better primary stability guaranteed by fixation screws that stimulate osteoconduction. The average follow-up was 11.5 years. The follow-up was performed through a roentgenographic control at 3, 6 and 12 months and then once a year. Mineralometric evaluation with a Hoxologic QDR apparatus [1,2] permitted quantitative examination of the periprosthetic bonestock. A questionnaire was administered to examine the characteristics of pain and the ability to perform daily activities, to go upstairs, to walk distances, to sit the down and to put on socks and shoes. We found no vascular complications because of the use of Ti screws; the cup, after a primary fixation, ran into osteointegration in most cases. We did not find any aseptic loosening due to the inadequate primary press-fit or to screw breaking. We did not find any periprosthetic bone loss due to the migration of Ultra High Molecular Weight Polyethylene (UHMWPE) wear particles from holes of the shell. When aseptic loosening of the femoral stem and UHMWPE wear particle formation did occur, the metal back was perfectiyl osteointegrated and we only had to substitute the insert. The results are clinically interesting considering the long-term follow-up, the large number of patients and, technically, the type of fixation (line-to-line without press-fit), the semplicity of assembly of UHMWPE without any bone loss around the cup, the good fixation of cups even if badly implanted because of other difficulties in impanting them or for a wrong technique. In our opinion, our choice of implanting HG1 cups line-to-line was successful 10–15 years later.