The Clinical and Radiographic Results of Primary Cementless PCA ( Porous-Coated Anatomic ) Total Hip Arthroplasties: Minimum 10-Year Follow-up Study

Hwang, Sung Kwan; Son, Young Ki

Abstract

PURPOSE: To assess the long-term results of primary cementless PCA total hip arthroplasty.
MATERIALS AND METHODS
We reviewed radiographs of 35 patients (43 hips) and evaluated clinical results of 44 patients (53 hips) who were followed up for a minimum of 10 years (10 to 12.8 years) after primary cementless PCA total hip arthroplasty.
RESULTS
The average preoperative Harris hip score was 50.3 point and average postoperative Harris hip score was 87.5 point at 1 year and 81.3 point at last follow-up. On last follow-up, radiographic findings showed that femoral stability was considered stable by bony ingrowth in 39 cases (90.7%), stable by fibrous ingrowth in 1 cases (2.3%), and unstable in 3 case (7.0%). Pelvic osteolysis occurred in 5 cases (11.6%) and femoral osteolysis in 17 cases (39.5%). Loosening of implant was observed in 3 cases (7.0%) around femoral stem and in 6 cases (14.0%) around acetabular socket. The mean linear wear of polyethylene liner was 1.37 mm (range 0.1 mm to 4.73 mm), and the linear wear rate was 0.25 mm/year. Eight of the 9 acetabular components that failed in our study had an acetabular component size of 55 mm or smaller.
CONCLUSIONS
The result of primary cementless PCA total hip arthroplasties was acceptable up to 10 years, but osteolysis and polyethylene wear became more common with time. Therefore, we recommend that patients with PCA total hip arthroplasties should be followed up carefully over the long term and a modification in articulation material is required to reduce osteolysis and polyethylene wear.