Abstract
Purpose: The long-term outcome of the Harris-Galante 1 (HGP1) stem is a controversial issue. A randomised study reported by Thanner (AOS 1999) mentioned a 72% survival at ten years, basically related to femoral osteolysis observed in 18% of the cases with mechanical failure requiring revision in 20%. We studied the clinical and radiological outcome of 191 HGP1 stems reviewed at a mean 12.5 years.
Material: This prospective study included a consecutive series of 181 patients (191 hips) 101 men and 80 women, mean age 62.1 years (range 19–83). Indication for arthroplasty was primary hip degeneration (80%), or osteonecrosis (14.6%). A metal-backed polyethylene cup and a 28 mm head were inserted in 86% of the cases. At review, 41 patients had died (43 hips), two were lost to follow-up, and x-rays were available for 109. Mean follow-up was 150.2±15.3 months.
Methods: The Postel Merle d’Aubigné (PMA) and Harris (HHS) scores were recorded for all patients. Position and quality of bone fixation were analysed. Stem migration was calculated on the different x-rays by calculating the distance between the centre of the head and the summit of the greater trochanter. Lucent lines (Gruen), osteolysis and the ARA score were noted. The SOFCOT 1997 radioclinical classification was used. Actuarial survival curves were plotted taking stem revision as the endpoint. Quantitative data were compared with the chi-square test.
Results: One patient died on day three. There were three displacements. The PMA pain score improved from 2.5 to 5.6 and the HHS improved from 52.5 to 85.6 points. The stem was perfectly aligned in 80 cases, and presented a varus deviation ≤ 3° in 26 cases. A change in the initial alignment was noted in three cases and stem impaction in 14. Eleven revisions were necessary for fibrous fixation (n=5), pain (n=2), femoral malposition, (n=1), fracture of the femur during the operation (n=1, and diaphyseal osteolysis (n=1). Finally, there were no radiographic anomalies for 69 hips (class A), radiographic anomalies without clinical expression for 34 (class B), basically because of severe osteolysis of the calcar (n=6), and stress shielding in zone 1A-B. Three hips caused pain without a detectable radiographic anomaly (class C), only one hip was in class D because of the poor clinical and radiological result. The 15-year actuarial survival taking stem revision as the endpoint was 89.5±3.7%.
Discussion: The 5% rate of unstable fibrous fixation observed in this series is very different from the 16% reported by Garcia Cimbrelo (2001). There was only one case of femoral shaft osteolysis limited to zone 3 which required revision, contrasting with the 16% (Thanner) and 24% (Garcia Cimbrelo) reported for shorter follow-ups.
Conclusion: With an 89.5% mid-term survival, the Harris Gallante 1 femoral stem has provided good clinical results and a solid fixation due to the proximal porous coating on the titanium. Although rare, stem failure was observed during the first six years of implantation.
The abstracts were prepared by Docteur Jean Barthas. Correspondence should be addressed to him at Secrétariat de la Société S.O.F.C.O.T., 56 rue Boissonade, 75014 Paris.
