Abstract
Introduction and Objectives: We compared the clinical and radiographic results of patients with JRA and primary arthritis using a non-cemented THR with an alumina-alumina THA.
Materials and Methods: We studied 29 THR (Cerafit cup and Multicone stem) implanted in 19 patients with JRA in group 1 and 135 with primary arthritis in group 2. Mean follow-up was 59.0 months. It was seen that 13 hips in group 1 had moderate-severe acetabular protrusion and allograft was used in 12 hips. The center of rotation was determined pre and postoperatively in group 1 according to Ranawat.
Results: In group 1 age (p< 0.001), weight (p< 0.001), and level of activity (p< 0.001) were less. Type A acetabulum (p=0.014) and a cylindrical femur (p< 0.01), according to Dorr, were more frequent in group 1. There was no noise or alumina breakage. There were two intraoperative femur fractures in group 1. There was a revision of 1 cup in group 1 and infection of 1 stem in group 2. In most of the group 1 cases anatomical position was recovered (p< 0.001). The preoperative center of rotation of the hip with acetabular protrusion was 23.2 mm and in the postoperative X-ray 5.6 mm.
Discussion and Conclusions: In spite of the differences, THR with alumina-alumina allows similar results to be obtained in the medium term in patients with JRA. The use of an allograft in those patients with severe acetabular protrusion makes it possible to reconstruct the center of rotation of the hip.
The abstracts were prepared by E. Carlos Rodríguez-Merchán, Editor-in-Chief of the Spanish Journal of Orthopaedic Surgery and Traumatology (Revista Española de Cirugía Ortopédica y Traumatología). Correspondence should be addressed to him at: Sociedad Española de Cirugía Ortopédica y Traumatología, calle Fernández de los Ríos 108, 28015-Madrid, Spain
