Forskjeller i bentetthet og kliniske parametre ved usementert eller sementert femurstamme ved total hofteprotese : 5 års oppfølging av en randomisert studie

Abstract

Objectives: To compare stability and bone remodeling between a custom-made uncemented hydroxyapatite-coated femoral stem and a standard cemented femoral stem after five year follow-up. Materials and methods: In this prospective study, 37 patients (38 hips) with non-inflammatory arthritis were randomized to receive either the uncemented or the cemented femoral stem. The uncemented stem used was Unique®, and the cemented stem was Elite Plus. The goals were to compare the implants for bone remodeling using dual energy X-ray absorptiometry (DXA), and clinical outcomes, using Harris Hip Score, Visual Analogue Scale and Merle d’Aubigné-Postel. Results: Bone remodeling measured by DXA showed a statistical significant decrease of BMD for Gruen zones 1, 6 and 7 in the Unique group compared to Elite Plus (Zone 1: -18.7% and +0.5%. Zone 6: -27.4% and -4.9%. Zone 7: -37.7 % and -5,4%, respectively). For zones 3, 4 and 5, there were a BMD increase in both groups, with a statistical significant greater increase in the Unique group to the Elite Plus group (Zone 5: +17.3% and +6.5%, respectively). Clinically we found a statistical significant better result for the Elite Plus patients on HHSpain (40 and 44, p=0.018) and on Merle d’Aubigné-Postel (15.5 and 18.0, p=0.028). Conclusion: The custom made uncemented stem does not prevent proximal bone loss, as does the cemented stem. Nevertheless, the BMD for the distal zones increased more in the Unique group compared to Elite Plus. Clinical results were better for the cemented stem.