Abstract
The present clinico-radiographical study evaluated the long term performance of a Ti-Al-V alloy cementless modular press-fit cups (Fitek™) having, on the outer surface, an oriented multilayer titanium mesh (Sulmesh™) with 65% tridimensional porosity and 2 fins applied to the outer surface. Fins were initially designed for anti-rotatory purposes but showed to give an excellent initial mechanical stability. Thus, in the following years, we have designed 2 other cups having 8 fins and ceramic insert. In this paper we compare the design and the results obtained with these 3 cups.
We have reviewed the first 100 consecutive FITEK cups implanted in 92 patients with an average FU of 9,7 years (range 9-11 years). Results were evaluated with the Harris score. We had 86 Excellent, 10 Good, 2 Fair and 2 Poor. In this series we always used 28 mm heads.
Dysplastic patients showed inferior results compared to arthritics patients in different parameters, as pain, limp, ROM (p < 0.05), putting socks and shoes (p < 0.05).
Radiographically, our cups were implanted in a fairly horizontal position (36.5° an average).
At the last FU radiolucent lines were present in 14 % of the cases, never progressive.
In no case we found a change of position of the cup, and in this series no revision was necessary.
Between 2005 and 2008 we have implanted 140 consecutive Delta Fins cups with ceramic-on-ceramic articulation. The fins of this cup have a trapezoidal shape, with HA coating. The cup has an interference of 2 mm. The Delta ceramic insert allows the use of 32 or 36 mm heads.
Clinico-radiographical results were very good. One cup needed to be revised for aseptic loosening consecutive to a surgical error (undersizing)
The H.M.S. cup is made of Porous Titanium with 8 fins having a triangular section, in order to increase their penetration into cortical bone. The ceramic insert allows even larger ceramic insert (32, 36 and 40). Preliminary clinico-radiographical results were excellent, with complete initial mechanical stability and great ROM due to the large ceramic heads.
The presence of fins on the outer surface of cementless cups enhances primary stability and fixation and the use of large ceramic heads improves ROM and subjective patients satisfaction.
