Press-fit cups have given excellent clinico-radiographical results. This is a retrospective clinico-radiographical study about the long term performance of pure Titanium cementless modular press-fit cups (FitekTM) having, on the outer surface, an oriented multilayer titanium mesh (SulmeshTM) with 65% porosity (average pore size=400–640 micron). The cup was implanted after underreaming the acetabulum by 2 mm. In the cup’s equatorial area there are two “fins” originary designed to improve rotational stability but actually representing two excellent primary mechanical stabilizers. We have evaluated the first 100 consecutive cups implanted in 92 patients with an average FU of 9,7 years (range 9–11 years). All operations have ben performed by the two Senior Authors (PGM and RB). Regarding etiology, we had 43 Primary Arthritis, 37 Dysplastic Arthritis, 12 Osteonecrosis and 8 Post-traumatic Arthritis. results were evaluated with the Harris score. Radiographic evaluation was performed using AP and lateral x-rays pre-op. post-op and at the last follow-up. We had 86 Excellent, 10 Good, 2 Fair and 2 Poor. The 2 Poor results were 2 aseptic loosenings of the stem The Mann-Whitney nonparametric U test and the Kruskal-Wallis test showed that the survival rate of the 100 analyzed cups, after a mean follow-up of 9.7 years, was 100% (end point: revision for any cause) Etiology was not statistically correlated with post-op score. Nevertheless, dysplastic patients showed inferior results compared to arthritic patients in different parameters, as pain, limp, Range Of Motion (p <
0.05), putting socks and shoes (p <
0.05). Our cups were intentionally implanted and radiographically appear in a fairly horizontal position (36.5° on average). In 6 cases we could calculate an eccentricity of the metal heads proving bidimensional linear wear of the liner (average 0.265 mm / year). At the last follow-up we had 3 femoral osteolysis, while in the acetabular side radiolucent lines were present in 14 % of the cases, never progressive. In no case we found a change of position of the cup. FitekTM cementless cups gave excellent results at 10 years with complete stability and osteo-integration. Excellent primary mechanical stability was given by the rough surface (SulmeshTM) and by the two “fins” in the equatorial area.
Little is published about the use of cementless conical stems in primary hip arthroplasty for congenital hip disease. A conical stem was designed in the 80’s by Prof. Wagner. The stem is made of a rough blasted titanium alloy with a cone angle of 5° and 8 sharp longitudinal “ribs” that cut into the inner cortex, designed to achieve rotational stability: The ribs depth of penetration ranges between 0.1 and 0.5 mm and is also very important to achieve osteo-integration. The CCD angle is 135°. The stem is straight and can be implanted in any degree of version thus being very useful for dysplastic arthritis with significant femoral neck anteversion. Between 1993 and 1998 the senior author (RB) implanted 92 conical stems in 88 consecutive patients with dysplastic arthritis. The acetabular component was cementless and titanium with tridimensional porosity. The articulating surface was a second generation Metal-on-Metal.with a femoral head of 28 mm. According to the Hartofilakidis classification 63 patients had type A, 18 type B and 11 type C. The average follow-up was 11.2 years (range 10.1–14.8) Using the Harris Hip Scoring system we had 82 (89%) satisfactory results, with excellent correction of pre-op pain (42/44 Harris) and no case of anterior thigh pain; 88% of patients had no or slight limp at follow-up. No patient required revision of the stem, but one cup required revision for loosening (Type C class). We had one dislocation (1%) that was treated conservatively Radiographically, all stems were osteo-integrated, 17% showed some resorption in femoral zone 1 and 7. In the same zones we observed 4 cases of real osteolysis without loosening. No radiolucent line was observed in other femoral zones. In the acetabular side we had 13 cases (14%) of radiolucency, but in only 1 case (1%) was it progressive. A straight conical titanium femoral stem gave very satisfactory clinico-radiographical results in dysplastic arthritis at a mean of 11.2 years of follow-up.