Short term outcomes of cementless total hip arthroplasties

Purpose: Aim of this study is to investigate the short term clinical and radiographic outcomes of cementless total hip arthroplasty in different etiological causes.Materials and Methods: The clinical and radiographic outcomes of 92 patients (102 hips) with consecutive cementless total hip arthroplasties were evaluated. The patients admitted to Gazi University Faculty of Medicine, Department of Orthopaedics and Traumatology between November 2003 and December 2010. The study group consisted of hydroxyapatite coated flattened press-fit EPF-PLUS cup and the tapered cementless with a rectangular cross-section and hydroxyapatite coated Zweymuller SL-PLUS stem. Clinical outcome was measured by comparing Harris Hip Scores pre-operatively and at last clinic visit. Radiolucencies and osteolysis with respect to the stem and acetabulum were classified according to the system of Callaghan and Engh on anteroposterior radiographs of the hip and pelvis. Direct lateral approach has been performed to the all patients. Heterotopic ossification (HO) formation was also graded by the criteria indicated in Brooker et al.Results. In total 24 (%26) of the 92 patients were men and 68 (%74) were women. The age ranges of the all patients varied between 22 and 80 years old and the average age for the whole patients was 55,66 years during the time of surgery. The average follow-up time was 34.9 (10-84) months. The average preoperative Harris Hip Score was 45,87 (30-67) points. At the time of the most recent follow-up visit, the average Harris Hip Score was found as 92,49 (68-100) points.According to the criteria of Engh et al., all femoral implants were graded as stable bone-ingrown. Radiolucent lines were mostly observed in Gruen zones 1 and zone 7 of the femur [zone 1 %67.32, zone 7 % 60.18 zone 2 %2.04, zone 3 %1.02, zone 6,2.04]. Radiolucent area occured in 42 (%42,84) cups [zone 2 %34.68, zone 3 (%21.42), zone 1 %18.36]. The inclination angle of the acetabular component was 47,25 (28-70).Postoperative neuropraxy were identified in four (%4.68) cases (siatic neuropraxy of in two cases, both of them recovered, and femoral neuropraxy in two cases, one of them recovered). The prevalence of thigh pain at the time of the latest follow-up was %1.02 (one case). One acetabular component needed revision surgery due to polyethylene insert wear. None of the femoral stems and acetabular components was changed as a result osteolysis. HO was observed in 10 hips (% 10,2). Heterotopic bone was graded as class I in 5 hips, class II in 3 hips, class 2 in 2 hips. Intraoperative femoral fissur was developed in 4 (%4.8) hips. One of the 6 subtrochanteric osteotomies and one of the 12 femoral head autograft were followed by nonunion.Conclusions: The results show that arthroplasty with Zweymuller femoral stem which is combined with a flattened, hydroxyapatite coated press-fit acetabular cup which was inserted without cement. These outcomes were found excellent in short term follow-up resultsKey Words: Zweymuller femoral stem, short term follow-up, uncemented hip arthroplasty.