Results of surgical treatment in patients with aseptic instability of components of hip joint endoprosthesis

Abstract

The aim. To study the results of revision endoprosthetics in patients with aseptic instability of the components of the hip joint endoprosthesis. Materials and methods. The basis of this work was the analysis of the revision prosthetics results in 152 patients (158 cases) with aseptic instability of components of hip joint endoprosthesis, who underwent surgery at the State Institution “Institute of Traumatology and Orthopedics of the National Academy of Medical Sciences of Ukraine” between 2008 and 2018. Total instability in the endoprosthesis components was observed in 43 cases (27.2 %), acetabular component instability – in 65 cases (41.1 %), femoral component instability was detected in 50 cases (31.6 %). Endoprosthesis dislocation occurred mostly between 5 and 9 years after the primary surgery. Clinical, radiological and statistical methods were used in the work. Results. Patients with acetabular component instability showed the best results of revision replacement for Paprosky I, II types acetabular defects (t = 9.3, P < 0.05). The vast majority of components became unstabile between 5 and 9 years after the primary replacement. The results of unstable femoral component revisions did not reveal any significant difference between cemented and cementless types of component fixation 10 years after the procedure. Recurrent aseptic instability was observed only in 7 cases, 5 of which (71.4 %) were fixated with cement. In the case of total instability, there was no difference in the revision implantation results between the use of primary components alone and in the combination with revision reconstructive systems. Component stability constituted the great majority (35 cases, which was 81.4 %) of cases after 10 years (t = 7.3, P < 0.05). The recurrent instability of one component was observed in 8 cases, which represented 18.6 % of the total number of revisions. Conclusions. In patients with instability of acetabular and femoral components in the presence of Paprosky I–II bone defects, the results of the revision replacement were better when implanting primary components using cementless type of fixation. The use of revision antiprotrusion acetabular and elongate femoral modular or monoblock systems with cementless type of fixation achieved better results in Paprosky III type acetabular and femoral bone defects. The revision of cemented components showed significantly worse results and implant survival rate compared to cementless fixation technique.