The Choice of the Placement of Acetabular Component of Endoprosthesis in Dysplastic Osteoarthritis Patients. Summary of the Doctoral Thesis

Abstract

From dysplastic osteoarthtitis usually suffer young, social active and working people in ages between 20 and 50, mostly women. Total hip replacement (THR) is an up-to-date method of treatment for dysplastic hip patients. At the same time great majority of authors consider that complication rate in dysplastic hip patients due to severely changed anatomy is much more higher than in primary osteoarthritic hip. There are no complex studies about the complication risks for patients who need radical anatomical-biomechanical reconstruction during total hip replacement. Our hypothesis is that the placement of acetabular component at the anatomical site not always gives the best clinical and functional result. The purpose of the study was to establish the most appropriate site for the placement of acetabular component due to the grade of dysplasia. Material and Methods. 106 THR were performed in 88 displastic hip patients in Riga State Hospital of Traumatology and Orthopaedics from 2008 till 2011. Special digital orthopaedic programme AGFA Orthopaedic Tools was used for radiographic measurements. For functional evaluation Merle d’Aubigne - Postel’s grading system was applied. Instrumental gait analysis was performed for 28 patients (who underwent 37 THRs ) not earlier than one year after operation. Results. The analysis of functional and radiographic outcome of 106 THR and postoperative complications was made in this study. On the basis of that analysis the algorithm for appropriate placement of the acetabular component during THR was created. The Latvian Republic Patent Nr.14412 (‘The method of prognostication of the loosening of the acetabular component of hip endoprosthesis in dysplastic osteoarthritis patients’) was approved. Conclusion. In severe dysplasia cases (grade II,III,IV - according to Crowe’s classification) the placement of acetabular component into the secondary socket allows to achieve good functional result and reduces the possible complication rate.