A Study of Pre-Operative Planning in CLS total Hip Arthroplasty

Abstract

This study involved 200 cementless primary total hip arthroplasties of which 100 had formal pre-operative planning as recommended by the manufacturer using standardised radiographs, templates and tracing paper. The remaining 100 had no formal pre-operative planning. The operations were performed by two different groups of surgeons using different surgical exposures. The variables measured included radiological magnification, component sizing, intra-operative lengthening, positioning of the centre of the femoral head and femoral component fit and fill. Clinical data was obtained from a questionnaire. The results indicate an improved position of the centre of rotation and better leg length equalisation in the planned group. There was no significant difference in the number of intra-operative fractures among the two groups. No correlation was found between femoral fit and upper femoral morphology nor between fit and the surgeon's seniority. There was no significant difference in the incidence of thigh pain in the two groups at an average follow-up of 28 months. The more striking finding was the poorer femoral fit and fill encountered in the unplanned group.