Useful Method for Neutral Positioning of the Femoral Stem in Cementless Total Hip Arthroplasty / 대한고관절학회지

ABSTRACT

PURPOSE: The aim of this study was to evaluate the usefulness of a method for positioning the femoral stem in neutral position refer to the measured value of "lateral distance" in pre-operative templating and the femoral stem position post-operatively. MATERIALS AND METHODS: A total of 81 hips in 76 patients underwent cementless total hip arthroplasty between March 2008 and April 2012 using the C2 stem (Lima Corporate S.P.A, Udine, Italy). We measured the perpendicular distance from the lateral outermost part of the greater trochanter to the lateral outermost part of the femoral stem (lateral distance, LD) in pre-operative templating. We aimed to insert the femoral stem in neutral position by comparing LD measured intra-operatively. We evaluated the position of the femoral stem on post-operative plain radiography. We compared the result of post-operative re-measurement of the LD with that of pre-operative measurement. RESULTS: In all of the 81 cases, the femoral stem was inserted in neutral position, defined as the femoral stem position within 3degreesvalgus or varus. The average angle of the inserted femoral stem was 1.20degrees(0.003-2.85degrees). LD measured in preoperative templating was 15.6 mm(10-21.5 mm), and it showed no correlation ratio with LD; LD re-measured post-operatively was 15.9 mm(10.3-23.5 mm) (P=0.781). CONCLUSION: Measuring LD pre-operatively and using the value intra-operatively is an effective method for insertion of the femoral stem in neutral position.