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

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.

Useful Method for Minimizing Leg Length Discrepancies in Hip Arthroplasty: Use of an Intraoperative X-ray

PURPOSE: There are numerous opinions about the methods and usefulness of minimizing leg length discrepancies after hip arthroplasty. In this study, we tried to evaluate the usefulness of an intraoperative x-ray in addition to preoperative templating for minimizing leg length discrepancy. MATERIALS AND METHODS: We reviewed pre- and post-operative pelvis AP x-rays of 46 patients who underwent hip arthroplasty due to a traumatic femoral neck fracture or intertrochanteric fracture between May 2008 and February 2009. A leg length discrepancy is the difference in vertical distance between a horizontal line drawn along the bottom of the ischial tuberosities and the most inferior points of the lesser trochanter. It was measured in a pelvis AP x-ray. In each case, pre-operative templating was performed and an intraoperative pelvis AP x-ray was taken again to assess the accuracy of preoperative planning. Implant positions were readjusted when necessary. RESULTS: The mean post-operative leg-length discrepancy was 0.3 mm (SD, 3.1 mm). The range was from -5.8 mm to +5.9 mm. CONCLUSION: Combining preoperative templating and intraoperative x-rays is a useful method of minimizing leg length discrepancy during hip arthroplasty.

Relationship between femoral isthmus and selection of femoral prosthesis in total hip arthroplasty / 第三军医大学学报

0.05). Conclusion Isthmus is an essential structure to determine the size of femoral component. The dimension of isthmus correlates fairly well with the size of femoral stem. As a measurement to choose the appropriate femoral implant in total hip arthroplasty, the isthmus-method has the similar accuracy as the common templating.