title: Radiographic measurement to restore femoral head center in hip arthroplasty.
abstract: OBJECTIVE
  The purpose of the present study was to find the anatomical landmarks used as a reference for restoration of the femoral head center in hip arthroplasty patients.
  
  
  METHODS
  One hundred anterior-posterior digital radiographs of the hip with no magnification were analyzed to measure the correlation between the distance from the center of the femoral head to the most prominent part of lesser trochanter and the femoral head diameter, and the relationship between the level of tip of the greater trochanter and the level of femoral head center.
  
  
  RESULTS
  The authors found the linear correlation between the distance from the femoral head center to the lesser trochanter and the femoral head diameter (Pearson's correlation coefficient = 0.95) with the average ratio of 1.023. The level of tip of the greater trochanter was found 75% higher than the femoral head center 15% below the femoral head center, and 10% at the same level. The average level of the tip of greater trochanter was 8 mm above the femoral head center.
  
  
  CONCLUSIONS
  The distance from the center of the femoral head to the most prominent part of the lesser trochanter is approximately equal to the diameter of the femoral head. The use of the level of the tip of greater trochanter as a reference point for the level of the femoral head center should be carefully evaluated because of the variability of anatomy.
authors: Department of Orthopaedic Surgery, Faculty of Medicine, Thammasat University, Pathumthani, Thailand. dr.panichkul@gmail.com
authors: Phonthakorn
authors: P
authors: Panichkul
authors: Piya
authors: P
authors: Pinsornsak
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000379:methods; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging*; D005270:Femur Head / Q000000981:diagnostic imaging; D006801:Humans; D007870:Leg Length Inequality / Q000517:prevention & control; D008297:Male; D011859:Radiography