title: Reconstruction of femoro-acetabular offsets using a short-stem.
abstract: OBJECTIVE
  Despite the fact that new and modern short-stems allow bone sparing and saving of soft-tissue and muscles, we still face the challenge of anatomically reconstructing the femoro-acetabular offset and leg length. Therefore a radiological and clinical analysis of a short-stem reconstruction of the femoro-acetabular offset and leg length was performed.
  
  
  METHODS
  Using an antero-lateral approach, the optimys short-stem (Mathys Ltd, Bettlach, Switzerland) was implanted in 114 consecutive patients in combination with a cementless cup (Fitmore, Zimmer, Indiana, USA; vitamys RM Pressfit, Mathys Ltd, Bettlach, Switzerland). Pre- and postoperative X-rays were done in a standardized technique. In order to better analyse and compare X-ray data a special double coordinate system was developed for measuring femoral- and acetabular offset. Harris hip score was assessed before and six weeks after surgery. Visual analogue scale (VAS) satisfaction, leg length difference and the existence of gluteal muscle insufficiency were also examined.
  
  
  RESULTS
  Postoperative femoral offset was significantly increased by a mean of 5.8 mm. At the same time cup implantation significantly decreased the acetabular offset by a mean of 3.7 mm, which resulted in an increased combined femoro-acetabular offset of 2.1 mm. Postoperatively, 81.7% of patients presented with equal leg length. The maximum discrepancy was 10 mm. Clinically, there were no signs of gluteal insufficiency. No luxation occurred during hospitalization. The Harris hip score improved from 47.3 before to 90.1 points already at six weeks after surgery while the mean VAS satisfaction was 9.1.
  
  
  CONCLUSIONS
  The analysis showed that loss of femoro-acetabular offset can be reduced with an appropriate stem design. Consequently, a good reconstruction of anatomy and leg length can be achieved. In the early postoperative stage the clinical results are excellent.
authors.affiliation: Department of Orthopaedic Surgery, St. Josefs Hospital Wiesbaden, Wiesbaden, Germany, kkutzner@joho.de.
authors.forename: Karl Philipp
authors.initials: KP
authors.lastname: Kutzner
authors.forename: Mark Predrag
authors.initials: MP
authors.lastname: Kovacevic
authors.forename: Christoph
authors.initials: C
authors.lastname: Roeder
authors.forename: Philipp
authors.initials: P
authors.lastname: Rehbein
authors.forename: Joachim
authors.initials: J
authors.lastname: Pfeil
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D007870:Leg Length Inequality; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011446:Prospective Studies; D011859:Radiography