title: Natural acetabular orientation in arthritic hips.
abstract: OBJECTIVE
  Acetabular component orientation in total hip arthroplasty (THA) influences results. Intra-operatively, the natural arthritic acetabulum is often used as a reference to position the acetabular component. Detailed information regarding its orientation is therefore essential. The aim of this study was to identify the acetabular inclination and anteversion in arthritic hips.
  
  
  METHODS
  Acetabular inclination and anteversion in 65 symptomatic arthritic hips requiring THA were measured using a computer navigation system. All patients were Caucasian with primary osteoarthritis (29 men, 36 women). The mean age was 68 years (SD 8). Mean inclination was 50.5° (SD 7.8) in men and 52.1° (SD 6.7) in women. Mean anteversion was 8.3° (SD 8.7) in men and 14.4° (SD 11.6) in women.
  
  
  RESULTS
  The difference between men and women in terms of anteversion was significant (p = 0.022). In 75% of hips, the natural orientation was outside the safe zone described by Lewinnek et al (anteversion 15° ± 10°; inclination 40° ± 10°).
  
  
  CONCLUSIONS
  When using the natural acetabular orientation to guide component placement, it is important to be aware of the differences between men and women, and that in up to 75% of hips natural orientation may be out of what many consider to be a safe zone. Cite this article: Bone Joint Res 2015;4:6-10.
authors: Golden Jubilee National Hospital, Agamemnon Street, Clydebank, Glasgow, G81 4DY, UK.
authors: S T
authors: ST
authors: Goudie
authors: Golden Jubilee National Hospital, Agamemnon Street, Clydebank, Glasgow, G81 4DY, UK.
authors: A H
authors: AH
authors: Deakin
authors: Golden Jubilee National Hospital, Agamemnon Street, Clydebank, Glasgow, G81 4DY, UK.
authors: K
authors: K
authors: Deep
keywords: Acetabulum; Orientation; Arthritis; Computer; Navigation; Inclination; anteversion; Total hip arthroplasty; THA
references: J Bone Joint Surg Am. 1978 Mar;60(2):217-20
references: 641088
references: J Arthroplasty. 2002 Apr;17(3):282-8
references: 11938502
references: J Bone Joint Surg Br. 2008 Mar;90(3):308-13
references: 18310751
references: J Bone Joint Surg Br. 1993 Mar;75(2):228-32
references: 8444942
references: Clin Orthop Relat Res. 1978 Jul-Aug;(134):135-8
references: 729230
references: Clin Orthop Relat Res. 2009 Jan;467(1):32-42
references: 18979147
references: Clin Orthop Relat Res. 2005 Aug;(437):132-7
references: 16056040
references: J Arthroplasty. 1999 Jun;14(4):509-13
references: 10428235
references: Comput Aided Surg. 2005 Jan;10 (1):37-43
references: 16199380
references: Clin Orthop Relat Res. 2007 Dec;465:92-9
references: 17693877
references: J Bone Joint Surg Am. 2013 Nov 20;95(22):e172
references: 24257672
references: J Orthop Surg Res. 2010 Oct 15;5:76
references: 20950444
references: Orthopedics. 2010 Oct;33(10 Suppl):38-42
references: 20954628
references: Clin Orthop Relat Res. 1990 Dec;(261):159-70
references: 2245542
references: Orthopedics. 2008 Oct;31(10):null
references: 19226017
references: J Am Acad Orthop Surg. 2003 Mar-Apr;11(2):89-99
references: 12670135
references: J Arthroplasty. 2009 Jan;24(1):15-21
references: 18534411
references: J Bone Joint Surg Am. 1994 May;76(5):677-88
references: 8175815
references: J Bone Joint Surg Br. 2006 Jul;88(7):883-6
references: 16798989
references: J Arthroplasty. 1998 Aug;13(5):530-4
references: 9726318
references: J Bone Joint Surg Br. 2005 Jun;87(6):762-9
references: 15911655
references: J Arthroplasty. 2010 Aug;25(5):812-9
references: 19553075