Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2007 Jul;127(5):375-9.
doi: 10.1007/s00402-007-0294-y. Epub 2007 Feb 13.

Poor accuracy of freehand cup positioning during total hip arthroplasty

B H Bosker  1 , C C P M Verheyen, W G Horstmann, N J A Tulp
Affiliations

Poor accuracy of freehand cup positioning during total hip arthroplasty

B H Bosker et al. Arch Orthop Trauma Surg. 2007 Jul.

Abstract

Several studies have demonstrated a correlation between the acetabular cup position and the risk of dislocation, wear and range of motion after total hip arthroplasty. The present study was designed to evaluate the accuracy of the surgeon's estimated position of the cup after freehand placement in total hip replacement. Peroperative estimated abduction and anteversion of 200 acetabular components (placed by three orthopaedic surgeons and nine residents) were compared with measured outcomes (according to Pradhan) on postoperative radiographs. Cups were placed in 49.7 degrees (SD 6.7) of abduction and 16.0 degrees (SD 8.1) of anteversion. Estimation of placement was 46.3 degrees (SD 4.3) of abduction and 14.6 degrees (SD 5.9) of anteversion. Of more interest is the fact that for the orthopaedic surgeons the mean inaccuracy of estimation was 4.1 degrees (SD 3.9) for abduction and 5.2 degrees (SD 4.5) for anteversion and for their residents this was respectively, 6.3 degrees (SD 4.6) and 5.7 degrees (SD 5.0). Significant differences were found between orthopaedic surgeons and residents for inaccuracy of estimation for abduction, not for anteversion. Body mass index, sex, (un)cemented fixation and surgical approach (anterolateral or posterolateral) were not significant factors. Based upon the inaccuracy of estimation, the group's chance on future cup placement within Lewinnek's safe zone (5-25 degrees anteversion and 30-50 degrees abduction) is 82.7 and 85.2% for anteversion and abduction separately. When both parameters are combined, the chance of accurate placement is only 70.5%. The chance of placement of the acetabular component within 5 degrees of an intended position, for both abduction and anteversion is 21.5% this percentage decreases to just 2.9% when the tolerated error is 1 degrees . There is a tendency to underestimate both abduction and anteversion. Orthopaedic surgeons are superior to their residents in estimating abduction of the acetabular component. The results of this study indicate that freehand placement of the acetabular component is not a reliable method.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Results of the distribution of the difference between the estimated and measured values (degrees) for abduction (a) and anteversion (b) of the acetabular components (N)
See this image and copyright information in PMC

References

    1. McCollum DE, Gray WJ (1990) Dislocation after total hip arthroplasty. Causes and prevention. Clin Orthop Relat Res (261):159–170 - PubMed
    1. {'text': '', 'ref_index': 1, 'ids': [{'type': 'DOI', 'value': '10.1054/arth.2002.30286', 'is_inner': False, 'url': 'https://doi.org/10.1054/arth.2002.30286'}, {'type': 'PubMed', 'value': '11938502', 'is_inner': True, 'url': 'https://pubmed.ncbi.nlm.nih.gov/11938502/'}]}
    2. Jolles BM, Zangger P, Leyvraz PF (2002) Factors predisposing to dislocation after primary total hip arthroplasty: a multivariate analysis. J Arthroplasty 17(3):282–288 - PubMed
    1. {'text': '', 'ref_index': 1, 'ids': [{'type': 'DOI', 'value': '10.1016/S0883-5403(98)80003-X', 'is_inner': False, 'url': 'https://doi.org/10.1016/s0883-5403(98)80003-x'}, {'type': 'PubMed', 'value': '9741436', 'is_inner': True, 'url': 'https://pubmed.ncbi.nlm.nih.gov/9741436/'}]}
    2. Del Schutte H Jr, Lipman AJ, Bannar SM, Livermore JT, Ilstrup D, Morrey BF (1998) Effects of acetabular abduction on cup wear rates in total hip arthroplasty. J Arthroplasty 13(6):621–626 - PubMed
    1. {'text': '', 'ref_index': 1, 'ids': [{'type': 'PubMed', 'value': '10724224', 'is_inner': True, 'url': 'https://pubmed.ncbi.nlm.nih.gov/10724224/'}]}
    2. D’Lima DD, Urquhart AG, Buehler KO, Walker RH, Colwell CW Jr (2000) The effect of the orientation of the acetabular and femoral components on the range of motion of the hip at different head-neck ratios. J Bone Joint Surg Am 82(3):315–321 - PubMed
    1. {'text': '', 'ref_index': 1, 'ids': [{'type': 'DOI', 'value': '10.1016/j.arth.2003.10.016', 'is_inner': False, 'url': 'https://doi.org/10.1016/j.arth.2003.10.016'}, {'type': 'PubMed', 'value': '15067657', 'is_inner': True, 'url': 'https://pubmed.ncbi.nlm.nih.gov/15067657/'}]}
    2. Widmer KH (2004) A simplified method to determine acetabular cup anteversion from plain radiographs. J Arthroplasty 19(3):387–390 - PubMed