Details

Autor(en) / Beteiligte

• Meermans, G
• Goetheer-Smits, I
• Lim, R F
• Van Doorn, W J
• Kats, J

Titel

The difference between the radiographic and the operative angle of inclination of the acetabular component in total hip arthroplasty: use of a digital protractor and the circumference of the hip to improve orientation

Ist Teil von

• The bone & joint journal, 2015-05, Vol.97-B (5), p.603-610

Ort / Verlag

England

Erscheinungsjahr

2015

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A high radiographic inclination angle (RI) contributes to accelerated wear and has been associated with dislocation after total hip arthroplasty (THA). With freehand positioning of the acetabular component there is a lack of accuracy, with a trend towards a high radiographic inclination angle. The aim of this study was to investigate whether the use of a digital protractor to measure the operative inclination angle (OI) could improve the positioning of the acetabular component in relation to a 'safe zone'. We measured the radiographic inclination angles of 200 consecutive uncemented primary THAs. In the first 100 the component was introduced freehand and in the second 100 a digital protractor was used to measure the operative inclination angle. The mean difference between the operative and the radiographic inclination angles (∆RI-OI) in the second cohort was 12.3° (3.8° to 19.8°). There was a strong correlation between the circumference of the hip and ∆RI-OI. The number of RI outliers was significantly reduced in the protractor group (p = 0.002). Adjusting the OI, using a digital protractor and taking into account the circumference of the patient's hip, improves the RI significantly (p < 0.001) and does not require additional operating time.