Abstract
Introduction
Accurate implantation is important for total hip arthroplasty to achieve a maximized, stable range of motion and to reduce the risk of dislocation. We had estimated total cup and stem anteversion(AV) visually during operations without navigation system. The purpose of this study is to assess the correlation between total AV estimated visually during operation and total AV evaluated with CT and X-ray postoperatively.
Materials & Methods
We investigated 145 primary total hip arthroplasties performed with direct anterior approach in supine position. 17 hips were in men and 128 in women. The mean age at operation was 65.6 years. During operations “intraoperative total AV” was defined as an angle from neutral hip position to internal rotated position at a concentric circle of acetabular rim and the equator of femoral head. We also measured cup inclination with X-ray and cup anteversion and stem anteversion with computed tomography after THA. “Radiographic total AV” was defined as the sum of cup and stem anteversion measured with CT. Correlation between “intraoperative total AV” and “Radiographic total AV” was evaluated statistically.
Results
The mean “intraoperative total AV” was 24.2±5.6 degree. The mean cup inclination was 44.8 ±5.4 degree. The mean cup and stem anteversion was 25.0 ±7.4 and 17.8 ±11.0 degree respectively. The mean “radiographic total AV” was 42.8 ±12.8 degree. “Intraoperative total AV” was correlated to stem anteversion and “radiographic total AV” statistically.
Discussions and Conclusions
“Intraoperative total AV” was correlated to “radiographic total AV”. Therefore, this method was useful to achieve an accurate implantation in THA.
