Preoperative Measurement to Estimate Stem Anteversion in DDH Patients after Total Hip Arthroplasty
10.16156/j.1004-7220.2019.04.02
- VernacularTitle:术前测量预估DDH患者全髋置换术后股骨柄前倾角方法
- Author:
Yongke SHAO
1
;
Huiwu LI
2
;
Yongyun CHANG
2
;
Qi SUN
2
;
Yao YUAN
3
;
Jingwei ZHANG
2
;
Fei ANG
2
Author Information
1. Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine；Department of Orthopaedics, Yuyao Peopole’s Hospital
2. Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine
3. Department of Orthopaedics, Yuyao Peopole’s Hospital
- Publication Type:Journal Article
- Keywords:
combined antevertion (CA);
femoral anteversion;
stem anteversion;
developmental dysplasia of the hip (DDH);
total hip arthroplasty (THA)
- From:
Journal of Medical Biomechanics
2019;34(4):E346-E351
- CountryChina
- Language:Chinese
-
Abstract:
Objective Based on the principle of uncemented stem design, the femoral anteversion in different CT planes before total hip arthroplasty (THA) and stem anteversion after THA was compared, so as to find out the preoperative measurement to estimate stem anteversion in patients with developmental dysplasia of the hip(DDH) after THA. Methods Twenty-one primary THA patients (28 hips) who were diagnosed with DDH between September 2007 and May 2013 in Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine were selected. Preoperative and postoperative CT scans were performed on all patients. The femoral anteversion angle was defined as the angle between the midcortical line between the anterior and posterior cortical line in five CT slices and the posterior condylar axis. The slice levels for the 4 femoral sites were selected，including the area just distal to the femoral head, the center of the lesser trochanter，1 cm height above center of the lesser trochanter, 2 cm height above center of the lesser trochanter (marked as femoral anteversion 1-4). Femoral anteversion 5 was defined as the midcortical line of the anterior cortical line in the slice of 2 cm height above center of the lesser trochanter and the posterior cortical line in the slice of 50% of the distance from the top of greater trochanter to the center of the lesser trochanter above the center of the lesser trochanter. The stem anteversion angle was defined as the angle formed by the stem neck major axis and the posterior aspect of the femoral condylar line. The cup version and stem alignment were also calculated. The difference value and correlation coefficients of femoral anteversion 1-5 and stem anteversion were compared. Results Femoral anteversion 1-5 was 17.70°±10.54°, 35.59°±7.21°, 31.09°±7.98°, 24.71°±9.11°, 21.94°±10.10°, respectively。Stem anteversion was 20.52°±10.90°. The difference value between stem anteversion and femoral anteversion 1-5 was 2.82°±6.27°, -15.08°±7.99°, -13.80°±15.68°, -4.19°±5.69°, -1.42°±4.07°, respectively. Cup anteversion was 25.60°±11.65°, and combined antevertion was 46.11°±13.28°，sagittal stem tilt was 1.13°±1.53°. There were statistically significant differences between femoral anteversion 1-4 and stem anteversion (P＜0.05), and no statistical difference was found between femoral anteversion 5 and stem anteversion. The correlation coefficients of femoral anteversion 1-5 and stem anteversion were 0.829, 0.681, 0.689, 0.853, 0.928, respectively. Conclusions Femoral anteversion 5 had a highly positive correlation with stem anteversion, which was an effective a substitute of stem anteversion before THA.
