- 作者：Julien Berhouet ; julien.berhouet@gmail.com" class="auth_mail" title="E-mail the corresponding author ; Lawrence Gulotta ; Andreas Kontaxis ; Daniel Choi ; Xiang Chen
- 刊名：Revue de Chirurgie Orthopédique et Traumatologique
- 出版年：2015
- 出版时间：November 2015
- 年：2015
- 卷：101
- 期：7_supp_S
- 页码：S178
- 全文大小：57 K
Materials and methods
Thirty 3D-CT scapulas with highly eroded glenoid were involved. Two surgeons (A and B) performed blind RSA in Mimics software, when only the glenoid was visible. Surgeon A performed full 3D structure assisted virtual surgery on the same group of scapulae, and achieved high accuracy in correcting tilt and version. For each subject, the center of the frontal surface of glenoid metaglene from 3D assisted surgeries was defined as the planned position for baseplate. Translation of baseplate was measured in sagittal plane (anterior-posterior and superior-inferior directions) as the distance from the planned position to the center of baseplate from blind surgeries. For three postoperative situations, four standard glenohumeral kinematics (abduction, forward flexion, and internal external rotation) were simulated. Impingements between the humeral prosthesis, humerus and scapula during motion were recorded.
Results
Relative to the planned position from 3D assisted surgeries, no statistical difference was found on positioning by different surgeons for the anterior-posterior and superior-inferior translations of the baseplate. No statistical difference was found in impingement free range of motion among three operative conditions for each activity. Compared to the planned positions, more inferiorly translated baseplates resulted in increased impingement free range of motion in forward flexion (P < 0.05), scapular plane elevation (P < 0.05), and internal external rotation (P < 0.05) by lowering the lower limit of impingement free range. Similar statistical differences (P < 0.05) were also found when comparing larger inferior translations to larger superior translations during each activity. More posteriorly translated positions increased impingement free range of motion in forward flexion (P < 0.05).
Discussion
Without the guidance of the full 3D structure, the location deviation of baseplate positioning for both surgeons were similar, but showed significant variability. However, surgical plans focusing only on alignment accuracy in RSA may not result in better positioning of glenoid component, therefore may not improve impingement free range of motion for patients. A more inferior and posterior position may be advantageous for a better functional outcome. Future studies should integrate better designs for both alignment and positioning accuracy.