Related Experiment Video
Updated: Jan 20, 2026
Individualized Stem-positioning in Calcar-guided Short-stem Total Hip Arthroplasty
Published on: February 27, 2018
Cup Alignment Change after Screw Fixation in Total Hip Arthroplasty
Yingyong Suksathien1, Urawit Piyapromdee1, Thanut Tippimanchai1
1Department of Orthopedic Surgery, Maharat Nakhon Ratchasima Hospital, Mueang, Nakhon Ratchasima Province, Thailand.
Background:
Cup malalignment increase impingement, dislocation, cup migration, and polyethylene wear. Screw fixation for enhanced stability is the preferred option in cases of doubtful primary cup stability. There have been few studies about alignment changes after screw fixation, which may be another cause of cup malalignment. This study aimed to evaluate cup alignment change after screw fixation.
Materials And Methods:
Patients undergoing imageless navigation total hip arthroplasty using screws fixation for acetabular cup were corrected. After the press-fit cup was fully seated, the cup orientation was recorded. After screws were inserted, the cup orientation was recorded again to calculate the alignment change.
Results:
There were 99 cases with a mean age 63.7 years (25-93). Alignment change after screw fixation was found in 73 cases (73.7%). There were 56 cases (56.6%) with inclination angle change and the mean change was 2.21° (0°-8°). The inclination angle increased in 47 cases (47.5%) with 9 cases (9.1%) increased by 5° or more and decreased in 9 cases (9.1%). There was statistically significant difference between patients using one screw and patients using two or more screws in inclination angle change, 1.56° (0°-5°) and 3.4° (0°-8°), respectively (P = 0.0039). There was statistically significant correlation between inclination angle change and number of screws (r = 0.5401, P < 0.01). There were 49 cases (49.5%) with anteversion angle change and the mean change was 1.67° (0°-5°). The anteversion angle increased in 31 cases (31.3%), decreased in 18 cases (18.2%) with two cases (2%) decreased by 5° or more. There was significant difference between patients using one screw and patients using two or more screws in anteversion angle change, 1.46° (0°-5°) and 2.21° (0°-5°), respectively (P = 0.009). There was significant correlation between anteversion angle change and number of screws (r = 0.284, P = 0.048).
Conclusions:
Changes in cup alignment after screw fixation were detected in most cases. It is one possible cause of cup malalignment.
Related Concept Videos
09:31Individualized Stem-positioning in Calcar-guided Short-stem Total Hip Arthroplasty
10:10Reverse Total Shoulder Arthroplasty
07:45The Use of Mixed Reality in Custom-Made Revision Hip Arthroplasty: A First Case Report
01:16The Total Effect of Price Change
Here, the price of only one product changes. For example, a student's monthly allowance is $100 for books and snacks. The price of a book drops from $20 per unit to $10 per unit, while the price of snacks remains at $5 per unit. This affects the budget constraint or the budget line. Now, the student can purchase ten...
05:57A Teleoperated Robotic System-Assisted Percutaneous Transiliac-Transsacral Screw Fixation Technique
12:25C-arm-Free Simultaneous OLIF51 and Percutaneous Pedicle Screw Fixation in a Single Lateral Position