Table 2. Postoperative angle change with time.
| Duration interval | Mean change±standard deviation (PD) |
| 6thmo-1sta (1n=131) | Exodrift (n=114) 1.90±2.21 |
| Esodrift (n=17) 3.65±1.71 | |
| 1sta-2nda (1n=119) | Exodrift (n=105) 2.29±2.91 |
| Esodrift (n=14) 3.07±1.87 | |
| 2nda-3rda (1n=86) | Exodrift (n=70) 1.97±3.87 |
| Esodrift (n=16) 3.06±2.16 | |
| 3rda-4tha (1n=56) | Exodrift (n=49) 1.68±3.13 |
| Esodrift (n=7) 4.56±2.99 | |
| 4tha-2last visit (1n=50) | Exodrift (n=38) 1.47±2.23 |
| Esodrift (n=12) 5.08±6.41 |
1Number of patients who took the postoperative examinations at either postoperative visit in the corresponding period to calculate the angle change; 2Average number of years in the last follow-up =5.63±1.12 (range: 4-8y).