Table 2.
Comparison of imaging data.
| PSI group (n = 16) |
CO group (n = 23) |
P 2 value | |
|---|---|---|---|
| WBL (weight-bearing line) ratio (%) | |||
| (i) Preop target | 60.16 ± 2.49 | 60.00 ± 3.11 | 0.868 |
| (ii) Postop value | 58.94 ± 3.35 | 56.67 ± 8.03 | 0.234 |
| (iii) P1 value | 0.063 | 0.017 | — |
| (iv) Absolute difference from designed target | 1.97 ± 1.83 | 5.42 ± 4.41 | 0.002 |
| HKA (hip-knee-ankle angle) (°) | |||
| (i) Preop target | 183.56 ± 1.03 | 183.46 ± 1.12 | 0.765 |
| (ii) Postop value | 182.86 ± 1.20 | 181.73 ± 2.69 | 0.085 |
| (iii) P1 value | 0.038 | 0.003 | — |
| (iv) Absolute difference from designed target | 1.12 ± 0.86 | 2.27 ± 1.97 | 0.018 |
| MPTA (medial proximal tibial angle) (°) | |||
| (i) Preop target | 91.33 ± 1.16 | 90.71 ± 0.65 | 0.072 |
| (ii) Postop value | 91.29 ± 1.49 | 90.45 ± 2.02 | 0.165 |
| (iii) P1 value | 0.917 | 0.503 | — |
| (iv) Absolute difference from designed target | 1.01 ± 0.57 | 1.48 ± 0.99 | 0.068 |
| Correction angle (°) | |||
| (i) Preop target | 9.26 ± 2.09 | 9.33 ± 1.35 | 0.907 |
| (ii) Postop value | 8.96 ± 2.06 | 9.06 ± 1.32 | 0.868 |
| (iii) P1 value | 0.182 | 0.072 | — |
| (iv) Absolute difference from designed target | 0.66 ± 0.58 | 0.64 ± 0.38 | 0.912 |
| PTSA (posterior tibial slope angle) (°) | |||
| (i) Preop value | 11.31 ± 1.90 | 10.05 ± 2.09 | 0.062 |
| (ii) Postop value | 11.33 ± 2.21 | 11.20 ± 2.49 | 0.866 |
| (iii) P1 value | 0.969 | 0.043 | — |
| (iv) Absolute difference from preop values | 1.30 ± 1.27 | 1.97 ± 1.99 | 0.244 |
| Insall–Salvati index | |||
| (i) Preop value | 0.95 ± 0.11 | 0.97 ± 0.10 | 0.453 |
| (ii) Postop value | 0.96 ± 0.13 | 1.01 ± 0.13 | 0.271 |
| (iii) P1 value | 0.449 | 0.134 | — |
(PSI: patient-specific instrumentation. CO: conventional operation. Preop: preoperative. Postop: postoperative. P1, using paired t test. P2: using two-sample t test).