Table 1 Summary of patient-specific and treatment-related characteristics and screw-specific accuracy
Variables* | Total (n = 60) | Navigation group (n = 35) | Freehand group (n = 25) | p value (two-tailed) |
|---|---|---|---|---|
Patient-specific characteristics | ||||
Age, years | 54.07 (17.93) | 54.80 (17.63) | 53.04 (18.66) | 0.711 |
Sex, male/female | 30/30 | 17/18 | 13/12 | 0.793 |
Body mass index, kg/m2 | 24.46 (3.98) | 24.73 (3.27) | 24.08 (4.85) | 0.559 |
Diagnosis | ||||
Tumor (%) | 29 (48.33) | 15 (42.86) | 14 (56.00) | 0.45 |
Degenerative disease (%) | 26 (43.33) | 16 (45.71) | 10 (40.00) | |
Trauma (%) | 5 (8.33) | 4 (11.43) | 1 (4.00) | |
Treatment-related characteristics | ||||
No. of screws | 341 | 191 | 150 | |
Distribution of screws | ||||
Thoracic (%) | 173 (50.73) | 86 (45.03) | 87 (58.00) | 0.017 |
Lumbosacral (%) | 168 (49.27) | 105 (54.97) | 63 (42.00) | |
Surgical time/screw, min | 18.83 (8.15) | 21.36 (8.85) | 15.28 (5.47) | 0.002 |
Blood loss, ml | 300 (375) | 300 (300) | 400 (450) | 0.652 |
Length of postoperative hospital stay, days | 16.95 (8.73) | 16.71 (6.99) | 17.28 (10.87) | 0.807 |
Radiation dose/screw, mSv | 1.49 (1.12) | 1.69 (1.62) | 1.25 (1.15) | 0.652 |
Screw-specific accuracy | ||||
Gertzbein-Robbins scale grade, % | ||||
A and B (%) | 318 (93.25) | 183 (95.81) | 135 (90.00) | 0.034 |
C, D, and E (%) | 23 (6.74) | 8 (4.19) | 15 (10.00) | |
Screw deviation | ||||
Cranial (%) | 5 (10.42) | 3 (12.50) | 2 (8.33) | 0.249 |
Caudal (%) | 9 (18.75) | 7 (29.17) | 2 (8.33) | |
Medial (%) | 18 (37.50) | 7 (29.17) | 11 (45.83) | |
Lateral (%) | 16 (33.33) | 7 (29.17) | 9 (37.50) | |