Table 3.
Mean measurements of cortical bone area from proximal (position 100 mm) to distal (position –20 mm), postoperatively and at follow-up. The coefficient of variation (precision of measurements) is given for each scan position derived from 5 repeated CT scans of 5 cadavers
| A | B | C | D | E | F | G | H | I |
|---|---|---|---|---|---|---|---|---|
| A–I: See Table 1. | ||||||||
| 100 mm | 2.3% | 1,300 (264) | 1,293 (184) | –7 (–1%) | 1.0 | 1,414 (229) | 114 (9%) | 0.02 |
| 90 mm | 1.5% | 1,055 (212) | 1,078 (187) | 23 (2%) | 1.0 | 1,175 (193) | 120 (11%) | 0.2 |
| 80 mm | 2.5% | 862 (143) | 891 (149) | 29 (3%) | 1.0 | 922 (157) | 60 (7%) | 1.0 |
| 70 mm | 0.9% | 741 (107) | 773 (114) | 32 (4%) | 1.0 | 786 (125) | 46 (6%) | 1.0 |
| 60 mm | 0.8% | 694 (98) | 714 (99) | 20 (3%) | 1.0 | 731 (116) | 37 (5%) | 1.0 |
| 50 mm | 0.4% | 665 (94) | 684 (96) | 19 (3%) | 1.0 | 696 (105) | 31 (5%) | 1.0 |
| 40 mm | 0.7% | 650 (95) | 663 (94) | 13 (2%) | 1.0 | 675 (102) | 25 (4%) | 1.0 |
| 30 mm | 0.6% | 642 (97) | 654 (96) | 11 (2%) | 1.0 | 661 (101) | 19 (3%) | 1.0 |
| 20 mm | 0.6% | 637 (100) | 655 (107) | 18 (3%) | 1.0 | 654 (102) | 17 (3%) | 1.0 |
| 10 mm | 0.4% | 635 (109) | 657 (126) | 22 (3%) | 1.0 | 660 (121) | 25 (4%) | 1.0 |
| 0 mm | 0.4% | 636 (122) | 662 (147) | 26 (4%) | 1.0 | 662 (141) | 26 (4%) | 1.0 |
| –10 mm | 0.1% | 643 (143) | 665 (174) | 21 (3%) | 1.0 | 663 (161) | 19 (3%) | 1.0 |
| –20 mm | 0.1% | 650 (176) | 668 (203) | 18 (3%) | 1.0 | 665 (192) | 15 (2%) | 1.0 |