Table 3.
Trigonometric Calculation of Osteotomy Size Based on Templated Correction Angle and Mediolateral Diameter of Osteotomy
| Mediolateral Diameter of Osteotomy | Preoperatively Measured Correction Angle |
|||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 4° | 5° | 6° | 7° | 8° | 9° | 10° | 11° | 12° | 13° | 14° | 15° | 16° | 17° | 18° | 19° | |
| 50 mm | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 16 |
| 55 mm | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 |
| 60 mm | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 14 | 15 | 16 | 17 | 18 | 19 | 20 |
| 65 mm | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 |
| 70 mm | 5 | 6 | 7 | 8 | 10 | 11 | 12 | 13 | 15 | 16 | 17 | 18 | 20 | 21 | 22 | 23 |
| 75 mm | 5 | 6 | 8 | 9 | 10 | 12 | 13 | 14 | 16 | 17 | 18 | 20 | 21 | 22 | 24 | 25 |
| 80 mm | 6 | 7 | 8 | 10 | 11 | 13 | 14 | 15 | 17 | 18 | 19 | 21 | 22 | 24 | 25 | 26 |
NOTE. Data represent the wedge size in millimeters. The wedge size can also be planned before surgery and confirmed intraoperatively. The mediolateral diameter of the osteotomy site is measured intraoperatively by measuring the length of the 2 initial guidewires that are placed from medial to lateral. The intraosseous lengths of the anterior and posterior guidewires are then averaged to provide the diameter reference for the chart.10 This wedge size should be used to guide placement of the second set of 2 guidewires that determine the wedge resection size.