- comminution:
- more than 50% cortical comminution is considered significant and increases chance of non union;
- displacement:
- > 50% frx displacement will significantly increase risk of non-union, due to instability of frx and predisposition for future displacement (if treated closed);
- accetable reduction:
- > 10 deg of angulation in any plane is unacceptable
- < 5 deg of varus or valgus;
- < 10 deg of anterior or posterior angulation;
- < 10 deg of rotation;
- < 1 cm for leg length discrepancy;
- no distraction is tolerated;
- distraction > 1.6 mm may affect length of healing;
- 5 mm of distraction may increase healing time to 8-12 months;
- as noted by Milner SA (1997), there is a considerable amount of tibial shaft alignment variety, and therefore, when there is a question of whether reduction is acceptable, x-rays of the opposite leg should be obtained;
- this author noted that the mechanical axis of the normal tibia may not pass down the center of the medullary canal;
- ref: A more accurate method of measurement of angulation after fractures of the tibia.