- Discussion:
-
accetable reduction:
- more than 50% of cortical overlap;
- > 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;
- 5 mm of distraction may increase healing time to 8-12 months;
-
indications for operative correction:
- valgus deformity of more than 10-12 deg;
- varus deformity of more than 6-10 deg;
- external rotation deformity more than 15-20 deg;
- internal rotation deformity of more than 10-15 deg;
- shortening of more than 2 cm;
-
pearls:
-
posterolateral approach for osteotomy and
grafting be attentive to the
safe zones;
- prevention of neurovascular injury:
- have somatosensory evoked potentials available if significant angulatory deformity is to be corrected;
- consider application of sterile pulse oximeter to great toe - which allows monitoring of pulses during osteotomy;
- for varus/valgus deformity the osteotomy cut should be made in the coronal plane, where as anterior/posterior angulatory
deformities should be managed w/ an osteotomy cut in the saggital plane;
- consider use of
femoral distractor w/ 6.0 mm half pins placed parallel to the joint surfaces of the tibial plateau and plafond;
- the distractor can then be used to align the half pins so that they are parallel (thus aligning the malunion);
- following operative correction of the malalignment, recheck the ROM of the ankle joint and consider the need for Achilles tendon lengthening;
Oblique osteotomy for the correction of tibial malunion.
Treatment of tibial malunions and nonunions with reamed intramedullary nails.
Effects of tibial malalignment on the knee and ankle.
No arthrosis of the ankle 20 years after malaligned tibial-shaft fracture.
Long term effects of tibial angulatory malunion on the knee and ankle joints.
RM Puno et al.
J. Orthop. Trauma. Vol 5. 1991. p 247-254.
