A 10-year-old girl has post-traumatic growth arrest of the distal tibia resulting in a 4 cm tibial shortening with 12° varus deformity. The Ilizarov method is planned for simultaneous lengthening and deformity correction. The rate of distraction used in Ilizarov bone transport/lengthening is:
- A 2 mm per day for rapid lengthening
- B 1 mm per day in 4 increments of 0.25 mm each (standard distraction rate) ✓
- C 0.5 mm per day to minimize pain
- D 3 mm per day to shorten treatment time
Explanation
The standard Ilizarov distraction rate is 1 mm per day, typically applied in 4 increments of 0.25 mm every 6 hours. This rate was empirically determined by Ilizarov to be optimal for regenerate bone formation (distraction osteogenesis) — faster rates lead to fibrous union (non-union) while slower rates lead to premature consolidation. The healing index is approximately 1 month per cm of lengthening. Deformity correction can be simultaneously performed by differential distraction. Rates above 1.5 mm/day risk inadequate regenerate formation; below 0.5 mm/day risk premature consolidation.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.