In the Ilizarov distraction osteogenesis technique, the optimal rate and rhythm of distraction is:
- A 1 mm/day in a single step
- B 2 mm/day in 2 equal increments of 1 mm every 12 hours
- C 1 mm/day in 4 equal increments of 0.25 mm every 6 hours ✓
- D 0.5 mm/day in 2 increments
Correct answer: C. 1 mm/day in 4 equal increments of 0.25 mm every 6 hours
Explanation
Ilizarov's original research established that the optimal distraction rate for maintaining robust regenerate bone formation while avoiding premature consolidation is 1 mm/day, applied in 4 equal increments (0.25 mm every 6 hours). Rates above 2 mm/day cause fibrous non-union in the regenerate; rates below 0.5 mm/day cause premature consolidation before adequate length is gained. The latency period of 5–7 days after corticotomy allows initial callus formation before distraction begins.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.