The external fixation index used to compare results of limb lengthening procedures is defined as:
- A Total length gained divided by duration of frame application
- B Number of pins per centimetre of lengthened bone
- C Number of days in the fixator per centimetre of length achieved ✓
- D Percentage of regenerate mineralised at frame removal
Correct answer: C. Number of days in the fixator per centimetre of length achieved
Explanation
The external fixation index expresses the total time the frame remains applied, including both distraction and consolidation phases, divided by the length gained, yielding days per centimetre. It allows comparison of fixation strategies, for example showing that lengthening over a nail reduces this index compared with a frame alone because consolidation proceeds protected internally. Option A inverts the relationship, and options B and D describe unrelated parameters that do not measure treatment efficiency.
Reference: Rockwood and Green's Fractures in Adults, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.