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Updated: Aug 19, 2026

Adjustable Stiffness, External Fixator for the Rat Femur Osteotomy and Segmental Bone Defect Models
Published on: October 9, 2014
Changes of blood circulation of the extremity after external fixation for tibia shaft defect: an experimental study
1Department of Orthopedics, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China.
Objective:
To assess and compare two approaches, end to end compression with lengthening (EECL) and segmental bone transport by lengthening (STBL), for long tubular bone defect and nonunion.
Methods:
Ten goats were used to establish the bone defect model of the mid-tibia. The bone defect ends were shortened step by step with a sulcated half-ring external fixator. Changes of the blood flow of the distal extremity were measured with pulse-Doppler monitor and angiography.
Results:
The blood flow in the distal extremity was not affected when bone defect was less than 15% of the original length. Blood circulatory disorder would appear in the distal extremity when bone defect ranged 15%-20% of the original length. The necrosis would appear in the extremity because of the blood circulatory obstacle when bone defect was more than 20% of the original length.
Conclusions:
EECL is an appropriate alternative of treatments if bone defect is less than 15%; while SBTL may be feasible if bone defect is over 20% of the original length. When bone defect ranges between 15% and 20%, EECL should be applied with great care on condition of keeping watch on the extremity circulation with pulse-Doppler monitor.

