Related Experiment Video
Updated: Oct 24, 2025
Adjustable Stiffness, External Fixator for the Rat Femur Osteotomy and Segmental Bone Defect Models
Published on: October 9, 2014
Simultaneous multisegmental and multifocal corrections of complex lower limb deformities with a hexapod external
Victor Ray1, Dmitry Popkov2, Pierre Lascombes3
1Service de chirurgie orthopédique et traumatologique pédiatrique, Hôpital d'enfant, CHU Nancy, Rue du Morvan, 54500 Vandœuvre-lès-Nancy, France.
Insights
Simultaneous multilevel correction of pediatric lower limb deformities using external fixators is feasible. This approach reduces treatment time without increasing complications or compromising results.
Area of Science:
- Orthopedic surgery
- Pediatric orthopedics
- Limb deformity correction
Background:
- External fixators are crucial for complex pediatric lower limb deformity correction.
- Current treatments are lengthy and significantly impact patients and families.
- Simultaneous multisegmental and/or multifocal correction is explored to reduce treatment duration.
Purpose of the Study:
- To evaluate the efficacy and safety of simultaneous multilevel correction for pediatric lower limb deformities.
- To compare complication rates and outcomes with sequential correction methods.
Main Methods:
- A retrospective study of 16 pediatric patients treated with hexapod external fixators.
- Corrections involved 23 limbs (12 femurs, 20 tibias) with 53 osteotomies.
- Outcomes assessed using mechanical axis deviation (MAD), limb length discrepancy (RLLD), and angular healing index (AHI).
Main Results:
- Significant improvements in MAD (30 to 13.5 mm) and RLLD (33.2 to 6.9 mm) were observed.
- The mean AHI was 74.1 days/cm.
- The overall complication rate was 56.5%, with most being low-grade.
Conclusions:
- One-stage multilevel corrections are technically challenging but feasible.
- This method reduces total treatment duration without compromising results or increasing complication rates.
- Simultaneous correction offers a viable alternative to successive procedures for complex pediatric limb deformities.
Introduction:
External fixators are a part of the therapeutic arsenal used in the correction of complex pediatric lower limb deformities. These long iterative procedures, which are commonly performed over several months, strongly impact the lives of these children and their families. To reduce these drawbacks, we perform, whenever possible, a simultaneous multisegmental and/or multifocal correction of these deformities.
Hypothesis:
Simultaneous multilevel correction of complex pediatric deformities using external fixators does not result in more complications than sequential corrections.
Materials And Methods:
Sixteen patients were treated with this hexapod external fixator correction procedure. The mean age was 13.9 years. The corrections involved 12 femurs and 20 tibias, representing 53 osteotomies on 23 limbs. The quality of the correction was assessed by measuring the mechanical axis deviation (MAD), residual limb length discrepancy (RLLD) and a new, specifically defined, criterion called the "angular healing index" (AHI). Complications were assessed according to Lascombes' classification.
Results:
The mean MAD went from 30 to 13.5 mm (P<.05) and the mean RLLD from 33.2 to 6.9 mm (P<.05). The mean AHI was 74.1 days/cm (16.7 to 319). The overall complication rate was 13/23 operated limbs or 56.5% (4.3% grade 1, 43.3% grade 2, 9.3% grade 3, and no grade 4).
Discussion:
One-stage multilevel corrections of complex pediatric lower limb deformities represent a difficult technical challenge, and any reduction in treatment time must not adversely impact the quality of the results. The rate and severity of complications compared to monofocal/segmental procedures were no higher than that reported in the literature. This study demonstrated the feasibility of multisegmental and multifocal corrections, which reduced the total treatment duration compared to successive corrections, without adversely affecting the result or increasing the complication rate.
Level Of Evidence:
IV; retrospective study.
