The mechanical test as a supplemental decision support tool for the safe removal of an Ilizarov circular external fixator

Abstract Background Timing the fixator removal is vital for a successful external fixation treatment. The purpose of this study was to determine the effectiveness of axial load–share ratio in vivo as a supplemental decision support tool for the safe removal of an Ilizarov circular external fixator....

Full description

Saved in:
Bibliographic Details
Main Authors: Yulin Xu, Jialin Liu, Jinghong Yang, Tao Zhang, Zhong Li, Yanshi Liu
Format: Article
Language:English
Published: BMC 2025-02-01
Series:European Journal of Medical Research
Subjects:
Online Access:https://doi.org/10.1186/s40001-024-02258-9
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1823862664402567168
author Yulin Xu
Jialin Liu
Jinghong Yang
Tao Zhang
Zhong Li
Yanshi Liu
author_facet Yulin Xu
Jialin Liu
Jinghong Yang
Tao Zhang
Zhong Li
Yanshi Liu
author_sort Yulin Xu
collection DOAJ
description Abstract Background Timing the fixator removal is vital for a successful external fixation treatment. The purpose of this study was to determine the effectiveness of axial load–share ratio in vivo as a supplemental decision support tool for the safe removal of an Ilizarov circular external fixator. Methods This prospective observational study consists of 83 patients undergoing tibial or femoral lengthening with Ilizarov circular external fixation in our institution, from January 2011 to October 2019. In group I (38 patients), the external fixator was removed based on the surgeon’s clinical experience and radiographs from January 2011 to June 2015. In group II (45 patients), from July 2015 to October 2019, the supplemental axial load–share (LS) ratio test was accomplished without the knowledge of the clinical results by another medical team. The test was performed by electronically measuring forces in the fixator rods and in a ground force plate. When the LS ratio < 10% was consistent with the conclusion (dense bone formation was achieved in the distraction zone) drawn from the corresponding routine radiographs by the treating surgeon, the external fixator was removed. Results There was no statistical significance in demographic data between the two groups (P > 0.05). In group I, 4 of the 38 patients suffered refracture (the refracture rate was 10.5%) after fixator removal, and bone union was finally achieved with further intervention by intramedullary nail. In group II, 36 patients terminated the external fixation after the first mechanical test, and another 9 patients terminated the external fixation at the subsequent test. None of the 45 patients in group II suffered refracture (the refracture rate was 0%). There was statistical significance in the refracture rate between the two groups (P < 0.05). Conclusions Adequate assessment of bone regenerate is crucial before removing an external fixator to prevent deformation or refracture. The axial load–share ratio in vivo is a practically quantitative method to supplement radiography and clinical experience for the assessment of regenerate healing, and the axial load–share ratio dropped below 10% is a safe limit for the Ilizarov circular external fixator removal.
format Article
id doaj-art-808e15dd8d924a0a9d2fc7f8c0fad8fb
institution Kabale University
issn 2047-783X
language English
publishDate 2025-02-01
publisher BMC
record_format Article
series European Journal of Medical Research
spelling doaj-art-808e15dd8d924a0a9d2fc7f8c0fad8fb2025-02-09T12:26:33ZengBMCEuropean Journal of Medical Research2047-783X2025-02-013011910.1186/s40001-024-02258-9The mechanical test as a supplemental decision support tool for the safe removal of an Ilizarov circular external fixatorYulin Xu0Jialin Liu1Jinghong Yang2Tao Zhang3Zhong Li4Yanshi Liu5Department of Orthopaedics, the Affiliated Hospital of Southwest Medical UniversityDepartment of Oral Implantology, the Affiliated Stomatology Hospital of Southwest Medical UniversityDepartment of Orthopaedics, the Affiliated Hospital of Southwest Medical UniversityDepartment of Orthopedics and Trauma, Tianjin HospitalDepartment of Orthopaedics, the Affiliated Hospital of Southwest Medical UniversityDepartment of Orthopaedics, the Affiliated Hospital of Southwest Medical UniversityAbstract Background Timing the fixator removal is vital for a successful external fixation treatment. The purpose of this study was to determine the effectiveness of axial load–share ratio in vivo as a supplemental decision support tool for the safe removal of an Ilizarov circular external fixator. Methods This prospective observational study consists of 83 patients undergoing tibial or femoral lengthening with Ilizarov circular external fixation in our institution, from January 2011 to October 2019. In group I (38 patients), the external fixator was removed based on the surgeon’s clinical experience and radiographs from January 2011 to June 2015. In group II (45 patients), from July 2015 to October 2019, the supplemental axial load–share (LS) ratio test was accomplished without the knowledge of the clinical results by another medical team. The test was performed by electronically measuring forces in the fixator rods and in a ground force plate. When the LS ratio < 10% was consistent with the conclusion (dense bone formation was achieved in the distraction zone) drawn from the corresponding routine radiographs by the treating surgeon, the external fixator was removed. Results There was no statistical significance in demographic data between the two groups (P > 0.05). In group I, 4 of the 38 patients suffered refracture (the refracture rate was 10.5%) after fixator removal, and bone union was finally achieved with further intervention by intramedullary nail. In group II, 36 patients terminated the external fixation after the first mechanical test, and another 9 patients terminated the external fixation at the subsequent test. None of the 45 patients in group II suffered refracture (the refracture rate was 0%). There was statistical significance in the refracture rate between the two groups (P < 0.05). Conclusions Adequate assessment of bone regenerate is crucial before removing an external fixator to prevent deformation or refracture. The axial load–share ratio in vivo is a practically quantitative method to supplement radiography and clinical experience for the assessment of regenerate healing, and the axial load–share ratio dropped below 10% is a safe limit for the Ilizarov circular external fixator removal.https://doi.org/10.1186/s40001-024-02258-9Axial load–share ratioBone healingIlizarov external fixatorTiming of fixator removal
spellingShingle Yulin Xu
Jialin Liu
Jinghong Yang
Tao Zhang
Zhong Li
Yanshi Liu
The mechanical test as a supplemental decision support tool for the safe removal of an Ilizarov circular external fixator
European Journal of Medical Research
Axial load–share ratio
Bone healing
Ilizarov external fixator
Timing of fixator removal
title The mechanical test as a supplemental decision support tool for the safe removal of an Ilizarov circular external fixator
title_full The mechanical test as a supplemental decision support tool for the safe removal of an Ilizarov circular external fixator
title_fullStr The mechanical test as a supplemental decision support tool for the safe removal of an Ilizarov circular external fixator
title_full_unstemmed The mechanical test as a supplemental decision support tool for the safe removal of an Ilizarov circular external fixator
title_short The mechanical test as a supplemental decision support tool for the safe removal of an Ilizarov circular external fixator
title_sort mechanical test as a supplemental decision support tool for the safe removal of an ilizarov circular external fixator
topic Axial load–share ratio
Bone healing
Ilizarov external fixator
Timing of fixator removal
url https://doi.org/10.1186/s40001-024-02258-9
work_keys_str_mv AT yulinxu themechanicaltestasasupplementaldecisionsupporttoolforthesaferemovalofanilizarovcircularexternalfixator
AT jialinliu themechanicaltestasasupplementaldecisionsupporttoolforthesaferemovalofanilizarovcircularexternalfixator
AT jinghongyang themechanicaltestasasupplementaldecisionsupporttoolforthesaferemovalofanilizarovcircularexternalfixator
AT taozhang themechanicaltestasasupplementaldecisionsupporttoolforthesaferemovalofanilizarovcircularexternalfixator
AT zhongli themechanicaltestasasupplementaldecisionsupporttoolforthesaferemovalofanilizarovcircularexternalfixator
AT yanshiliu themechanicaltestasasupplementaldecisionsupporttoolforthesaferemovalofanilizarovcircularexternalfixator
AT yulinxu mechanicaltestasasupplementaldecisionsupporttoolforthesaferemovalofanilizarovcircularexternalfixator
AT jialinliu mechanicaltestasasupplementaldecisionsupporttoolforthesaferemovalofanilizarovcircularexternalfixator
AT jinghongyang mechanicaltestasasupplementaldecisionsupporttoolforthesaferemovalofanilizarovcircularexternalfixator
AT taozhang mechanicaltestasasupplementaldecisionsupporttoolforthesaferemovalofanilizarovcircularexternalfixator
AT zhongli mechanicaltestasasupplementaldecisionsupporttoolforthesaferemovalofanilizarovcircularexternalfixator
AT yanshiliu mechanicaltestasasupplementaldecisionsupporttoolforthesaferemovalofanilizarovcircularexternalfixator