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Intra-Operative Bone Stability Test
Christopher A Iobst1,2, Darvin Bunhor3, David L Skaggs3
1Department of Orthopedic Surgery, Nationwide Children's Hospital.
Techniques in Orthopaedics (Rockville, Md.)
|December 14, 2018
Summary
Surgeons can now test pediatric elbow fracture stability intraoperatively. Applying specific stresses like external rotation and lateral translation helps determine fixation effectiveness, potentially avoiding repeat X-rays.
Area of Science:
- Orthopedic Surgery
- Pediatric Orthopedics
- Biomechanics
Background:
- Supracondylar humerus fractures are the most frequent elbow fractures in children.
- Assessing fracture stability after surgical fixation (pinning) is crucial for optimal outcomes.
- Current methods often rely on postoperative imaging, delaying definitive stability assessment.
Purpose of the Study:
- To evaluate intraoperative methods for testing the stability of pinned supracondylar humerus fractures.
- To identify specific stress maneuvers that effectively reveal instability in a cadaver model.
- To provide surgeons with a practical technique for immediate post-pinning stability assessment.
Main Methods:
- Created a transverse supracondylar humerus fracture model in adult cadaver specimens.
- Utilized lateral entry technique with three 2.0 mm pins for "A" pinning fixation.
- Applied various stresses (external rotation, lateral translation, etc.) to the distal fragment and measured displacement.
Main Results:
- Distraction maneuvers did not cause significant displacement.
- External rotation, lateral translation, posterior translation, and valgus stress were most effective in creating temporary deformity.
- These specific stresses provide a reliable indicator of construct stability.
Conclusions:
- A combination of external rotation, lateral translation, posterior translation, and valgus stress maneuvers can reliably assess intraoperative stability.
- This technique offers a potential method to determine fixation stability immediately after pinning.
- Intraoperative assessment may reduce the need for postoperative radiographs to confirm stability.
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