Published in:
Open Access 01-12-2018 | Research article
Sternal instability measured with radiostereometric analysis. A study of method feasibility, accuracy and precision
Published in: Journal of Cardiothoracic Surgery | Issue 1/2018
Login to get accessAbstract
Background
A small, but unstable, saw-gap may hinder bone-bridging and induce development of painful sternal dehiscence. We propose the use of Radiostereometric Analysis (RSA) for evaluation of sternal instability and present a method validation.
Methods
Four bone analogs (phantoms) were sternotomized and tantalum beads were inserted in each half. The models were reunited with wire cerclage and placed in a radiolucent separation device. Stereoradiographs (n = 48) of the phantoms in 3 positions were recorded at 4 imposed separation points. The accuracy and precision was compared statistically and presented as translations along the 3 orthogonal axes. 7 sternotomized patients were evaluated for clinical RSA precision by double-examination stereoradiographs (n = 28).
Results
In the phantom study, we found no systematic error (p > 0.3) between the three phantom positions, and precision for evaluation of sternal separation was 0.02 mm. Phantom accuracy was mean 0.13 mm (SD 0.25).
In the clinical study, we found a detection limit of 0.42 mm for sternal separation and of 2 mm for anterior-posterior dislocation of the sternal halves for the individual patient.
Conclusion
RSA is a precise and low-dose image modality feasible for clinical evaluation of sternal stability in research.
Trial registration
ClinicalTrials.gov Identifier: NCT02738437, retrospectively registered.