Abstract
Introduction
The clinical tests currently used to assess spinal biomechanics preoperatively are unable to assess true mechanical spinal stiffness. They rely on spinal displacement without considering the force required to deform a patient’s spine. We propose a preoperative method for noninvasively quantifying the three-dimensional patient-specific stiffness of the spines of adolescent idiopathic scoliosis patients.
Methods
The technique combines a novel clinical test with numerical optimization of a finite element model of the patient’s spine.
Results
A pilot study conducted on five patients showed that the model was able to provide accurate 3D reconstruction of the spine’s midline and predict the spine’s stiffness for each patient in flexion, bending, and rotation. Statistically significant variation of spinal stiffness was observed between the patients.
Conclusion
This result confirms that spinal biomechanics is patient-specific, which should be taken into consideration to individualize surgical treatment.
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Bibliography
Riseborough EJ, Wynne-Davies R (1973) A genetic survey of idiopathic scoliosis in Boston, Massachusetts. J Bone Jt Surg 55:974–982
Cheung KM, Luk KD (1997) Prediction of correction of scoliosis with use of the fulcrum bending radiograph. J Bone Jt Surg Am 79:1144–1150
Vedantam R, Lenke LG, Bridwell KH, Linville DL (2000) Comparison of push-prone and lateral-bending radiographs for predicting postoperative coronal alignment in thoracolumbar and lumbar scoliotic curves. Spine (Phila Pa 1976) 25:76–81
Davis BJ, Gadgil A, Trivedi J, Ahmed E-NB (2004) Traction radiography performed under general anesthetic: a new technique for assessing idiopathic scoliosis curves. Spine (Phila Pa 1976) 29:2466–2470
Chen Z-Q, Wang C-F, Bai Y-S et al (2011) Using precisely controlled bidirectional orthopedic forces to assess flexibility in adolescent idiopathic scoliosis: comparisons between push-traction film, supine side bending, suspension, and fulcrum bending film. Spine (Phila Pa 1976) 36:1679–1684
Ghista DN, Viviani GR, Subbaraj K et al (1988) Biomechanical basis of optimal scoliosis surgical correction. J Biomech 21:77–88. doi:10.1016/0021-9290(88)90001-2
Lamarre M-E, Parent S, Labelle H et al (2009) Assessment of spinal flexibility in adolescent idiopathic scoliosis: suspension versus side-bending radiography. Spine 34:591–597. doi:10.1097/BRS.0b013e318193a23d
Büchler P, de Oliveria ME, Studer D et al (2014) Axial suspension test to assess pre-operative spinal flexibility in patients with adolescent idiopathic scoliosis. Eur Spine J. doi:10.1007/s00586-014-3386-8
Petit Y, Aubin CE, Labelle H (2004) Patient-specific mechanical properties of a flexible multi-body model of the scoliotic spine. Med Biol Eng Comput 42:55–60
Schumann S, Thelen B, Ballestra S et al (2014) X-ray image calibration and its application to clinical orthopedics. Med Eng Phys 36:968–974. doi:10.1016/j.medengphy.2014.04.001
Vrtovec T, Pernus F, Likar B (2009) A review of methods for quantitative evaluation of axial vertebral rotation. Eur Spine J 18:1079–1090. doi:10.1007/s00586-009-0914-z
Weiss H-R (1995) Measurement of vertebral rotation: Perdriolle versus Raimondi. Eur Spine J 4:34–38
Panjabi MM, Brand RA, White AA (1976) Three-dimensional flexibility and stiffness properties of the human thoracic spine. J Biomech 9:185–192
Reutlinger C, Hasler C, Scheffler K, Büchler P (2012) Intraoperative determination of the load–displacement behavior of scoliotic spinal motion segments: preliminary clinical results. Eur Spine J 21(Suppl 6):S860–S867. doi:10.1007/s00586-012-2164-8
Acknowledgments
This work was supported by the Swiss National Science Foundation (SNSF) via the project 320030 138527.
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Berger, S., Marcello, O., Schuman, S. et al. Patient-specific spinal stiffness in AIS: a preoperative and noninvasive method. Eur Spine J 24, 249–255 (2015). https://doi.org/10.1007/s00586-014-3623-1
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DOI: https://doi.org/10.1007/s00586-014-3623-1