1. Invention ⌈ Tai Chi pedicle screw placement technique ⌋
Tai Chi drilling fully utilizes the natural anatomic and physical characteristics of pedicles and unconstrained circular force.
By nature, a drill bit driven by unconstrained circular force would migrate within the pedicle along a path of least resistance, advancing along the central cancellous bone tunnel spontaneously. Accurate drilling was achieved by following the nature and sticking to the hand sensation when the drill bit broke through the cancellous bone.
Our findings suggest that the Tai Chi pedicle screw placement technique, which does not require intraoperative radiographic imaging, is an accurate, reliable, safe, and timesaving method of placing pedicle screws in severe scoliotic spines.
This thesis was published in J Spinal Disord Tech:
Kao-Wha Chang, Xiangyang Leng, Ching-Wei Cheng, et al. Tai Chi (太極) Pedicle Screw Placement for Severe Scoliosis. J Spinal Disord Tech 2012; 25.
2.Invent ⌈ Quality Control of Reconstructed Sagittal Balance for Sagittal Imbalance ⌋
A method was developed to determine the lumbosacral curve in a way that theoretically would bring sagittal balance to an ideal state by calculation and simulation for each patient before surgery and then template rods of the curve and a blueprint were made accordingly for operative procedures.
Moreover, at present, our method is the unique for control of surgical reconstruction of sagittal balance quality in the thesis and published a textbook of Orthopedics.
This thesis was published in Spine: Kao-Wha Chang, Xiangyang Leng, Wenhai Zhao,et al. Quality Control of Reconstructed Sagittal Balance for Sagittal Imbalance. Spine 2011;36(3):186-97.
3.Invent ⌈ Broader Curve Criteria for Selective Thoracic Fusion ⌋
To evaluate the outcome of selective thoracic fusion (STF) by using cantilever bending technique (CBT) and the direct vertebral rotation (DVR) technique for major thoracic-compensatory lumbar (MTCL) curves selected by new curve criteria, which are broader than Lenke curve criteria for STF.
CBT and DVR can broaden the current curve criteria of MTCL curves for STF to have more MTCL curves treatable with STF and optimize instrumented thoracic and spontaneous lumbar correction. A more effective surgical technique can not only improve instrumented thoracic and spontaneous lumbar correction but also can broaden the MTCL curve criteria for STF to have more MTCL curves treatable with STF.
This thesis was published in Spine: Kao-Wha Chang, Xiangyang Leng, Wenhai Zhao,et al. Broader Curve Criteria for Selective Thoracic Fusion. Spine 2011;36:1658-64.