We present a new analysis tool for cervical flexion-extension radiographs based on machine vision and computerized image\nprocessing. The method is based on semiautomatic image segmentation leading to detection of common landmarks such as the\nspinolaminar (SL) line or contour lines of the implanted anterior cervical plates. The technique allows for visualization of the local\ncurvature of these landmarks during flexion-extension experiments. In addition to changes in the curvature of the SL line, it has\nbeen found that the cervical plates also deform during flexion-extension examination. While extension radio graphs reveal larger\ncurvature changes in the SL line, flexion radio graphs on the other hand tend to generate larger curvature changes in the implanted\ncervical plates. Furthermore, while some lordosis is always present in the cervical plates by design, it actually decreases during\nextension and increases during flexion. Possible causes of this unexpected finding are also discussed.The described analysis may lead\nto a more precise interpretation of flexion-extension radiographs, allowing diagnosis of spinal instability and/or pseudoarthrosis\nin already seemingly fused spines.
Loading....