ABSTRACT
Objective To evaluate the safety of dynamic anterior plate fixation for cervical distractive flexion injuries and compare its rigidity between different types of plate design. Methods Twelve sets of cadaveric calf spine were used in this test. All the specimens were made into distractive flexion injury models (C4-C5) ac- cording to Allen's method. After discectomy and grafting, they were randomized into three groups in which Orion, Codman, and Window instrumentations were used respectively. The stiffness of each construct was tested in flexion, extension, lateral bending and axial torsion conditions sequentially. Results Compared with an intact cervical spine, the range of motion (ROM) of an injured cervical spine increased whatever plate was applied. Orion in- strumentation presented stiffness the closest to that of the normal control, except for less torsional stiffness. Codman instrumentation provided stiffness close to that for normal and Orion groups only in lateral bending. Window's was the weakest mad not enough in all kinds of movement. Conclusions Static anterior fixation is the first choice for cervical injuries. Dynamic plate fixation may sacrifice stiffness to some extent, especially when a shifting kind of design is to be chosen.
ABSTRACT
The defects in observation methodology of diseases,in knowledge of diseases,and in doctors' clinical knowledge and skill were analyzed in this article,which were believed as main medical internal defects(MID).High risks as well as medical disputes cannot be avoided in medical practice due to MID,which also led to ethical challenges in medical disputes prevention and treatment.Emphasis on the knowledge of MID during public education on medical disputes prevention may decrease medical disputes.