Spinal Disorders: Fundamentals of Diagnosis and Treatment Part 87. Spinal disorders are among the most common medical conditions with significant impact on health related quality of life, use of health care resources and socio-economic costs. Spinal surgery is still one of the fastest growing areas in clinical medicine. | 858 Section Fractures Dislocated Type II and Type IIA fractures are indications for surgery The technical issue of whether one or two screws are needed has been addressed in various studies 25 115 188 . Although there is a theoretical advantage of preventing rotation with two screws there is no increased strength for bending movements and no difference in successful bony fusion. Although two screws are theoretically desirable fixation with one screw is sufficient with adequate technique 115 188 Case Study 1 . Apfelbaum et al. 25 compared anterior screw fixation for recent and remote odontoid fractures in 147 patients at two institutions 138 Type II 9 Type III . Anterior screw fixation was performed either within 6 months of injury or more than 18 months after injury. At a mean follow-up of 18 months the fusion rates were 88 and 25 respectively. These results indicate that remote dens fractures do not favorably respond to anterior screw fixation. An alternative technique for augmentation or salvage procedures of failed anterior screw fixation is an anterior atlantoaxial screw fixation Fig. 16e f . In cases with remote dens fractures dens non-union os odontoideum or elderly patients with osteoporosis a posterior approach is more likely to be successful. The classical treatment is a posterior instrumented fusion according to Case Study 1 This 51-year-old male patient fell from his mountain bike and complained about neck pain. On admission the patient was neurologically intact ASIA E . Standard anteroposterior and lateral a radiographs demonstrated a Type II odontoid fracture. The sagittal CT reconstruction confirmed the diagnosis of the fracture at the base of the odontoid process b . Repositioning and anterior stabilization with a single screw was performed. Follow-up radiographs c d demonstrated an anatomical reduction of the fracture and bony healing. Cervical Spine Injuries Chapter 30 859 Figure 17. Posterior atlantoaxial stabilization techniques Posterior C1 2 .
