Purpose
To compare change in biomechanical function at operated and adjacent segments and clinical results after inserting three different designs of cervical artificial arthroplasty devices.
Materials and Methods
Retrospective analysis was performed for 60 patients who had undergone single level cervical artificial arthroplasty in authors’ hospital from November 2003 to January 2010. Bryan, Prestige LP and Prodisc– C artificial discs were used in 34, 17 and 9 patients respectively. We compared preoperative and postoperative biomechanical function of operated and adjacent segments radiographically and clinical results using VAS and NDI.
Results
Biomechanical results showed as follows: range of motion(ROM) of operated and overall cervical spine was well maintained postoperatively regardless of type of devices; Prodisc – C showed statistically significant recovery of sagittal alignment at the operated segment compared to preoperative status(p=0.021); adjacent level just inferior to the operated segment showed decrease in postoperative ROM with Bryan(p=0.000); anterior intervertebral height also decreased at that segment(p=0.001); no difference showed with VAS and NDI in the three artificial disc devices.
Conclusion
Clinical results of cervical artificial arthroplasty did not show significant difference during the follow-up period, but there were statistically significant changes in biomechanical function. Therefore, adequate selection of disc device is important in cervical arthroplasty.

A 45 year-old male was brought to our hospital with severe back pain and motor, sensory impairment in both lower extremities. He had no underlying diseases including coagulapathy. Motor weakness below both hip joint and decreased sensory below T12 dermatome, voiding dysfunction were examined. The MRI showed a spinal subdural hematoma at the thoracolumbar region, which was extremely rare. Medical treatment was applied without surgical interventions. After two weeks, motor weakness, sensory impairment, and voiding dysfunction were improved. And he returned to his daily activities. We present this case and literature reviews because traumatic spinal subdural hematoma is an extremely rare disease and the condition was treated successfully in conservative manner.