The influence of spine surgery on motor recovery between 1 month and 1 year was assessed prospectively in a group of 269 patients following traumatic spinal cord injury (SCI) using the classification system originally developed by the American Spinal Injury Association. The Allen classification was used to categorize cervical vertebral pathology and the Denis system was used for injuries to the thoracic and lumbar spine. Gunshot injuries were classified based upon the bullet trajectory and location relative to the spinal canal. Individuals undergoing surgery were divided into various subgroups depending on the type of surgery performed: anterior decompression with or without spine fusion and instrumentation, posterior decompression/laminectomy with or without spine fusion and instrumentation and spine fusion with instrumentation. Motor score recovery between 1 month and 1 year after injury was highly dependent (P < or = 0.001) on the level and completeness of injury averaging 0.7 +/- 2.7 for complete paraplegics, 7.8 +/- 4.8 for complete tetraplegics, 11.8 +/- 8.3, for incomplete paraplegics and 22.2 +/- 10.9 for incomplete tetraplegics. Motor recovery did not significantly differ between patients categorized in various surgical subgroups or between those having surgery and those treated non-operatively. Additionally, although the sample size was small, motor recovery among tetraplegic individuals did not depend on whether unilateral and bilateral facet dislocations were reduced and in patients with incomplete lesions, those with reductions actually had a poorer outcome than those who were left in a dislocated position.