Professional liability and potential liability. 
Operations on the nervous system continue to result in claims that rank among the most costly.  A retrospective review of 300 cases of alleged or potential liability referred for opinion over an 11-year period is reported to catalog areas of vulnerability for the neurosurgeon and to alert younger practitioners in particular.  Spinal surgery produced the largest single group of neurosurgical malpractice cases, 136 of the 300; among these, 71 came from operations on the lumbar spine.  Cerebral and spinal trauma accounted for 54 cases, the next largest group.  Subgroups were studied in detail and provide individual features of some importance.  Other conclusions are that 37% of all cases reviewed were found to have some merit in favor of the claimant; plaintiffs and their attorneys can be dissuaded from legal pursuit if the deficit is not serious; many defensible cases are settled or lost on the basis of disability rather than merit; and some type of reform of the present system is clearly needed.