A study of the results of all spine-fusion operations performed during the ten-year period from 1936 through 1945, at the New York Orthopaedic Dispensary and Hospital, shows that, of the 1096 patients followed at least one year from the time of spine fusion, the incidence of pseudarthrosis has been 16.6 per cent.
The diagnosis of pseudarthrosis can be made, in most cases, after careful clinical and roentgenographic evaluation. In a smaller group of cases, the diagnosis will not be definitely established until the area of fusion has been explored.
The benefits of the operation of spine fusion for any disease or deformity of the spine cannot be determined except in patients in whom a successful fusion has been definitely obtained.