A follow-up study was performed on ninety cases that were followed for more than one year after operation.
The age at the time of operation ranged from 29 years to 77 years old with an average age being 53.1 years old.
A tracing period was an interval in nine-eight months from one year and an average tracing period was four years and one month.
According to an international classification, the results of ninety cases were excellent in 55, good in 23, fair in 7 and poor in 5.
The results of many cases of the combined and the spondylolitic spondylolithesis were satisfactory.
Althongh intermittent claudication improved in almost all cases, low back pain and pain or numbness of the legs still remained in about half of the cases.
