The purpose of this study was to establish new fusion criteria to complement existing Brantigan-Steffee fusion criteria. The primary purpose of intervertebral cage placement is to create a proper biomechanical environment through successful fusion. The existence of a traction spur is an essential predictable radiologic factor which shows that there is instability of a fusion segment. We studied the relationship between the existence of a traction spur and fusion after a posterior lumbar interbody fusion (PLIF) procedure.
