Comparision of Non-locking Monocortical and Bicortical Screw System for Anterior Cervical Fusion and Plating in Degenerative Cervical Spondylosis

Lee, Sun Ho; Sung, Joo Kyung

Abstract

OBJECTIVE
Non-locking bicortical screw and locking monocortical screw system have usually been used in anterior cervical spine fusion and plating. The purpose of this study is to evaluate the differences in stability and safety between the non-locking bicortical and monocortical screw-plate system. METHODS: The authors reviewed 135 cervical spondylotic patients who underwent anterior cervical fusion from Jan. 1995 through Jun. 2002. The patients were separated into two groups: Group 1. consisted of 68 patients (male: 55, female 13 and mean age: 50.5years) treated with non-locking bicortical screw system, Group 2. consisted of 67 patients (male 50, female 17, mean age: 59.6 years) treated with non-locking monocortical screw system. The mean follow-up duration was 50 months (from 9 to 101 months). A comprehensive evaluation between two groups were made. RESULTS: There were no graft material related complications in both groups. But instrument related complications were 1 case of screw breakage and 1 case of screw loosening in group 1 and 1 case of screw loosening in group 2. Mean time for plate and screw fixation was less required in group 2 than group 1. Fusion had occurred in all patients of both groups. CONCLUSION: Non-locking monocortical screw fixation can be recommended for anterior cervical fusion and plating in degenerative disease, making the procedure quicker, easier, and safer compare with non-locking bicortical screw.