Anterior Screw Fixation using Herbert Screw for Type II Odontoid Process Fractures.

Sung, Joo Kyung

Original Article

Journal of Korean Neurosurgical Society 2005;37(5): 345-349.

Department of Neurosurgery, Kyungpook National University School of Medicine, Daegu, Korea. jksung@knu.ac.kr

ABSTRACT

OBJECTIVE
Anterior screw fixation provides the best anatomical and functional results for type II odontoid process fracture (type II-A, II-N, and II-P) with intact transverse ligament. The purpose of this study is to evaluate the usefulness of the 4.5mm diameter, cannulated Herbert screw in anterior screw fixation. METHODS: From Jan. 2003 to Feb. 2004, consecutive 10cases of type II odontoid process fractures were treated with anterior screw fixation using a Herbert screw. The Herbert screw has double threads, with different pitches on the distal and proximal ends. It has no head, so it can be inserted through articular cartilage and buried below bone surface. It was originally developed for treating scaphoid fractures. RESULTS: There were 8male and 2female patients whose ages ranged from 15 to 67years (mean 42.1years). The fracture type was type II-A in 4patients, II-N in 3patients, and II-P in 3patients. The fracture line was oblique downward and backward in 6cases, oblique downward and forward in 1case, and horizontal in 3cases. The range of follow-up was 5 to 18months (mean 12months). Bone fusions were achieved in all cases without any instrumental failures or postoperative complications.
CONCLUSION
The Herbert screw is very useful in anterior fixation for type II odontoid process fracture. This series showed successful results also in type II-A odontoid fracture when treated with the Herbert screw, but further more studies are required.

Key Words: Herbert screw; Atlanto-axial instability; Type II odontoid process fracture; Anterior screw fixation