Biomechanical study of anterior cervical corpectomy and step-cut grafting with bioabsorbable screws fixation in cadaveric cervical spine model.

摘要

STUDY DESIGN: An in vitro biomechanical study. OBJECTIVE: To determine the initial stability of a novel construct in a 1-level cadaveric cervical spine model by comparing it with a conventional method. SUMMARY OF BACKGROUND DATA: Lots of endeavors have been made to enhance fusion rates and reduce complications in the anterior cervical spine procedure. METHODS: There were 12 fresh human cadaveric cervical spines (C3-C7) randomly divided into 2 groups: group 1, 1-level corpectomy of C5 and step-cut grafting with bioabsorbable screw fixation (SCAS); and group 2, 1-level corpectomy of C5 and strut grafting with anterior plate fixation (SP). For each specimen, the intact underwent a flexibility test first, followed by the instrumented construct. Rotational angles of the C4-C6 segment were measured to study the immediate stability of anterior cervical corpectomy and SCAS, compared with the intact and anterior cervical corpectomy and SP. RESULTS: Both anterior cervical corpectomy with SCAS and with SP significantly (P < 0.01) decreased the motions of C4-C6 in all 6 degrees of freedom after instrumentation. Compared with anterior cervical corpectomy and SP, anterior cervical corpectomy and SCAS had higher stability (P < 0.05) in extension, and comparable stability (P > 0.05) in flexion and axial rotation, but lower stability (P