Rigid Versus Nonrigid Occipitocervical Fusion

Abstract

Retrospective data review. To report clinical outcomes of both rigid and nonrigid occipitocervical (OC) fusion constructs of a multicenter cervical spine study group. The OC junction is susceptible to a wide variety of pathologic conditions that predispose it to instability. The need for arthodesis in symptomatic or neurologically unstable cases has led to the development of a variety of fusion techniques that can be classified as either nonrigid fixation techniques, such as sublaminar wiring or onlay bone grafting, or rigid internal fixation constructs, such as screws with plate or rods. Rigid fixation provides immediate stability and eliminates the need for external fixators, that is, halo-vest. Although a rigid construct would seem to confer several advantages over a nonrigid construct with external inmobilization supplementation, comparative clinical data are is lacking. A clinical comparison of the rigid and the nonrigid forms of OC fusion was done retrospectively from the data of a multicenter cervical spine study group. A total of 71 occipitocervical fusion patients were identified: 25 with a nonrigid technique and 46 with a rigid construct. Average follow-up time was 6.3 months with a range of 1.5 to 36 for the rigid construct cohort and 15.7 months with a range of 1 to 36 months for the nonrigid cohort. Complications were recorded and correlated to the type of fixation and the type of external immobilization used. A χ analysis was done to evaluate the significant differences between complication rates of both the groups, that is, rigid and nonrigid constructs. Twenty-five nonrigidly fused patients had a complication rate of 48%, whereas 46 rigidly fused patients had a complication rate of 10% (P<0.01). Rigid forms of internal fixation for OC fusion has a significantly lower complication rate in short term. In addition to the many advantages of a rigid occipitocervical construct, the clinical complication rates are statistically significantly lower versus a nonrigidly fixed construct.