Stand-Alone Interbody Fusion Versus Instrumented Interbody Fusion

Abstract

There is controversy regarding the use of interbody fusion cages as stand-alone devices in patients with degenerative disk disease. A clinical comparison was made between a stand-alone cage procedure and a cage with pedicle screw procedure. This retrospective review compared 2 data sets, including consecutive patients who were diagnosed with degenerative disk disease and were fused from 1 to 4 levels of the lumbar spine using a posterior approach. Surgical and hospital details, patient demographics, and pain and function scores were collected. The stand-alone group included 72 patients (35 male and 37 female, 30 smokers). The posterior fixation group included 65 patients (39 male and 26 female, 26 smokers). Length of hospitalization for the posterior fixation group was significantly greater at 6.2 days compared with 4.7 days in the stand-alone group. Both groups showed significant improvement in back and leg pain after surgery. There were no statistically significant differences in back or leg pain or postoperative function. Group 1 had a fusion rate of 94%, whereas group 2 had a fusion rate of 89%. Multilevel cases showed a significant interaction between the procedure and time point, suggesting that multilevel pedicle screw patients show more rapid improvement after surgery. Intraoperative complication rates were 23.6% in group 1 and 21.2% in group 2. Postoperative complications and revisions were 7.6% and 9.1% in the pedicle screw group compared with 9.7% and 4.2% in the stand-alone group. Comparison of these 2 data sets reveals few differences. A faster improvement may be traded for higher revision rates and longer hospitalization.