Comparison of lumbar interbody fusion techniques using ray threaded fusion cages and pedicle screw fixation systems

Study design: Three groups of patients with low back pain, with or without sciatica, caused by degenerative disc disease were treated by lumbar interbody fusion. Objectives: To determine the differences, if any, in clinical outcomes, fusion status, and cost-effectiveness among patients who underwent three variations of lumbar interbody fusion surgery. Summary of background data: Lumbar interbody fusion is an accepted treatment option in the management of patients with degenerative disc disease. Controversy with regard to interbody fusion centers on indications for surgery, surgical technique, and interpretation of results. Reported costs vary significantly among different surgical treatments, whereas patient outcomes have varied little. Materials and methods: Prospective study of 46 patients who underwent 1 of 3 lumbar interbody fusion procedures was conducted. Group I had anterior lumbar interbody fusion using Ray threaded fusion cages (ALIF/TFC). Group 2 underwent posterior lumbar interbody fusion with Ray threaded fusion cages (PLIF/TFC). Patients in group 3 underwent posterior lumbar interbody fusion with concomitant posterior stabilization (PLIF/Plate). Clinical outcomes were assessed using the Prolo socioeconomic/functional improvement scale at 6 weeks, 6 months, 1 year, and 2 years after surgery. Fusion status was determined from flexion-extension, lateral, and anterior-posterior radiographs. Cost comparisons were made through data obtained from patient chart entries and billing records. Results: Satisfaction and willingness to undergo the procedure again was reported in all but 1 case. Clinical outcomes at 1 year after surgery (P < 0.0001) were significantly increased with 28% of patients reporting excellent results, 41% reporting good results, 11% fair, and 20% poor. Similar results were reported at 2 years after surgery. Although all 46 (100%) of the patients met the outlined criteria for arthrodesis at 12 months after surgery, 4 (0.09%) patients reported persistent back pain requiring additional surgery at adjacent vertebral levels. There were no significant statistical differences among the 3 treatment groups except for operative time, anesthesia time, and cost. The total cost for PLIF/TFC and PLIF/Plate was significantly higher than for the ALIF/TFC group (P < 0.01). The mean combined costs, including surgeons' fees and instrumentation, averaged $12,040 for ALIF/TFC, $13,675 for PLIF/TFC, and $15,432 for PLIF/Plate. Conclusion: The results of this study demonstrate that there are no significant differences in clinical outcomes among the 3 treatment groups. Significant statistical differences were observed in operative time, including anesthesia time, and cost. Based on these data, it is difficult to justify (from a fiscal point of view) routine use of PLIF/Plate technique as a cost-effective treatment modality for patients with degenerative disc disease.