Comparison of Cage and Allograft Mixed Bone Marrow for Monosegmental Instrumented Posterior Lumbar Interbody Fusion

ABSTRACT

STUDY DESIGN: A retrospective study. OBJECTIVES: To compare the radiological and clinical results between cage and cancellous allograft mixed with bone marrow for monosegmental instrumented posterior lumbar interbody fusion (PLIF). SUMMARY OF THE LITERATURE REVIEW Allograft has potential problems, such as delayed union. Autologous bone marrow provides for improving the capability of bone induction with allograft. There are rare reports on PLIF using allograft mixed with autologous bone marrow. MATERIALS AND METHODS: Monosegmental instrumented PLIF was performed on 51 patients who had lumbar degenerative disease, cage for 28 patients (cage group) and allograft mixed with bone marrow for 23 patients (allograft group). The clinical and radiological results in each group were compared. RESULTS: The mean follow-up was 45 (30 - 111) months. At the final follow up, there was no significant difference between the cage group and the allograft group in the Korean Version Oswestry Disability Index (p=0.72) and Visual Analogue Score for back pain (p=0.54) and radiating pain to the leg (p=0.26). The radiological fusion rate was 92.8% in the cage group, and 82.6% in the allograft group (p=0.02). At the last follow up, disc height was decreased to 1.5+/-0.8 mm of the cage group, and 3.0+/-1.5 mm of the allograft group (p=0.0001). CONCLUSIONS: PLIF using cancellous allograft mixed bone marrow has low fusion rate contrast to good clinical results. It is necessary to take a careful selection of the allograft mixed bone marrow for PLIF.