Introduction: The early inflammation reaction to rhBMP-2 manifesting with radicular symptoms has been previously reported in patients undergoing TLIF. There is a disagreement in regards to the factors affecting its occurrence and whether such symptoms are dose-dependent. The purpose of this study was to determine the incidence of rhBMP-2 induced radiculitis and its relationship to dose.
Methods: A retrospective cohort analysis was performed of the prospectively collected data. All consecutive patients (n=204) who underwent one- or two-level TLIF and instrumented posterolateral fusion with an off-label rhBMP-2 use were included in this analysis. The patients that developed radiculitis in the immediate postoperative period were believed to have rhBMP-2-induced radiculitis in the absence of any other morphological abnormalities. The primary outcome measure was radicular symptoms identified in the immediate postoperative period. Correlations between the total rhBMP-2 dose, dose per spinal level and incidence of radiculitis were evaluated.
Results: The incidence of postoperative radiculitis was 11.3% (23 out of 204). The average total rhBMP-2 dose was 4.9 mg (range 2.1-12) and the average dose per spinal level was 3.8 mg (range 1.05-12). Logistic regression analysis did not identify any significant correlations between the rhBMP-2 doses and the incidence of radiculitis (p=0.6).
Conclusions: The incidence of rhBMP-2-induced radiculitis in patients undergoing TLIF is quite high, but there were no dose-related correlations found.
Patient Care: The reported high incidence of postoperative rhBMP-2 induced radiculitis reinforces surgeons’ awareness of this complication.
Learning Objectives: The participants will be able to realize the lack of correlations between the rhBMP-2 dose and incidence of BMP-induced radiculitis.