Case Series of Anterior Intervertebral Graft Extrusions in Transforaminal Lumbar Interbody Fusion Surgeries

BACKGROUND: According to the published reports, revision surgery is sometimes recommended even in patients with asymptomatic anterior lumbar intervertebral graft migrations. The main purpose of this chart review study was to report on the clinical course and outcomes of patients who had anterior intervertebral graft extrusions after transforaminal lumbar interbody fusion (TLIF). METHODS: From July 2002 to July 2014, 1259 consecutive TLIF surgeries were performed. These were reviewed, and patients who had anterior intervertebral graft extrusions were identified. RESULTS: The incidence of graft extrusion was 0.6% (7 of 1259 patients). There were 6 female patients and 1 male patient with an average age of 65.7 years (range, 44-80 years). All patients underwent TLIF with bilateral pedicle screw fixation, and 6 received recombinant human bone morphogenetic protein-2. Graft migrations were diagnosed between 5 days and 8 months postoperatively except for 2 cases in which migration occurred intraoperatively. The patients were closely followed for an average of 27.4 months (range, 12-43 months). All patients remained asymptomatic during the follow-up period and had solid fusion despite extrusions with an average time to fusion of 13 months (range, 10-18 months). No other adverse events occurred during the follow-up period. CONCLUSIONS: The risks of additional and highly invasive revision surgery should be weighed against the potential short-term and long-term complications associated with graft extrusions or migrations. It was demonstrated that fusion may take longer but can be achieved, and close observation may be adequate for asymptomatic patients.