154. The use of autologous free vascularized fibula grafts in reconstruction of the mobile spine following tumor resection: illustrated surgical technique and outcomes

Abstract

BACKGROUND CONTEXT Reconstruction of the mobile spine following total en bloc spondylectomy (TES) of one or multiple vertebral bodies in patients suffering from malignant spinal tumors is a challenging procedure with high failure rates. One of the most common reasons for reconstructive failure is nonunion, which is an even greater problem in the setting of local radiation. Radiation is an integral part of the management of primary malignant bone tumors in the spine at our institution. Vascularized grafts may help prevent nonunion in the setting of radiation therapy. We have routinely utilized free vascularized fibular grafts (FVFG) for the reconstruction of the mobile spine following TES. PURPOSE The purpose of this study is to describe the surgical technique utilized for vascularized reconstruction of defects following TES. In addition, we report the outcomes of a consecutive series of patients treated with this technique. STUDY DESIGN/SETTING Retrospective review of electronic health records at one tertiary care center and an illustrated explanation of the surgical technique. PATIENT SAMPLE Adult patients, 18 years or older, undergoing total en bloc resection of primary malignant tumors of the mobile spine followed by reconstruction using a free vascularized fibula graft. OUTCOME MEASURES The primary outcome was reconstruction failure of the construct. METHODS Thirty-nine patients treated at our tertiary care institution between 2010 and 2018 for a diagnosis of malignant tumor in the mobile spine with the use of FVFG following TES were reviewed. Postoperative union, complications, neurological outcome, reoperations, and survival were reported. The median time of follow-up was 50 months (range, 14 – 109 months). RESULTS The cohort consisted of 26 males and 13 females, with a median age of 58 years. Chordoma was the tumor that occurred most often (67%) and tumors occurred most often in the lumbar spine (46%). Complete union was seen in 26 patients (76%), the overall complication rate was 56%, and instrumentation failure was the most common complication with 26% of patients affected. In total 12 patients (31%) suffered from – instrumentation loosening or breakage, nonunion, graft fracture, or a combination of these – for which ten patients (26%) required revision surgery. The fixation was revised a total of 15 times (42% of reoperations). In 18 patients (46%) one or more reoperations were needed. The overall 1-, 3-, and 5-year survival rate was 95%, 92%, and 87%, respectively. CONCLUSIONS The FVFG is an adequate reconstruction technique of the mobile spine following TES for malignant tumors. Although we see higher union rates and comparable complication rates compared to other techniques, the rate of instrumentation failure was high. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.