Outcome of Sacropelvic Resection and Reconstruction Based on a Novel Classification System

Background:Sacral tumor resections require a multidisciplinary approach to achieve a cure and a functional outcome. Currently, there is no accepted classification system that provides a means to communicate among the multidisciplinary teams in terms of approach, osseous resection, reconstruction, and acceptable functional outcome. The purpose of this study was to report the outcome of sacral tumor resection based on our classification system.Methods:In this study, 196 patients (71 female and 125 male) undergoing an oncologic en bloc sacrectomy were reviewed. The mean age (and standard deviation) was 49 ± 16 years, and the mean body mass index was 27.2 ± 6.4 kg/m². The resections included 130 sarcomas (66%). The mean follow-up was 7 ± 5 years.Results:Resections included total sacrectomy (Type 1A: 20 patients [10%]) requiring reconstruction, subtotal sacrectomy (Type 1B: 5 patients [3%]) requiring reconstruction, subtotal sacrectomy (Type 1C: 104 patients [53%]) not requiring reconstruction, hemisacrectomy (Type 2: 29 patients [15%]), external hemipelvectomy and hemisacrectomy (Type 3: 32 patients [16%]), total sacrectomy and external hemipelvectomy (Type 4: 5 patients [3%]), and hemicorporectomy (Type 5: 1 patient [1%]). The disease-specific survival was 66% at 5 years and 52% at 10 years. Based on the classification, the 5-year disease-specific survival was 34% for Type 1A, 100% for Type 1B, 71% for Type 1C, 65% for Type 2, 57% for Type 3, 100% for Type 4, and 100% for Type 5 (p < 0.001). Tumor recurrence occurred in 67 patients, including isolated local recurrence (14 patients), isolated metastatic disease (31 patients), and combined local and metastatic disease (22 patients). At 5 years, the local recurrence-free survival was 77% and the metastasis-free survival was 68%. Complications occurred in 153 patients (78%), most commonly wound complications (95 patients [48%]). Following the procedure, 154 patients (79%) were ambulatory, and the mean Musculoskeletal Tumor Society (MSTS93) score was 60% ± 23%.Conclusions:Although resections of sacral malignancies are associated with complications, they can be curative in a majority of patients, with a majority of patients ambulatory with an acceptable functional outcome considering the extent of the resection. At our institution, this classification allows for communication between surgical teams and implies a surgical approach, staging, reconstruction, and potential functional outcomes.Level of Evidence:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.