(P 300) RECONSTRUCTION FOLLOWING SACROILIAC TUMOR RESECTION: A SYSTEMATIC REVIEW

Objective: Internal hemipelvectomy involving sacroiliac joint resection is a technically demanding procedure associated with high complication rates and subsequent pelvic ring instability. Although internal hemipelvectomy with sacroiliac resection procedures are not traditionally reconstructed, surgeons are increasingly pursuing pelvic ring reconstruction to theoretically improve stability, function, and early ambulation. Methods of reconstruction are highly variable but can include plate and screw construct fixation with or without cement augmentation, allograft prosthesis composites (APCs), vascularized and non-vascularized autografts, or some combination of these methods.

This study performed a systematic review of the current literature and evaluated postoperative complications, functional outcomes, implant survivorship and patient survival for each reconstruction technique utilized for sacroiliac tumor resection and reconstruction without periacetabular involvement. We secondarily aimed to compare outcomes between individuals with and without reconstruction of their residual pelvic defects.

Methods: PubMed and MEDLINE were queried for studies published between January 1990 and October 2020 pertaining to sacroiliac neoplasm resection with subsequent reconstruction. All prospective and retrospective English language studies that specified clinical outcomes based on the construct used for reconstruction were included. Patient demographics, primary histopathologic diagnosis, reconstruction technique, Musculoskeletal Tumor Society (MSTS) scores, and oncologic outcomes were collected and evaluated. Individual study data was pooled for whole group analysis, then separated based on reconstruction technique and whether reconstruction was performed.

Results: 23 studies reporting outcomes on 201 patients were included for analysis after meeting inclusion criteria. Reconstruction was performed in 79.1% of all cases with non-vascularized autografts (45.8%) being the most common technique used and allograft prosthesis composites (4%) being the least common technique. The overall complication rate was 54.8%. However, the complication rate amongst reconstructed patients was significantly higher at 62.3% compared to 25.7% in non-reconstructed patients (p< 0.001) (Table 1). There were also higher infection rates in the reconstructed patients at 13.7% compared to 0% in the non-reconstructed patients (p=0.020). The reconstruction technique with the highest complication rate was allograft the APC group at 100% compared to 44.4% in the vascularized autograft technique. The mean MSTS functional score trended higher in non-reconstructed patients at 82% compared to reconstructed patients at 71.6% (Figure 1). Amongst those with reconstruction, the highest functional scores were reported in the vascularized autograft group at 75.7%, and the lowest scores were in the rod and screw construct group at 63.7%.

Conclusion: Reconstruction after sacroiliac resection produced higher complication rates and poorer physical recovery when compared to non-reconstructed resection. The systematic review suggests that patients with spinopelvic junction instability may experience superior outcomes without reconstruction. However, the decision to reconstruct the pelvic girdle is complex and multifactorial. Ultimately, it depends on factors such as the size of the tumor, patient prognosis and a patient’s desired functional goals.