The Sacral Frame Technique: A Novel Trans/Extrasacral Approach for Giant Sacral Schwannomas Resection with Sacropelvic Biomechanics Preservation.

Background: Giant sacral schwannomas present a significant surgical challenge, often requiring extensive resections that compromise neurological function and sacropelvic biomechanics. Conventional approaches frequently necessitate sacral bone sacrifice, resulting in the deafferentation of key pelvic stabilizers and subsequent long-term functional deficits. This study introduces the novel single-posterior "Sacral Frame Technique," designed to preserve the lateral sacral bone margin and optimize functional reconstruction. Methods: We describe the surgical technique and report on a case of a 55-year-old female with a giant sacral schwannoma extending into the spinal canal and presacral space. The resection was performed via a combined trans-sacral and extrasacral approach, employing an intralesional piecemeal strategy to maintain the lateral sacral bone margin. The gluteus maximus muscles, along with the sacrotuberous and sacrospinous ligaments, were meticulously reattached to their natural insertion sites on the preserved bone. Clinical and radiological outcomes were evaluated at six months post-operatively. Results: Complete tumor resection was achieved without post-operative neurological deficits or sphincter dysfunction. The patient achieved early mobilization, returned to pre-operative activity levels, and showed no evidence of sacropelvic instability at the six-month follow-up. Post-operative imaging confirmed complete tumor clearance and the structural integrity of the preserved sacral bone margin. Conclusions: The "Sacral Frame Technique" offers a potential strategy for the safe and effective resection of giant sacral schwannomas. By prioritizing the preservation of the lateral sacral bone margin, the technique facilitates the anatomical reattachment of pelvic stabilizers, potentially mitigating long-term biomechanical deficits. Further studies with larger cohorts are warranted to fully validate these findings and establish the broader applicability of this bone-preserving approach.