Biomechanical comparison of triangular osteosynthesis and triangular minimally invasive spinopelvic stabilization technique for pelvic fragility fractures

Title : Biomechanical comparison of triangular osteosynthesis and triangular minimally invasive spinopelvic stabilization technique for pelvic fragility fractures

Abstract:

Introduction: Triangular Osteo Synthesis (TOS) is considered the gold-standard for treatment of Type IV Fragility Fractures of the Pelvis (FFP). as it provides vertical and horizontal stability through lumbopelvic fixation and iliosacral screws. An emerging Triangular Minimally Invasive Spinopelvic Stabilization (TMSS) technique has been clinically introduced [Riesner et al 2021] as an alternative. This study aims to biomechanically compare the stability of TOS and TMSS in a cadaveric model of FFP Type IV U-shaped fractures.

Methods: Six fresh-frozen osteoporotic human cadaveric lumbopelvic spine specimens underwent simulated Type IV U-shaped sacral fractures and were instrumented with either TOS or TMSS constructs, the TOS (L4 Pedicle Screws – Iliac Screw), while the TMSS construct replaced the iliosacral screw with an inferior iliac screw and transverse rod for compression. They were subjected to cyclic loading (200 – 430 N for 25,000 cycles) simulating 3 to 4-week post-operative mobilization. Fracture displacement was measured using a 3D motion tracking system and the magnitude of the combined translation in the three cardinal planes (t-test (p<0.05)).

Results: The TMSS construct demonstrated after 25,000 cycles reduced maximum fracture displacement (6.05 mm) compared to TOS (12.12 mm), though statistical significance was not reached (p=0.071). Each, TOS and TMSS constructed exhibited 56% and 62% of the maximum facture displacement within the first 1,000 cycles.

Conclusions: The TMSS construct provides comparable biomechanical stability to TOS in stabilizing Type IV FFPs. Given its minimally invasive approach and promising biomechanical performance, TMSS represents a viable alternative for treating FFPs.

Biography:

Hans-Joachim Riesner completed his secondary education at Kolleg St. Blasien in Germany, graduating with a German secondary school diploma in 1988. Since 1988, he has served in the German Armed Forces and currently holds the rank of Colonel while practicing as a physician within the German military healthcare system. Between 1990 and 1997, he studied Human Medicine at the University of Ulm, laying the foundation for his distinguished medical and military career. Following graduation, he pursued extensive specialist training in Orthopedic and Trauma Surgery. His residency and advanced training included positions at the German Armed Forces Hospital in Ulm (1997–1999 and 2002–2004), the ABC Defense and Self-Protection School in Sonthofen (1999–2002), the Hessing Foundation in Augsburg (2005–2006), and the University of Leipzig (2006–2008), where he served as Deputy in Orthopedic and Trauma Surgery.

From 2008 onward, he held several leadership positions within the German Armed Forces medical system, serving as Deputy in the Department of Orthopedic and Trauma Surgery at the German Armed Forces Hospital in Berlin (2008–2009) and later in Ulm (2009). Since 2010, he has been Vice Director of the Department of Orthopedic and Trauma Surgery at the German Armed Forces Hospital and Chief of the Spine Surgery Section. His professional qualifications continued to advance with additional certifications as a Special Trauma Surgeon in 2012 and a Special Orthopedic Surgeon in 2015. In 2022, he earned his State Doctorate in Orthopedic and Trauma Surgery and was promoted to the rank of Colonel, further recognizing his significant contributions to military medicine, orthopedic surgery, trauma care, and spine surgery.