16th German Spine Congress Annual Meeting of the German Spine Society 9th to 11th December 2021 Muenster, Germany

TY - JOUR

T1 - 16th German Spine Congress Annual Meeting of the German Spine Society 9th to 11th December 2021 Muenster, Germany

T2 - Design and biomechanical investigation of a novel anatomic osteosynthesis plate for the treatment of type II dens axis fractures

AU - Köpke, Leon-Gordian

AU - Heuer, Annika

AU - Münch, M

AU - Stangenberg, Martin

AU - Dreimann, Marc

AU - Viezens, Lennart

PY - 2021/11

Y1 - 2021/11

N2 - Introduction: Type II Anderson and D'Alonzo fractures of the dens axis (DFTII) are common fractures, especially in geriatric patients with poor bone status. They require prompt treatment to avoid complications including tetraplegia and death. In terms of cure rate, surgical treatment options appear superior to conservative treatment options in this regard. The current surgical gold standard is anterior screw osteosynthesis according to Böhler et al.. However, poor bone quality is a negative predictor of success. Material loosening and pseudarthrosis frequently occur over time. In everyday clinical practice, revision surgery is often necessary, which places a burden on the patient and the health care system. The aim of this project was to design a novel osteosynthesis plate (OSP) for angular stable screw osteosynthesis in DFTII and to test it biomechanically in comparison to the classic Böhler screw (BS).Material/Method: An OSP with a guide sleeve for an angular stable screw was designed. The angle for the trajectory of the screw was determined using polytrauma CTs without injuries to the cervical spine. A plate prototype was then created using a 3D printer and subsequently manufactured as a titanium print (Stryker Germany). Figure 1 shows the designed, fabricated and implanted OSP (Fig. 1). Subsequently, biomechanical testing was performed in comparison to the BS in the artificial bone model. A DFTII was simulated using osteotomy and then fixed with a regularly used BS or the novel OSP. Using standardized dorsal tensile forces and ventral compressive forces simulating flexion and extension movements between C1 and C2, the osteosyntheses were analyzed and compared in static testing using a Zwick material testing machine.Results: In static testing of ventral compressive forces, the BS showed failure at a median maximum force (mFmax) of N N- N). In contrast, the OSP showed failure at an mFmax of N N-217.93 N) (p < 0.001). In static testing of dorsal tensile forces, the BS showed failure at an mFmax of N N- N). The OSP did not fail in this testing up to an mFmax of (206.79 N- N) (p < 0.001). The elasticity of the artificial bone limited the forces at higher loads. Excerpts of the force curves are shown in Figure 2 (Fig. 2).Discussion: The results show that our newly developed OSP is significantly superior to the classic BS in stabilizing a DFTII in the artificial bone in static biomechanical testing of dorsal tensile forces and ventral compressive forces (p < 0.001). For further biomechanical testing of the novel OSP, dynamic testing on artificial bone and subsequent static and dynamic testing in human cadaveric bone will now be performed.

AB - Introduction: Type II Anderson and D'Alonzo fractures of the dens axis (DFTII) are common fractures, especially in geriatric patients with poor bone status. They require prompt treatment to avoid complications including tetraplegia and death. In terms of cure rate, surgical treatment options appear superior to conservative treatment options in this regard. The current surgical gold standard is anterior screw osteosynthesis according to Böhler et al.. However, poor bone quality is a negative predictor of success. Material loosening and pseudarthrosis frequently occur over time. In everyday clinical practice, revision surgery is often necessary, which places a burden on the patient and the health care system. The aim of this project was to design a novel osteosynthesis plate (OSP) for angular stable screw osteosynthesis in DFTII and to test it biomechanically in comparison to the classic Böhler screw (BS).Material/Method: An OSP with a guide sleeve for an angular stable screw was designed. The angle for the trajectory of the screw was determined using polytrauma CTs without injuries to the cervical spine. A plate prototype was then created using a 3D printer and subsequently manufactured as a titanium print (Stryker Germany). Figure 1 shows the designed, fabricated and implanted OSP (Fig. 1). Subsequently, biomechanical testing was performed in comparison to the BS in the artificial bone model. A DFTII was simulated using osteotomy and then fixed with a regularly used BS or the novel OSP. Using standardized dorsal tensile forces and ventral compressive forces simulating flexion and extension movements between C1 and C2, the osteosyntheses were analyzed and compared in static testing using a Zwick material testing machine.Results: In static testing of ventral compressive forces, the BS showed failure at a median maximum force (mFmax) of N N- N). In contrast, the OSP showed failure at an mFmax of N N-217.93 N) (p < 0.001). In static testing of dorsal tensile forces, the BS showed failure at an mFmax of N N- N). The OSP did not fail in this testing up to an mFmax of (206.79 N- N) (p < 0.001). The elasticity of the artificial bone limited the forces at higher loads. Excerpts of the force curves are shown in Figure 2 (Fig. 2).Discussion: The results show that our newly developed OSP is significantly superior to the classic BS in stabilizing a DFTII in the artificial bone in static biomechanical testing of dorsal tensile forces and ventral compressive forces (p < 0.001). For further biomechanical testing of the novel OSP, dynamic testing on artificial bone and subsequent static and dynamic testing in human cadaveric bone will now be performed.

U2 - 10.1007/s00586-021-07017-6

DO - 10.1007/s00586-021-07017-6

M3 - Conference abstract in journal

VL - 30

SP - 3362

EP - 3362

JO - EUR SPINE J

JF - EUR SPINE J

SN - 0940-6719

IS - 11

M1 - P4

ER -