Unlike conventional single-screw or blade implants, the Vertex HFN employs two fixation points within the femoral head: a lag screw and a diverging screw, oriented at a 10° angle relative to each other. This unique configuration enhances the resistance to femoral head rotation, distributing torsional forces across a broader surface area and reducing the likelihood of fixation loss. The result is improved construct stability, especially in osteoporotic bone or complex fracture patterns where rotational control is paramount.

Rotational instability in femoral head fixation can disrupt fracture alignment, impact bone healing, and increase the risk of screw cutout. Traditional single-screw systems like Stryker’s Gamma3® rely solely on a single large-diameter lag screws to resist rotational forces. Whilst blade-based implants such as DePuy’s TFNA® use a press-fit mechanism to improve torsional resistance. Despite these advances, biomechanical limitations remain. By introducing the dual-screw diverging design, Vertex HFN aims to overcome these shortcomings, delivering greater resistance to femoral head torsion and, ultimately, more reliable fixation.

Biomechanical testing was conducted using rigid polyurethane foam blocks to simulate osteoporotic cancellous bone in proximal femur fractures. The following constructs were evaluated:

• OrthoXel Vertex HFN with dual diverging screws
• Stryker Gamma3® with single lag screw
• DePuy Synthes TFNA® with helical blade construct

Each construct was subjected to controlled torsional loading up to 15° of rotation, with maximum torque measured as the primary outcome.

Vertex HFN demonstrated significantly higher resistance to torsional forces than both competitor implants:

Maximum Torque (N·m):

• Vertex HFN: 7.88 ± 0.22
• TFNA®: 2.78 ± 0.086
• Gamma3®: 1.50 ± 0.048

Statistical analysis confirmed that Vertex HFN’s performance was superior, with a mean difference of more than 6 N·m compared to Gamma3® and over 5 N·m compared to TFNA® (p < 0.001 for both). The data highlights a clear mechanical advantage of the dual-screw diverging design in resisting femoral head rotation.

Through this white paper, OrthoXel demonstrates that the Vertex HFN provides superior femoral head rotational fixation, setting a new benchmark in hip fracture treatment and reaffirming its focus on design innovation and patient outcomes.