Fibula Nail versus Locking Plate Fixation-A Biomechanical Study

Abstract

In the treatment of ankle fractures, complications such as wound healing problems following open reduction and internal fixation are a major problem. An innovative alternative to this procedure offers a more minimally invasive nail stabilization. The purpose of this biomechanical study was to clarify whether this method was biomechanically comparable to the established method. First, the stability (range of motion, diastasis) and rotational stiffness of the native upper ankle were evaluated in eight pairs of native geriatric specimens. Subsequently, an unstable ankle fracture was created and fixed with a locking plate or a nail in a pairwise manner. The ankles showed significantly less stability and rotational stiffness properties after nail and plate fixations than the corresponding native ankles (p < 0.001 for all parameters). When comparing the two methods, both showed no differences in their range of motion (p = 0.694) and diastasis (p = 0.166). The nail also presented significantly greater rotational stiffness compared to the plate (p = 0.001). However, both fixations remained behind the native stability and rotational stiffness. Due to the comparable biomechanical properties of the nail and plate fixations, an early weight-bearing following nail fixation should be assessed on a case-by-case basis considering the severity of fractures.

Keywords: biomechanical; fibular nail; geriatric fracture; geriatric trauma; open reduction and internal fixation; osteosynthesis; syndesmosis; syndesmotic screw; trauma surgery; upper ankle joint.

Figure 1

X-ray (A,B) fixations with the Vitus-Fi Fibula Nail System (nail group) with two locking and two syndesmotic screws in anterior–posterior and lateral radiographs; X-ray (C,D) fixations with locking plate (plate group) with two syndesmotic screws in the anterior–posterior and lateral radiographs.

Figure 2

(A) The test setup with the material testing machine and optical 3D measuring system, (B) a prepared specimen with implanted vitus fibula nail, (C) the arrangement of the marker plates M1 (distal tibia) and M2 (distal fibula), (D) test setup with the placement of the marker plates M1 and M2. Torque was applied by repeated external/internal rotations of the tibia plateau against the fixed foot.

Figure 3

Results for the ROM, RS, and diastasis for native condition versus plate fixation (row 1), native condition versus nail fixation (row 2), and plate versus nail fixation (row 3). The data are presented with 95% confidence intervals. Non-overlapping intervals indicate significant differences.