Biomechanical Evaluation of a New Device for Internal Fixation of Femoral Neck Fractures

Abstract

This study aimed to compare the fixation stability of a new device (SCCAB) for femoral neck fractures and the cancellous lag screws. Standardized femoral neck osteotomies were created in seven pairs of cadaver femurs and stabilized with either SCCAB or cancellous lag screws. The specimens were subjected to incremental axial loading to 1300 N and cyclic loading at 1300 N for 104 cycles. No significant differences in downward femoral head displacement, change in the superior osteotomy gapping, and load to failure were observed between the two groups. SCCAB may be potentially useful to treat femoral neck fractures.

Comparison of Three Fixation Methods for Femoral Neck Fracture in Young Adults: Experimental and Numerical Investigations

“…Then, the extracted frames were converted to the appropriate movies and imported into SkillSpector V.1.3.2 (Video4-coach, Denmark). The loading steps used to simulate partial weight-bearing in the immediate postoperative period were as follows [ 12 , 22 – 24 ]: (I) incremental loading: each specimen was loaded to a maximum of 700 N at a rate of 1 mm/min displacement before and after fixation; (II) cyclic loading: each fixed sample was tested under sinusoidal cyclic loading, in which a 100–700 N force was applied at a frequency of 3 Hz for 10,000 cycles (this number of cycles approximates the expected interval for fracture consolidation) [ 12 , 22 ]; and (III) failure loading: survived specimens were loaded at a rate of 1 mm/min until the failure criterion, defined as axial femoral head displacement or fracture displacement of equal or greater than 5 mm or instability in the load–displacement curve [ 22 ]. It is worth mentioning that the failure criterion used in this study was based on a fracture displacement of 5 mm or more.…”

Biomechanical effects of internal fixation with self-lock compression anti-rotation blade for Pauwels type III femoral neck fractures: a comparative finite element analysis

“…The tail fins are arranged in a "V" shape to provide an antirotation effect (Fig. 1) [20]. A parallel cannulated screw at the distal end creates a planar configuration with SCAB that further enhances the overall anti-rotation capacity and mechanical stability of the internal fixation.…”

“…As in this research the threaded part of CS had little influence on the analytical results, the structure of thread was simplified, instead as a cylinder of equal diameter [21,22]. The model of SCAB was made based on real geometrical dimensions (total length 95 mm, helical blade diameter 10 mm, helical blade length 24.8 mm, body diameter 9 mm, and the sleeve part diameter 10 mm) [20]. The diagram of SCAB was shown in Fig.…”

“…To provide an alternative option for the fixation of FNF, we designed a novel implant named the self-lock compression anti-rotation blade (SCAB) and obtained the patent (Patent number: ZL200710121931.7) [19]. Our previous study has demonstrated that SCAB is mechanically reliable and has the advantages of being minimally invasive, antirotation, of high pull-out strength, and no loss of bone during implantation [20].…”

Novel slide compression anatomic plates of the femoral neck for treating unstable femoral neck fracture: A biomechanical study

“…Previous studies did not establish a uniform standard for the loading force, loading rate, or number of cycles. In static incremental loading, some researchers use a loading rate of 1 mm/min until the load reaches approximately 1400 N to terminate the experiment, 37,38 and some researchers choose a loading rate of 5 mm/min 39 or even greater than 10 mm/min, 40 and calculate the stiffness of the internal fixture within the elastic deformation zone of the load-displacement curve. Cyclic load dynamically reflects the mechanical properties of the implant in sine wave loading.…”