Narrow Results

The aim of this paper is to compare the biomechanical characteristics of a newly designed assembly locking compression plate (NALCP) and traditional locking compression plate (LCP) for internal fixation of femoral-shaft comminuted fractures. A femoral-shaft wedge fracture model (AO classification 32-C2.1) was created in six pairs of femoral specimens ($n=12$) randomly divided into two equal groups. Biomechanical properties were tested with axial and torsional loading tests. The relative maximum displacement of fracture blocks and strain was recorded. A strain diagram was made; the fatigue test results of NALCP specimens under axial load were recorded. Under axial load, the relative maximum displacement of fracture blocks in the $X$, $Y$, and $Z$ axes was smaller in NALCP specimens than in LCP specimens ($P<0.05$ and 0.01, respectively). Under torsional load, the relative maximum displacement of fracture blocks in the $X$ and $Z$ axes in NALCP specimens was less than that in LCP specimens ($P<0.01$) but no statistically significant difference in the $Y$ axes ($P>0.05$) was found. In both cases, the main NALCP strain was higher than the LCP strain ($P<0.01$) but no statistically significant difference in mean strain ($P>0.05$) was found. Our NALCP provides strong mechanical stability for comminuted femoral fractures and can effectively avoid stress concentration, reduce stress shielding, and facilitate bone healing.