ABSTRACT
Objective To explore a new way assisted by digital technology to establish a quantitative index to assess the matching performance of anatomically contoured plate. Methods We collected the thin-slice CT data of 20 adults with normal tibias who had received 32-slice spiral CT scanning from April 2015 to June 2016. They were 10 males and 10 females, aged from 28 to 52 years (average, 36.2 years). 3D reconstruction of the tibias was performed with Mimics 18.0. Two brands of 8-hole anatomically contoured plate for distal tibia (Kongli versus GE) were digitized. The curve of the plate facing the bone surface was extracted. The operational process of putting the plate curve on the medial surface of the distal tibia was simulated in Rhino 5.0. The volume of the gap between plate curve and bone surface was measured. The mean distance of the gap between plate cure and bone surface was figured out after the volume divided by the plate area. The inverse value of the mean distance of the gap was used as the index for matching performance. The wall thickness analyzing tool in 3-matic Research was used to mark the various thicknesses of the gap with different colors. The matching performances of the 2 brands of plate were assessed and compared according to the matching performance index and nephogram. Results Of the Kongli 8-hole distal tibial plate, the gap volume was 3,834 mm3± 701 mm3, the mean thickness 1.8 mm ± 0.3 mm, and the matching index 0.56 ± 0.10. Of the GE 8-hole tibial plate, the gap volume was 7,690 mm3± 1,503 mm3, the mean thickness 3.0 mm ± 0.6 mm, and the matching index 0.34 ± 0.06. The significant difference in matching performance between the 2 kinds of plate favored the Kongli plate (t=10.402, P <0.01). There were no significant differences in matching per-formance between different genders among the plates of the same brand (P> 0.05). The nephogram showed a large fixed red area at the proximal part in the GE 8-hole tibial plate. Conclusions As this index for matching performance is simple and intuitive, it can be used to assess and compare the matching performances between different kinds of plates. It can be also used before operation to assess the matching performance of a specific plate for a specific patient to avoid mismatch because of individual differences.