ObjectiveTo use claw-shaped blade plate and self-made 'titanium clip' blade plate for rib fracture fixation, and compare outcomes of these two internal fixation methods through mechanical tests. MethodsThoracic cage specimens of six adults (male)corpses were numbered. Bilateral 4th, 6th and 8th thoracic ribs of each corpse were taken from the rib nodules (0%)to costal cartilage junction (CJJ points, 100%)along the long axis of the ribs. Rib fragments about 130 mm in length with 50% locus were selected for mechanical tests of the lateral area. A total of 36 rib fragments were sampled and numbered. Each rib fragment was placed on electronic universal mechanical tester. A span of 100 mm and a loading speed of 2.5 mm/min were set to perform a three-point bending test until specimens fractured. The loads at displacement of 2, 4, 6, 8, 10, 15 and 20 mm respectively and maximum load were recorded, then the load-displacement curve was drawn. Above rib fragments were randomly divided into 2 groups, which were fixed using 'titanium clip' blade plate (titanium plate group)and claw-shaped blade plate (claw-shape group)respectively. Three-point bending test was performed under above loading conditions until the fixed specimens fractured again, and relevant data were recorded. ResultsBefore fixation, there was no statistical difference in maximum load and peak deformation of the 4th, 6th and 8th ribs between the 2 groups (P > 0.05). Maximum load and peak deformation of the 4th, 6th and 8th ribs in the claw-shape group after fixation were statistically different from those before fixation (P < 0.05). Maximum load and peak deformation of the 4th, 6th and 8th ribs in the titanium plate group after fixation were also statistically different from those before fixation (P < 0.05). After fixation, maximum loads of the 4th, 6th and 8th ribs in the claw-shape group were statistically different from those in the titanium plate group (P < 0.05), but there was no statistical difference in peak deformation between the 2 groups (P > 0.05). ConclusionsFractured ribs fixed with 'titanium clip' blade plates are more stable and stronger than those fixed with claw-shaped blade plates.
ObjectiveTo provide geometric morphometric parameters for anatomical plate design by measuring the geometry of the 3rd to 9th ribs of adults using X-ray computed tomography (CT). MethodsTwenty patients receiving chest CT scan in Hebei Province General Hospital from May to July of 2012 were recruited in this study. There were 10 Han males and 10 Han females with their height of 167-180 (173±8) cm and age of 16-58 (37±18) years. None of the patients had thoracic trauma history or other disease which might influence the shape or density of ribs. After general chest CT scan, three-dimensional images of thoracic bones were constructed. The geometric shape of the ribs was analyzed and measured. ResultsThe ribs were divided into 3 sections as followed, from rib head to-37.5% of rib (section 1), 25%-75% (section 2), and 50%-100% (section 3). The maximum curvature of general curved ribs on long axis occurred in section 1 of the ribs. The third rib had the largest curvature (20.24±2.86/m). Section 2 of the 8th rib had the smallest curvature (6.14±0.96/m). The curvature of section 2 of 7th to 9th ribs was smaller than that of other 2 sections. The smallest curvature appeared in section 3 of 3rd to 6th ribs. Each rib had a retroversion angle along its longitudinal axis, and its numerical value was 30-50 degrees. The rib unrolled angle decreased firstly and then increased gradually. The cross-sectional area of marrow cavity ranged from 27.59 mm2 at the rear to 55.91 mm2 in the front. ConclusionMulti-slice spiral CT three-dimensional reconstruction of ribs can accurately measure the morphological characteristics of ribs, and provide a practical method for designing internal rib fixation plates.