Aims With relatively thinner cortical thickness, the management of acetabulum osteoporotic fractures in elderly patients is difficult. The aim of the research was to compare and present the morphological characteristics of the quadrilateral plate in young and elderly age groups, such as the area, and position distribution of the thin cortical thickness region, fracture lines maps, and propose a revised design plate for elderly patients based on these anatomic information. Methods As a retrospective research, acetabular fracture with one normal hemipelvises, including 110 men and 39 women, were collected to present the morphological characteristics of the quadrilateral region. The subjects were divided into three different age groups: Group I = 18–40 years (31.3 ± 6.6 years), Group II = 41–60 years (49.9 ± 5.3 years), and Group III ≥ 61 years (68.7 ± 6.8 years). The area of the quadrilateral surface, the area and position distribution of the thin cortical thickness region, the ratio and fracture lines maps were calculated and compared with Mimics in different groups. Results The thin cortical thickness/width region area (TCWRA) was significantly increased in Group III compared with Group I and Group II. The ratio of TCWRA accounted for in the quadrilateral region was also significantly increased in Group III (≥ 61 years) compared with Group I (P = 0.01) and Group II (P = 0.011). None of the subjects had a component involving the “A” zone, thirty-three thin cortical thickness regions were located in the “B” zone, and one hundred and sixteen involved both zones of the quadrilateral plate (“A + B” zone). Furthermore, there were a significant differences in the fracture line distributions in three age groups. More fracture lines of elderly patients were located at anterior part (B zone) compared with Group I and Group II. Conclusions It was identified the area of thin cortical thickness region increased as age grown, and fracture lines were inclined to be more distributed in “B” zone in elderly patients. To meet the demands of acetabular fixation in different age groups, cortical thickness changes in young and elderly individuals should be given special attention when the quadrilateral surface plate is designed. Level of evidence Level IV, observational study.

ObjectiveResearch on proximal fractures in the humeral bicipital groove (BG), a region in which bones are not commonly fractured, is considered sparse in the literature. The objective of this research was to present the definite characteristics and distribution of BG fractures.MethodsThis retrospective study included and enrolled 119 proximal humeral fractures in adult patients with complete radiography data to identify the fracture distribution in the BG from January 2021 to August 2021. The bicipital region was divided into three parts, i.e. the upper 1/3, middle 1/3, and lower 1/3 of the BG, and the distribution of fracture lines was transcribed on the male or female template, as appropriate. In addition, the normal contralateral humerus was used to calculate the cortical thickness of the supratubercular groove and different parts of the BG (upper, middle, and lower parts). The Mann–Whitney test or one‐way ANOVA along with LSD tests were used to determine differences in the fracture distribution and cortical thickness between men and women.ResultsFractures of the BG in both men and women were mainly located in the upper 2/3 region of the BG, especially in the middle 1/3 of the BG. There were significant differences in the cortical thickness of the BG in men compared with that in women. The cortical thickness was highest in the supratubercular ridge but not the BG in men and women, respectively.ConclusionThis research concluded that bony BG fractures were always observed in the middle part of the BG and were mainly found in patients with four fractures of the proximal humerus. As a unique fracture pattern, the existence of a bony BG fracture always means that a patient has been injured by a relatively severe mechanism, and more attention should be given to these proximal humeral fractures.

Background Percutaneous screw placement, especially the insertion of LC2 screws, is technically demanding. Although the traditional LC2 bony canal spans the anterior inferior iliac spine (AIIS) to the posterior superior iliac spines (PSIS), a high perforation rate has been reported. Objection The aim of this research was to design a revised bony canal, measure the canal width and length and guide the insertion of LC2 screws for pelvic fractures. Materials and methods The plane tool in the Mimics analysis menu was used to draw a midplane connecting the midpoint between the anterior inferior spine and the PSIS upper flat region with pelvic CT data. The minimum widths of the upper, middle, lower surfaces of the tunnel and perforation rate were measured and compared. The ideal screw length was also measured along the longitudinal axis running through the midpoint of the midplane. Results The minimum widths of the upper, middle and lower surfaces of the revised canal were 3.63 mm, 7.7 mm, and 11.93 mm, respectively, in males and 5.97 mm, 9.93 mm, and 12.45 mm, respectively, in females. Significant differences were observed among the upper, middle and lower surfaces of the revised canal in male patients (P < 0.001). In female subjects, the upper canal surface was significantly different from the middle and lower canal surfaces (P < 0.001). The perforation rate was significantly decreased especially in females pelvic. The channel length passing through the midpoint of the narrowest position of the pelvis was 130.85 ± 8.02 mm in males and 124.30 ± 7.71 mm in females and was significantly different for male and female pelvises (P = 0.004). Conclusion The LC2 screw should be inserted along the intersection line of the AIIS lateral wall and the iliac body. The screw should be inserted under the line between the midpoint of the AIIS and the PSIS upper flat region to ensure accuracy of placement. LC2 screws can be more easily inserted in males than in females, and the rate of cortical perforation can be significantly decreased under the guidance of the newly proposed canal.