Abstract Objective To investigate the role of CT examination in preventing missed diagnosis of periarticular fractures and assisting in surgical treatment. Methods A retrospective review of the diagnosis and treatment of patients with periarticular fractures admitted to our hospital from 2000 to 2008 was conducted, and the diagnosis of fractures by radiography and by CT examination was compared, and the preoperative operations using CT reconstruction and non-reconstruction were grouped, and the relevant data were statistically analyzed. Results The leakage rate of CT examination was significantly lower than that of radiography; the excellent rate of CT 3D reconstruction surgery was higher than that of the non-reconstruction group. Conclusion CT examination has significant advantages in preventing periarticular fracture leakage and guiding surgery. Periarticular fractures are often caused by violence, and the fractures are mostly comminuted, which are easily missed by conventional radiographs. To avoid adverse consequences of missed diagnosis, we reviewed the diagnosis and treatment of patients with periarticular fractures in our hospital from 2000 to 2008, reviewed the period radiographs and CT images, and analyzed them as follows. Data and methods 1.1. General data There were 326 cases in this group, including 21 males and 11 females, the oldest being 54 years old and the youngest 21 years old. The fracture sites were selected as knee joint, fracture, acetabular fracture, heel fracture, elbow joint and other periarticular fractures. All patients underwent X-ray examination upon admission. At the time of admission, 204 cases were diagnosed by X-ray and 122 cases were diagnosed by CT. Twenty-eight cases were missed on initial admission, accounting for 8.5% of the patients in this group. The most missed site was the knee joint, with 17 cases, accounting for 42% of all missed patients, followed by the hip joint with 6 cases, and then the ankle joint and elbow joint. All patients underwent surgery, and 118 cases underwent CT 3D reconstruction before treatment, while the rest did not. 1.2, Methods The areas around the bone joints that are easy to be missed were selected for the study, involving mainly the knee joint, hip joint, ankle joint, elbow joint, and heel and talon joint. Fractures that were not detected from the time of admission to the end of the initial treatment were defined as missed fractures. A total of 28 eligible cases were divided into two groups of patients who had X-ray and CT examinations at the time of admission, and all patients were confirmed postoperatively for preoperative leakage. Their respective leakage rates and the relationship between them were compared and statistically analyzed. Patients with common periarticular fractures of the knee and hip were selected and divided into two groups according to whether or not they had preoperative 3D reconstruction of CT images, and the impact of 3D reconstruction on surgery was compared. This group mainly observed the degree of conformity between pre-hand plan and actual surgery, complications and so on, and the relevant data were statistically processed. 1.3. Postoperative follow-up All patients were followed up after surgery, and the follow-up period was 12-18 months, with an average of 14 months. The follow-up mainly focused on the intraoperative detection rate and postoperative complications, the degree of repositioning and the degree of firm fixation in patients who did not undergo CT examination before surgery. 1.4. Efficacy assessment and statistical methods The presence or absence of CT examination in addition to X-ray examination and the influence of the examination on the diagnosis of the two groups of cases. Patients undergoing surgery were evaluated on the basis of operative time, bleeding, complications and functional recovery, and the diagnosis and postoperative evaluation were evaluated with or without CT examination. The measured data were analyzed by t-check of group design data, and the count data were examined by X2 check and rank check with a value of 0.05. Results Among the 28 missed cases, 24 cases were diagnosed by X-ray examination, accounting for 85.7% of the missed cases, and 4 cases were missed by CT examination, accounting for 14.3% of the missed cases. There was a significant difference of P < 0.05 between the two, i.e., there was a difference in the diagnosis of periarticular fractures by X-ray and CT. The rate of missed diagnosis was much higher in the former than in the latter; preoperative CT 3D reconstruction was performed in 118 cases, while the rest did not have preoperative CT 3D reconstruction, and the preoperative planning and actual surgery compliance rate was 95% in the former and 83% in the latter. p > 0.05, indicating that there was no significant difference between the two in terms of adjunctive surgical treatment. Therefore, in addition to careful physical examination and high-quality radiographs, a deeper examination should be sought for complex fractures of the osteoarticular region, and CT can basically meet this requirement. I. Reasons for missed diagnosis around the bone and joint The complex structure of the bone and joint area, coupled with the small fracture lines or fracture blocks obscuring each other, makes it easy to miss the diagnosis on radiographs. The most frequently missed fractures are coronal fractures of the femoral condyles (Hoffa fractures), posterior column fractures of the tibial plateau, POLIT fractures of the ankle, acetabular fractures, and heel fractures. Macarini et al. performed radiographs and multilayer CT with 3D reconstruction in 25 patients and showed that the diagnostic agreement between radiographs and CT was only 48%. Another scholar, by analyzing the imaging of the pelvis, concluded that the diagnostic accuracy of radiographs was 66%, which was not sufficient to provide a reliable diagnosis completely. In our group, 28 cases showed a missed diagnosis. Of the 204 cases in which only X-ray was performed at the time of admission, 24 cases showed a missed diagnosis, with a rate of 11.8%, which is generally consistent with the usual statistics. Statistical analysis of this group also showed a significant difference between the two (P < 0.05 II. The role of CT in the diagnosis of periarticular fractures CT imaging cuts the fracture end into different planes and then shows its localization. Therefore, there is no problem of mutual occlusion of fracture fragments. If necessary, CT imaging can also reconstruct the cut plane in three dimensions and then observe the fracture from different angles, which is not only clearly visible but also realistic, and can give the physician a comprehensive understanding of the fracture end and provide a good preoperative plan for the surgical treatment of the fracture. Chen Fangqing, Luo Congfeng et al. used X-ray and CT to diagnose the posterior column fracture of tibial plateau respectively, and confirmed it by surgery, and found that the diagnosis rate of fracture by X-ray and CT were 89. 6% and 100% respectively. For this group, the rate of fracture missed after using CT examination was 3.3%, which was significantly lower than those diagnosed by X-ray examination only. Liu Jun, Shao Ying et al. routinely performed radiographs and CTA examinations in 66 patients with bone and joint injuries and clearly showed the presence of trapped fractures, incomplete fractures, linear fractures, small avulsion fractures and their displacement at different sites by 2D MPR and 3D VR techniques in transverse, coronal, sagittal, or arbitrary oblique views. With the rapid development of computer technology, the emergence of digital multilayer spiral CT and its powerful advantages and post-processing functions have opened up a broad prospect for the diagnosis and treatment of bone and joint injuries. Third, the advantages of CT three-dimensional reconstruction in assisting periarticular fracture surgery CT imaging followed by three-dimensional reconstruction allows the operator to have a more comprehensive understanding of the fracture and provides guidance for surgical treatment. The placement of the plate, the direction of the screws, and the repositioning of the fracture block can be simulated preoperatively after 3D reconstruction of the fracture, laying the foundation for the intraoperative operations. Wicky et al. performed X-ray and spiral CT 3D reconstruction on 42 patients with tibial plateau fractures and developed surgical plans for 22 of them. In China, Yanling Hu, Dan Jin et al. performed virtual surgical design for 8 cases of acetabular fractures, imported acetabular fractures, CT data in dicom format into Mimics software, performed image segmentation, established a 3D model of the fracture, and performed virtual repositioning, constructed a suitable plate, and selected the appropriate length plate according to the plate placement position. As a result, the virtual surgical design of acetabular fracture internal fixation methods were all basically consistent with the actual intraoperative situation. In this group, there were two cases of acetabular fractures with severe fractures, and in order to perform the preoperative design, we performed CT 3D reconstruction, selected the appropriate plate according to the 3D graphics, and performed a virtual repositioning of the preoperative fracture block, and the intraoperative situation was also basically the same as the simulated situation. However, the statistics showed no significant difference between the preoperative 3D reconstruction of the fracture site and the simulated surgical operation and those without the modeled operation (P > 0.05). It may be related to the small sample. The true relationship still needs further study. IV. Inadequate diagnosis and treatment of periarticular fractures by CT Although CT has many advantages over radiographs in the diagnosis of periarticular fractures, because the image presented by CT is a two-dimensional figure, especially plain CT, if the fracture plane happens to be in the plane scanned, it can also be missed, and this study showed that there was still a 3.3% missing rate after CT examination, probably because the slice spacing during CT scanning This may be due to the large slice spacing and small fracture line during CT scan. In our group, there was a patient with lumbar stabbing injury who had neurological symptoms in the lower extremities, but no fracture was found on X-ray and CT examination, and subsequently, transverse fracture lines were found in the small articular processes of the vertebral body on further MRI examination. Therefore, for those who are still highly suspicious of fracture after CT examination, MRI examination is feasible to reduce the occurrence of missed diagnosis. In conclusion, periarticular fractures are often missed because of the specificity of the fracture site and the limitations of radiographs, whereas CT can not only reduce the occurrence of missed diagnoses but also serve as a good guide for preoperative planning of fractures. Therefore, the proper application of CT examination for this type of fracture can improve the confirmation rate and play an important role in improving the quality of surgery. However, while emphasizing the importance of CT in the examination of periarticular fractures, the limitations of CT in solving such problems should be understood, and only in this way can such fractures be more comprehensively diagnosed and treated.