The Accuracy Assessment Of MRI Diagnosing Tibial Plateau Fracture Combined With Meniscus Injury

Objective: To evaluate the diagnostic accuracy of knee MRI in patients with tibial plateau fracture combined with meniscus injury and explore whether a conventional MRI examination in tibial plateau fracture combined with meniscus injury can accurately reflect the meniscus injury situation and provide guidance for the surgery.Methods: A total of 40 cases of patients(40 knees)with tibial plateau fractures were enrolled from our department from October 2014 to February 2016.Among them,there were 23 male patients(23 knees)and 17 female patients(17 knees)with an age range of 23-68 years and a mean age of 48 ± 0.55 years.The causes of the injuries were as follows: 29 cases of traffic injuries(electric bike fall injuries in 23 cases)and fall injuries in 6 cases.According to Schatzker classification,there were 4 cases in type I,6 cases in type II,8 cases in type III,2 cases in IV type,4 cases in V type and 16 cases in type VI.All the patients had no history of knee-joint surgery,no severe knee-joint osteoarthritis,no rheumatoid arthritis or other diseases causing severe knee-joint deformity and damage,no coagulation disorders,no knee-joint infection and no suffering from other systemic diseases and other reasons causing surgery unacceptable situation.Patients all underwent preoperative knee MRI,X ray plain film and CT examination.Because all patients had obvious lateral plateau fracture displacement or collapse and had uninvolved or relatively complete interior articular surface,this paper only discussed the injury condition of tibial plateau fracture combined with meniscus injury.MRI results were read by a physician with a senior professional post at radiology department and MRI report was provided,and lateral meniscus injury and injury form were assessed.All patients were subjected to plateau fracture open reduction internal fixation by the chief physician at our department.Conventional investigation of the lateral meniscus was conducted intraoperatively,injury condition was recorded and the injury condition was compared with MRI diagnosis results preoperatively.Statistical data: SPSS 19.0 statistical software was applied for data processing.MRI diagnostic sensitivity,specificity and accuracy were calculated.Sensitivity = true positive/(true positive + false negative);specificity = true negatives/(true negative + false negative);accuracy =(true positive + true negative)/total.Paired count data chi square test was used to compare the differences between MRI diagnosis and intraoperative investigation results.P values were calculated based on χ2 value and a P < 0.05 was considered statistically significant.Results: Among 40 patients(40 knees),MRI showed 36 cases(90%)of lateral meniscus injury and 4 cases(10%)of no injury.Intraoperative investigation showed 33 cases(82.5%)of lateral meniscus injury and 17 cases(17.5%)of no injury.Among the 33 cases of meniscus injuries,there were 17 cases(51.52%)of meniscus bruise or minor level tear without need of surgical repair.There were 16 cases(48.48%)requiring surgical repair including 8 cases with 1.5-3 cm dissociation from anterior lateral meniscus,3 cases with meniscus impacted among collapsed fracture fragments,4 cases with anterior horn of meniscus longitudinal tear and 1 case of meniscal transection injury.Among the 3 patients with meniscus impacted among collapsed fracture fragments,lateral condyle blocks were opened along the bone fracture line to expose the fracture collapsed area to find dissociated meniscus and the dissociated meniscus was reset and sutured with joint capsule.The remaining meniscal repairs were obtained: the joint capsule was cut open form the lower edge of the meniscus during the surgery,the lateral meniscus was pulled up,the torn part was given repair,and the edge dissociation of the joint capsule was sutured.Injured meniscus was investigated and repaired during the surgery and the surgery time will not be significantly increased.The reset of the dissociated meniscus was conducive to the reset of collapsed fractures.The sensitivity of MRI to the lateral meniscus was 93.75%,the specificity was 75% and the accuracy was 45%.Paired count data chi square test was used to compare the differences between MRI diagnosis and intraoperative investigation results.P < 0.001 was obtained according to χ2 and a P < 0.05 was considered statistically significant.The result suggested that there was a significant difference in the MRI diagnosis and intraoperative investigation results.Conclusion: The sensitivity of MRI to the lateral meniscus was 93.75%,the specificity was 75% and the accuracy was 45%.The diagnostic accuracy of MRI for tibial plateau fracture combined with meniscus injury was relatively low and there was a significant difference in the MRI diagnosis and intraoperative investigation results.The MRI diagnosis cannot decide whether there is a need to conduct surgical repair for meniscus injury.For MRI diagnosis of meniscus injury in patients,intranperative conventional investigation is needed to determine whether there is a need to repair the injury.