Objective To investigate the value of magnetic resonance (MR)diffusion kurtosis imaging (DKI)in diagnostic classi-fication of astrocytic tumors.Methods 31 patients with astrocytic tumors confirmed by operation and pathology were collected,in-cluding low-grade tumors (WHO gradeⅠ and Ⅱ)in 14 and high-grade ones (WHO grade Ⅲ and Ⅳ)in 1 7.Routine MRI and DKI scan were preoperatively conducted using Siemens 3.0T MR scanner.Mean kurtosis (MK),radial kurtosis (RK)and axial kurtosis (AK)values were calculated in the solid portion of the tumors and the contralateral normal white matter.Results The MK,RK and AK values in tumors were lower than those in contralateral normal white matter,and were significantly higher in high-grade tumors than those in low-grade ones (P <0.05).Conclusion The MK,RK and AK values obtained by DKI reflect the histological structure changes of the astrocytic tumors.DKI is helpful for the diagnostic classification of astrocytic tumors,exhibiting more value in optimi-zing the treatment.

Objective To investigate the value of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) based on ISHIM sequence in the grading of astrocytic tumor.Methods We collected excised tumors confirmed by histological diagnosis from 42 patients including high-grade astrocytic tumors (10 WHO grade Ⅲ,18 WHO grade Ⅳ),and 14 low-grade astrocytic tumors (1 WHO grade Ⅰ and 13 WHO grade Ⅱ).All patients underwent conventional MR imaging,ISHIM IVIM-DWI,and contrast-enhanced MR imaging.Parameters of tumor parenchyma region,peripheral edema regions and the contralateral normal brain white matter sites were measured,and the statistical analysis was conducted.Results The D value in tumor parenchyma region was significantly lower,but the D* and f values were higher in high-grade astrocytic tumor when compared with lowgrade one and all had statistical significance;in tumor peripheral edema region,D value was lower in high-grade astrocytic tumor than that in low-grade one,and the difference had statistical significance but there was no significant difference in terms of the D* and f values.There was no significant difference of the D,D* and f values in contralateral normal brain white matter sites in both high-and low-grade astrocytic tumor.Conclusion The D,D* and f values measured by ISHIM IVIM-DWI are helpful to the judgment of tumor grade and it has greatapplication value in the differential diagnosis of high-and low-grade astrocytic tumor.

Objective:To compare the clinical effects of minimally invasive reduction through a bone tunnel combined with Jail screwing and those of posterolateral locking plating in the treatment of simple posterolateral tibial plateau fractures.Methods:A retrospective analysis was conducted of the data of 48 patients who had been operatively treated and completely followed up at Department of Orthopedics, Suqian Hospital of Nanjing Drum Tower Hospital Group for simple posterolateral tibial plateau fractures from October 2016 to October 2020. There were 26 males and 22 females, aged from 35 to 68 years. They were divided into a minimally invasive group (25 cases subjected to minimally invasive reduction through a bone tunnel combined with Jail screwing) and an incision group (23 cases subjected to posterolateral locking plating) according to their surgical methods. The operation time, incision length, intraoperative blood loss, fracture healing time, cumulative fluoroscopy time, hospital stay and posterior inclination angles of the tibial plateau and Hospital for Special Surgery (HSS) knee function scores at 1, 3, 6, 9, and 12 months after operation were compared between the 2 groups. Complications in the 2 groups of patients were recorded.Results:There was no significant difference in the preoperative general data between the 2 groups, showing comparability ( P>0.05). The 48 patients were followed up for 12 to 36 months (average 16.5 months). The minimally invasive group was significantly better than the incision group in operation time [(42.6±9.1) min versus (65.7±11.5) min], incision length [(4.0±0.4) cm versus (15.0±1.5) cm], intraoperative blood loss[(22.6±5.8) mL versus (31.5±8.8) mL], hospital stay [(7.6±1.4) d versus (11.1±2.4) d], and HSS score one month after operation [(84.8±1.9) points versus (72.9±4.1) points], but the cumulative fluoroscopy time in the incision group [(4.1±1.4) s]was significantly less than that in the minimally invasive group [(22.3±4.2) s] ( P<0.05). There were no significant differences in fracture healing time, HSS scores at 3, 6, 9, or 12 months after operation, or posterior inclination angle of the tibial plateau between the 2 groups ( P>0.05). There were no such complications as wound infection, vascular injury, internal fixation failure, nonunion or malunion of fractures in either of the 2 groups. Two cases in the incision group presented with symptoms of common peroneal nerve injury but recovered 3 months after operation. Conclusions:Although both minimally invasive reduction through a bone tunnel combined with Jail screwing and posterolateral locking plating can achieve satisfactory outcomes in the treatment of simple posterolateral tibial plateau fractures, the minimally invasive technique is preferable because it shows the advantages of a smaller incision, less bleeding, shorter operation time, a lower operation risk, quicker postoperative recovery and shorter hospital stay.

Objective:To explore the efficacy of the proximal tibial lateral locking plate with rafting screws combined with Jail screws in the treatment of collapse fracture of the lateral tibial plateau.Methods:A retrospective case series study was performed on clinical data of 36 patients with collapse fracture of the lateral tibial plateau admitted to Suqian Hospital of Nanjing Drum Tower Hospital Group from January 2016 to January 2020, including 19 males and 17 females, aged 34-68 years [(48.6±5.8)years]. Schatzker classification was type II in 28 patients and type III in 8 patients. All patients were treated using the proximal tibial lateral locking plate with raft screws combined with Jail screws. The operation time, intraoperative blood loss and fracture healing were detected. The distance of articular surface collapse of the tibial plateau, posterior inclination angle (PSA) of the tibial plateau, tibial plateau varus angle (TPVA) and Rasmussen anatomical score were compared before operation and at day 2 and 1 year after operation. The Hospital for Special Surgery (HSS) score was used to evaluate knee function at day 2 and 1 year after operation. Complications were also recorded.Results:All patients were followed up for 12-32 months [(19.5±3.1)months]. The operation time was 56-82 minutes [(68.5±9.1)minutes]. The intraoperative blood loss was 40-100 ml [(75.6±10.2)ml]. The fracture was clinically healed by first-stage, with the healing time of 8 to 15 weeks [(12.5±1.3)weeks]. The distance of articular surface collapse of the tibial plateau was improved from (15.5±4.2)mm before operation to (0.7±0.3)mm at day 2 after operation and (1.0±0.2)mm at 1 year after operation (all P<0.01). The PSA was improved from (21.2±2.1)° before operation to (8.9±0.8)° at day 2 after operation and (9.2±0.6)° at 1 year after operation (all P<0.01). The TPA was improved from (100.2±3.7)° before operation to (88.9±1.8)° at day 2 after operation and (87.2±1.6)° at 1 year after operation (all P<0.05). The Rasmussen anatomical score changed from (7.8±1.8)points before operation to (17.1±0.9)points at day 2 after operation and (16.3±0.7)points at 1 year after operation (all P<0.01). There were no significant difference in the distance of articular surface collapse of the tibial plateau, PSA, TPVA and Rasmussen anatomical score at day 2 and 1 year after operation (all P>0.05). The HSS score was (92.8±3.2)points at 1 year after operation, significantly higher than (74.8±3.5) points at day 2 after operation ( P<0.01). Two patients sustained superficial wound infection after operation, which healed after debridement and dressing change. No deep infection occurred. Conclusion:For patients with collapse fracture of the lateral tibial plateau, the proximal tibial lateral locking plate with rafting screws combined with Jail screws can effectively prevent secondary collapse of the articular surface and obtain satisfactory anatomical reduction, good functional recovery and few postoperative complications.