Objective To evaluate the risk of chondral injury during anterior cruciate ligament (ACL) reconstruction using a double cross-pin femoral fixation device via the anteromedial portal in Chinese cadavers. Methods Nine specimens of the knee (6 left ones and 3 right ones) were taken from 5 male and 4 female conservative cadavers of Chinese adult. The average age of the cadavers were 34.8 (26 to 45)years old. Femoral tunnel drilling and cross-pin guide insertion were performed using the Rigidfix Cross Pin device through the anteromedial portal. The ACL reconstructions were simulated at 3 entrance points of the cross-pin (0°, 45° and 90° relative to the horizontal plane) . The risks of chondral injury were statistically analyzed when the cross-pin entrance point was at the 3 different positions relative to the femoral chondral surface. Results The incidence of chondral injury was 100% when the Rigidfix cross-pin guide was at 90° relative to the horizontal plane. When the Rigidfix cross-pin guide was at 45° and 0° the incidences of chondral injury were 66. 7% and 22. 2% respectively. Conclusion Since there is always a risk of chondral injury when the Rigidfix cross-pin device is used to reconstruct ACL via the anteromedial portal, the anteromedial portal is not recommended for the ACL reconstruction using Rigidfix femoral fixation.

Objective:To investigate the effects of ligamen remnant preservation on knee joint function and proprioception recovery in patients with anterior cruciate ligament (ACL) injuries during ACL reconstruction under arthroscope.Methods:The clinical data of 266 patients with ACL injuries,who were treated in the 174th hospital of PLA from January 2010 to March 2016,were retrospectively analyzed.All the patients underwent ACL reconstruction under arthroscopy,among them,163 patients with remnant preservation were chosen as remnant preservation group;103 patients with completely clearing remnant preservation in the operation,as non remnant preservation group.All the patients were followed up for more than 12 months,and the knee function and proprioception recovery of the two groups were evaluated.Results:There were no significant differences in the knee ipsilateral Lysholm score,international knee documentation committee knee assessment scale (IKDC) score,passive activity detection threshold,passive angle regeneration test results between the two groups before operation,9 and 12 months after operation (P＞0.05).The Lysholm scores and IKDC scores of the two groups at each time point were significantly higher than those before operation,the passive activity detection threshold and passive angle regeneration test results were significantly lower than those before operation (P＜0.05).The Lysholm scores and IKDC scores in the remnant preservation group 3 and 6 months after operation were higher than those in the non remnant preservation group,the passive activity detection threshold and the passive angle regenerated test results were lower than the non remnant preservation group,the difference was statistically significant (P＜0.05).Conclusion:Remnant preservation in the ACL reconstruction under arthroscopy can accelerate the recovery of knee joint function and proprioception,and satisfactory clinical results are achieved,which is worth popularizing.

Objective: To evaluate the elastic modulus of Beagle's periodontal ligament(PDL) by means of nanoindentation, and to help build constitutive model of PDL precisely. Methods: 24 cross sections were obtained from the tooth root of lower first molars of beagle dog. With nanoindentation, intrusion and unloading to PDL sites on different planes of long axial and in different directions on the same plane of tooth root were achieved, and the load-displacement curves were obtained, from which the elastic modulus was calculated and analyzed. Results: The elastic modulus of the beagle's periodontal ligament varied from 0. 452-1. 542 Mpa. There was no significant difference in elastic modulus of the beagle's lower first premolar PDL in relation to different planes of long axial, while significant difference was found in different directions (buccal/lingual sides and mesial/distal sides) on the same plane of tooth root(P＜ 0. 05). Conclusion: There was a difference in the elastic modulus of periodontal ligament in buccal/lingual sides and mesial/distal sides of the same tooth root.

Objective:To investigate the application value of pelvic floor ultrasound in screening early postpartum stress urinary incontinence (SUI).Methods:A total of 220 postpartum women, who were admitted by the Department of Gynecology and Obstetrics of The People's Hospital of Hechi from January 2018 to June 2019, were selected for this study. These women were divided into SUI ( n = 52) and no SUI ( n = 168) groups according to whether SUI occurred within 42 days after delivery. Pelvic floor ultrasound parameters and clinical data were compared between the two groups. The effects of each ultrasound parameter on postpartum SUI were assessed. The receiver operating characteristic (ROC) curve was plotted for each parameter. The area under the ROC was calculated. The risk factors for postpartum SUI were investigated using the logistic regression analysis. Results:The number of deliveries (≥ 2 times), the proportion of women subjected to vaginal delivery, and neonatal weight in the SUI group were significantly higher than those in the no SUI group [ χ2 = 4.13, 3.30, t = 4.43, all P < 0.05]. There were significant differences in the bladder neck position and levator hiatus area in the resting state between the two groups ( t = 2.29, 3.09, both P < 0.05). There were significant differences in the bladder neck position, levator hiatus area, urethral rotation angle, and bladder neck mobility during the Valsalva movement between the two groups ( t = 13.14, 4.27, 15.64, 8.54, all P < 0.05). The areas under the ROC of bladder neck position and levator hiatus area in the resting state and the areas under the ROC of bladder neck position, levator hiatus area, urethral rotation angle, and bladder neck mobility during the Valsalva movement were 0.707, 0.725, 0.730, 0.771, 0.813, and 0.836, respectively. The area under the ROC of parameters used in combination was 0.849. Logistic regression analysis results revealed that the number of deliveries (≥ 2 times), bladder neck position (> 27.286 mm) and levator ani hiatus area in resting state (> 16.663 cm 2), and bladder neck position (< -2.774 mm), levator hiatus area (> 21.915 cm 2), urethral rotation angle (> 80.445°), and bladder neck mobility (> 30.501°) during the Valsalva movement were the risk factors for postpartum SUI. Conclusion:Combined use of pelvic floor ultrasound parameters is valuable for the diagnosis of postpartum SUI. Abnormal changes in the bladder neck position, levator ani hiatus area, urethral rotation angle, and bladder neck mobility are closely related to the occurrence of postpartum SUI. Therefore, combined use of pelvic floor ultrasound parameters can be preferred to screen early postpartum SUI.

Objective: To identify the pathophysiological characteristics of cortical stroke survivors′ swallowing. Methods: Sixty cortical stroke survivors with dysphagia and cognitive impairment were enrolled into the observation group, while another 16 with dysphagia but without cognitive impairment formed the unimpaired control group and 16 healthy counterparts were selected for a normal control group. Each subject was recorded videofluoroscopically while swallowing 5ml of a liquid of medium consistency. The occurrence of refusing to eat, mouth opening difficulty, incomplete oral closure, residue in the oral cavity, residue in the pharyngeal cavity, leakage and aspiration were observed. Each subject′s swallowing time and kinematic parameters were analyzed from the fluoroscopic videos. Results: The incidence of refusing to eat (37.5%) and/or incomplete mouth closure (68.75%) were significantly higher in the observation group than in the other two groups. The incidence of difficulty in opening the mouth (37.5%), residue in the oral cavity (81.25%), residue in the pharyngeal cavity (56.25%), leakage (56.25%) and aspiration (50%) of the observation group were significantly higher in the observation group than among the normal controls, but were not significantly different from those incidences among the group without cognitive impairment. The average oral transit time and soft palate elevation time of the observation group were significantly longer than those of the other two groups. The observation group′s average hyoid movement time was significantly longer than that of the normal control group, but not significantly different from that of the group without cognitive impairment. There were no significant differences among the groups in average upper esophageal sphincter opening time, larynx closure time or the kinematic parameters. Conclusions Stroke survivors with dysphagia and cognitive impairment present dysphagia characteristic of oral phase swallowing difficulties.