Biomechanical Analysis and Optimization of Minimally Invasive Pelvic Internal Fixation / 医用生物力学

Objective By comparing biomechanical properties of two-screw rod and three-screw rod for fixing pelvic fracture, the difference in mechanical effects of different screw rod fixation positions in pelvic minimally invasive surgery was studied.Methods The mechanical models of pelvis fixed by two-screw rod and three-screw rod were established, and biomechanical characteristics of the pelvis during standing on both legs, during single-legged standing on healthy side or affected side, as well as in sitting posture were compared and analyzed by finite element simulation, and the fixation effect of three-screw rod was verified by clinical experiments.Results Both fixation methods could restore mechanical transmission of the pelvis. But for three-screw rod fixation, the stress on both sides of the pelvis was more balanced, and the displacement of the whole body and fracture surface was also lower during single-legged standing.Conclusions The three-screw rod fixation has an excellent effect in stability, which is more beneficial for fracture recovery.

Analysis of surgical strategy of percutaneous endoscopic lumbar discectomy in young and middle-aged double-segment patients with lumbar disc herniation / 北京大学学报(医学版)

OBJECTIVE@#To investigate clinical efficacy and safety of single and double segmental percutaneous lumbar discectomy for young and middle-aged patients with double-segment disc herniation.@*METHODS@#Retrospective analysis was undertaken for 32 young and middle-aged patients with percutaneous endoscopic lumbar discectomy (PELD) in the treatment of double-segment lumbar disc herniation from January 2015 to October 2018 in Peking University First Hospital. In the study, 18 cases were treated with single-segment treatment and 14 cases with double-segment treatment. Visual analogue score (VAS) and oswestry disability index (ODI) assessment were used to compare clinical symptom outcomes before surgery, 3 months after surgery and at the last follow-up. Macnab criteria were used to assess the patients' overall satisfaction after surgery. Imaging parameters included lumbar lordosis, intervertebral height at each segment and endplate angle of lesion segment on the X-ray. And Michigan State University(MSU) rating and Pfirrmann scoring system were used to evaluate the grade of disc herniation and disc degeneration respectively on magnetic resonance imaging (MRI). The perioperative parameters included the surgeon, anesthesia method, operation time, postoperative hospital stay, postoperative bracing time and perioperative complications.@*RESULTS@#The mean follow-up time was (26.78±10.64) months. There was no significant difference in the follow-up time and baseline information between the two groups(P > 0.05). ODI scores 3 months post-operatively and at the last follow-up were lower in the double segment (P < 0.05). The ODI improvement was also more significant in the double-segment group at the last follow-up (P < 0.05). There was no significant difference in radiographic parameters at baseline (P>0.05). MSU scale for the primary segment was significantly lowered after both operations (P < 0.05). MSU scale for secondary segment was significantly lowered in double segment group but not in single segment group. Other imaging parameters were similar between the two groups (P > 0.05). The operation time of the single-segment group was significantly shorter than that of the double-segment group(P < 0.001). No perioperative complications were found in either group, but three patients underwent secondary lumbar surgery during the postoperative follow-up period in the single-segment group.@*CONCLUSION@#For young and middle-aged patients with double-segment disc herniation, this study suggests double-segment PELD may be more advantageous than single-segment PELD in terms of asuring clinical efficacy without increasing perioperative risks.

Reconstruction of coracoclavicular ligament combined with hook plate technique for treatment of distal clavicle fractures involving avulsion of coracoclavicular ligament / 中华骨科杂志

Objective@#To explore the operative strategy of distal clavicle fracture involving coracoclavicular ligament.@*Methods@#Data of 17 cases of distal clavicle fracture involving coracoclavicular ligament in our hospital from January 2013 to December 2018 were analyzed retrospectively. According to whether the coracoclavicular ligament was reconstructed or not, the patients were divided into two groups: non reconstruction group (10 cases), male (7 cases), female (3 cases), 19-60 years old (37.9±11.9). In the reconstruction group, 7 cases were male 5, female 2, 25-62 years old (44.9±13.0). Three dimensional CT was used to judge the ligament injury and X-ray was used to evaluate the fracture reduction and healing after operation. The time of fracture healing was compared between the two groups. The function of shoulder joint was evaluated by visual analog scale (VAS) and Constant score of shoulder joint.@*Results@#The patients in both groups were followed up for (18.7±6.7) months (range, 9-27 months). At the latest follow-up, the time of fracture healing in the reconstruction group was 12.6±0.7 weeks (range, 12-14 weeks); VAS score was 3.0±1.3 and Constant-Murley score was 85±11. While those in the non reconstruction group were 23.7±7.9 (range, 16- 48 weeks), 3.1±1.8 and 77±10 respectively. The time of fracture healing was statistically significant (t=3.361, P=0.004). There was no significant difference in VAS score and Constant score (P> 0.05). In the non reconstruction group, there were 1 case of delayed union of fracture (healed 48 weeks after operation), 1 case of loosening of clavicular hook plate, 5 cases of acromioclavicular joint dislocation (Rockwood type II) after removal of internal fixation, and the overall complication rate was 70% (7/10). Reconstruction group: 1 case of acromial fracture, the overall complication rate was 14.3% (1/7). There was significant difference between the two groups (χ2=5.13, P=0.024).@*Conclusion@#Reconstruction of clavicular insertion of coracoclavicular ligament can effectively reduce the postoperative complications of distal clavicular fracture involving the coracoclavicular insertion. Attention should be paid to the repair and reconstruction of coracoclavicular ligament injury during fracture treatment.

A case report of acute posterior dislocation of shoulder with fracture of greater tubercle of humerus / 中华骨科杂志

A case of acute posterior dislocation of shoulder with fracture of greater tubercle of humerus was reported. The patient came to hospital complaining pain and limited motion of left shoulder caused by traffic accident. The diagnosis of posterior dislocation of the left shoulder and fracture of the greater tubercle was confirmed by medical history, physical examination and imaging. After the failure of manual reduction under anesthesia, MRI was conducted which revealed that the biceps brachii longus and supraspinatus and infraspinatus muscle were embedded between the head of humerus and glenoid scapula. Then open reduction and internal fixation was performed. The biceps brachii longus was cut off and then fixed in the inter nodal groove. After the rotator cuff was relieved from the impaction, the dislocation of the humeral head was successfully reduced and the fracture of the greater tubercle was reduced and fixed. According to the operation process, the possible trauma mechanism is discussed as follows: the displaced fracture of the greater tubercle destroyed the integrity of the lateral wall of the inter tubercular groove, and the biceps brachii longus slipped out of the inter tubercular groove and shifted to the medial side, which was embedded between the humeral head and the scapular glenoid, thus forcing the humeral head to fall posteriorly, and causing the fracture of the greater tubercle to move anteriorly and inferiorly. Attention should be paid to the possible acute dislocation of shoulder joint for the patients with high energy injury. The only way to avoid missed diagnosis is to combine with multi-directional X-ray or CT examination of shoulder. MRI should be used to determine whether there is tendon incarceration of rotator cuff and/or biceps brachii longus in patients with acute posterior dislocation of shoulder. Anatomic reduction of tubercle fracture is the key to recover the range of motion and muscle strength of shoulder joint.

Reconstruction of coracoclavicular ligament combined with hook plate technique for treatment of distal clavicle fractures involving avulsion of coracoclavicular ligament / 中华骨科杂志

Objective To explore the operative strategy of distal clavicle fracture involving coracoclavicular ligament.Methods Data of 17 cases of distal clavicle fracture involving coracoclavicular ligament in our hospital from January 2013 to December 2018 were analyzed retrospectively.According to whether the coracoclavicular ligament was reconstructed or not,the patients were divided into two groups:non reconstruction group (10 cases),male (7 cases),female (3 cases),19-60 years old (37.9± 11.9).In the reconstruction group,7 cases were male 5,female 2,25-62 years old (44.9± 13.0).Three dimensional CT was used to judge the ligament injury and X-ray was used to evaluate the fracture reduction and healing after operation.The time of fracture healing was compared between the two groups.The function of shoulder joint was evaluated by visual analog scale (VAS) and Constant score of shoulder joint.Results The patients in both groups were followed up for (18.7±6.7) months (range,9-27 months).At the latest follow-up,the time of fracture healing in the reconstruction group was 12.6±0.7 weeks (range,12-14 weeks);VAS score was 3.0± 1.3 and Constant-Murley score was 85± 11.While those in the non reconstruction group were 23.7±7.9 (range,16-48 weeks),3.1± 1.8 and 77± 10 respectively.The time of fracture healing was statistically significant (t=3.361,P=0.004).There was no significant difference in VAS score and Constant score (P＞ 0.05).In the non reconstruction group,there were 1 case of delayed union of fracture (healed 48 weeks after operation),1 case of loosening of clavicular hook plate,5 cases of acromioclavicular joint dislocation (Rockwood type Ⅱ) after removal of internal fixation,and the overall complication rate was 70％ (7/10).Reconstruction group:1 case of acromial fracture,the overall complication rate was 14.3％ (1/7).There was significant difference between the two groups (x2=5.13,P=0.024).Conclusion Reconstruction of clavicular insertion of coracoclavicular ligament can effectively reduce the postoperative complications of distal clavicular fracture involving the coracoclavicular insertion.Attention should be paid to the repair and reconstruction of coracoclavicular ligament injury during fracture treatment.

Anti-tumor immune response in vitro induced by fusion of Tca8113 cells with macrophages / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the therapeutic effectiveness of fusion tumor vaccine in tongue cancer treatment.</p><p><b>METHODS</b>Human macrophages fused with human tongue carcinoma cell line Tca8113 cell. The fusion cells were selected by magnetic cell sorting (MACS) and cultured. The biological properties of fusion cells and anti-tumor immune response in vitro induced by fusions were observed.</p><p><b>RESULTS</b>In contrast to Tca8113, the fused cells grew significantly slow in vitro. The expression of MHC I, II antigen of the fusion cells which was detected by flow cytometry (FCM) was higher than that of Tca8113. The fused cells significantly increased the proliferation of mixed lymphocyte and induced their cytotoxicity on parental Tca8113.</p><p><b>CONCLUSIONS</b>The fusion tumor vaccine of macrophages and OSCC cells increase in vitro immunogenicity significantly. This indicates that fusion tumor vaccine could be a new method of anti-tumor immunotherapy, which has important potentials for effective individualized human OSCC vaccine.</p>