Objective:To explore the advantages of minimally invasive internal fixation assisted by an orthopedic robot in the treatment of tibial plateau fractures of Schatzker types Ⅱ and Ⅲ that can be indirectly reduced.Methods:A retrospective study was conducted of the 18 patients who had been treated for tibial plateau fractures of Schatzker types Ⅱ and Ⅲ at Department of Orthopaedics, The Fourth Hospital of Wuhan from December 2019 to December 2021. They were 12 males and 6 females with an age of (45.2±9.6) years. All fractures were closed. Of them, 6 were complicated with an avulsion fracture at the insertion point of the anterior cruciate ligament, 1 with tear of the medial collateral ligament, and 8 with tear of the lateral meniscus. All patients were treated with minimally invasive internal fixation using the "fence" screw technique after indirect reduction assisted by an orthopedic surgical robot. Those combined with avulsion fracture of the anterior cruciate ligament and meniscus tear underwent one-stage arthroscopic surgery, while those combined with tear of the medial collateral ligament underwent one-stage open repair. The fracture reduction was evaluated according to the Rasmussen radiological scoring system, and the knee joint function evaluated using the American Hospital for Special Surgery (HSS) scoring system.Results:All the 18 patients were fully followed up for (10.6±1.9) months. The X-ray films immediately after surgery showed good fracture reduction. The fractures healed after (11.3±1.2) weeks. At 6 months after surgery, the Rasmussen knee score was (16.8±1.0) points, giving 5 excellent and 13 good cases; the HSS score was (93.2±3.0) points, giving 17 excellent and 1 good cases. By the last follow-up, no serious complications occurred, such as common peroneal nerve injury, popliteal vascular injury, postoperative infection, or internal fixation failure.Conclusion:Since minimally invasive internal fixation assisted by an orthopedic robot can lead to fine clinical efficacy for tibial plateau fractures of Schatzker types Ⅱ and Ⅲ, this technique can be widely applied in clinical practice.

Objective:To compare the clinical efficacy between coracoclavicular ligament anatomical reconstruction and clavicular hook plate in the treatment of Neer Ⅱb distal clavicular fractures.Methods:A total of 64 patients with Neer Ⅱb clavicular fracture were treated at Department of Orthopaedics, The First Affiliated Hospital to Nanjing Medical University from September 2016 to June 2019. They were 35 males and 29 females, aged from 19 to 68 years (average, 50.7 years). They were assigned into 2 groups according to their operative methods: a reconstruction group of 30 cases undergoing coracoclavicular ligament anatomical reconstruction and a hook plate group of 34 cases undergoing fixation with a clavicular hook plate. The 2 groups were compared in terms of hospital stay, operation time, intraoperative blood loss, surgical incision length, postoperative coracoclavicular separation ratio, visual analogue scale (VAS) and Constant-Murley shoulder scores at 3, 6 and 12 months after operation, and postoperative complications.Results:There was no significant difference in general data between the 2 groups, showing comparability between groups ( P>0.05). Operations were completed uneventfully and surgical incisions healed by primary intention in both groups after operation. All the patients were followed up for 12 to 24 months (average, 14.6 months). The operation time [(74.6±22.0) min] and incision length [(10.4±0.4) cm] were significantly shorter but the intraoperative blood loss [(90.2±5.3) mL] was significantly less in the hook plate group than those in the reconstruction group [(95.6±20.8) min, (12.4±0.9) cm and (74.2±3.5) mL] ( P<0.05). There was no significant difference in hospital stay between the 2 groups ( P>0.05). At 3, 6 and 12 months after operation, the VAS scores (1.8±0.5, 1.2±0.3 and 1.1±0.2) and Constant-Murley scores (85.2±4.6, 91.1±2.6 and 92.1±2.2) in the reconstruction group were significantly better than those in the hook plate group (3.2±1.0, 1.6±0.3 and 1.5±0.3; 73.6±2.9, 85.9±4.6 and 87.0±3.1) ( P<0.05). At the last follow-up, the postoperative coracoclavicular separation ratio (elevation) in the hook plate group (0.20±0.16) was significantly greater than that in the reconstruction group (0.10±0.05) ( P<0.05). Conclusion:In the treatment of Neer ⅡB distal clavicular fractures, coracoclavicular ligament anatomical reconstruction may lead to better fixation and fewer postoperative complications than a clavicular hook plate, demonstrating fine clinical efficacy.

Objective:To compare the clinical efficacy of anatomical reconstruction of coracoclavicular ligament at the original insertion point and clavicular hook plate fixation in the treatment of acromioclavicular joint dislocation.Methods:Retrospective analysis was made on the data of 67 patients with acromioclavicular joint dislocation who received surgical treatment in the Department of Orthopaedics of the First Affiliated Hospital of Nanjing Medical University from June 2015 to January 2021. According to the surgical method, they were divided into reconstruction group (using the technique of anatomical reconstruction of coracoclavicular ligament at the original insertion point) and hook plate group (using the clavicular hook plate). There were 37 cases in the reconstruction group, including 26 males and 11 females, aged 47.2±9.6 years (range, 18-65 years), 13 cases on the left and 24 cases on the right. Among the 37 patients, 8 were sports injuries, 14 were falls, 11 were traffic accidents, and 4 were external force injuries. The average time from injury to surgery was 8.3±2.3 days. There were 30 cases in the hook plate group, including 24 males and 6 females, aged 47.4±9.7 years (range, 18-67 years), 12 cases on the left and 18 cases on the right. Among the 30 patients, 7 were sports injuries, 11 were falls, 9 were traffic accidents, and 3 were external force injuries. The average time from injury to surgery was 7.9±2.6 days. The surgical time, incision length, intraoperative bleeding, hospital stay, postoperative coracoclavicular separation ratio, and postoperative complications were compared between the two groups. Constant-Murley score and visual analog scale (VAS) were used to assess the shoulder joint function and pain degree of patients.Results:Both groups of patients were followed up, with a follow-up time of 12.3±0.4 months for the reconstruction group and 12.2±0.5 months for the hook plate group. The operation time (105.8±10.0 min), incision length [12.0 (11.0, 13.0) cm] and hospitalization time (6.8±2.1 d) in the reconstruction group were longer than those in the hook plate group [48.3±4.9 min, 10.0 (10.0, 11.0) cm, and 5.5±2.7 d], while the intraoperative blood loss (75.1±3.9 ml) was less than that in the hook plate group (90.3±6.3 ml), the differences were statistically significant ( P<0.05). The VAS [4.0 (3.0, 5.0), 3.0 (3.0, 3.0), 2.0 (1.0, 2.0) points] and Constant-Murley score (65.4±4.5, 84.9±2.5, 90.1±2.5 points) of the reconstruction group at 3 days, 3 months, and 12 months after surgery were better than those of the hook plate group [5.0 (4.0, 5.0), 4.0 (4.0, 4.0), 3.0 (3.0, 4.0) and 56.9±3.5, 79.6±4.0, 86.8±2.4 points], the difference was statistically significant ( P<0.05). At the last follow-up, there was a statistically significant difference in the separation ratio of coracoclavicular distance between the reconstruction group (0.12±0.08) and the hook plate group 0.22±0.15 ( t=3.25, P=0.002). There was no significant difference ( Z=-0.52, P=0.605) in the separation ratio of acromioclavicular distance [0.16 (0.05, 0.25) and 0.16 (0.04, 0.40)]. In the hook plate group, 6 cases had shoulder joint foreign body sensation and 2 cases had acromioclavicular joint redislocation (both Rockwood type III). Because the shoulder joint function did not affect their daily life, neither patient underwent secondary surgery. And no case of acromioclavicular joint redislocation occurred in the reconstruction group. Conclusion:Compared with the clavicular hook plate fixation, anatomic reconstruction of coracoclavicular ligament at the original insertion point in the treatment of acromioclavicular joint dislocation can reduce the pain of the shoulder joint earlier, which has the characteristics of small trauma, good effect, and reduces the steps of internal fixation removal, and has good clinical curative effect.

Objective:To establish a new classification system for distal clavicle fracture and evaluate its clinical effectiveness.Methods:A retrospective case series study was conducted to analyze the clinical data of 101 patients with distal clavicle fracture admitted to First Affiliated Hospital of Nanjing Medical University from January 2015 to March 2022, including 57 males and 44 females, aged 19-86 years [(53.8±14.0)years]. Before treatment, patients were routinely subjected to bilateral anteroposterior radiography of the shoulder joints to measure the length of the fractured fragments, coracoclavicular distance, and acromioclavicular distance. According to the correlation between the location of the fracture line and the insertion of the coracoclavicular ligament, distal clavicle fracture was divided into three types: type I, with the fracture line lateral to the coracoclavicular ligament region; type II, with the fracture line in the coracoclavicular ligament region; type III, with the fracture line medial to the coracoclavicular ligament region. According to the injury severity of the coracoclavicular ligament and acromioclavicular ligament, type I was further subdivided into type IA, IB, IC and ID, and type II fracture was further subdivided into type IIA, IIB, IIC, IID and IIE. All the 101 patients were classified and randomly reclassified at an interval of 3 months by 10 senior and 10 junior shoulder surgeons according to the new classification method. Kappa coefficients were used to evaluate the inter- and intra-observer consistency of the new classification. Fifty-two patients with stable fracture (types IA, IB, IIC, and IID) were treated non-surgically, while 49 patients with unstable fracture (types IC, ID, IIA, IIB, IIE, and III) were treated surgically, including 26 patients with anatomic coracoclavicular ligament reconstruction, 9 with locking plate fixation, 8 with clavicle hook plate fixation, 4 with anatomic coracoclavicular ligament reconstruction combined with locking plate fixation, and 2 with anatomic coracoclavicular ligament reconstruction combined with tension screw fixation. The patients were assessed using the visual analogue scale (VAS) and Constant-Murley shoulder score before treatment and at 3, 6, 12, and 18 months after treatment. The coracoclavicular distance and acromioclavicular distance on the anteroposterior radiographs of the healthy and affected shoulder joints were measured at 3, 6, 12, and 18 months after treatment, and fracture healing time and complications were observed.Results:The length of the fractured fragments was 12.9 (9.7, 17.6)mm in patients with type I fracture, 24.7 (21.8, 27.8)mm in patients with type II fracture, and 43.6 (41.2, 46.9)mm in patients with type III fracture ( P<0.01). There were no significant differences in the coracoclavicular distance and acromioclavicular distance of the affected and healthy shoulders among the patients with types IA, IB, IIC, IID, and III fracture ( P>0.05); For the patients with types IC, IIA, IIB and IIE fracture, the coracoclavicular distance of the affected shoulder was significantly increased compared with that of the healthy shoulder ( P<0.01), while there was no significant difference in the acromioclavicular distance of the affected and healthy shoulders ( P>0.05). Both of the inter- and intra-observer consistency of the new classification was good. The inter- and intra-observer Kappa values were 0.69 and 0.71 respectively among the senior shoulder surgeons, and 0.61 and 0.64 respectively among the junior shoulder surgeons. All the patients were followed up for 18-104 months [28(23, 32)months]. At 3, 6, 12 and 18 months after treatment, the VAS scores of non-surgical patients were 3(2, 3)points, 2(1, 2)points, 1(0, 1)points and 0(0, 1)points respectively, significantly decreased compared with 6(5, 6)points before treatment ( P<0.01); the VAS scores of surgical patients were 3(2, 3)points, 2(1, 2)points, 1(1, 1)points and 0(0, 1)points respectively, significantly decreased compared with 6(5, 7)points before treatment ( P<0.01); the Constant-Murley shoulder scores of non-surgical patients were (76.6±5.3)points, (84.3±5.0)points, (88.4±4.0)points and (91.9±3.8)points respectively, significantly higher than (42.7±5.2)points before treatment ( P<0.01); the Constant-Murley shoulder scores of surgical patients were (77.4±4.6)points, (84.4±4.7)points, (87.6±3.7)points and (91.7±4.0)points respectively, significantly higher than (42.8±5.3)points before treatment ( P<0.01). At 3, 6, 12 and 18 months after treatment, the coracoclavicular distance of the affected shoulder in non-surgical patients was not significantly different from that before treatment ( P>0.05), while the acromioclavicular distance of the affected shoulder in surgical patients was significantly reduced compared with that before treatment ( P<0.01). There were no significant differences in the coracoclavicular distance of the healthy shoulder or bilateral acromioclavicular distance in non-surgical and surgical patients at 3, 6, 12, and 18 months after treatment compared with those before treatment ( P>0.05). Fractures were healed within 12 months after treatment in all the patients, without dislocation or subluxation of the acromioclavicular joint, internal fixation failure or internal fixator breakage. Eight patients treated with clavicular hook plate fixation had shoulder pain associated with limited mobility after operation, and all underwent a second operation to remove the clavicular hook plate at 12 months after operation. Conclusions:The new classification system for distal clavicle fracture is established, which comprehensively considers the position of the fracture line, injury of the coracoclavicular and acromioclavicular ligaments, and fracture stability. The new classification system exhibits good inter- and intra- observer consistency, and the effectiveness of its preliminary clinical application is satisfactory.

Isogenic cells growing in identical environments show cell-to-cell variations because of the stochasticity in gene expression. High levels of variation or noise can disrupt robust gene expression and result in tremendous consequences for cell behaviors. In this work, we showed evidence from single-cell RNA sequencing data analysis that microRNAs (miRNAs) can reduce gene expression noise at the mRNA level in mouse cells. We identified that the miRNA expression level, number of targets, target pool abundance, and miRNA-target interaction strength are the key features contributing to noise repression. miRNAs tend to work together in cooperative subnetworks to repress target noise synergistically in a cell type-specific manner. By building a physical model of post-transcriptional regulation and observing in synthetic gene circuits, we demonstrated that accelerated degradation with elevated transcriptional activation of the miRNA target provides resistance to extrinsic fluctuations. Together, through the integrated analysis of single-cell RNA and miRNA expression profiles, we demonstrated that miRNAs are important post-transcriptional regulators for reducing gene expression noise and conferring robustness to biological processes.