A Novel Missense Variant in the CHST3 Underlies Spondyloepiphyseal Dysplasia with Congenital Joint Dislocations.

Background: Spondyloepiphyseal dysplasia (SED) is characterized by skeletal dysplasia and multiple joint dislocations. SEDs encompass various types, such as SED congenita, SED tarda (SED-T), SED with congenital joint dislocations (SED-CJD), SED stanescu, and SED-T with progressive arthropathy. Methods and Results: In the present study, we clinically and genetically characterized a consanguineous Pakistani family with SED-CJD. The affected member showed large joint dislocation, spinal deformities, and previously unreported facial features. Exome sequencing followed by Sanger sequencing revealed a missense variant, [c.601T>A; p.(Tyr201Asn)], in the CHST3. Conclusion: This study has not only expended the mutation spectrum in the gene CHST3 but also will facilitate diagnosis and genetic counseling of related features in the Pakistani population.

5 months old neglected anterior shoulder dislocation treated with open reduction and laterjet procedure: A case report.

INTRODUCTION: Shoulder dislocation is very common. However, neglected or chronic shoulder dislocations are extremely rare. The position of the humeral head determines the classification of shoulder dislocation. Anterior shoulder dislocation accounts for most cases, while inferior dislocation is rare. Negligence from the patient and misdiagnosis are the leading causes of chronic shoulder dislocation. Treatment of the condition poses a significant challenge for surgeons since there is no widely accepted treatment protocol. CASE PRESENTATION: A 56-year-old woman presented with a neglected anterior subglenoid dislocation of the shoulder joint. The dislocation occurred due to a cow kick, and initial treatment from a traditional healer and an unqualified health practitioner failed. Clinical examination and X-ray confirmed the dislocation without associated fractures. An initial attempt at closed reduction under sedation was unsuccessful. Subsequently, open reduction and a Latarjet procedure were performed successfully, resulting in a satisfactory outcome. DISCUSSION: Chronic anterior dislocation primarily affects the elderly population. Open reduction and fixation procedures have shown satisfactory outcomes. The choice of treatment depends on several factors, including bone deficiencies, soft tissue damage, and the presence of Hill-Sachs or Bankart lesions. Open reduction and laterjet procedure is a validated treatment. However, early physical therapy contributes to favorable outcomes. CONCLUSION: The condition's rarity makes it difficult to establish a well-accepted treatment protocol. Early and strict rehabilitation protocols will lead to a favorable outcome.

Natural and Artificial Aging Effects on the Deformation Behaviors of Al-Mg-Zn Alloy Sheets.

This study investigated the effects of aging profiles on the precipitate formation and the corresponding strengthening and deformation behaviors of Al-Mg-Zn alloys. The alloys subjected to natural aging (NA) demonstrated significantly enhanced ductility at equivalent stress levels compared to those subjected to artificial aging (AA). In AA-treated alloys, η' and η-phases with incoherent interfaces were formed, while GP zones and solute clusters were dominantly exhibited in the NA-treated alloy with a coherent interface with the matrix. Due to the change in interface bonding, the dislocation movement and pinning behavior after deformation are varied depending on the aging conditions of Al-Mg-Zn alloy sheet. Thus, the elongation to fracture of the NA alloy sheet was improved compared to that of the AA alloy sheet because of the enhanced work-hardening capacity and the thin precipitate-free zone (PFZ). Deformation textures and dislocation densities varied between NA and AA treatments, as revealed by electron backscatter diffraction (EBSD) and kernel average misorientation (KAM) analysis. The interactions between the precipitates, dislocations, and the PFZ in the AA- and NA-treated alloys were analyzed via transmission electron microscopy (TEM). The insights gained from this research provide a valuable foundation for industrial applications, particularly in sectors demanding lightweight, high-strength materials, where optimizing the aging process can lead to significant performance improvement and cost savings.

The Loop Technique in Cardiac Resynchronization Therapy: A Prospective Cohort Study.

Objective: A new approach called the loop technique has been proven safe and effective for repeated intraoperative transvenous left ventricular (LV) lead dislocations during cardiac resynchronization therapy (CRT) in a 3-year follow-up. This study aimed to report on the 5-year safety and effectiveness of the loop technique. Methods: This study was a prospective cohort study. Forty-four patients who underwent CRT device implantation at the Cardiology Department of Shaanxi Provincial People's Hospital between January 2013 and June 2019 were included. Data on patient demographics, medical history, laboratory test results, and echocardiography images at admission were collected. The loop technique was performed with repeated intraoperative dislocations of the LV lead. The intraoperative CRT parameters were also recorded. All patients were followed for 5 years. Several auxiliary examinations were performed during follow-up. Results: The 44 patients were divided into the traditional operation group (n=36, 81.8%) and loop technique group (n=8, 18.2%). The baseline patient characteristics were almost balanced. During the 5-year follow-up, 8 (22.2%) patients in the traditional operation group and 2 (25.0%) patients in the loop technique group died. No lead dislocation or other complications related to CRT were observed. There were no significant differences in mortality rate (P=0.87), cardiac function (P=0.56), echocardiographic indices, threshold (P=0.58), or impedance (P=0.22) of the LV lead. There were no significant differences in the threshold and impedance between postoperative, 3-year, and 5-year follow-ups in the loop technique group (P=0.53). Conclusion: The loop technique is an ideal solution for repeated intraoperative LV lead dislocation during CRT implantation.

Sex and Age-Specific Analysis of Basketball-Related Shoulder Dislocations in the United States: A National Injury Data Review.

HYPOTHESIS/PURPOSE: Basketball-related shoulder dislocations frequently present to emergency departments (EDs) in the US. This study aimed to identify the primary mechanisms, distributions, and trends of these injuries. METHODS: All data was extracted from the National Electronic Injury Surveillance System (NEISS), a public database representing approximately 100 US EDs. NEISS was queried for all basketball-related injuries and shoulder dislocations from January 1, 2013 to December 31, 2022. Clinical narratives were used to assign injury mechanisms and the presence of player contact. RESULTS: Between 2013 and 2022, 52,417 basketball-related shoulder dislocations were reported. 30.9% of all basketball-related shoulder injuries were dislocations, and 30.5% of all joint dislocations occurred at the shoulder. Basketball-related shoulder dislocations decreased significantly from 2013-2022 (p<.001). From 2019 to 2020, a 31.0% decrease was identified. The most common mechanism of shoulder dislocation was falling (36.9%). Males accounted for 92.5% of all shoulder dislocations. However, females were significantly more likely than males to dislocate their shoulders from player contact (15.5% of female dislocations v. 10.0% of male dislocations, p<.001). Only 0.2% of all dislocations resulted in hospitalization. 10.4% of dislocations resulted from contact with another player. Compared to other age groups, young adults (43.3%) and adolescents (42.7%) presented with the majority of shoulder dislocations. Children were more likely to dislocate their shoulder from sustaining a direct blow (25.5%), while all other age groups were more likely to have fallen. Children were also the most likely to sustain a dislocation involving player contact (23.9%). CONCLUSION: Basketball-related shoulder dislocations decreased significantly from 2013 to 2022. Females and children were significantly more likely to present with a dislocation by sustaining player contact. Across all demographics, teaching athletes how to break their falls safely may decrease rates of dislocation by minimizing impacts on a posteriorly outstretched arm.

Functional and subjective outcomes after surgical management of complex elbow dislocations: a retrospective study.

INTRODUCTION: Dislocations of the elbow are the second most frequent upper-body injury after shoulder dislocations, comprising 11-28% of all elbow injuries. Complex elbow dislocations pose challenging management due to the involvement of critical stabilizing structures. This study aimed to investigate functional and subjective outcomes (MEPS, DASH, Oxford score) in 44 patients with complex elbow dislocations who underwent surgery between 2018 and 2020, with subgroup analysis focusing on gender and age differences. MATERIAL AND METHODS: A retrospective analysis was conducted on patients treated at C.T.O. Hospital, Turin, for complex elbow dislocations between January 2018 and December 2020. Surgical approaches included radial head synthesis, coronoid fixation, ligamentous repair, and ulnar nerve management. Postoperatively, patients followed a standardized or individualized program. Data analysis involved t-tests to assess score differences between subgroups. RESULTS: Among the 44 analyzed patients, the mean age was 48 years, and the mean follow-up time was 29 months. Various types of complex dislocations were identified, with radial head and coronoid fractures classified accordingly. Surgical approaches included multiple methods of reduction and synthesis. While most patients adhered to postoperative programs, subsequent reoperations were conducted in 11% of cases. Scores did not significantly differ between genders, although a trend toward better DASH scores in males was observed. Younger patients showed better, though not statistically significant, outcomes in mobility and functional measures. CONCLUSION: This study underscores the importance of pre-operative assessment for positive surgical outcomes in complex elbow dislocations. Additionally, findings suggest that younger age may correlate with slightly better functional outcomes. Despite limitations such as retrospective design and sample size, the study enhances our understanding of complex dislocation outcomes and provides valuable insights for future interventions.

Isolated cuboid dislocation: case report.

Isolated cuboid dislocation without fracture is a rare injury, and there is a lack of literature describing its treatment. Studies report the use of closed or open reduction, with Kirschner wire fixation in the treatment of these injuries. This case report presents the clinical condition of a 24-year-old male patient who arrived at the emergency department with an isolated dislocation of the right foot cuboid bone without the presence of a fracture, after suffering trauma during a football game. Open reduction was performed in the surgical center with stabilization and fixation using a Kirschner wires. The patient showed an excellent response to the treatment, with no loss of the foot's range of motion.

A Locked Posterior Shoulder Dislocation: An Injury Not to Miss.

Locked posterior shoulder dislocations are dislocations that remain unreduced for more than three weeks. In most cases, they are associated with other injuries. We report the case of a 38-year-old male who presented with pain and total functional impotence due to a complex injury, including posterior glenohumeral dislocation, a reverse Hill-Sachs lesion, and a clavicle fracture. Because of the unsuccessful attempts at closed reduction, the patient underwent surgery. We performed the McLaughlin technique, which included the transfer of the subscapularis tendon to the reverse Hill-Sachs lesion, stabilized by bone anchors. At the last follow-up, the patient was doing well and had regained full range of motion with no recurrent dislocation. Clinicians should maintain clinical and radiological suspicion about this injury to timely manage this rare and dangerous injury.

Management of Pediatric Elbow Fractures and Dislocations.

Pediatric elbow fractures and dislocations have always been a challenge from a diagnostic and therapeutic point of view, primarily due to the complex nature of the pediatric elbow, especially its developmental anatomy. They must be diagnosed and treated on time to prevent numerous complications with long-term consequences. With the development of radiology and pediatric surgery and orthopedics, as well as the development of modern osteosynthesis materials, concerning current scientific and professional knowledge, the outcomes are getting better, with fewer acute and chronic complications. This comprehensive review aims to provide clinicians current knowledge about pediatric elbow fractures and dislocations so that in daily practice they have as few doubts as possible with the best possible treatment outcomes.

Characterization of extended defects in 2D materials using aperture-based dark-field STEM in SEM.

Quantitative diffraction contrast analysis with defined diffraction vectors is a well-established method in TEM for studying defects in crystalline materials. A comparable transmission technique is however not available in the more widely used SEM platforms. In this work, we transfer the aperture-based dark-field imaging method from the TEM to the SEM, thus enabling quantitative diffraction contrast studies at lower voltages in SEM. This is achieved in STEM mode by inserting a custom-made aperture between the sample and the STEM detector and centering the hole on a desired reflection. To select individual reflections for dark-field imaging, we use our Low Energy Nanodiffraction (LEND) setup [Schweizer et al., Ultramicroscopy 213, 112956 (2020)], which captures transmission diffraction patterns from a fluorescent screen positioned below the sample. The aperture-based dark-field STEM method is particularly useful for studying extended defects in 2D materials, where (i) stronger diffraction at the lower voltages used in SEM is advantageous, but (ii) two-beam conditions cannot be established, making quantitative diffraction contrast analysis with standard bright-field and annular dark-field detectors impossible. We demonstrate the method by studying basal plane dislocations in bilayer graphene, which have attracted considerable research interest due to their exceptional structural and electronic properties. Direct comparison of results obtained on identical dislocations by the established TEM method and by the new aperture-based dark-field STEM method in SEM shows that a reliable Burgers vector analysis is possible by applying the well-known g·b=0 invisibility criterion. We further use the LEND setup to acquire 4D-STEM data and show that the virtual dark-field images match well with those in aperture-based dark-field STEM images for reliable Burgers vector analysis.

A Novel Uni- and Biplanar External Fixator for Initial and Definitive Complex Foot Trauma.

Background: Evidence concerning the complex foot trauma, especially its definitive management, is scarce. Soft tissue envelope sequalae are the primary parameters that delay or make internal fixation implausible. Stability conferred by external fixators makes them a reasonable initial treatment choice. Although AO or circular fixators can be applied around the foot, this can involve a learning curve and substantial costs, especially for the circular fixator. There is little evidence as to how well external fixators work as a definite method of fixation in patients where progression to internal fixation cannot be made. Methods: We prospectively evaluated 10 adult patients with severe and complex foot trauma who were consecutively treated at our clinic. Initial reduction and stabilization were performed with an external fixator that was initially conceived for distal radius fractures, applied during the initial procedure and mantained throughout the treatment. Results: Fracture healing was obtained in all 10 cases, and both internal and external column length was restored. One of the patients developed chronic osteomyelitis. At the 1-year follow-up visit, these patients averaged 45.6 points in the physical and 44.8 points on the mental status sections of the 12-Item Short Form Health Survey (SF-12). The Foot Function Index findings for pain, disability, and daily activities limitations were 33.3, 39, and 41.5, respectively, which suggest moderate residual impairment. Conclusion: In this relatively small case series of complex foot trauma, we found that the use of simple external fixation as definitive treatment worked reasonably well. Level of Evidence: Level III, prospective cohort study.

Evaluation of chronic perilunate dislocations: A comparative study of single-stage, two-stage ORIF, and salvage procedures.

OBJECTIVE: This study aims to evaluate the outcomes of open reduction and internal fixation (ORIF) for chronic perilunate dislocations using single-stage, two-stage, and salvage procedures. The study also compares these approaches with each other and with results from existing literature. METHODS: A total of 15 patients with chronic perilunate injuries from 2013 to 2019 were included in the study. Pre-operative and post-operative assessments were conducted using plain radiographs, with CT scans performed selectively for detailed morphology and fracture pattern analysis. Among the patients, 13 underwent ORIF, while 2 underwent salvage procedures. Among the ORIF cases, single-stage procedures were performed in 4 patients, and two-stage procedures in 9 patients. External fixators, including unilateral uniplanar external fixators (UUEF) and bilateral uniplanar external fixators (BUEF), were applied in 5 and 4 patients, respectively. Our methodology of treating chronic perilunate injuries has evolved over the years. We started with single stage ORIF then graduated to a two staged procedure initially using a external fixator as a carpal distractor applied only on the radial side and finally settling down with bilateral carpal distraction using external fixators both on the radial and ulnar sides. RESULTS: Among the 15 patients, 3 were lost to follow-up. Of these, one underwent four-corner fusion, while the remaining two had UUEF. The mean time interval between injury and surgery was 3.60 months. The post-operative mean scapholunate angle measured 52.46°, with a negative radio-lunate angle (indicating flexion) observed in two patients, while others showed a positive angle (indicating extension). Two cases exhibited nonunion and avascular necrosis (AVN) of the scaphoid, while one case presented with lunate AVN. Mid-carpal and radio-carpal arthritis was observed in 4 and 2 patients, respectively. Functional outcomes were evaluated using Mayo's wrist score categorized as good for two-stage BUEF cases and satisfactory for UUEF and single-stage procedures. CONCLUSION: Staged reduction utilizing the BUEF followed by open reduction has demonstrated superior outcomes when compared to UUEF, single-stage open reduction and salvage procedures. LEVEL OF EVIDENCE: 4.

Vascular Injuries in Multiligament Knee Injuries (MLKIs).

Purpose: Vascular injuries are rarely associated with severe knee injuries; nonetheless, it is imperative to efficiently detect this condition and plan for either immediate or definitive treatment at later stages. The diagnosis and management of multiligament knee injuries still present unresolved issues, particularly in the early detection of vascular issues and the sequential stabilisation of ligaments. High-energy trauma is a frequently encountered cause, however, even low-energy trauma in those who are morbidly obese might pose a significant risk. Advancements in detection and management methods have greatly decreased the occurrence of vascular complications and amputation rates over time. MLKIs after transient knee dislocations are frequently misdiagnosed for vascular injuries, underscoring the necessity for improved diagnostic techniques to avoid avoidable amputations. Methods: This article is a new conceptual review of vascular injuries associated with MLKIs. It provides a full overview of these conditions and includes a review of the most recent literature. We have included pertinent citations from the literature, together with suggestions derived from the latest studies. This review article had additional evaluation by proficient specialists with commendable outcomes and more than a decade of expertise in surgical techniques. Results: This article offers a detailed overview of orthopaedic management, including new definitions and summaries of the causes, evaluation of patients, clinical assessment, identification of vascular injuries, and initial management in patients with vascular impairment following major limb and joint injuries (MLKIs). Conclusion: MLKIs (patients with lower limb ischaemia) who have vascular damage necessitate meticulous physical assessment and sophisticated treatments in order to decrease amputation rates. Prompt identification and timely treatment of vascular lesions, namely in the popliteal artery, can substantially reduce the occurrence of amputations. Emerging research suggests that there is a heightened risk in low-energy situations, particularly amongst individuals who are extremely obese. Progress in vascular intervention has led to a reduction in amputation rates, whilst the implementation of new guidelines has enhanced identification. Thorough patient assessment is essential, utilising physical examinations and imaging techniques such as Computed tomography angiography, magnetic resonance angiography (CTA or MRA) to guide treatment decisions. MRA, in particular, is capable of identifying both vascular and knee structural damage. Level of Evidence: Level IV, Literature reviews.

Haematoma block is the most efficient technique for closed forearm fracture reduction: a retrospective cohort study.

BACKGROUND: Forearm fractures are a common ED presentation. This study aimed to compare the resource utilisation of three anaesthetic techniques used for closed forearm fracture reduction in the ED: haematoma block (HB), Bier's block (BB) and procedural sedation (PS). METHODS: A retrospective multicentre cohort study was conducted of adult patients presenting to either Port Macquarie Base Hospital ED or Kempsey District Hospital ED in New South Wales, Australia, from January 2018 to June 2021. Patients requiring a closed reduction in the ED were included. ED length of stay (LOS) was compared using a likelihood ratio test. Successful reduction on the first attempt and the number of ED specialists present for each method were both modelled with a linear regression. Staff utilisation by the level of training, cost of consumables and complications for each group were presented as descriptive statistics. RESULTS: A total of 226 forearm fractures were included. 84 used HB, 35 BB and 107 PS. The mean ED LOS was lowest for HB (187.7 min) compared with BB (227.2 min) and PS (239.3 min) (p=0.023). The number of ED specialists required for PS was higher when compared with HB and BB (p=0.001). The cost of consumables and a total number of staff were considerably lower for HB compared with PS and BB methods. PS had the highest proportion of successful reductions on the first attempt (94.4%) compared with BB (88.6%) and HB (76.2%) (p=0.006). More patients experienced complications from PS (17.8%) compared with BB (14.3%) and HB (13.1%). CONCLUSIONS: In this study, the HB method was the most efficient as it was associated with a shorter ED LOS, lower cost and staff resource utilisation. Although PS had a significantly greater proportion of successful reductions on the first attempt, HB had fewer complications than BB and PS. EDs with limited resources should consider using HB or BB as the initial technique for fracture reduction with PS used for failed HB or when regional blocks are contraindicated.

Fewer Dislocations After Total Hip Arthroplasty With Robotic Assistance or Fluoroscopic Guidance.

BACKGROUND: Computer navigation and robotic assistance may reduce total hip arthroplasty (THA) dislocations by improving the accuracy and precision of component positioning. We investigated dislocation rates for THAs using conventional techniques, robotic assistance, and computer navigation, while controlling for surgical approach, dual mobility (DM) use, and fluoroscopic guidance. METHODS: We reviewed 11,740 primary THAs performed between June 2016 and December 2022, including 5,873 conventional, 1,293 with robotic-arm assistance, and 4,574 with navigation. The approach was posterior in 6,580 (56.0%), anterior in 4,342 (37.0%), and lateral in 818 (7.0%). A DM was used in 10.4%. Fluoroscopy was used in 3,653 cases and only with the anterior approach. Multivariate analyses yielded odds ratios (OR) for dislocation and revision. Additional regression analyses for dislocation were performed for approach and DM. RESULTS: Raw dislocation rates were as follows: conventional 1.2%, robotic 0.4%, navigation 0.9%, anterior with fluoroscopy 0.4%, anterior without fluoroscopy 2.3%, posterior 1.3%, and lateral 0.5%. Upon multivariate analysis, use of robotics was found to be associated with significantly reduced dislocation risk compared to conventional (OR: 0.3), as did anterior (OR: 0.6) compared to posterior approach; navigation and lateral approach were not found to be associated with a significant reduction in risk. For the anterior approach, multivariate analysis demonstrated that fluoroscopy significantly reduced dislocation risk (OR: 0.1), while DM, robotics, and navigation were not significant. For the posterior approach, the dislocation risk was lower with robotics than with conventional (OR: 0.2); the use of navigation or DM did not demonstrate a significant reduction in risk. CONCLUSIONS: The use of robotics was associated with a reduction in dislocations for this cohort overall. Further, fluoroscopy in the anterior approach and robotic assistance in the posterior approach were both associated with decreased dislocation risk. The role of imageless computer navigation and DM implants requires further study.

Thermoelectric Performance Enhancement in SnS Polycrystals Owing to Hole Doping Combined with Textured Microstructures.

Recently, the earth-abundant tin sulfide (SnS) has emerged as a promising thermoelectric material due to its phonon and electron structure similar to that of tin selenide (SnSe). However, compared with SnSe, limited progress has been achieved in the thermoelectric property enhancement of SnS. Textured SnS polycrystals with an enhanced thermoelectric performance have been developed in this work. The high carrier mobility benefited from the enhanced texture through the repressing strategy of spark plasma sintering, improving the electrical conductivity. In addition, Sn atom deficiencies in the texture sample led to an increased hole concentration, further boosting the electrical conductivity and power factor. The power factor exceeded 4.10 µW/cm·K2 at 423 K and 5.50 µW/cm·K2 at 850 K. The phonon scattering was strengthened by adjusting the multiscale microstructures including dislocations, defect clusters, etc., leading to an ultralow lattice thermal conductivity of 0.23 W/m·K at 850 K. A figure of merit zT > 1.3 at 850 K and an average zTave of 0.58 in the temperature range 373-850 K were achieved in the SnS polycrystal.

Total Closed Talar Dislocation without Ankle Fracture: A Case Report.

We report a case of a 61-year-old female who presented to the emergency room after a fall from stairs. A total closed talar dislocation without talus or ankle fracture was diagnosed. The treating surgeon indicated an open reduction after an unsuccessful attempt at closed reduction. After six months of follow-up, the patient reported mild pain and partial weight-bearing with no discomfort; however, signs of talar avascular necrosis were present on magnetic resonance images and CT scans.

Proximal radial neck fracture with complete 180-degree rotation of radial head: A case report.

Radial neck fractures with radial head rotation are very rare and extremely difficult to manage. We present the case of an 11-year-old girl who fell on her outstretched left upper extremity and damaged her left elbow in a road traffic accident. An arthrotomy was performed under a C-Arm fluoroscope, which confirmed the radial head displacement of 180° along with the fracture. The fracture site was reduced and fixed with two Kirschner wires, cutting the wire short at its distal end for a complete closure. Open reduction and internal fixation were followed by casting for five weeks. After two years of follow-up, she had complete pain free range of motion of the affected limb. No post-operative complications have been observed till date. Open reduction and internal fixation with two Kwires is a viable option for such complex injuries. However, further evaluation of outcomes and post-operative complications are required.

Acromioclavicular joint dislocation with loop double endobutton fixation assisted by orthopaedic surgery robot positioning system.

OBJECTIVE: Acute acromioclavicular (AC) joint dislocation is a common orthopedic injury that can significantly impair shoulder function and reduce quality of life. Effective treatment methods are essential to restore function and alleviate pain. To investigate the short-term clinical efficacy of the minimally invasive closed-loop double endobutton fixation assisted by orthopaedic surgery robot positioning system (TiRobot) in the treatment of AC joint dislocation, and to evaluate its feasibility and safety. METHODS: The clinical data of 19 patients with AC joint dislocation who underwent treatment with closed-loop double Endobutton fixation assisted by TiRobot between May 2020 and December 2022 were retrospectively analyzed. Visual Analog Scale (VAS) pain scores, the Constant Murley Score (CMS), and shoulder abduction range of motion were assessed and compared preoperatively and at the last follow-up. Computed tomography (CT) parameters of the acromioclavicular joint, including acromioclavicular distance (ACD), the distance between the upper and lower Endobutton (DED), the horizontal distance between the anterior edge of the distal clavicle and the anterior edge of the acromion (DACC), the diameter of the clavicular tunnel (DCT), and coracoid tunnel diameter (DC), were compared at 2 days, and 1 month after surgery, as well as at the last follow-up, along with the evaluation of intraoperative and postoperative complications. RESULTS: The postoperative VAS, CMS, and shoulder-abduction range of motion were significantly improved compared with the preoperative (all, P<0.05). The statistical analysis showed no significant difference in the CT image parameters of the acromioclavicular joint at 2 days and 1 month after surgery(all, P>0.05). Comparisons of DCT and DC revealed statistically significant differences between the last follow-up and 1 month after surgery (P<0.05), and no statistically significant difference was found in ACD, DED, and DACC(all, P>0.05). There were no complications such as infection or vascular or neurological damage, no cases of rostral or clavicle fractures, loss of reduction, heterotopic ossification, shoulder stiffness, and no loosening or breaking of internal fixations. CONCLUSION: Closed-loop double endobutton internal fixation assisted by TiRobot is an ideal method for the treatment of acute acromioclavicular (AC) joint dislocation. This method has the advantages of relatively simple operation, more accurate localization of bone tunnel during operation, less surgical trauma, and good recovery of shoulder function.