A comparative cadaveric study for percutaneous scaphoid fixation: robotic vs freehand.

PURPOSES: To compare the robotic-assisted and the traditional freehand percutaneous scaphoid fixation in number of guidewire attempts, duration of fluoroscopy time, amount of radiation dose, and screw centrality. METHODS: Twenty cadaveric specimens were randomized into either the robotic or freehand group. The scaphoids in both groups were fixed by either the same attending or resident from our hand surgery department. The operation duration, amount of radiation from intraoperative fluoroscopy, total fluoroscopy time, and the number of guidewire attempts were documented and compared. Postoperatively, all the specimens had a computed tomography (CT) scan performed, and the difference in the final position of the screw and the central axis of the scaphoid was examined. RESULTS: In the robotic group, all the guide wires were satisfactorily positioned within a single attempt, while the median number of attempts in the traditional freehand group was 18 (quaternion 14-65). This also meant that the surgeon in the robotic group experienced significantly lower radiation exposure dose and time as compared to the freehand group. There were no significant differences in the final screw position as compared to the central axis of the scaphoid in both groups. Although there was no difference in surgeon performance in the robotic group, the operative time for the attending was significantly lower as compared to the resident in the freehand group. CONCLUSION: Robotic-assisted surgery for scaphoid fracture fixation is superior to the traditional freehand method as it facilitates accurate screw placement with lower radiation exposure and fewer guide wire attempts.

Aloe-emodin targets multiple signaling pathways by blocking ubiquitin-mediated degradation of DUSP1 in nasopharyngeal carcinoma cells.

Aloe-emodin (AE) has been shown to inhibit the proliferation of several cancer cell lines, including human nasopharyngeal carcinoma (NPC) cell lines. In this study, we confirmed that AE inhibited malignant biological behaviors, including cell viability, abnormal proliferation, apoptosis, and migration of NPC cells. Western blotting analysis revealed that AE upregulated the expression of DUSP1, an endogenous inhibitor of multiple cancer-associated signaling pathways, resulting in blockage of the extracellular signal-regulated kinase (ERK)-1/2, protein kinase B (AKT), and p38-mitogen activated protein kinase（p38-MAPK） signaling pathways in NPC cell lines. Moreover, the selective inhibitor of DUSP1, BCI-hydrochloride, partially reversed the AE-induced cytotoxicity and blocked the aforementioned signaling pathways in NPC cells. In addition, the binding between AE and DUSP1 was predicted via molecular docking analysis using AutoDock-Vina software and further verified via a microscale thermophoresis assay. The binding amino acid residues were adjacent to the predicted ubiquitination site (Lys192) of DUSP1. Immunoprecipitation with the ubiquitin antibody, ubiquitinated DUSP1 was shown to be upregulated by AE. Our findings revealed that AE can stabilize DUSP1 by blocking its ubiquitin-proteasome-mediated degradation and proposed an underlying mechanism by which AE-upregulated DUSP1 may potentially target multiple pathways in NPC cells.

MECOM-related disorder: Radioulnar synostosis without hematological aberration due to unique variants.

PURPOSE: The etiology for a considerable proportion of patients with congenital radioulnar synostosis (RUS) remains unclear. This study aimed to investigate the genetic cause of RUS without a known cause. METHODS: Patients with RUS were investigated. Exome sequencing and/or Sanger sequencing was performed. Bioinformatics analysis was also performed. Pathogenicity was evaluated for variants of interest. RESULTS: We identified unique missense variants in MECOM (encodes EVI1) associated with RUS in 8 families. Of them, 6 families had variants in residue R781, including 3 families with R781C (c.2341C>T), 2 families with R781H (c.2342G>A), and 1 family with R781L (c.2342G>T). Another 2 variants included I783T (c.2348T>C) in 1 family and Q777E (c.2329C>G) in 1 family. All these variants were clustered within the ninth zinc finger motif of EVI1. Phenotype evaluation identified that most of these patients with RUS harboring mutant MECOM had finger malformations, but none of them had identifiable hematological abnormalities. Functional experiments showed that MECOM R781C led to alterations in TGF-ß-mediated transcriptional responses. CONCLUSION: This study examined MECOM variants by focusing on RUS instead of hematological abnormalities. The R781 residue in EVI1 is a hotspot for human RUS variants. Mutant MECOM is the second most common cause for familial RUS.

CCR5 as a prognostic biomarker correlated with immune infiltrates in head and neck squamous cell carcinoma by bioinformatic study.

BACKGROUND: C-C chemokine receptor 5 (CCR5) has recently been recognized as an underlying therapeutic target for various malignancies. However, the association of CCR5 with prognosis in the head and neck squamous cell carcinoma (HNSC) patients and tumor-infiltrating lymphocytes (TILs) is unclear. METHODS: In the current experiment, methods such as the Tumor Immune Estimation Resource Analysis (TIMER), Gene Expression Profiling Interactive Analysis (GEPIA), UALCAN, and Kaplan-Meier plotter Analysis were used to comprehensively evaluate the expression of CCR5 in human various malignancies and the clinical prognosis in HNSC patients. Subsequently, we used the TIMER database and the TISIDB platform to investigate the correlation between CCR5 expression levels and immune cell infiltration in the HNSC tumor microenvironment. Furthermore, immunomodulatory and chemokine profiling were performed using the TISIDB platform to analyse the correlation between CCR5 expression levels and immunomodulation in HNSC patients. RESULTS: We found that CCR5 expression in HNSC tumor tissues was significantly upregulated than in normal tissues. In HNSC, patients with high CCR5 expression levels had worse overall survival (OS, HR = 0.59, p = 0.00015) and worse recurrence-free survival (RFS, HR = 3.27, p = 0.00098). Upregulation of CCR5 expression is closely associated with immunomodulators, chemokines, and infiltrating levels of CD4+ T cells, neutrophils, macrophages, and myeloid dendritic cells. Furthermore, upregulated CCR5 was significantly associated with different immune markers in the immune cell subsets of HNSC. CONCLUSIONS: High expression of CCR5 plays an important prognostic role in HNSC patients and may serve as a prognostic biomarker correlated with immune infiltration, and further studies are still needed to investigate therapeutic targeting HNSC patients in the future.

Clinical features and ultrasound findings of a rare musculoskeletal system disease-neuromuscular choristoma.

BACKGROUND: Neuromuscular choristomas (NMCs), are extremely rare developmental lesions that, have been previously established associated with recurrent fibromatosis after surgery, leading to several operations or even amputation. However, reports on the ultrasound imaging features and clinical conditions of NMCs are rare. The purpose of this study is to describe the ultrasound features and clinical analysis of NMCs to provide suggestions to identify the optimal management strategy. METHODS: From September 2020 to September 2021, 7 patients with a confirmed diagnosis of NMC who underwent ultrasound examination in our department were enrolled in our study. Physical examinations were performed to detect motor deficits, sensory deficits, neuropathic pain, limb undergrowth, muscular atrophy, cavus foot and bone dysplasia. Ultrasound imaging was performed and investigated both in affected nerves and neuromuscular choristomas associated desmoid-type fibromatosis (NMC-DTF). All patients had a definite history and regular follow-up. The clinical course, physical examinations, ultrasound features and pathologic results of NMC patients were analyzed. RESULTS: Seven patients with an average age of 7.0 ± 7.2 years (range: 2-22 years) were enrolled in our study. The affected nerves included the sciatic nerve (6 cases) and the brachial plexus (1 case). Six patients (85.7%) presented with limb undergrowth, 6 (85.7%) with muscular atrophy, and 5 (71.4%) with cavus foot deformity. Based on ultrasound findings, all the visibly affected nerve segments presented with hypoechoic and fusiform enlargement with intraneural skeletal muscle elements. Five patients (71.4%) had NMC-DTFs at the site of the affected nerve. All NMC-DTFs were shown as hypoechoic solid lesions adjacent to the nerve and were well circumscribed. In the subset of the surgery group, all 5 patients presented with progression to NMC-DTFs at the site of the NMCs. No fibromatosis was detected in the other two nonsurgical patients. CONCLUSIONS: Understanding the typical ultrasound features and clinically associated conditions would support the early diagnosis of this rare disease. When a potential diagnosis is determined, an invasive procedure such as biopsy or resection might not be a good choice given the frequent occurrence of complications such as aggressive recurrence.

Accuracy of fluoroscopic examination in the treatment of Bennett's fracture.

BACKGROUND: Restoration of joint congruity is an important factor for the prevention of subsequent arthritis in patients with Bennett's fracture. Surgical treatment of Bennett's fracture is thus generally recommended for displaced intra-articular fractures to the proximal aspect of the thumb metacarpal. Fluoroscopic examination is used to evaluate the adequacy of closed reduction after pinning of Bennett's fracture. The purpose of this study was to determine the accuracy of fluoroscopy to determine the reduction of Bennett's fractures. METHODS: A model was created, to mimic a Bennett's fracture utilizing ten fresh-frozen cadaveric hands. An oblique cut was made in the proximal aspect of the thumb metacarpal using an oscillating saw. The small oblique fragment involved 1/4-1/3 of the joint surface was then shifted in position creating a step-off or gap at the fracture site. An anatomical reduction model, gap models (1 mm, 2 mm, 3 mm), and step-off models (1 mm, 2 mm, 3 mm) were created using percutaneous fixation with two 1.0 mm Kirschner wires for each cadaveric hand. Fluoroscopic assessment then took place and was reviewed by 2 attending hand surgeons blinded to the actual position. Their estimated fluoroscopic position was then compared to the actual displacement. RESULTS: The step-off and gap on fluoroscopic examination showed a significant difference compared to the step-off and gap from direct visualization. The frequency of underestimation for the 3 mm displacement models from the fluoroscopic examination was 60%. The frequency for overestimated was 9% for the models in which displacement was within 2 mm (0, 1, 2 mm). CONCLUSIONS: The assessment of articular gap and step-off using PA (postero-anterior), AP (antero-posterior), and lateral view of fluoroscopic examination is not accurate as compared to the examination by direct visualization. Surgeons need to be aware that PA, AP and lateral view of fluoroscopic examination alone may not be sufficient to judge the final position of a reduced Bennett's fracture. Other methods such as live fluoroscopy in multiple different planes, 3-dimensional fluoroscopy or arthroscopic examination should be considered.

Clinical and epidemiological features of heart-hand syndrome, an updated analysis in China.

BACKGROUND: The purpose of this study was to prospectively recruit patients treated with limb malformation and to explore the prevalence and the clinical and epidemiological features of Heart-Hand Syndrome (HHS) in China. METHODS: The consecutive patients treated for congenital upper limb malformation in Beijing Ji Shui Tan Hospital from October 1st, 2016 to October 1st, 2019 were prospectively recruited. We reviewed the patients' medical records and identified patients with abnormal electrocardiogram (ECG) and/or abnormal ultrasonic cardiogram as well as their basic demographic and clinical characteristics. RESULTS: A total 1653 (1053 male and 600 female) patients with congenital upper extremity malformations were prospectively recruited. Among them, 200 (12.1%) had abnormal ultrasonic cardiogram (181patients, 10.9%) and/or abnormal ECG (19 patients, 1.1%). The commonest type of abnormal heart structure was atrial septal defect (69/181 38.1%), and the commonest abnormal ECG was wave patterns (7/19, 36.8%). HHS patients had a higher comorbidity rate (11%) than non-HHS patients (6.9%). Patients with HHS were classified into four groups by the types of congenital upper extremity malformations, among which the most common group was thumb type (121/200, 60.5%). CONCLUSIONS: HHS occurred frequently among patients with congenital upper extremity malformation in China, particularly for those with multiple congenital malformations. The commonest type of hand malformations of HHS patients was thumb malformation.

Radial Pronation Angle: A Novel Radiological Evaluation Index of Congenital Proximal Radioulnar Synostosis.

INTRODUCTION: Congenital proximal radioulnar synostosis (CPRUS) is a relatively rare forearm deformity that is characterized by a fixed pronated forearm of varying severity. The osseous synostosis between the proximal part of the ulna and the radius can be seen on the X-ray images in most cases. Many researchers have attempted to identify methods to measure the disease severity to guide in the treatment of CPRUS. However, to describe the overall deformity, the use of multiple indicators is essential, and some of these measurements require special software or need to be conducted on cadavers. OBJECTIVE: The aim of the current study was to introduce the radius pronation angle (RPA), a novel radiological evaluation index of CPRUS, and analyze the relationship between the RPA and the severity of the deformity. METHODS: Three-dimensional models of 43 CPRUS forearms (19 left forearms and 24 right forearms) of 32 patients (23 males and 9 females; average age was 6 years 8 months; range, from 1.5 to 27 years) treated at Beijing Ji Shui Tan Hospital during 2016 to 2019 were reconstructed using a computer-assisted technique. The special flexed posterior-anterior views of the X-ray image (the f-PA view) of the forearms were obtained, and the forearm rotation angle and the ulnar inner rotation angle were measured on each forearm. The RPA was measured on the f-PA view, and the lengths of the osseous synostosis, ulna, and the radial head were measured on the computed tomography scan images using the multiplanar reconstruction function. The Pearson index was analyzed between the RPA and the other measurements. RESULTS: The RPAs were correlated with the forearm rotation angle, ulnar inner rotation angle, relative length of the osseous synostosis, and the relative length of the radial head (P < 0.05). CONCLUSIONS: The RPA can be measured quickly and easily on the f-PA view of the X-ray image and can be used as a reliable indicator of the severity of CPRUS.

Isolated ring-little finger metacarpal synostosis: a new classification system and treatment strategy.

PURPOSE: To devise a comprehensive classification system for isolated ring-little finger metacarpal synostosis that offers a clear guide to specific treatment for each variation of the deformity. METHODS: Based on the experience of 13 cases (20 hands) of isolated ring-little finger metacarpal synostosis, we devised a classification system that takes into account 2 key pathological features of this malformation: the fourth-fifth intermetacarpal angle and the severity of hypoplasia of the fifth ray. In our classification, all patients were divided into 3 types, according to the fourth-fifth intermetacarpal angle, and each type was further subdivided into 2 subtypes according to the length of the fifth ray. RESULTS: All 20 hands could be classified according to our classification, including 2 hands of type A (both A1), 10 hands of type B (9 B1; 1 B2), and 8 hands of type C (7 C1; 1 C2). Patients of different classification types received different treatments according to our proposed classification-related guidelines. It was also possible to classify all the cases found in literature according to this scheme. CONCLUSIONS: Our classification for ring-little finger metacarpal synostosis is simple and easy to remember. It is applicable to all possible variations of the congenital anomaly and can guide treatment for the whole spectrum of the deformity. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Establishing a central zone in scaphoid surgery: a computational approach.

PURPOSE: Scaphoid fractures are commonly fixed with headless cannulated screws positioned centrally in the scaphoid. Judgement of central placement of the screw may be difficult. We generated a central zone using computer analysis of 3D reconstructions of computed tomography (CT) images. As long as the screw axis is completely contained within this central zone, the screw would be considered as centrally placed. METHODS: Thirty cases of 3D CT reconstructions of normal scaphoids in a computerised operation planning and simulation system (Vxwork software) were obtained. The central zone was established after some distance shrinkage of the original scaphoid surface reconstruction model using the function "erode" in the software. The shape of the central zone was evaluated, and the width of the central zone in the proximal pole, waist portion and distal pole was measured. We also established the long axis of the scaphoid to see whether it stays in the central zone. RESULTS: All central zones could be divided into distal, waist and proximal portions according to the corresponding irregular shape of the scaphoid. As the geometry of the central zone was so irregular and its width very narrow, it was possible to completely contain the screw axis either in the proximal portion alone, waist alone or distal central zone alone. CONCLUSIONS: Establishing the central zone of scaphoid 3D CT images provided a baseline for discussion of central placement of a scaphoid screw. The geometry of the scaphoid central zone determined that the screw could hardly be inserted through entire scaphoid central area during surgery.

Consecutive flap transfer for repairing massive soft tissue defects in the opisthenar with improved donor site closure.

OBJECTIVE: To explore a surgical model of utilizing consecutive free scapular flap and adjacent pedicled flap transfer for repairing massive soft tissue defects on the dorsum of the hand while minimizing the donor site morbidity. METHODS: Six patients with massive soft tissue injuries on the opisthenar and forearm were treated with free scapular flaps. Afterwards, a pedicled flap adjacent to the donor site was transferred to cover the donor site defect by direct closure. RESULTS: All six free scapular flaps survived without signs of infection. Three adjacent pedicled flaps presented minor signs of insufficient blood flow on the distal apex, which resolved after six weeks with only conservative therapy. All the incisions healed without other complications. At six-month follow-up, the patients regained full shoulder function. CONCLUSION: With the assistance of an adjacent pedicled flap, the scapular flap is a highly applicable approach in repairing massive soft tissue defects in the opisthenar. It can achieve positive outcomes in both reconstructive and aesthetic aspects.

Arthroscopic Bone Grafting and Robot-assisted Fixation for Scaphoid Nonunion.

OBJECTIVES: Scaphoid nonunion remains a challenging problem to manage with no general consensus on its treatment recommendations. We propose a novel minimally invasive (MIS) technique of arthroscopic bone grafting (ABG) with robot-assisted fixation for the treatment of scaphoid nonunions. METHODS: Patients with radiographically proven scaphoid nonunion treated by this novel surgical technique were included. Following arthroscopic debridement and iliac crest bone grafting, the scaphoid was fixed percutaneously using either multiple Kirschner (K)-wires or a headless compression screw using a robotic navigation system. RESULTS: Six male patients with an average age of 29.2 years were enrolled. Four patients had scaphoid waist fractures, and the other two were proximal pole fractures. During wrist arthroscopy, punctate bleeding of the proximal scaphoid fragment was observed in four out of the six patients. Half of the patients were fixed using a headless compression screw and the other half using multiple K-wires. All the guidewires were placed with a single-attempt using the robotic navigation system. Postoperatively, all the scaphoid fractures had complete radiographic union by 16 weeks. At a mean follow-up of 18.3 months, there were significant improvements in wrist range of motion, grip strength, and patient-rated outcomes. No intraoperative or early postoperative complications were encountered in any of our patients. CONCLUSION: Arthroscopic bone grafting with robot-assisted fixation is a feasible and promising therapeutic option for scaphoid nonunions, regardless of the vascularity of the proximal pole fragment. This novel technique allows for anatomic restoration of the scaphoid alignment and accurate, targeted placement of implants into the scaphoid nonunion site within a single-attempt using a robotic navigation system.

Biodegradable conduit small gap tubulization for peripheral nerve mutilation: a substitute for traditional epineurial neurorrhaphy.

Nerve regeneration and re-innervation are usually difficult after peripheral nerve injury. Epineurium neurorrhaphy to recover the nerve continuity is the traditional choice of peripheral nerve mutilation without nerve defects, whereas the functional recovery remains quite unsatisfactory. Based on previous research in SD rats and Rhesus Monkeys, a multiple centers clinical trial about biodegradable conduit small gap tubulization for peripheral nerve mutilation to substitute traditional epineurial neurorrhaphy was carried out. Herein, the authors reviewed the literature that focused on peripheral nerve injury and possible clinical application, and confirmed the clinical possibilities of biodegradable conduit small gap tubulization to substitute traditional epineurial neurorrhaphy for peripheral nerve mutilation. The biodegradable conduit small gap tubulization to substitute traditional epineurial neurorrhaphy for peripheral nerve mutilation may be a revolutionary innovation in peripheral nerve injury and repair field.

[Central placement of screw fixation for scaphoid fracture: a biomechanical study].

OBJECTIVE: To evaluate the effect to the fixation stability of central screw placement during scaphoid fracture surgery. METHODS: We designed oblique osteotomies for 32 identical sawbone scaphoids and fixed each specimen with a cannulated screw. Sawbone scaphoids were divided into 4 groups, according to position of the osteotomy (distal waist portion or proximal waist portion) and the position of the screw (central or eccentric). We performed Computed Tomography scanning to one specimen, and then the central zone of the scaphoid was established from volume data by using the preoperative planning system software (VxWork 4.0). The position of the osteotomy plane, the entrance and exit points of the screw guide pin were designed on the software as well. We placed the specimens under the increasing load of a pneumatically driven plunger to compare the load to failure and the distance at failure between the central and eccentric screw groups. RESULTS: In general, we found the statistical differences of the load to failure and the displacement of fracture between the groups (F=31.485,P=0.001; F=33.328,P=0.018). The average load to failure and fracture displacement was more statistically different in the central group [(80.82 ± 15.63) N, (2.3 ± 0.5) mm] for proximal waist fracture than in the eccentric group [(58.32 ± 17.18) N, (3.1 ± 0.5) mm]. As to the distal waist fracture, the average load to failure and fracture displacement was better in the central group [(76.83 ± 14.54) N, (2.2 ± 0.7) mm] than in the eccentric group [(70.38 ± 13.32) N, (2.5 ± 0.6) mm] without significant difference. CONCLUSION: In this biomechanical model of an unstable oblique scaphoid fracture, we find that higher stability of fixation has been achieved with a screw placed centrally in the scaphoid, compared with a screw peripherally placed.

[Segmental schwannomatosis in upper-extremity: 5 cases report and literature review].

OBJECTIVE: Multiple schwannomas localized in a single body part not crossing the midline constitute a rare variant of neurofibromatosis, segmental schwannomatosis. We report our experience with 5 cases of segmental schwannomatosis of the upper extremity and review the related literature to improve our skills in diagnosis and differentiation. METHODS: Five patients with segmental schwannomatosis received surgical treatment in our department from 2003 to 2012, of whom 4 were female and the other one male. The mean age was 38 years, ranging from 29 to 48 years. In retrospect, we discussed the clinical appearance, histologic characteristics, genetic data and surgical management. RESULTS: A total of 351 patients with schwannomas were treated in the recent decade. There were 326 patients with solitary schwannoma, accounting for 92.88%, 25 with neurofibromatosis type 2 (NF-2), occupying 7.12% and 5 with segmental schwannomatosis representing 1.42% of the total. Schwannomas are limited in one upper extremity and randomly located at ulnar nerve, median nerve and radial nerve and their branches, with no obvious predisposition. Their family history was negative for cutaneous tumors or central nervous system disease. Neurological examinations did not reveal symptoms related to vestibular nerves or optic nerves, which excluded NF-2 preliminarily. The prior symptom of three cases was pain which could be irradiated to the nerve distribution area. No pain but slight numbness was found in two cases. MRI disclosed multiple masses along the course of the nerves. They were isointense to muscle on T1-weighed images and hyperintense to subcutaneous fat on T2-weighed images. All schwannomas were resected and histological sections exhibited a characteristic feature of schwannoma. Follow-up work of 4.5 years was done to 4 cases and no recurrence or impairment of nerves was found. CONCLUSION: Segmental schwannomatosis is characterized by multiple schwannomas localized in one limb (upper extremity in our cases) without vestibular nerve tumors, most frequently seen in females at the age of 30-60 years. Segmental schwannomatosis is rarely seen in the previous literature. We found around 20 cases in English articles and no cases in domestic articles. In consideration of the clinical appearances of these 5 cases and the genetic research in the related literature, we recommend that segmental schwannomatosis is a distinct form of neurofibromatosis which needs to be more studied. We should also pay more attention to differentiating this disease from other forms of neurofibromatosis.

A Novel Mini-Invasive Technique of Arthroscopic-Assisted Reduction and Robot-Assisted Fixation for Trans-Scaphoid Perilunate Fracture Dislocations.

OBJECTIVE: Perilunate injuries are rare but devastating carpal injuries. The treatment of perilunate injuries remains challenging and contentious. This study aims to describe a novel mini-invasive surgical technique of arthroscopic-assisted reduction and robot-assisted fixation for the treatment of trans-scaphoid perilunate fracture dislocations (PLFDs). METHODS: We retrospectively reviewed patients with PLFDs after surgical treatment from February 2021 to March 2021. The patients underwent arthroscopic-assisted precise reduction and robot-assisted headless screw fixation. Times of guide wire placement were recorded intraoperatively. Periodic follow-up was performed until union of scaphoid fracture was confirmed. Range of motion of the wrist, grip strength, the Visual Analog Scale (VAS) score, the Mayo Wrist Score, the Quick Disabilities of Arm, Shoulder, and Hand (QuickDASH) score, the Patient-Rated Wrist Evaluation (PRWE), and osteoarthritis were evaluated at the final follow-up. RESULTS: Two male patients presenting with PLFDs with an average age of 24.5 years old (32 and 17 years) were included in this study. Intraoperatively, anatomic reduction of the scaphoid fracture was achieved under arthroscopic guidance. A robotic-assisted single-attempt guidewire insertion was performed for scaphoid fracture and lunotriquetral interval. The CT scans at 8 and 12 weeks showed the union of the scaphoid fracture. At final mean follow-up of 13.5 months, the extension, radial-ulnar deviation, and pronation-supination were consistent with the contralateral side in both patients. One patient experienced mild limited range of motion with the flexion 46° of the injured wrist compared with 81°of the contralateral wrist. The VAS score was 0 and 2. The grip strength was 32 and 26 kg compared with 24 and 42 kg of the contralateral wrist. The PRWE score was 13 and 10 and the QuickDASH score was 2 and 7. The Mayo Wrist Score was 100 and 65. No sign of osteoarthritis was found at the last follow-up. CONCLUSIONS: Arthroscopic-assisted reduction and robot-assisted fixation is a viable and promising alternative for the treatment of perilunate fracture dislocations. This technique allows precise reduction and accurate placement of the K-wires/screws into the carpal bones through the optimal biomechanical paths.

Abnormal MRI signal intensity of the triangular fibrocartilage complex in asymptomatic wrists.

We investigated abnormal MRI findings of the triangular fibrocartilage complex in 154 asymptomatic volunteers (21-79 years). Except prevalence, we focused on the morphological features of abnormal signals in relation to age. The majority of full-thickness tears were located in the articular disc (63 participants). The incidence of disc perforation with characteristics of ulnar impaction syndrome increased significantly with age. Asymptomatic full-thickness tears of the ulnar attachment were found in ten participants (seven over 60 years old). The proximal and distal laminae of the ulnar attachment could not be differentiated in 36 participants. In conclusion, MRI is of limited value for the elderly in diagnosing triangular fibrocartilage disorders. For young subjects, MRI is still valuable, especially in diagnosing ulnar detachment, although the ability to distinguish between proximal and distal laminae remains questionable. Disc perforations in volunteers mimicked ulnar impaction syndrome, therefore age, clinical signs and other factors should also be considered in clinical diagnosis.Level of evidence: III.

Evaluation of a convolutional neural network to identify scaphoid fractures on radiographs.

This study aimed to develop and evaluate a convolutional neural network for identifying scaphoid fractures on radiographs. A dataset of 1918 wrist radiographs (600 patients) was taken from an orthopaedic referral centre between 2010 to 2020. A YOLOv3 and a MobileNetV3 convolutional neural network were trained for scaphoid detection and fracture classification, respectively. The diagnostic performance of the convolutional neural network was compared with the majority decision of four hand surgeons. The convolutional neural network achieved a sensitivity of 82% and specificity of 94%, with an area under the receiver operating characteristic of 92%, whereas the surgeons achieved a sensitivity of 76% and specificity of 96%. The comparison indicated that the convolutional neural network's performance was similar to the majority vote of surgeons. It further revealed that convolutional neural network could be used in identifying scaphoid fractures on radiographs reliably, and has potential to achieve the expert-level performance.Level of evidence: III.

Quantitative Analysis of Deformity in Digital Model of Congenital Radioulnar Synostosis.

OBJECTIVE: The deformity of congenital radioulnar synostosis is quite complicated and difficult. This study aims to find out the related factors of the "forearm rotation angle" (FR) which relate to the severity of congenital radioulnar synostosis (CRUS), and try to quantify the internal relations of each deformity and help to understand the reconstruction method in surgery treatment of this disease. METHODS: This study is case series research. We established 48 digital three-dimensional forearm bone models of 48 patients with congenital radioulnar synostosis classified as Cleary and Omer type 3. All the patients were treated at our institution from January 2010 to June 2016. In total, 10 independent deformities (the rotation angle of forearm; the internal rotation, radial, and dorsal angulation of radius and ulna; the relative length of osseous fusion at PRUJ; the relative dislocation distance of distal radioulnar joint; the relative area of proximal radial epiphysis) involved in the CRUS complex deformity were measured. Pearson correlation analysis for each deformity which was mentioned above was performed, and multivariate linear regression analysis was also performed with FR as the dependent variable and the other deformities as the influential factors. RESULTS: The "dorsal angle of radius" (DAR, 21.69° ± 21.55°) had the strongest correlation with the FR (79.72° ± 40.39°), the Pearson correlation coefficient was 0.601 (p < 0.01), the internal rotation angle of the radius (IRAR, 82.69° ± 54.98°) had a moderate correlation with FR, the Pearson correlation coefficient was 0.552 (p < 0.01). A forearm deformity equation was established: FR = 35.896 + 0.271 DAR + 0.989 IRAR. CONCLUSION: The dorsal angulation deformity of radius may be the most important deformity that effects the severity of CRUS and should be correct in the first place during reconstruction operation.

Initial phase of neuropathic pain within a few hours after nerve injury in mice.

We tested a hypothesis that the spinal plasticity induced within a few hours after nerve injury may produce changes in cortical activities and an initial phase of neuropathic pain. Somatosensory cortical responses elicited by vibratory stimulation were visualized by transcranial flavoprotein fluorescence imaging in mice. These responses were reduced immediately after cutting the sensory nerves. However, the remaining cortical responses mediated by nearby nerves were potentiated within a few hours after nerve cutting. Nerve injury induces neuropathic pain. In the present study, mice exhibited tactile allodynia 1-2 weeks after nerve injury. Lesioning of the ipsilateral dorsal column, mediating tactile cortical responses, abolished somatic cortical responses to tactile stimuli. However, nontactile cortical responses appeared in response to the same tactile stimuli within a few hours after nerve injury, indicating that tactile allodynia was acutely initiated. We investigated the trigger mechanisms underlying the cortical changes. Endogenous glial cell line-derived neurotrophic factor (GDNF), found in the Meissner corpuscles, induced basal firing ∼0.1 Hz or less in its Aß tactile afferents, and disruption of the basal firing triggered the potentiation of nontactile cortical responses. Application of 10 nm LY341495 [(2S)-2-amino-2-[(1S,2S)-2-carboxycycloprop-1-yl]-3-(xanth-9-yl) propanoic acid], a specific antagonist of group II metabotropic glutamate receptors (mGluRs), on to the surface of the spinal cord also induced the potentiation of nontactile cortical responses. Together, it is suggested that low-frequency afferent firing produced by GDNF in touch-sensitive nerve fibers continuously activated spinal group II mGluRs and that failure of this activation triggered tactile allodynia.