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Introduction: The purpose of this study was to clarify the relationship between seasonal variation and distal radius fractures using diagnosis procedure combination data in Japan. Materials and Methods: The participants were hospitalized patients who underwent surgical treatment for distal radius fracture as the primary injury at hospitals that introduced the diagnosis procedure combination system between April 2011 and March 2016. We obtained a summary table of the month of admission, region of residence, age at admission, and sex of the patients from the Ministry of Health, Labour and Welfare and evaluated it by month, region, age group, and sex. Results: The total number of patients for the 5 years from 2011 to 2016 was 105,025. There were 29,224 male and 75,801 female participants, with a female-to-male ratio of 2.6. The mean age was 60.2 (standard deviation, 20.8) years. Distal radius fractures occurred more frequently in the winter, especially among female individuals in eastern Japan. Female participants aged ≥ 50 years tended to have a higher incidence of distal radius fracture in winter. The incidence of distal radius fracture among male participants aged 0–19 years was higher from spring to autumn. Conclusion: Surgically treated distal radius fractures occur frequently during the winter months among female individuals in eastern Japan or those aged ≥ 50 years and increase from school age to adolescence, especially in male individuals from spring to autumn. We should be aware of the high incidence of distal radius fractures in winter, especially in regions with snowfall and cold temperatures. [ABSTRACT FROM AUTHOR]

Background: We have been using a simplified Sauvé–Kapandji (SK) procedure using a headless compression screw for the treatment of osteoarthritis (OA) of the distal radio-ulnar joint (DRUJ). Unlike a standard SK procedure, the simplified SK procedure does not require exposure of the DRUJ to prepare the opposing surfaces of the sigmoid fossa and the ulnar head or any procedures to stabilise the proximal stump of the ulna. The aim of this study is to report the radiological outcomes of the simplified SK procedure. Methods: We retrospectively reviewed data of all patients who underwent a simplified SK procedure for osteoarthritis of the DRUJ at our hospital between October 2008 and September 2020 with a follow-up of at least 25 weeks. Baseline demographic and clinical characteristics were investigated. We also measured radiographic parameters and performed statistical analyses to evaluate the shelf-forming region, ulnar stump and deviation of the carpal region. Results: Our study included 10 patients with a mean follow-up of 52.3 weeks. There was no instance of complications such as nonunion of DRUJ arthrodesis, callus formation at ulnar pseudoarthrosis and painful instability at the proximal stump of the ulna. According to the Wilcoxon signed rank test, no radiographic parameters significantly changed during the follow-up period. There was a significant negative correlation between radioulnar width and the variation of ulnar translation index. Conclusions: All radiographic parameters were well maintained, at least during the short follow-up period. There was no instance of nonunion of DRUJ arthrodesis. The simplified SK with simple headless compression screw insertion may be a reliable method for treating OA of the DRUJ. Level of Evidence: Level IV (Therapeutic) [ABSTRACT FROM AUTHOR]

In peroneal nerve palsy with closed knee injury, most of the case improves by follow‐up. We present a case of peroneal nerve rupture with closed multiple ligament knee injury, requiring nerve transplantation. In multiple ligament knee injury, it is necessary to consider the possibility of peroneal nerve rupture. [ABSTRACT FROM AUTHOR]

Nafamostat mesylate (NM) has been used to treat pancreatitis and disseminated intravascular coagulation during hemodialysis (HD). However, there have been some reports of adverse effects related to anaphylactic reactions. We present a case in which anaphylactic reactions caused by NM during preoperative HD caused repeated postponement of surgery for carpal tunnel syndrome. Symptoms including fever, shivering, chills, low blood pressure, tachycardia, nausea, and vomiting appeared during preoperative HD, and surgery was postponed thrice. Initially, the patient was misdiagnosed with sepsis because of elevated C-reactive protein and procalcitonin levels. However, since the symptoms appeared only when NM was administered and disappeared quickly after the administration of NM was terminated, the condition was diagnosed as anaphylactic reactions caused by NM. Therefore, it is essential to consider anaphylactic reactions caused by NM as differential diagnoses, when symptoms, such as fever, are observed during perioperative HD. [ABSTRACT FROM AUTHOR]

Background: We evaluated how artificial nerves filled with adipose-derived stem cell (ADSC) sheets could facilitate peripheral nerve regeneration.Methods: We prepared ADSC sheets following previously described protocols. We transected the sciatic nerve in 12-week-old Wistar rats, fixed the nerve ends to the artificial conduit, and prepared three groups: (1) conduits alone (control group); (2) conduits filled with ADSCs (ADSCs group), and (3) conduits filled with ADSC sheets (ADSC sheet group). We assessed the subjects 4 and 12 weeks post-transplantation (n = 24). We investigated βIII-tubulin and anti-S100 expression at 4 and 12 weeks post-transplantation, in longitudinal- and cross-sections of the central portion in the regenerated tissues. The vascular endothelial growth factor A (VEGFA) and neuregulin-1 expressions were analyzed using real-time reverse-transcription polymerase chain reaction (real-time RT-PCR). We evaluated the tibialis anterior muscle wet weight (affected/healthy sides, %) and sciatic function index (SFI) 12 weeks post-transplantation.Results: The ADSC sheet group comprised more S100-positive cells than the other groups. The regenerated axon length in the ADSC sheet group was markedly the longest among the studied groups. The immunostaining revealed a positive area in the regenerated tissue center in all groups, tending to be the largest in the ADSC sheet group. The muscle wet weight indicated that the ADSC sheet group exhibited significantly higher weight than the control. The mean SFI showed that the ADSC sheet group exhibited significantly better results than the control. The VEGFA expression was higher both in the ADSC and the ADSC sheet group than in the control. The neuregulin-1 expression was higher both in the ADSC and the ADSC sheet group than in the control.Conclusions: The ADSC sheets could potentially support transplanting an adequate number of ADSCs at the target site. Compared with the conventional method of attaching ADSCs, the use of ADSC sheets promotes accelerated nerve regeneration. [ABSTRACT FROM AUTHOR]

Background: Despite the movement of the thumb carpometacarpal joint has been studied, many unclarified points remain regarding the movement of this joint. The purpose of this study was to evaluate the in vivo kinematics of the thumb carpometacarpal joint during flexion and abduction using computed tomography images. Methods: The subjects were 9 healthy males. Computed tomography images were obtained in 4 equally-divided positions from maximum extension to maximum flexion, and maximum adduction to maximum abduction of the thumb. A three-dimensional model was constructed from these images, and the models of each position were superimposed with reference to the trapezium. The amount of angular change around the bone axes of first metacarpal bone and rotation axes were evaluated. Results: We found that the first metacarpal bone showed relatively simple behavior during abduction. However, during flexion, it exhibited a particular movement in which the amount of angular change of the metacarpal bone with respect to the trapezium rapidly increased with deep flexion. Conclusions: These results suggest that the thumb carpometacarpal joint exhibits a special movement during flexion, especially deep flexion. [ABSTRACT FROM AUTHOR]

Background: Although it is important to understand the risk factors affecting the reduction of pediatric supracondylar humerus fractures (PSHFs), no inclusive study has been conducted so far. We performed a retrospective cohort study to identify the risk factors affecting the quality and difficulty of reduction for PSHFs. Methods: We reviewed 160 cases with a PSHF that had been surgically treated in our hospital between January 2007 and December 2019. We investigated age, sex, injured side, body mass index (BMI), modified Gartland classification, neurological deficit or an absent radial artery pulse at an initial examination, start time of the operation, waiting time from injury to surgery, operative time, reduction technique, and perioperative radiographic parameters. We calculated independent predictors of unsuccessful closed reduction, prolonged operative time, and malreduction using multivariate analyses. Results: In a logistic regression analysis, modified Gartland type III was a significant predictor of unsuccessful closed reduction (OR 14.50 [95% CI 4.03–51.90]; P < 0.01) and BMI was a significant predictor of malrotation (OR 1.59 [95% CI 1.06–2.39]; P = 0.025). In a multiple linear regression analysis, BMI and open reduction were significant predictors of prolonged operative time (BMI, P = 0.011; open reduction, P < 0.01). Conclusions: If closed reduction fails, we should not hesitate to immediately switch to other methods. Obesity was an independent predictor of both prolonged operative time and malrotation, a finding that has not been previously reported. Rotational alignment should be carefully checked, especially for obese children, and accurately be reduced. Open reduction also extended operative time. [ABSTRACT FROM AUTHOR]

Purpose: While many studies have been conducted on peripheral nerve regeneration, few have focused on strengthening the nerve autografts. This study hypothesized that adding autologous stromal vascular fraction (SVF) to a nerve autograft will improve nerve regeneration. The purpose of this study was to compare the results of nerve autograft with and without SVF. Methods: An adipose tissue sample was excised from the right inguinal region of female Wistar rats, and SVF was separated by centrifugation. The left sciatic nerve was resected at a length of 15 mm and the defect was bridged by a resected nerve autograft. We added SVF with collagen gel around the nerve autograft in the SVF group and added saline in the control group. At 12 weeks after surgery, the wet muscle weight, distal latency, and amplitude of the compound muscle action potential of the tibialis anterior were evaluated by the ratio of left and right sides. Sciatic functional index (SFI) was also evaluated. Results: The wet muscle weight was significantly better in the SVF group than in the control group. The results of distal latency, amplitude, and SFI were not significantly different between the two groups; however, these results tended to be better in the SVF group than in the control group. Conclusion: SVF added to artificial nerve grafts has been reported to promote axonal regeneration through secretion of angiogenic, neurotrophic, and anti-apoptotic factors. This study indicates that SVF may also be effective for nerve autografts and improve the clinical result of nerve autograft. [ABSTRACT FROM AUTHOR]

Distal radius fractures often involve comminuted fragments of the dorsal cortex of the radius, but bone fragments rarely protrude into the radiocarpal joint. We report two cases of distal radius fracture with bone fragment protrusion into the radiocarpal joint. To the best of our knowledge, there are no English reports of distal radius fracture with bone fragment protrusion into the radiocarpal joint. Despite the rarity of these cases, clinicians should still be mindful of such injuries and not overlook the possibility of presence of bone fragments within the joint. Missed intra-articular fragments may cause pain, limited range of motion, and subsequent osteoarthritis. [ABSTRACT FROM AUTHOR]

Introduction: Many reports have indicated that adipose-derived stem cells (ADSCs) are effective for nerve regeneration. We investigated nerve regeneration by combining a polyglycolic acid collagen (PGA-c) tube, which is approved for clinical use, and Schwann cell-like differentiated ADSCs (dADSCs).Methods: Fifteen-millimeter-long gaps in the sciatic nerve of rats were bridged in each group using tubes (group I), with tubes injected with dADSCs (group II), or by resected nerve (group III).Results: Axonal outgrowth was greater in group II than in group I. Tibialis anterior muscle weight revealed recovery only in group III. Latency in nerve conduction studies was equivalent in group II and III, but action potential was lower in group II. Transplanted dADSCs maintained Schwann cell marker expression. ATF3 expression level in the dorsal root ganglia was equivalent in groups II and III.Discussion: dADSCs maintained their differentiated state in the tubes and are believed to have contributed to nerve regeneration. [ABSTRACT FROM AUTHOR]

The most common surgical treatment for congenital pseudarthrosis of the clavicle (CPC) is resection of the pseudarthrosis, placement of an autologous bone graft, and Kirschner wire or plate fixation. However, in some cases, bone fusion cannot be achieved at the first surgery, and an additional surgery is required. We present a case report of a boy with a right CPC who failed radiographic bone union after the first surgery. He subsequently underwent revision surgery with resection of the pseudarthrosis, plate fixation, and establishment of a vascularized medial femoral condyle (MFC) flap to ensure bone union. Three months after the revision surgery, a radiographic bone union was achieved, and no symptoms were observed for one year after the operation. There have been no previous reports of the use of a vascularized MFC flap as a treatment for CPC. We believe that this technique effectively ensures bone union during revision surgery for CPC. [ABSTRACT FROM AUTHOR]

Background: Pediatric supracondylar humerus fracture (PSHF) is one of the most common fractures of the elbow seen among boys aged between 5 and 7 years. The timing of surgical treatment for this type of fracture is still controversial. Thus, we aimed to investigate whether the timing of surgery for PSHFs affects the incidence of early postoperative complications and reduction of PSHFs. Methods: We retrospectively reviewed the medical records of PSHF patients who underwent surgery at our hospital between January 2007 and March 2019. We classified patients who underwent surgery within 12 h and more than 12 h after the fracture as the early and delayed groups, respectively. The outcome measures compared between the two groups were the incidence of postoperative early complications such as neurological deficits, including iatrogenic ulnar nerve injury, vascular compromise, compartment syndrome, K-wire migration, and unplanned returns to the operating room. We also examined surgical time, reduction procedure, and perioperative radiographic parameters. Results: There was no significant difference in the incidence of early complications between the early and delayed groups for either modified Gartland type II or type III fractures. There was also no significant difference in surgical time, reduction procedure, or perioperative radiographic parameters between the two groups. Conclusions: Delayed surgery was not associated with an increased rate of postoperative early complications in either type II or type III fractures. The timing of surgery does not affect the difficulty or quality of reduction. [ABSTRACT FROM AUTHOR]

Background: Perineural adhesion is a potential complication of manipulating peripheral nerves. Using a model of median nerve manipulation in the carpal tunnel, perineural adhesion preventive effects of an alginate gel formulation were examined. Methods: After exposing carpal tunnels of Japanese white rabbits and dissecting the median nerve, the gliding floor was excised as much as possible and the transverse carpal ligament was repaired to induce a perineural tissue reaction. Prior to wound closure, 0.5 ml of alginate gel formulation was administered into the right carpal tunnel (formulation group) and 0.5 ml of physiological saline was administered into the left carpal tunnel (control group). At 1, 2, 3, and 6 weeks after treatment, electrophysiological evaluation of thenar distal latency, macroscopic evaluation with adhesion score, and pathological evaluation of carpal tunnel cross sections were performed (N = 4–5 at each time point). Results: Although distal latency tended to be low in the formulation group, there was no significant difference between the groups according to electrophysiological evaluation. Macroscopic evaluation revealed that the adhesion score was always lower in the formulation group than in the control group; over the course of treatment, it remained unchanged in the formulation group, but peaked at 3 weeks after treatment in the control group. In pathological evaluation, neural perfusion peaked at 2–3 weeks after treatment in both groups; neural perfusion tended to be lower in the formulation group than in the control group. Conclusions: Results suggested that the peak tissue response associated with nerve dissection occurred 2–3 weeks after treatment and that the repair process started subsequently. The alginate gel formulation modified the surrounding environment of the nerve and promoted repair by acting as a physical barrier against perineural fibrosis. The preventive effect of alginate gel on perineural adhesion may improve treatment outcomes of constrictive neuropathy. [ABSTRACT FROM AUTHOR]

Morel-Lavallée lesion (MLL) is a degloving injury in soft tissues caused by shear force accompanying trauma. Even if it is a small lacrimal wound at the initial visit, there is a range of skin necrosis which is not suitable for it. As a cause of the injury, a shearing force was applied over a wide range, and penetrating blood vessel damage to the skin occurred, resulting in skin necrosis. Attention is required. [ABSTRACT FROM AUTHOR]

Purpose. Elevation of the sural artery flap with the sural nerve is associated with donor-site morbidities, such as postoperative sensory disturbance of the lower extremity. We evaluated the sensory disturbance of the lower extremity after elevation of the sural artery flap. Methods. This study included 7 patients who underwent surgery using the sural artery flap. The sensory disturbances immediately after surgery and at present were evaluated on a 10-point scale. The influences of surgery on activities of daily living and patient satisfaction were also evaluated. Results. The sensory disturbance was 4.48 immediately after surgery and 2.24 presently, and the difference between the timepoints was not statistically significant. The influence of surgery on activities of daily living was 2.30, and the patient satisfaction was 7.90. Conclusion. It may be necessary to consider the sural artery flap, which does not include the sural nerve, to avoid unnecessary complications. When it is unavoidable to use the sural artery flap, including the sural nerve, it is important to thoroughly inform patients beforehand about the postsurgery sensory disturbance in the lower extremities. [ABSTRACT FROM AUTHOR]

The treatment methods used for Blauth type IIIB hypoplastic thumbs are controversial. We performed a nonvascularized, hemilongitudinal metatarsal bone transfer on a 5-year-old boy with a type IIIB hypoplastic thumb. Despite the child's age, the growth of the thumb was confirmed and the thumb had stabilized. Moreover, growth disorder of the donor toe was not observed. This method is relatively easy to perform. And donor toe deformation can be prevented, because of the preservation of more than half of the metatarsal bone. In our case, the patient was 5 years of age; nevertheless, the epiphyseal line was opened and the grafted metatarsal bone grew. This method is useful in terms of its simplicity and prevention of postoperative complications. [ABSTRACT FROM AUTHOR]

Background: Chronic tenosynovitis of the wrist and hand is commonly seen by orthopedists, especially hand surgeons. However, cases with rice body formation are comparatively rare. Thus, we retrospectively reviewed the cases of chronic tenosynovitis in our department and evaluated the necessity of antibiotic therapy in the early post-surgical stage. Methods: We analyzed the medical and surgical records of patients who had undergone surgery for chronic tenosynovitis with rice body formation in our department from 1997 to 2015. We evaluated the causes of chronic tenosynovitis, culture findings, pathological findings, and post-operative treatment courses. Results: Nineteen patients with 23 involved hands underwent surgery for chronic tenosynovitis, and 9 patients had rice body formation. The most common cause of chronic tenosynovitis was non-tuberculous mycobacteriosis, and other causes were fungal infection and infection of unknown origin. Recurrence was observed in 2 cases of mycobacteriosis and 1 case of fungal infection; 1 case of mycobacteriosis also had a re-recurrence. Conclusions: In the diagnosis of chronic tenosynovitis with rice body formation, it is necessary to consider not only non-tuberculous mycobacteriosis, but also fungal infection as its origin. However, it is difficult to define the cause of synovitis, but in cases in which these infections are suspected, anti-bacterial therapy in the early post-surgical period could be effective. [ABSTRACT FROM AUTHOR]

The Galeazzi-equivalent fracture is a rare injury that occurs in children. The most important issue is the distal ulnar epiphyseal injury. Although there have been some case reports, most of them performed only short term follow-up. This article describes two cases of this fracture with long term follow-up until epiphyseal closure. First case is a 12-year-old girl who sustained a Galeazziequivalent fracture of her right forearm and underwent emergency surgery. At follow-up of 5 years and 10 months postsurgery, radiographs show ulnar growth arrest of one mm and she has mild pain. Second case is a 15-year-old boy who sustained an open Galeazzi-equivalent fracture of his left forearm and underwent emergency surgery. At follow-up of 3 years and 3 months postsurgery, radiographs show no growth arrest of the distal ulna. He has no residual complaint. Long term follow-up is absolutely necessary to monitor ulnar growth. [ABSTRACT FROM AUTHOR]

Aramid fiber (AF) has a limited application as reinforced composite due to its smooth and inert surface properties. To improve the interfacial properties of AF in reinforced composite applications, we developed a surface modification of AF using acrylic acid (AA) in supercritical carbon dioxide (scCO 2). In this study, scCO 2 was adopted as an alternative to conventional organic solvents in the modified reaction media. AA was then introduced onto the surface of AF by free radical grafting polymerization using scCO 2. The modified AF observed by scanning electron microscopy had a rough surface with a dense polymer coating. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis revealed that the AF surface was decorated by –COOH groups through covalent bonding (C–N). The interfacial shear strength as a fiber-matrix interfacial property was increased by 53.4 % while effectively maintaining the strength of AF after surface modification. [Display omitted] • Free radical grafting polymerization of AA on AF surface using scCO 2. • Dense PAA coating was formed on the surface of modified AF. • Covalent bonding (C–N) of PAA on the modified AF surface. • Interfacial shear strength (IFSS) of modified AF was increased by 53.4 %. • No loss in fiber strength after surface modification. [ABSTRACT FROM AUTHOR]

Vasospasm is a phenomenon that can complicate microsurgery. We report a case in which vasospasm was quickly relieved by topical application of fasudil hydrochloride. A 36-year-old man underwent preoperative chemotherapy and wide excision for a malignant soft tissue tumor around the knee joint. We planned reconstruction using a free latissimus dorsi muscle flap for the resulting soft tissue defect and selected the peroneal vessels as the recipient vessels. However, there was no arterial blood flow from the peroneal vessels, which we diagnosed as vasospasm. Conventional treatment of the vasospasm was attempted, but blood flow was not achieved. Topical application of fasudil hydrochloride solution promptly relieved the vasospasm. To the best of our knowledge, this is the first clinical report of the use of fasudil hydrochloride for vasospasm during soft tissue reconstruction using a free flap. [ABSTRACT FROM AUTHOR]

Scaphoid fracture is the most common fracture in carpal bones. Although the reported union rate of conservatively-treated fractures is more than 90%, there is a controversy over the most appropriate treatment. In recent years, many reports have compared the clinical outcomes of conservatively-treated scaphoid fractures with the results of operatively treated ones using randomized controlled trials and meta-analyses. However, there is no consensus regarding the optimal treatment. In this paper, based on literature review, we provide an overview of the management of the acute scaphoid fractures particularly focusing on the issues related to conservative treatment. [ABSTRACT FROM AUTHOR]

Background: We have proposed that a positive tendon irritation test is suggestive of flexor pollicis longus (FPL) tendon damage that can lead to tendon rupture after volar plate fixation for distal radius fractures. We investigated cases of postsurgical hardware removal and validated the tendon irritation test as a way to elicit a sign of FPL tendon irritation. Patients and methods: We performed hardware removal from 30 wrists in 28 consecutive patients after volar plate fixation. Subjects included 9 men and 19 women with an average age of 58.8 years. The duration of internal fixation averaged 14.5 months. We investigated the efficacy of the tendon irritation test to elicit a sign of tendon irritation before hardware removal, and we intraoperatively evaluated the presence of FPL tendon injuries. Results: Twenty-four of 30 wrists exhibited a sign of tendon irritation. There was no statistical correlation between a sign of tendon irritation and patient age or the duration of internal fixation. We diagnosed 10 wrists with tenosynovitis and 8 frayed tendons. The sensitivity of the tendon irritation test to identify a sign of tendon irritation that was associated with FPL tendon injuries was 80.0 %, and its specificity to correctly identify non-injured FPL tendons was 40.0 %. The duration of internal fixation associated with tendon fraying was significantly longer than it was in cases of non-injured tendons and tenosynovitis. Conclusion: Our results suggest that subsequent examinations should be performed when the tendon irritation test is positive for signs of tendon irritation that may require plate removal. [ABSTRACT FROM AUTHOR]

We hypothesized that wrist joint motion involves a "wrist rhythm" similar to the scapulohumeral rhythm. Therefore, we used a flat-panel detector to evaluate the ratio of radiolunate and capitolunate joint motions during wrist joint motion by dynamic radiography. The subjects were 20 healthy men. Dynamic imaging of the wrist joint was performed during active exercise for a total of ten seconds. In this study, we defined the radiocarpal (RL angle) and midcarpal joint angle (CL angle) as the wrist joint angle in the obtained images and measured the variation of these angles. The average curve was plotted and regression lines calculated from the average curve. The ratio was calculated from the slopes of the regression lines of the RL CL angles. These findings indicated that the ratio of the RL and CL angle motions was approximately 1:4 during palmar flexion and approximately 2:1 during dorsiflexion. [ABSTRACT FROM AUTHOR]

Glial cells have various important roles in regulation of brain functions. For such events, extracellular nucleotides/P2 receptors have central roles. Although there have been huge amount of literature about activation of P2 receptors and glial functions, little is known about what happens in glia or the brain if glial P2 receptor is inhibited. Here we show that the inhibition of P2 receptors in astrocytes, the most abundant glial cells and cause a constitutive release of nucleotides, resulted in secretion of metalloproteinase-9 (MMP-9), a metal-dependent endopeptidase that degrades extracellular matrix molecules and is important in regulation of brain remodeling. When cultured astrocytes were treated with apyrase (ecto-nucleotidase), reactive blue 2 (P2 receptor antagonist), and pertussis toxin, they secreted MMP-9, suggesting that Gi-coupled P2Y receptor-mediated signals constitutively suppress the production of MMP-9. Among Gi-coupled P2Y receptors, we found that an inhibition of P2Y receptor, a receptor for nucleotide-sugars such as UDP-glucose, is responsible for the production of MMP-9 by pharmacological and molecular biochemical analysis. As for the mechanisms, the inhibition of P2Y receptors resulted in the release of tumor necrosis factor (TNF)-α which then acted on astrocytes to induce MMP-9. Taken together, our results suggest that the constitutive releases of nucleotide-sugars in astrocytes should play an important role in maintaining the normal status of the cell, through Gi-coupled P2Y receptors, and when the signal is removed, the cells start to release TNF-α, which then acts on astrocytes in a feedback fashion to boost MMP-9 synthesis and secretion. [ABSTRACT FROM AUTHOR]

We evaluated the presence of "tendon irritation" of flexor pollicis longus (FPL) for cases of distal radius fracture treated with volar plates to prevent FPL tendon rupture. This report details cases of 24 patients. The presence of pain or a sense of incompatibility and subdermal crepitus around the wrist with an active thumb motion were defined as symptoms of FPL tendon irritation. Twelve of 24 patients complained of FPL tendon irritation. The plates were removed in nine of these 12 patients, while tendon injury was found in three cases. The other 12 patients did not complain of FPL tendon irritation. Four of these 12 patients underwent plate removal, and tendon injury was not detected. The results of this study indicate that FPL tendon irritation is likely to appear before tendon rupture. Therefore, FPL tendon rupture might be prevented by plate removal in patients who complained of tendon irritation. [ABSTRACT FROM AUTHOR]

We report three cases of malunion after fractures of the proximal phalangeal neck in children. A 12-year-old boy and a 7-year-old girl had malunited fractures with dorsal and ulnar deviation of their fingers. Several years later remodeling had been achieved well for dorsal deviation but little for the ulnar deviation in each case. A 10-year-old boy had a similar malunited fracture with dorsal and ulnar deviation of his finger. The proximal bony spike, which protruded to the volar side, collided with the middle phalanx during flexion of the proximal interphalangeal (PIP) joint, so we shaved it. One year after operation, flexion of the PIP joint had improved. In cases of these malunited fractures in children, remodeling is considered possible for dorsal deviation but difficult for ulnar deviation. Surgical shaving of the protruding bone should be considered. [ABSTRACT FROM AUTHOR]

We report the long-term result of operative treatment of a flexion contracture of the fingers resulting from sarcoidosis, in which the contracture recurred. Even with complete excision of the granulomatous lesion, a new lesion may appear in a previously healthy area, so a radical cure by operation alone is difficult. [ABSTRACT FROM AUTHOR]

The novel coronavirus (COVID-19) that emerged in 2019 and spread globally in 2020 has resulted in the imposition of lockdowns or a state of emergency in many cities worldwide. In Japan, a "new lifestyle" is being advocated. We hypothesize that the new lifestyle has changed people's use of their upper limbs during the COVID-19 pandemic. Therefore, through this questionnaire study, we aimed to determine the factors associated with exacerbation of symptoms during the pandemic and to investigate the current status of patients who require hand surgery. This study was a prospective multi-center questionnaire survey. This study was conducted in Japan from December 2020 to July 2021 at university and general hospitals in nine prefectures. A questionnaire was administered to patients who visited a hospital with symptoms of nerve entrapment syndrome, osteoarthritis, or tenosynovitis. A total of 502 patients with a mean age of 63.8 years responded. The 240 patients who experienced exacerbation (exacerbated and markedly exacerbated) were compared with other patients (unchanged, improved, and markedly improved). An increase in the time spent on personal computers and smartphones was associated with exacerbation of hand symptoms. Patients who wanted to undergo surgery but were postponed due to COVID-19 accounted for 23.5% of the outpatients. The mean scores for pain, jitteriness, and anxious depression in these patients were significantly higher than those of patients who did not want surgery. Our results suggest that an increase in the time spent on personal computers and smartphones is associated with exacerbation of hand symptoms during the COVID-19 pandemic. Patients who wanted to undergo surgery but were postponed by COVID-19 experienced greater pain, jitteriness, and anxious depression. [ABSTRACT FROM AUTHOR]

We examined the color processing of the commodity plastic buttons made of acrylic, polyester, nylon, and casein with scCO2. The buttons' dyeing color depth (K/S) was measured over a wide range of scCO2 and correlated accurately with the response surface method. Moreover, we measured the solubility of C.I. Disperse Red 22 in scCO2 to formulate a dye-sorption model for the K/S value in the color processing of the plastic buttons. Finally, the dye-sorption model for the K/S value combining the dye solubility in scCO2 with the dye diffusion inside the buttons successfully represented the color processing of the buttons. [ABSTRACT FROM AUTHOR]

Background. We report a retrospective case series analysis of clinical outcomes of patients with soft tissue sarcoma around the elbow. Methods. Twenty-two patients underwent surgical tumor excision between January 1999 and May 2017, with a mean follow-up of 85.2 months. Results. Six tumors were localized in the upper arm, nine in the elbow, and seven in the forearm. Sixteen tumors were deep-seated, and six were superficially located. Fifteen patients underwent wide excision, including one amputation, and 18 achieved (81.8%) negative margins histologically. Two local recurrences and four distant metastases developed. The mean Musculoskeletal Tumor Society score was 92.0% (range, 33.3–100). The 5-year local recurrence-free survival rate, metastasis-free survival rate, and overall survival rate were 90.0%, 77.0%, and 79.7%, respectively. Conclusions. Local control and limb function can have favorable outcomes when the tumor excised has a histologically negative margin without sacrificing the major structure. [ABSTRACT FROM AUTHOR]

Background: Under most circumstances, the resection of soft tissue sarcomas of the extremities can be limb-sparing, function-preserving oncologic resections with adequate margins. However, en bloc resection may require resection of the major peripheral nerves, causing poor function in the extremities. Although liquid nitrogen treatment has been used to sterilize malignant bone tumors, its use in the preparation of nerve grafts has, to our knowledge, not been reported. Hence, this study aimed to investigate the tumor recurrence and function after peripheral nerve reconstruction using liquid nitrogen–treated tumor-bearing nerves in a rat model. Questions/purposes: (1) Do liquid nitrogen–treated frozen autografts have regeneration capabilities? (2) Do liquid nitrogen–treated tumor-bearing nerves cause any local recurrences in vivo in a rat model? Methods: Experiment 1: Twelve-week-old female Wistar rats, each weighing 250 g to 300 g, were used. A 10-mm-long section of the right sciatic nerve was excised; the prepared nerve grafts were bridge-grafted through end-to-end suturing. The rats were grouped as follows: an autograft group, which underwent placement of a resected sciatic nerve after it was sutured in the reverse orientation, and a frozen autograft group, which underwent bridging of the nerve gap using a frozen autograft. The autograft was frozen in liquid nitrogen, thawed at room temperature, and then thawed in distilled water before application. The third group was a resection group in which the nerve gap was not reconstructed. Twenty-four rats were included in each group, and six rats per group were evaluated at 4, 12, 24, and 48 weeks postoperatively. To assess nerve regeneration after reconstruction using the frozen nerve graft in the nontumor rat model, we evaluated the sciatic functional index, tibialis anterior muscle wet weight ratio, electrophysiologic parameters (amplitude and latency), muscle fiber size (determined with Masson trichrome staining), lower limb muscle volume, and immunohistochemical findings (though neurofilament staining and S100 protein produced solely and uniformly by Schwann cells associated with axons). Lower limb muscle volume was calculated via CT before surgery (0 weeks) and at 4, 8, 12, 16, 20, 24, 32, 40, and 48 weeks after surgery. Experiment 2: Ten-week-old female nude rats (F344/NJcl-rnu/rnu rats), each weighing 100 g to 150 g, were injected with HT1080 (human fibrosarcoma) cells near the bilateral sciatic nerves. Two weeks after injection, the tumor grew to a 10-mm-diameter mass involving the sciatic nerves. Subsequently, the tumor was resected with the sciatic nerves, and tumor-bearing sciatic nerves were obtained. After liquid nitrogen treatment, the frozen tumor-bearing nerve graft was trimmed to a 5-mm-long tissue and implanted into another F344/NJcl-rnu/rnu rat, in which a 5-mm-long section of the sciatic nerve was resected to create a nerve gap. Experiment 2 was performed with 12 rats; six rats were evaluated at 24 and 48 weeks postoperatively. To assess nerve regeneration and tumor recurrence after nerve reconstruction using frozen tumor-bearing nerve grafts obtained from the nude rat with human fibrosarcoma involving the sciatic nerve, the sciatic nerve's function and histologic findings were evaluated in the same way as in Experiment 1. Results: Experiment 1: The lower limb muscle volume decreased once at 4 weeks in the autograft and frozen autograft groups and gradually increased thereafter. The tibialis anterior muscle wet weight ratio, sciatic functional index, muscle fiber size, and electrophysiologic evaluation showed higher nerve regeneration potential in the autograft and frozen autograft groups than in the resection group. The median S100-positive areas (interquartile range [IQR]) in the autograft group were larger than those in the frozen autograft group at 12 weeks (0.83 [IQR 0.78 to 0.88] versus 0.57 [IQR 0.53 to 0.61], difference of medians 0.26; p = 0.04) and at 48 weeks (0.86 [IQR 0.83 to 0.99] versus 0.74 [IQR 0.69 to 0.81], difference of median 0.12; p = 0.03). Experiment 2: Lower limb muscle volume decreased at 4 weeks and gradually increased thereafter. The median muscle fiber size increased from 0.89 (IQR 0.75 to 0.90) at 24 weeks to 1.20 (IQR 1.08 to 1.34) at 48 weeks (difference of median 0.31; p< 0.01). The median amplitude increased from 0.60 (IQR 0.56 to 0.67) at 24 weeks to 0.81 (IQR 0.76 to 0.90) at 48 weeks (difference of median 0.21; p < 0.01). Despite tumor involvement and freezing treatment, tumor-bearing frozen grafts demonstrated nerve regeneration activity, with no local recurrence observed at 48 weeks postoperatively in nude rats. Conclusion: Tumor-bearing frozen nerve grafts demonstrated nerve regeneration activity, and there was no tumor recurrence in rats in vivo. Clinical Relevance: A frozen nerve autograft has a similar regenerative potential to that of a nerve autograft. Although the findings in a rat model do not guarantee efficacy in humans, if they are substantiated by large-animal models, clinical trials will be needed to evaluate the efficacy of tumor-bearing frozen nerve grafts in humans. [ABSTRACT FROM AUTHOR]

This paper examines three cases of spontaneous ruptures of the extensor pollicis longus (EPL) with the extensor pollicis brevis (EPB) deformity. The patients ranged from 39 to 71 years old. Non-dominant hands were involved in all three cases. There were no trauma nor pathological cause of EPL ruptures. A tendon transfer using the extensor indicis proprius was performed in each case. Intraoperative findings showed hypoplastic EPB in one case and EPB defects in two cases. A weak or defective EPB puts an excessive load on the EPL, which might be one of the causes of spontaneous EPL rupture. [ABSTRACT FROM AUTHOR]

Irradiation by light emitting diode (LED) promotes fibroblast proliferation and wound healing. However, its mechanism is still unknown. The purpose of this study was to clarify the mechanism of fibroblast proliferation by LED irradiation. Cultured NIH3T3 fibroblasts from normal mice were irradiated by LED with a center wavelength of 627 nm. LED irradiation was performed with an energy density of 4 J/cm(2), at subculture and 24 h later. The expression of several growth factors and their receptors was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR): platelet-derived growth factor (PDGF)-A, PDGF-B, and PDGF-C, transforming growth factor-beta (TGF-beta), basic fibroblast growth factor (bFGF), PDGF-alpha receptor, and TGF-beta receptor. Then, the activation of the extracellular signal-regulated kinase (ERK) pathway was examined by Western blotting with and without the PDGF receptor inhibitor. LED irradiation induced cell growth of NIH3T3 fibroblasts. The expression of PDGF-C had significantly increased in the irradiated group (P < 0.01). Although strong activation of the ERK pathway was observed in the irradiated group, its activation was completely suppressed by the PDGF receptor inhibitor. We concluded that LED irradiation promotes fibroblast proliferation by increasing autocrine production of PDGF-C and activating the ERK pathway through phosphorylation of the PDGF receptor. [ABSTRACT FROM AUTHOR]

Microglia, brain immune cells, engage in the clearance of dead cells or dangerous debris, which is crucial to the maintenance of brain functions. When a neighbouring cell is injured, microglia move rapidly towards it or extend a process to engulf the injured cell. Because cells release or leak ATP when they are stimulated or injured, extracellular nucleotides are thought to be involved in these events. In fact, ATP triggers a dynamic change in the motility of microglia in vitro and in vivo, a previously unrecognized mechanism underlying microglial chemotaxis; in contrast, microglial phagocytosis has received only limited attention. Here we show that microglia express the metabotropic P2Y6 receptor whose activation by endogenous agonist UDP triggers microglial phagocytosis. UDP facilitated the uptake of microspheres in a P2Y6-receptor-dependent manner, which was mimicked by the leakage of endogenous UDP when hippocampal neurons were damaged by kainic acid in vivo and in vitro. In addition, systemic administration of kainic acid in rats resulted in neuronal cell death in the hippocampal CA1 and CA3 regions, where increases in messenger RNA encoding P2Y6 receptors that colocalized with activated microglia were observed. Thus, the P2Y6 receptor is upregulated when neurons are damaged, and could function as a sensor for phagocytosis by sensing diffusible UDP signals, which is a previously unknown pathophysiological function of P2 receptors in microglia. [ABSTRACT FROM AUTHOR]

Camurati-Engelmann disease (CED) is a rare, progressive diaphyseal dysplasia characterized as diaphyseal hyperostosis and sclerosis of the long bones. Corticosteroids, bisphosphonates, and losartan have been reported to be effective systemic medications used to reduce CED symptoms. There are no reports of osteoblastoma in patients with CED, and osteoblastoma in the distal radius is rare. We present a patient diagnosed with CED, based on radiological and histological examinations, at 11 years old. At 22 years old, she experienced severe pain in her right forearm and was treated with bisphosphonate, losartan, and prednisolone; however, the pain continued. An expansive and sclerotic lesion at the distal radius was observed on radiography. A follow-up plain radiograph indicated that the lesion was growing. Fluorodeoxyglucose positron emission tomography revealed solitary, intense radiotracer uptake, and a biopsy and surgical resection were performed due to suspected malignancy. Pathologic analysis showed anastomosing bony trabeculae rimmed by osteoblasts observed in a loose fibrovascular stroma. The lesion was diagnosed as an osteoblastoma. Following bone excision and artificial bone grafting, the patient's severe pain almost completely disappeared. At final follow-up, no evidence of osteoblastoma recurrence was noted. To our knowledge, this is the first case report of osteoblastoma arising in a patient with CED. Bone excision and artificial bone grafting may be a treatment option for local symptomatic osteoblastoma in patients with CED. [ABSTRACT FROM AUTHOR]

Background: A histological diagnosis obtained from an intraoperative frozen section (FS) during biopsy confirms the adequacy of tumor tissue in the specimen. However, some cases show a discrepancy among the intraoperative FS diagnosis, permanent section (PS) diagnosis of the biopsy specimen, and the final diagnosis of the excised tumor specimen. In this study, we retrospectively investigated the diagnostic accuracy of the FS and PS for different types of bone tumors. Methods: This study included 377 patients with 411 bone tumors who underwent tumor excision after an open biopsy with intraoperative FS diagnosis. FS, PS, and final diagnoses of the patients were classified into benign tumors/tumor-like lesions, intermediate malignancies, and malignant tumors. To assess diagnostic accuracy, the histological grades in FS and PS diagnoses were compared with those in the final diagnoses. Results: The overall diagnostic accuracies of FS and PS were 93% and 97%, respectively. The accuracy of FS and PS for histological grade was 84% and 93% for chondrogenic tumors, 90% and 96% for osteogenic tumors, 97% and 98% for osteoclastic giant cell-rich tumors, 100% and 100% for tumors of undefined neoplastic nature, and 95% and 99% for other bone tumors, respectively. Conclusion: These data suggest that surgical planning based on PS diagnosis is recommended for chondrogenic and osteogenic tumors. [ABSTRACT FROM AUTHOR]

• Outcomes of decellularized nerve grafts seem inconsistent when using long grafts. • We developed adipose-derive stem cell (ADSC) sheets. • Decellularized nerves wrapped with ADSC sheets were used for implantation. • Accelerated nerve regeneration was observed with ADSC sheets wrapping. • Humoral factors ADSCs secrete may have positive effects on nerve regeneration. We developed a sheet of stem cells derived from adipose tissue (ADSC sheet). To improve transplantation, we wrapped decellularized nerves with ADSC sheets and examined the efficacy of this recellularized nerves in nerve regeneration. Decellularized nerves were prepared from sciatic nerves of Sprague-Dawley rats. Wistar rats were subjected to sciatic nerve injury and then randomly assigned to three groups (n = 7 per group), which were transplanted with 15-mm bridge grafts; the first group received a decellularized allogenic nerve implant, the second an ADSC sheet-wrapped decellularized allogenic nerve implant, and the third an autogenous nerves were implant. No significant differences were found in S100-positive and neurofilament-positive areas, axon density, and sciatic functional index (SFI) score between rats transplanted with ADSC sheet-wrapped nerve grafts and those that received autografts. In contrast, these parameters except SFI and the amplitude ratio were significantly larger in rats grafted with ADSC sheet-wrapped nerve than with the decellularized nerve. These results suggest that the number of regenerating axons, as well as their regenerating velocity, and the number of migrating Schwann cells into the implant in rats transplanted with ADSC sheet-wrapped nerves matched those in rats transplanted with autografts. These positive effects are possibly attributable to secretion of growth factors of ADSCs. [ABSTRACT FROM AUTHOR]

Background: For excised tumor specimens, histological grades can differ between the biopsy diagnosis and the final diagnosis. Methods: We retrospectively investigated the diagnostic accuracies of histological grades for frozen-section and permanent-section diagnoses from patients with soft-tissue tumors. Frozen-section, permanent-section, and final diagnoses were classified as benign tumors/tumor-like lesions, intermediate malignancies, or malignant tumors. Diagnostic accuracies of the histological grades from the frozen and permanent sections were evaluated by comparing the final diagnoses for the resected specimens. Results: The diagnostic accuracies of the histological grades for the frozen- and permanent-section diagnoses were 95% (387/408 lesions) and 97% (395/408 lesions), respectively. Among the tumor types, the diagnostic accuracies of the histological grades for the frozen-section and permanent-section diagnoses were 84% and 87% for adipocytic tumors, 87% and 91% for fibroblastic/myofibroblastic tumors, 99% and 100% for nerve-sheath tumors, 98% and 98% for fibrohistiocytic tumors, 90% and 98% for tumors of uncertain differentiation, 100% and 100% for vascular tumors, and 97% and 98% for other tumors, respectively. Conclusions: Histological grades from frozen-section diagnoses yielded low diagnostic accuracies in adipocytic and fibroblastic/myofibroblastic tumors. Treatment should be planned based on permanent-section diagnosis and radiological findings for these tumors. [ABSTRACT FROM AUTHOR]

Background: Use of an implant is one of the risk factors for surgical site infection (SSI) after malignant bone tumor resection. We developed a new technique of coating titanium implant surfaces with iodine to prevent infection. In this retrospective study, we investigated the risk factors for SSI after malignant bone tumor resection and to evaluate the efficacy of iodine-coated implants for preventing SSI.Methods: Data from 302 patients with malignant bone tumors who underwent malignant bone tumor resection and reconstruction were reviewed. Univariate analyses were performed, followed by multivariate analysis to identify risk factors for SSI based on the treatment and clinical characteristics.Results: The frequency of SSI was 10.9% (33/302 tumors). Pelvic bone tumor (OR: 4.8, 95% CI: 1.8-13.4) and an operative time ≥ 5 h (OR: 3.4, 95% CI: 1.2-9.6) were independent risk factors for SSI. An iodine-coated implant significantly decreased the risk of SSI (OR: 0.3, 95% CI: 0.1-0.9).Conclusion: The present data indicate that pelvic bone tumor and long operative time are risk factors for SSI after malignant bone tumor resection and reconstruction, and that iodine coating may be a promising technique for preventing SSI. [ABSTRACT FROM AUTHOR]

Background: Postoperative deep infection after bone tumor surgery remains a serious complication. Although there are numerous reports about risk factors for postoperative deep infection in general surgery, there is only a small number of reports about those for bone tumor surgery. This retrospective study aimed to identify risk factors for postoperative deep infection after bone tumor resection. Methods: We reviewed data of 681 patients (844 bone tumors) who underwent surgery. Associations between variables, including age, recurrent tumor, pathological fracture, surgical site (pelvis/other), chemotherapy, biological reconstruction, augmentation of artificial bone or bone cement, the use of an implant, intraoperative blood loss, operative time, additional surgery for complications, and postoperative deep infection were evaluated. Results: The rate of postoperative deep infection was 3.2% (27/844 tumors). A pelvic tumor (odds ratio [OR]: 3.4, 95% confidence interval [CI]: 1.0–11.3) and use of an implant (OR: 9.3, 95% CI: 1.9–45.5) were associated with an increased risk of deep infection. Conclusions: This retrospective study showed that pelvic tumor and use of an implant were independent risk factors for deep infection. This information will help surgeons prepare an adequate surgical plan for patients with bone tumors. [ABSTRACT FROM AUTHOR]

Nano TiO2 was dispersed in ethylene glycol (EG) by the replacement of dispersion medium from water sol. EG/TiO2 suspension was well stabilized by the electrostatic repulsive force when pH value of suspension was less than 4.3. In situ polymerization starting from bis(2-hydroxyethyl) terephthalate (BHET) and EG/TiO2 suspension was carried out to prepare a series of poly(ethylene terephthalate) (PET)/TiO2 nanocomposites. Under highly acidic conditions, 97% particles dispersed in PET matrix had the size less than 100 nm. With the increase of pH value, aggregation occurred and larger size particles appeared. A tensile test showed that Young's modulus of PET was increased by the addition of nano TiO2 [ABSTRACT FROM AUTHOR]

Simple Summary: Background: It is challenging to differentiate between enchondromas and atypical cartilaginous tumors (ACTs)/chondrosarcomas. Methods: To evaluate the diagnostic usefulness of radiological findings for differentiation between enchondromas and chondrosarcomas, correlations between various radiological findings and final diagnoses were investigated. Based on the correlations, a scoring system combining these findings was developed. Results: In a cohort of 81 patients, periosteal reaction on X-ray, endosteal scalloping and cortical defect on CT, extraskeletal mass, multilobular lesion, abnormal signal in adjacent tissue on MRI, and increased uptake in bone scan and thallium scan was significantly correlated with final diagnoses. Based on the correlations, a radiological scoring system combining radiological findings was developed. In another cohort of 17 patients, the sensitivity, specificity, and accuracy of the radiological score rates for differentiation between enchondromas and chondrosarcomas were 88%, 89%, and 88%, respectively. Conclusion: Comprehensive assessment combining radiological findings is recommended to differentiate between enchondromas and ACTs/chondrosarcomas. Background: It is challenging to differentiate between enchondromas and atypical cartilaginous tumors (ACTs)/chondrosarcomas. In this study, correlations between radiological findings and final diagnosis were investigated in patients with central cartilaginous tumors. Methods: To evaluate the diagnostic usefulness of radiological findings, correlations between various radiological findings and final diagnoses were investigated in a cohort of 81 patients. Furthermore, a new radiological scoring system was developed by combining radiological findings. Results: Periosteal reaction on X-ray (p = 0.025), endosteal scalloping (p = 0.010) and cortical defect (p = 0.002) on CT, extraskeletal mass (p < 0.001), multilobular lesion (p < 0.001), abnormal signal in adjacent tissue (p = 0.004) on MRI, and increased uptake in bone scan (p = 0.002) and thallium scan (p = 0.027) was significantly correlated with final diagnoses. Based on the correlations between each radiological finding and postoperative histological diagnosis, a radiological scoring system combining these findings was developed. In another cohort of 17 patients, the sensitivity, specificity, and accuracy of the radiological score rates for differentiation between enchondromas and ACTs/chondrosarcomas were 88%, 89%, and 88%, respectively (p = 0.003). Conclusion: Radiological assessment with combined radiological findings is recommended to differentiate between enchondromas and ACT/chondrosarcomas. [ABSTRACT FROM AUTHOR]