Shoulder girdle recognition using electrophysiological and low frequency anatomical contraction signals for prosthesis control

Shoulder disarticulation amputees account for a small portion of upper-limb amputees,thus little emphasis has been devoted to developing functional prosthesis for this cohort of amputees.In this study,shoulder girdle recognition was investigated with acquired data from electrophysiological(electromyography[EMG])and low frequency contraction(accelerometer[Acc])signals from both amputee and non-amputee participants.The contribution of this study is based around the contrast of the classification accuracy(CA)for different sensor configurations using a unique set of signal features.It was seen that the fusion of the EMG-Acc produced an enhancement in the CA in the range of 10%-20%,depending on which windowing parameters were considered.From this,it was seen that the best combination of a windowing scheme and classifier would likely be for the 350 ms and spectral regression discriminant analysis,with a fusion of the EMG-Acc information.The results have thus provided evidence that the two sensors can be combined and used in practice for prosthesis control.Taking a holistic view on the study,the authors conclude by providing a framework on how the shoulder motion recognition could be combined with neuromuscular reprogramming to contribute towards easing the cognitive burden of amputees during the prosthesis control process.

Mechanisms of shoulder trauma: Current concepts

Acute traumatic injuries to the glenohumeral articulation are common.The types of injuries depend on age,muscle strength,bone density,and biomechanics of the traumatic event.Understanding the different mechanisms of trauma and how they affect the functional anatomical structures of the shoulder joint is crucial for the treatment of these lesions.Therefore,when clinicians have knowledge of these mechanisms they can accurately diagnose and treat shoulder pathology and predict distinct injury patterns.Here,we have described the fundamentals of the mechanisms of injury of the glenohumeral dislocation,dislocation with fracture of the humeral head,and the proximal humerus fracture.We have focused on common injury mechanisms and the correlation with radiological diagnostics.Radiological and laboratory findings of distinct types of injury were also discussed.

Buechel Pappas Resurfacing Shoulder Replacement: Evolution and over 40 Years of Clinical Experience

Background: Early exploration of the semi constrained “Floating-Socket” total shoulder replacement (TSR) in 1974 led to a proliferation of various unconstrained designs that allowed resection or retention of the humeral head, depending upon the pathological process involved. Degenerative glenohumeral arthritis with mild to moderate involvement of subchondral bone allowed for a resurfacing option, while severe humeral head involvement required a partial or full humeral head replacement attached to an intramedullary stem for fixation. All components evolved from cemented to cementless application by 1982. The purpose of this paper is to describe the progression of Buechel-Pappas (B-P) shoulder replacement development from the early 1970’s in both cemented and cement less applications. Methods: Clinical evaluations of “Floating-Socket” TSR, followed by B-P stem-type, resurfacing types, bipolar-type and revision components, all of which comprise the B-P Shoulder Replacement System, were performed over a 49-year period. Results: “Floating-Socket” implants improved the results of simple, constrained ball-in-socket designs, but generally failed by glenoid component loosening in both chimpanzee and human applications. Unconstrained resurfacing-type components, both anatomical humeral head and full proximal humeral components, were quite successful, with minimal failures observed in long-term studies. Bipolar salvage implants, used for severe proximal deficiencies, revisions and massive rotator cuff arthropathy, were also very successful;providing overhead range of motion in many patients. Conclusions: Resurfacing hemiarthroplasty, in patients with intact or repairable rotator cuff mechanisms, gave the most satisfactory results and were the least technically complicated to perform, requiring minimal instrumentation. Resurfacing of full proximal humeral deficiencies, using femoral resurfacing components, gave similar clinical results to more complex semi-constrained devices, also with less technical difficulties and simple instrumentation.

Indication and surgical approach for reconstruction with endoprosthesis in bone-associated soft tissue sarcomas:Appropriate case management is vital

It is important for surgeons performing sarcoma surgery to know that bone resection and tumor prosthesis applications in soft tissue sarcomas(STS)have unique features in terms of indication,surgical approach and follow-up,in terms of the management of these cases.Some STS are associated with bone and major neurovascular structures.Bone-associated STS are generally relatively large and relatively deep-seated.Additionally,the tendency for metastasis is high.In some cases,the decision about which structures to resect is difficult.These cases are often accompanied by poor oncological and surgical outcomes.Management of cases should be done by a multidisciplinary team in advanced centers specialized in this field.The surgical team must have sufficient knowledge and experience in the field of limb-sparing surgery.Preoperative evaluation and especially good planning of bone and soft tissue reconstruction are vital.

Surgical Treatment of Anterior Shoulder Instabilities Using the Latarjet Technique (about 40 Cases)

Purpose: Surgical treatment of chronic anterior shoulder instability is a difficult therapeutic challenge for contact athletes. The aim of our study is to evaluate the clinical and radiological results of 40 cases of chronic anterior shoulder instability treated in our institution by Latarjet technique. Methods: We report our experience with the intervention of Latarjet modified by the analysis of a retrospective study of 40 cases. They were all young athletic men, with an average age of 29 years with a predominance of the dominant shoulder. Results: Eighty percent had bone lesions, the first dislocation being traumatic (plating). One patient had a recurrence of his instability due to a new trauma and 67% resumed sport within an average period of eight months, some of whom still had functional discomfort in sports practice (9 patients). After an average follow-up of 75 months, 93% of patients were satisfied with their intervention. Only two mechanical complications were observed. Conclusion: Chronic anterior shoulder instability is pathology of young and active subjects. The preregulenoid coracoid block according to Latarjet represents the therapeutic method of choice in the treatment of chronic anterior instabilities of the shoulder, especially in young and athletic subjects. The result of this intervention remains good despite the complications that can occur such as pseudarthrosis, osteoarthritis, lysis or mobility of the screw.

Effect of Wearing a Maxillofacial Prosthesis on Masticatory Rhythm Improvement in Mandibulectomy Patients

Background: Recording jaw movement rhythms in patients with jaw defects is challenging using conventional tracking devices. However, masticatory rhythm is crucial for masticatory performance and nutritional intake. This study aimed to explore the impact of using a maxillofacial prosthesis to restore masticatory rhythm in mandibulectomy patients with a novel wearable device. Methods: Twelve patients who underwent mandibulectomy and were rehabilitated with maxillofacial prosthesis were recruited. Chewing rate, cycle durations, coefficient of variation of cycle durations (CV), changing times of skin morphology on the back of the ear pinna area (SM), and masticatory performance were measured during gum chewing without and with a denture using a wearable jaw movement rhythm tracking device. A paired t-test and the Pearson correlation coefficient were used for statistical analysis. Results: The chewing rate increased by 8.6 cycles/min with dentures (P P = 0.01). The CV and SM decreased with dentures (P = 0.004 and P = 0.01, respectively). Significant correlations were found between the CV and SM without dentures (P = 0.004). Conclusion: 1. Wearing maxillofacial prostheses can improve masticatory rhythm in patients who undergo mandibulectomy with Eichner B2 occlusal supports. 2. The wearable device is available for measuring masticatory rhythm in patients with jaw defects in clinics. 3. Changing times of the skin morphology on the back of the ear pinna indicate jaw movement stability through a simpler process than the coefficient of variation of cycle durations.

Transfer film effects induced by 3D-printed polyether-ether-ketone with excellent tribological properties for joint prosthesis

Based on the building principle of additive manufacturing,printing orientation mainly determines the tribological properties of joint prostheses.In this study,we created a polyether-ether-ketone(PEEK)joint prosthesis using fused filament fabrication and investigated the effects of printing orientation on its tribological properties using a pin-on-plate tribometer in 25% newborn calf serum.An ultrahigh molecular weight polyethylene transfer film is formed on the surface of PEEK due to the mechanical capture of wear debris by the 3D-printed groove morphology,which is significantly impacted by the printing orientation of PEEK.When the printing orientation was parallel to the sliding direction of friction,the number and size of the transfer film increased due to higher steady stress.This transfer film protected the matrix and reduced the friction coefficient and wear rate of friction pairs by 39.13%and 74.33%,respectively.Furthermore,our findings provide a novel perspective regarding the role of printing orientation in designing knee prostheses,facilitating its practical applications.

Stresses in the Scapular Fossa Do Not Exceed the Yield Stress When Elevated up to 135 Degrees of Abduction after Reverse Shoulder Arthroplasty

Reverse shoulder arthroplasty (RSA) is an effective treatment for rotator cuff tears. Despite its advantages, complications occur at a high rate. Complications requiring revision include a high rate of base plate failure, 38% of which are due to instability. The primary stability the base plate ensures is a crucial factor and, thus, is the subject of much debate in clinical studies and biomechanical research. This study is aimed to provide data that will contribute to the base plate’s pri-mary stability and glenoid longevity by clarifying the stresses at the scapular fossa and base plate interface associated with elevation after RSA. A 3D finite element model was created from the DICOM data for the scapulohumeral joint and SMR shoulder system. For loading conditions, 30 N was applied for each posi-tion with abduction angles of 0, 45, 90, and 135 degrees. A three-dimensional fi-nite element analysis was performed using the static implicit method with LS-DYNA. The von Mises stresses in the scapular fossa were found not to exceed the yield stress on the bone even after elevation to an abduction angle of 135 de-grees after RSA. It is rough to uniformly compare the yield stress and the von Mises stress, but it was inferred that the possibility of fracture is low unless a large external force is applied. A maximum von Mises stress showed 0 degrees of abduction, suggesting that the lowered position is in a more severe condition than the elevated position. If better improvement is desired, it may be necessary to devise ways to reduce the stress on the upper screw. .

Effect of electroacupuncture combined with rehabilitation techniques on shoulder function in patients with rotator cuff injuries

BACKGROUND The rotator cuff is located below the acromion and deltoid muscles and comprises multiple tendons that wrap around the humeral head,maintaining shoulder joint stability.AIM To explore the effect of electroacupuncture combined with rehabilitation techniques on shoulder function in patients with rotator cuff injuries.METHODS We selected 97 patients with rotator cuff injuries treated in the People's Hospital of Yuhuan from February 2020 to May 2023.Patients were grouped using the envelope method.RESULTS After treatment,the study group’s treatment effective rate was 94.90%(46/49 patients),significantly higher than that in the control group(79.17%,38/48 cases;P<0.05).Before treatment,there was no difference in Constant Murley Score(CMS)scores,shoulder mobility,or 36-Item Short Form Health Survey(SF-36)scale scores(P>0.05).Compared with those before treatment,the CMS scores(including pain,daily living ability,shoulder mobility,and muscle strength),all aspects of shoulder mobility(forward flexion,posterior extension,external rotation,internal rotation),and SF-36 scale scores(including physiological,psychological,emotional,physical,vitality,and health status)were higher in both groups after treatment and significantly higher in the study group(P<0.05).There was no difference in the occurrence of complications between the two treatment groups(P>0.05).CONCLUSION Electroacupuncture combined with rehabilitation techniques has a good treatment effect on patients with rotator cuff injuries,helps accelerate the recovery of shoulder function,improves the quality of life,and is highly safe.

High rate of clinically relevant improvement following anatomical total shoulder arthroplasty for glenohumeral osteoarthritis

BACKGROUND The minimal clinically important difference(MCID)is defined as the smallest meaningful change in a health domain that a patient would identify as important.Thus,an improvement that exceeds the MCID can be used to define a successful treatment for the individual patient.AIM To quantify the rate of clinical improvement following anatomical total shoulder arthroplasty for glenohumeral osteoarthritis.METHODS Patients were treated with the Global Unite total shoulder platform arthroplasty between March 2017 and February 2019 at Herlev and Gentofte Hospital,Denmark.The patients were evaluated preoperatively and 3 months,6 months,12 months,and 24 months postoperatively using the Western Ontario Osteoarthritis of the Shoulder index(WOOS),Oxford Shoulder Score(OSS)and Constant-Murley Score(CMS).The rate of clinically relevant improvement was defined as the proportion of patients who had an improvement 24 months postoperatively that exceeded the MCID.Based on previous literature,MCID for WOOS,OSS,and CMS were defined as 12.3,4.3,and 12.8 respectively.RESULTS Forty-nine patients with a Global Unite total shoulder platform arthroplasty were included for the final analysis.Mean age at the time of surgery was 66 years(range 49.0-79.0,SD:8.3)and 65%were women.One patient was revised within the two years follow-up.The mean improvement from the preoperative assessment to the two-year follow-up was 46.1 points[95%confidence interval(95%CI):39.7-53.3,P<0.005]for WOOS,18.2 points(95%CI:15.5-21.0,P<0.005)for OSS and 37.8 points(95%CI:31.5-44.0,P<0.005)for CMS.Two years postoperatively,41 patients(87%)had an improvement in WOOS that exceeded the MCID,45 patients(94%)had an improvement in OSS that exceeded the MCID,and 42 patients(88%)had an improvement in CMS that exceeded the MCID.CONCLUSION Based on three shoulder-specific outcome measures we find that approximately 90%of patients has a clinically relevant improvement.This is a clear message when informing patients about their prognosis.

Ultrasound of the Rotator Cuff in Non-Fractured Shoulder Trauma: 30 Cases at the Yalgado Ouedraogo University Hospital of Ouagadougou (Burkina Faso)

Introduction: Ultrasound is the imaging technique of choice for the study of rotator cuff lesions. However, in the case of shoulder trauma, it is rarely requested in our context. This study aimed to show ultrasound lesions of the rotator cuff in cases of non-fracture shoulder trauma at the CHUYO in Ouagadougou. Methodology: This was a prospective descriptive cross-sectional study running from August 1 to November 30, 2017, in the medical imaging department of CHUYO. The study population consisted of patients received in the department for ultrasound in the context of non-fracture shoulder trauma. Results: We collected 20 cases (66.67%) of rotator cuff lesions out of 30 non-fracture shoulder injuries. The mean age of the patients was 27.6 years. Road traffic accidents accounted for 60% of injuries, sports accidents for 30%, and domestic accidents for 10%. Ultrasound lesions were mainly tendon ruptures (36.67%) and tendinitis (23.33%). Ruptures were non-transfixing in 90.90% of cases. The supraspinatus was the most affected (81.81%). Conclusion: Ultrasound can help diagnose rotator cuff injuries, particularly in non-fractured shoulder trauma.

Microstructure and mechanical properties of stationary shoulder friction stir welding joint of 2A14-T62 aluminum alloy

2A14-T62 butt joint was successfully welded by stationary shoulder friction stir welding(SSFSW)method.The results showed that using a pin with small shoulder could broaden the process window,and under a rotation speed of 2000 r/min and welding speed of 30 mm/min,joint with smooth surface,small reduction in thickness and little inner defects was obtained.The weld nugget zone was approx-imately circular,which was a unique morphology for SSFSW.The heat-affected zone(HAZ)and thermo-mechanically affected zone(TMAZ)were both quite narrow due to the lower heat input and slight mechanical action of the stationary shoulder.The fraction of high angle grain boundaries(HAGBs)exhibited a“W”shape along horizontal direction(from advancing side to retreating side),and the minim-um value located at HAZ.The average ultimate tensile strength and elongation of the joint were 325 MPa and 4.5%,respectively,with the joint efficiency of 68.3%.The joint was ductile fractured and the fracture surface contained two types of dimples morphology in different re-gions of the joint.Microhardness distribution in the joint exhibited a“W”shape,and the difference along the thickness direction was negli-gible.The joint had strong stress corrosion cracking susceptibility,and the slow stain rate tensile strength was 139 MPa.Microcrack and Al2O3 particulates were observed at the fracture surface.

Study on the Effect of Repetitive Peripheral Magnetic Stimulation Combined with Conventional Rehabilitation Measures on Shoulder Dysfunction in Early Stroke

Objective:To study the effect of repetitive peripheral magnetic stimulation(rPMS)combined with conventional rehabilitation measures on shoulder dysfunction in early stroke.Methods:60 patients with shoulder dysfunction in early stroke were selected,and all of them were admitted to our hospital from August 2021 to August 2023.The patients were randomly grouped into a control group(conventional rehabilitation measures intervention,30 cases)and an intervention group(rPMS and conventional rehabilitation measures intervention,30 cases)according to the lottery method.The pain scores,shoulder mobility,and motor function scores of the two groups were compared.Results:The pain score was lower in the intervention group,and the shoulder mobility and motor function scores were higher in the intervention group(P<0.05)as compared to that of the control group.Conclusion:The effect of combining rPMS and conventional rehabilitation measures in treating shoulder dysfunction in early stroke was remarkable and should be popularized.

Efficacy and safety of intravenous tranexamic acid in total shoulder arthroplasty:A meta-analysis

BACKGROUND Total shoulder arthroplasty(TSA)results in a large amount of perioperative blood loss due to severe trauma.AIM To investigate the safety and efficacy of intravenous tranexamic acid(TXA)in TSA.METHODS We searched the PubMed,Cochrane Library,Embase and Web of Science databases for randomized controlled trials(RCTs)on the use of TXA in TSA.And all the results were checked and assessed by Reference Citation Analysis(https://www.referencecitationanalysis.com/).A meta-analysis was performed with Review Manager 5.3 to calculate the odds ratio(OR)or weighted mean difference(WMD)of related outcome indicators.RESULTS A total of 5 RCTs with level 1 evidence were included.There were 369 cases,with 186 in the TXA group and 183 in the placebo group.The meta-analysis showed that TXA can significantly reduce total blood loss during the perioperative period[WMD=-249.56,95%confidence interval(CI):-347.6 to-151.52,P<0.0001],and the incidence of adverse reactions was low(OR=0.36,95%CI:0.16-0.83,P=0.02).Compared with the placebo group,the TXA group had significantly less total haemoglobin loss(WMD=-34.39,95%CI:-50.56 to-18.22),less haemoglobin fluctuation before and after the operation(WMD=-0.6,95%CI:-0.93 to-0.27)and less 24-h drain output(WMD=-136.87,95%CI:-165.87 to-106.49).There were no significant differences in the operation time(P=0.11)or hospital length of stay(P=0.30)between the two groups.CONCLUSION The application of intravenous TXA in the perioperative period of TSA can significantly reduce the total volume of perioperative blood loss and reduce the incidence of adverse reactions,so TXA is worthy of widespread clinical use.

Effects of different positions on rehabilitation after rotator cuff repair under shoulder arthroscopy

Objective Shoulder arthroscopic rotator cuff tear repair is currently the main treatment for full-thickness rotator cuff tears,and postoperative rehabilitation training is essential.However,pain and limitation of activity during the rehabilitation process will lead to poor results.Hence,identifying rehabilitation approaches is crucial.This study aimed to compare patient's rehabilitation outcomes and experience between rehabilitation in the supine position and in the standing position.Methods This prospective study included patients diagnosed with full-thickness rotator cuff tears who underwent shoulder arthroscopic double-row rivet repair at Sir Run Run Shaw Hospital,Zhejiang University School of Medicine from March 2019 to September 2021.The patients were randomly assigned to the standing rehabilitation exercise group(group A)and the supine rehabilitation exercise group(group B).All patients were followed up for 6 months to record and compare the visual analog scale(VAS)scores,shoulder range of motion,and rehabilitation compliance.Results Altogether,86 patients participated in the study,of whom 79 patients completed the 6-month follow-up.Groups A and B had 39 and 40 patients,respectively.Before operation,the VAS score,forward flexion and extension angle,and abduction angle were comparable between groups A and B.After operation,the patients in groups A and B all experienced a significant improvement in the VAS score,forward flexion and extension angle,and abduction angle(p<0.05).In addition,patients in group B had better VAS score(4.58±0.87 vs.5.21±1.13,p=0.0068;2.15±0.66 vs.2.51±0.51,p=0.0078;0.78±0.86 vs.1.33±0.81,p=0.0015),forward flexion and extension angle(109.30±2.87°vs.102.33±3.74°,p=0.0001;109.53±3.39°vs.104.18±2.76°,p=0.0001;125.22±6.05°vs.117.59±2.27°,p=0.0001),and abduction angle(91.78±2.77°vs.82.92±2.12°,p=0.0001;91.62±2.78°vs.82.82±1.45°,p=0.0001;109.48±3.37°vs.100.10±2.94°,p=0.0001)at 2 wk,6 wk and 6 m postoperatively.Conclusion After 6 months of follow-up,the patients who performed rehabilitation exercises in the supine position achieved better rehabilitation outcomes than those who performed rehabilitation exercises while standing.

Gait Analysis of a Subject with Tarsometatarsal Prosthesis

Introduction: Gait analysis of an adult man after trans-metatarsal unilateral amputation is described. Objective: Instrumental gait analysis of a subject 15 years after trans-metatarsal unilateral amputation in two footwear conditions: while walking barefoot and with prosthesis. Materials and Methods: In a movement analysis laboratory, locomotion studies were carried out at freely chosen walking speed by a 65-year-old subject, obtaining kinematic, kinetic and surface electromyographic data in time and space. Gait analysis was performed using instrumental technologies from a digital eco-system applying walking protocols. Results: When the patient wore the prosthesis, several positive improvements were observed in various aspects of gait. These included enhancements in the base of support, gait speed, and joint range of movements. Additionally, there was a slight improvement in the vertical ground reaction forces pattern, indicating a positive effect of the assistive technology. Furthermore, the use of the prosthesis led to a more organized pattern of muscle activity, which further supports its beneficial impact. However, it is worth noting that some challenges still persisted, particularly regarding stabilizing the body during the double support phase. Despite this difficulty, the overall findings suggest that the use of the prosthesis offers valuable improvements to the patient’s gait dynamics. Conclusions: After conducting a thorough analysis of the parameters related to the gait of a subject who underwent a trans-metatarsal unilateral amputation fifteen years ago, it was found that the use of prosthesis had a positive impact. This study demonstrated important improvements in some kinematic and kinetic parameters, including muscle activation patterns, indicating an increase in comfort and confidence while utilizing the prosthetic device.

Electrophysiological evaluation of alterations in penile sensation due to penile prosthesis implantation in patients with erectile dysfunction

Objective The present study was aimed to determine the effect of penile prosthesis implantation(PPI)surgery on penile sensation by evaluating the penile electromyography(EMG)variables.Methods The research was designed as a prospective study.Thirty patients who were diagnosed with organic erectile dysfunction and had underwent PPI surgery between January 2017 and January 2018 in the Urology Clinic of Antalya Training and Research Hospital were included in this study.Penile sensory EMG was performed on each patient 1 day prior to the surgery by the Physical Therapy and Rehabilitation clinic.Additionally,the control EMG study was also performed in the 3rd and 6th postoperative months.Results We included 27 patients in this study who attended regular follow-ups and had complete EMG results.Out of the 27 patients,23(85.2%)patients had received malleable(ProMedon)penile prosthesis,one(3.7%)patient had received a two-piece inflatable(Ambicor)penile prosthesis,and three(11.1%)patients had received a three-piece inflatable(AMS 700 CXR)penile prosthesis.The mean nerve conduction value(NCV)of the patients was 29.85(standard derivation:22.54;range:0-78.4)m/s during the preoperative period,whereas it was 27.64(standard derivation:24.72;range:0-83.3)m/s in the 3rd postoperative month and 24.80(standard derivation:22.31;range:0-88.4)m/s in the 6th postoperative month.There was no significant difference between preoperative NCV and 3rd postoperative month NCV(p=0.607).Similarly,no significant difference was observed between preoperative NCV and 6th postoperative month NCV(p=0.276).Additionally,the change between NCV values at postoperative 3rd and 6th months was not statistically significant(p=0.553).Conclusion Significant loss of penile sensation does not occur in patients who undergo PPI surgery.

Recent Traumatic Dislocations of the Shoulder in Adults: Epidemiological, Therapeutic and Evolutionary Aspects

Introduction: Shoulder dislocations represent about 50% of all joint dislocations. The objective was to describe the epidemiological, therapeutic and evolutionary aspects of traumatic shoulder dislocations in Bouaké. Methods: This retrospective and descriptive study was conducted between January 2017 and December 2019. It concerned patients over 15 years of age with a recent traumatic shoulder dislocation treated and followed in the department. The variables studied were epidemiological, therapeutic and evolutionary. The severity of the trauma was assessed according to the Injury Severity Score (ISS). Functional outcome was assessed according to the Constant score. Results: There were 49 patients (49 dislocations) out of 22,569 patients. The prevalence was 0.2%. The mean age was 32 years (17 - 62). There were 38 men (77.5%). The sex ratio was 3.4. Students predominated (n = 10;20.4%). The etiology was dominated by road traffic accidents (n = 19;38.8%). Anterior dislocation was the most common (n = 45;92%). The ISS score was minor (n = 46;93.8%). The mean time to reduction was 7 hours (4 - 16). Orthopaedic reduction using the Kocher technique predominated (n = 44;89.8%). The mean duration of external rotation immobilisation of the shoulder was 23 days (16 - 45). Recurrence occurred in 8 patients (21.6%). The functional outcome at a mean Constant follow-up of 15 months (8 - 20) was satisfactory (n = 44;89.8%). Conclusion: Traumatic dislocation of the shoulder represented 0.2%. Treatment was mainly orthopaedic. Recurrence was rare.

Atypical progress of frozen shoulder after COVID-19 vaccination:A case report

BACKGROUND After vaccination was mandated worldwide,various adverse effects associated with the coronavirus disease 2019(COVID-19)vaccination,including shoulder pain,have been reported.Here,we report a case of new-onset shoulder pain after BNT162b2(Comirnaty,Pfizer-BioNTech)mRNA vaccination.CASE SUMMARY A 50-year-old man visited our rehabilitation center with left shoulder range of motion(ROM)limitation that had persisted for more than 5 mo.The history included no specific noteworthy events,except vaccination.The pain in the patient’s left deltoid muscle appeared 1 day after the second BNT162b2 vaccination and intensified to severe pain.The patient self-administered aspirin,with which the pain subsided immediately,whereas ROM limitation persisted.At the first visit,the patient complained of dull pain and ROM restriction of the left shoulder(flexion 130°,abduction 110°,and external rotation 40°).Among the diagnostic studies conducted for the evaluation of the shoulder,magnetic resonance imaging showed a thickened coracohumeral ligament.Nerve conduction studies and needle electromyography showed no electrodiagnostic abnormalities.The patient received comprehensive rehabilitation for 7 mo and had an overall improvement in pain and ROM of the left shoulder.CONCLUSION In this case of severe shoulder pain after COVID-19 vaccination that subsided immediately with aspirin treatment,the exact cause and mechanism of pain are unclear.However,the clinical symptoms and diagnostic workups in our report suggest the possibility that the COVID-19 vaccination triggered an immunochemical response that resulted in shoulder pathology.

Application of Tranexamic Acid in Shoulder Arthroscopic Surgery:A Randomised Controlled Trial

Objective To explore the optimal administration route of tranexamic acid(TXA)in shoulder arthroscopic surgery.Methods Patients undergoing arthroscopic rotator cuff repair were randomly divided into four groups:control group(without TXA treatment),intravenous group(TXA was intravenously administered 10 minutes before surgery),irrigation group(TXA was added to the irrigation fluid during subacromial decompression and acromioplasty),and intravenous plus irrigation group(TXA was applied both intravenously and via intra-articular irrigation).The primary outcome was visual clarity assessed with visual analog scale(VAS)score,and the secondary outcomes included irrigation fluid consumption and time to subacromial decompression and acromioplasty procedure.Results There were 134 patients enrolled in the study,including 33 in the control group,35 in the intravenous group,32 in the irrigation group,and 34 in the intravenous plus irrigation group.The median and interquartile range of VAS scores for the intravenous,irrigation,and intravenous plus irrigation groups were 2.70(2.50,2.86)(Z=-3.677,P=0.002),2.67(2.50,2.77)(Z=-3.058,P<0.001),and 2.91(2.75,3.00)(Z=-6.634,P<0.001),respectively,significantly higher than that of the control group[2.44(2.37,2.53)].Moreover,the control group consumed more irrigation fluid than the intravenous group,irrigation group,and intravenous plus irrigation group(all P<0.05).The intravenous plus irrigation group consumed less irrigation fluid than either the intravenous group or the irrigation group(both P<0.001).There was no difference in subacromial decompression and acromioplasty operative time among the four groups.Conclusion TXA applied both topically and systematically can improve intraoperative visual clarity,and the combined application is more effective.