Elevated fluid and glycosaminoglycan content in the Achilles tendon contribute to higher intratendinous pressures:Implications for Achilles tendinopathy

Background:Tendinopathy alters the compositional properties of the Achilles tendon by increasing fluid and glycosaminoglycan content.It has been speculated that these changes may affect intratendinous pressure,but the extent of this relationship remains unclear.Therefore,we aimed to investigate the impact of elevated fluid and glycosaminoglycan content on Achilles tendon intratendinous pressure and to determine whether hyaluronidase(HYAL) therapy can intervene in this potential relationship.Methods:Twenty paired fresh-frozen cadaveric Achilles tendons were mounted in a tensile-testing machine and loaded up to 5% strain.Intratendinous resting(at 0% strain) and dynamic pressure(at 5% strain) were assessed using the microcapillary infusion technique.First,intratendinous pressure was measured under native conditions before and after infusion of 2 mL physiological saline.Next,80 mg of glycosaminoglycans were administered bilaterally to the paired tendons.The right tendons were additionally treated with 1500 units of HYAL.Finally,both groups were retested,and the glycosaminoglycan content was analyzed.Results:It was found that both elevated fluid and glycosaminoglycan content resulted in higher intratendinous resting and dynamic pressures(p <0.001).HYAL treatment induced a 2.3-fold reduction in glycosaminoglycan content(p=0.002) and restored intratendinous pressures.Conclusion:The results of this study demonstrated that elevated fluid and glycosaminoglycan content in Achilles tendinopathy contribute to increased intratendinous re sting and dynamic pressures,which can be explained by the associated increased volume and reduced permeability of the tendon matrix,respectively.HYAL degrades glycosaminoglycans sufficiently to lower intratendinous pressures and may,therefore,serve as a promising treatment.

Application of real-time shear wave elastography to Achilles tendon hardness evaluation in older adults

BACKGROUND Real-time shear wave elastography(SWE)is a non-invasive imaging technique used to measure tissue stiffness by generating and tracking shear waves in real time.This advanced ultrasound-based method provides quantitative information regarding tissue elasticity,offering valuable insights into the mechanical properties of biological tissues.However,the application of real-time SWE in the musculoskeletal system and sports medicine has not been extensively studied.AIM To explore the practical value of real-time SWE for assessing Achilles tendon hardness in older adults.METHODS A total of 60 participants were enrolled in the present study,and differences in the elastic moduli of the bilateral Achilles tendons were compared among the following categories:(1)Age:55-60,60-65,and 65-70-years-old;(2)Sex:Male and female;(3)Laterality:Left and right sides;(4)Tendon state:Relaxed and tense state;and(5)Tendon segment:Proximal,middle,and distal.RESULTS There were no significant differences in the elastic moduli of the bilateral Achilles tendons when comparing by age or sex(P>0.05).There were,however,significant differences when comparing by tendon side,state,or segment(P<0.05).CONCLUSION Real-time SWE plays a significant role compared to other examination methods in the evaluation of Achilles tendon hardness in older adults.

Adenylate cyclase activates the cAMP signalling pathway to enhance platelet-rich plasma-treated Achilles tendon disease,a theoretical bioinformatics-based study

The effectiveness of platelet-rich plasma(PRP)for the treatment of Achilles tendon disorders still needs to be evaluated through a series of prospective studies,but genomic analysis can reveal the existence of complementary PRP treatment options.Based on the 96 platelet activation-related genes in the Kyoto Encyclopedia of Genes and Genomes(KEGG)database,we performed Gene Ontology functional enrichment analysis and KEGG enrichment analysis,pathway correlation analysis,and enrichment mapping to determine the enrichment results of the gene set enrichment analysis and found that the cAMP signalling pathway may be the key to enhancing the effectiveness of PRP treatment.The cAMP signalling pathway interacts with the Rap1 signalling pathway and cGMPPKG signalling pathway to mediate the entire pathophy-siological process of Achilles tendon disease.Moreover,ADCY1-9 may be the key to the activation of the cAMP signalling network.Further based on the data in the Gene Expression Omnibus database,it was found that ADCY4 and ADCY7 may be the players that play a major role,associated with the STAT4-ADCY4-LAMA5 axis and the GRbeta-ADCY7-SEMA3C axis,which is expected to be a complementary target for enhancing the efficacy of PRP in the treatment of Achilles tendon disease.

Epidemiology of insertional and midportion Achilles tendinopathy in runners:A prospective cohort study

Background:Achilles tendinopathy(AT)is a common problem among runners.There is only limited evidence for risk factors for AT,and most studies have not defined the AT subcategories.No study has compared the incidence and risk factors between insertional AT and midportion AT,though they are considered distinct.This study aimed to assess incidence and risk factors of AT based on data from a large prospective cohort.The secondary aim was to explore differences in risk factors between insertional and midportion AT.Methods:Participants were recruited from among registered runners at registration for running events.Questionnaires were completed at baseline,1 month before the event,1 week before the event,and 1 month after the event.Information concerning demographics,training load,registered events,and running-related injuries were collected at baseline.The follow-up questionnaires collected information about new injuries.A pain map was used to diagnose midportion and insertional AT.The primary outcome was the incidence of AT.Multivariable logistic regression analysis was applied to identify risk factors for the onset.Results:We included 3379 participants with a mean follow-up of 20.4 weeks.The incidence of AT was 4.2%.The proportion of insertional AT was 27.7%and of midportion AT was 63.8%;the remaining proportion was a combined type of insertional and midportion AT.Men had a significantly higher incidence(5%,95%confidence interval(95%CI):4.1%-6.0%)than women(2.8%,95%CI:2.0%-3.8%).AT in the past12 months was the most predominant risk factor for new-onset AT(odds ratio(OR)=6.47,95%CI:4.27-9.81).This was similar for both subcategories of AT(insertional:OR=5.45,95%CI:2.51-11.81;midportion:OR=6.96,95%CI:4.24-11.40).Participants registering for an event with a distance of 10/10.55 km were less likely to develop a new-onset AT(OR=0.59,95%CI:0.36-0.97)or midportion AT(OR=0.47,95%CI:0.23-0.93).Higher age had a significant negative association with insertional AT(OR=0.97,95%CI:0.94-1.00).Conclusion:The incidence of new-onset AT among recreational runners was 4.2%.The proportion of insertional and midportion AT was 27.7%and 63.8%,respectively.AT in the past 12 months was the predominant risk factor for the onset of AT.Risk factors varied between insertional and midportion AT,but we could not identify clinically relevant differences between the 2 subtypes.

Effectiveness of platelet-rich plasma in the treatment of Achilles tendon disease

BACKGROUND The effectiveness of Platelet-Rich Plasma(PRP)in the treatment of patients with Achilles tendon rupture(ATR)and Achilles tendinopathy(AT)has been controversial.AIM To assess PRP injections’effectiveness in treating ATR and AT.METHODS A comprehensive review of relevant literature was conducted utilizing multiple databases such as Cochrane Library,PubMed,Web of Science,Chinese Science and Technology Journal,EMBASE,and China Biomedical CD-ROM.The present investigation integrated randomized controlled trials that assessed the effectiveness of platelet-rich plasma injections in managing individuals with Achilles tendon rupture and tendinopathy.The eligibility criteria for the trials encompassed publications that were published within the timeframe of January 1,1966 to December 2022.The statistical analysis was performed utilizing the Review Manager 5.4.1,the visual analogue scale(VAS),Victorian Institute Ankle Function Scale(VISA-A),and Achilles Tendon Thickness were used to assess outcomes.RESULTS This meta-analysis included 13 randomized controlled trials,8 of which were randomized controlled trials of PRP for AT and 5 of which were randomized controlled trials of PRP for ATR.PRP for AT at 6 wk[weighted mean difference(WMD)=1.92,95%CI:-0.54 to 4.38,I2=34%],at 3 mo[WMD=0.20,95%CI:-2.65 to 3.05,I2=60%],and 6 mo[WMD=2.75,95%CI:-2.76 to 8.26,I2=87%)after which there was no significant difference in VISA-A scores between the PRP and control groups.There was no significant difference in VAS scores between the PRP group and the control group after 6 wk[WMD=6.75,95%CI:-6.12 to 19.62,I2=69%]and 6 mo[WMD=10.46,95%CI:-2.44 to 23.37,I2=69%]of treatment,and at mid-treatment at 3 mo[WMD=11.30,95%CI:7.33 to 15.27,I2=0%]after mid-treatment,the PRP group demonstrated better outcomes than the control group.Post-treatment patient satisfaction[WMD=1.07,95%CI:0.84 to 1.35,I2=0%],Achilles tendon thickness[WMD=0.34,95%CI:-0.04 to 0.71,I2=61%]and return to sport[WMD=1.11,95%CI:0.87 to 1.42,I2=0%]were not significantly different between the PRP and control groups.The study did not find any statistically significant distinction between the groups that received PRP treatment and those that did not,regarding the Victorian Institute of Sport Assessment-Achilles scores at 3 mo[WMD=-1.49,95%CI:-5.24 to 2.25,I2=0%],6 mo[WMD=-0.24,95%CI:-3.80 to 3.32,I2=0%],and 12 mo[WMD=-2.02,95%CI:-5.34 to 1.29,I2=87%]for ATR patients.Additionally,no significant difference was observed between the PRP and the control groups in improving Heel lift height respectively at 6 mo[WMD=-3.96,95%CI:-8.61 to 0.69,I2=0%]and 12 mo[WMD=-1.66,95%CI:-11.15 to 7.83,I2=0%]for ATR patients.There was no significant difference in calf circumference between the PRP group and the control group after 6 mo[WMD=1.01,95%CI:-0.78 to 2.80,I2=54%]and 12 mo[WMD=-0.55,95%CI:-2.2 to 1.09,I2=0%]of treatment.There was no significant difference in ankle mobility between the PRP and control groups at 6 mo of treatment[WMD=-0.38,95%CI:-2.34 to 1.58,I2=82%]and after 12 mo of treatment[WMD=-0.98,95%CI:-1.41 to-0.56,I2=10%]there was a significant improvement in ankle mobility between the PRP and control groups.There was no significant difference in the rate of return to exercise after treatment[WMD=1.20,95%CI:0.77 to 1.87,I2=0%]and the rate of adverse events[WMD=0.85,95%CI:0.50 to 1.45,I2=0%]between the PRP group and the control group.CONCLUSION The use of PRP for AT improved the patient’s immediate VAS scores but not VISA-A scores,changes in Achilles tendon thickness,patient satisfaction,or return to sport.Treatment of ATR with PRP injections alone improved long-term ankle mobility but had no significant effect on VISA-A scores,single heel lift height,calf circumference or return to sport.Additional research employing more extensive sampling sizes,more strict experimental methods,and standard methodologies may be necessary to yield more dependable and precise findings.

Achilles测试介绍及常见问题分析

本文围绕工控设备的Achilles测试,介绍了主要测试内容及关键测试环节,分析了测试中的常见问题,以期推动工控设备的网络安全防护能力建设。

Endoscopic debridement for non-insertional Achilles tendinopathy with and without platelet-rich plasma

Background:When non-operative management fails to improve symptoms in patients with non-insertional Achilles tendinopathy,surgery may be required.Various open and endoscopic techniques have been proposed,and platelet-rich plasma(PRP)injections have been proposed as an adjunct to aid tendon healing.Methods:Thirty-six patients with mid-portion Achilles tendinopathy were randomized to undergo endoscopic debridement alone(n=19)or in combination with intraoperative PRP application(n=17).Clinical outcome measures included the Visual Analogue Scale for pain,function,and satisfaction and the Victorian Institute of Sports Assessment-Achilles(VISA-A)questionnaire.Patients were followed-up at 6 weeks,3months,6 months,and 12 months after surgery.An MRI examination at 3 and 12 months was used to assess signal alterations within the tendon.Results:Both groups showed significant clinical improvement(p<0.05)after surgery,with no difference between the 2 groups.Tendon diameter increased at 3 months and decreased at 12 months.The tendinopathy area increased at 3 months and decreased at 12 months below baseline level in both groups.There was no significant difference between the groups regarding the MRI parameters.Nodular thickening and MRIdetected signal alteration persisted after surgery,with no association between imaging and clinical outcome.Five minor complications were reported:2 in the PRP group and 3 in the control group.Conclusion:Endoscopic debridement of the Achilles tendon improved clinical outcomes in patients with mid-portion tendinopathy.The addition of PRP did not improve outcomes compared to debridement alone.MRI parameters showed no association with clinical outcomes.

Application of internal fixation of steel-wire limited loop in early Achilles tendon rupture

Objective:To explore the clinical effect and safety of internal fixation of steel-wire limited loop in early Achilles tendon rupture.Methods:Seventy-six patients respectively with early transected and avulsed types of Achilles tendon rupture were selected and treated with internal fixation of steel-wire limited loop.The patients began to take exercise for their lower limbs through continous passive motion as early as possible after surgical repair,and the loops were removed after 3-5 months.Six months later,the condition of complications including Achilles tendon re-rupture,wound fistula,wound infection and skin necrosis,cutaneous sensation in sural nerve dominance region,time back to preinjury work or learning as well as time to physical activities were observed.One year later,the therapeutic effect was evaluated,and the maximum circumferences of bilateral legs and raptured plane circumferences of Achilles tendon were measured.Results:The wound of all patients healed well,no complications like Achilles tendon re-rupture,wound fistula,wound infection and skin necrosis occured,and the cutaneous sensation in sural nerve dominance region was normal.The mean time back to preinjury work or learning as well as to pysical activities of all patients were respectively 10 and 22 weeks.Seventy out of 76 patients(92.1%) achieved an excellent effect,and 6(7.9%) good effect.The excellent and good rate came up to 100%.The maximum circumference in the affected leg decreased to 2 mm averagely compared with the offside,while the ruptured plane circumferences of Achilles tendon in the affected side increased to 2.2 mm compared with the offside.Conclusions:Kor early Achilles tendon rupture,internal fixation of steel-wire limited loop can recover the ankle function better,return to the preinjury state in the shortest lime,and has few complications.

Active Achilles tendon kinesitherapy accelerates Achilles tendon repair by promoting neurite regeneration

Active Achilles tendon kinesitherapy facilitates the functional recovery of a ruptured Achilles tendon However, protein expression during the healing process remains a controversial issue. New Zealand rabbits, aged 14 weeks, underwent tenotomy followed immediately byAchilles tendon microsurgery to repair the Achilles tendon rupture. The tendon was then immobilized or subjected to postoperative early motion treatment （kinesitherapy）. Mass spectrography results showed that after 14 days of motion treatment, 18 protein spots were differentially expressed, among which, 12 were up-regulated, consisting of gelsolin isoform b and neurite growth-related protein collapsing response mediator protein 2. Western blot analysis showed that gelsolin isoform b was up-regulated at days 7-21 of motion treatment. These findings suggest that active Achilles tendon kinesitherapy promotes the neurite regeneration of a ruptured Achilles tendon and gelsolin isoform b can be used as a biomarker for Achilles tendon healing after kinesitherapy.

Management of achilles tendon injury: A current concepts systematic review

Achilles tendon rupture has been on the rise over recent years due to a variety of reasons. It is a debilitating injury with a protracted and sometimes incomplete recovery. Management strategy is a controversial topic and evidence supporting a definite approach is limited. Opinion is divided between surgical repair and conservative immobilisation in conjunction with functional orthoses. A systematic search of the literature was performed. Pubmed, Medline and EmB ase databases were searched for Achilles tendon and a variety of synonymous terms. A recent wealth of reporting suggests that conservative regimens with early weight bearing or mobilisation have equivalent or improved rates of re-rupture to operative regimes. The application of dynamic ultrasound assessment of tendon gap may prove crucial in minimising re-rupture and improving outcomes. Studies employing functional assessments have found equivalent function between operative and conservative treatments. However, no specific tests in peak power, push off strength or athletic performance have been reported and whether an advantage in operative treatment exists remains undetermined.

Minimally invasive surgeries for insertional Achilles tendinopathy:A commentary review

Studies of minimally invasive surgery for insertional Achilles tendinopathy are limited.To establish this surgery,the following techniques must be minimally invasive:Exostosis resection at the Achilles tendon insertion,debridement of degenerated Achilles tendon,reattachment using anchors or augmentation using flexor hallucis longus(FHL)tendon transfer,and excision of the posterosuperior calcaneal prominence.Studies on these four perspectives were reviewed to establish minimally invasive surgery for insertional Achilles tendinopathy.Techniques for exostosis resection were demonstrated in one case study,where blunt dissection around the exostosis was performed,and the exostosis was resected using an abrasion burr under fluoroscopic guidance.Techniques for debridement of degenerated Achilles tendon were demonstrated in the same case study,where the space left after resection of the exostosis was used as an endoscopic working space,and the degenerated Achilles tendon and intra-tendinous calcification were debrided endoscopically.Achilles tendon reattachment techniques using suture anchors have been demonstrated in several studies.However,there are no studies on FHL tendon transfer techniques for Achilles tendon reattachment.In contrast,endoscopic posterosuperior calcaneal prominence resection is already established.Additionally,studies on ultrasound-guided surgeries and percutaneous dorsal wedge calcaneal osteotomy as minimally invasive surgery were reviewed.

Fracture of ossified Achilles tendons:A review of cases

Fracture of an ossification of the Achilles tendon(OAT)is a rare entity,and its etiology,pathology,and treatment remain unclear.We reviewed and scrutinized 18 cases(16 articles)of the fracture of an OAT.The most common etiologies of the ossifications include previous surgery and trauma.The fractures often occur without any trigger or with minimal trigger.The long,>5 cm,ossification in the body of the Achilles tendon may have a higher risk of fracture.The OAT itself is often asymptomatic;however,its fracture causes severe local pain,swelling,and weakness of plantar flexion,which forces patients to undergo aggressive treatments.Regarding the treatments of the fractures,nonoperative treatment by immobilizing ankle joint could be an option for elderly patients.However,because it often cannot produce satisfactory results in younger patients,surgical treatment is typically recommended.Excision of the fractured mass and repairing the tendon is applicable if the remnant is enough.If there is a defect after the excision,reconstruction with autologous grafts or adjacent tendon transfer is performed.Gastrocnemius fascia turndown flap,hamstring tendon and tensor fascia lata are used as autologous grafts,whereas peroneus brevis and flexor hallucis longus tendons are used for the tendon transfer.If the fracture of an OAT is treated properly,the functional result will be satisfactory.

Analyzing the Use of Ultrasound: Achilles Tendon Rupture

Growing evidence has made it obvious that early intervention in patients with Achilles tendon rupture extensively affects the prognosis. This requires the use of easily accessible imaging modalities such as ultrasound in establishing accurate diagnosis of tendinopathies so that early therapeutic decisions can be made. Ultrasound allows for assessment of tendons in a dynamic real time setting. Physicians can interact with patients and receive feedback regarding the symptomatic area, and assessing the tendon from different angles while under stress. It also offers a faster method to diagnose Achilles tendon rupture and therefore provide early intervention. Furthermore, ultrasound is a safe, non-invasive, and a patient friendly method that has become less expensive, portable, and a faster imaging modality to diagnose tendinopathies. In this paper, we review the application of ultrasound in diagnosing Achilles tendon rupture and comparing it with other imaging modalities, after thoroughly studying the current literature.

Management of Acute Achilles Tendon Rupture Using the Krackow and Tendon-Bundle Techniques

Background Acute Achilles tendon rupture is a severe injury of the lower extremities;however,optimal treatment options are not yet available.This study aimed to investigate the surgical method and clinical effect of the Krackow and tendon-bundle techniques for managing acute Achilles tendon rupture.Methods This retrospective case series study analyzed 17 cases of acute Achilles tendon rupture at the Beijing Jishuitan Hospital from December 2012 to January 2020.There were 16 men and one woman,aged 27–45 years,with an average of 39.6 years.Thirteen patients were injured while playing basketball or badminton,and 4 patients were injured while participating in a football match or other sports.All injuries were repaired using the Krackow and tendon-bundle techniques.Postoperative evaluation indicators included active range of motion during ankle plantar flexion and dorsiflexion,height of single foot heel lifting,Amer-Lindholm Achilles tendon function score,and American Orthopedic Foot and Ankle Society(AOFAS)score.Results The patients were followed-up for 6–45 months(average,18.9 months).There was no re-rupture of the Achilles tendon,wound infection,or sural nerve injury.At the final follow-up,the affected and contralateral sides exhibited plantar flexion of 42.1±4.4°and 43.8±2.8°,dorsiflexion of 15.8±2.9°and 16.6±2.9°,respectively,and one foot exhibited a heel lifting height of 7.2±1.0 cm and 7.5±0.9 cm,respectively.There was no significant difference between the affected and contralateral sides(P>0.05).At the final follow-up,the Amer-Lindholm Achilles tendon function score was excellent in 94.1%(16/17)of the patients and good in 5.9%(1/17)of the patients.The AOFAS scores ranged from 90 to 100,with an average of 96.4±3.7.Conclusion Krackow and tendon-bundle techniques can improve the strength of the suture used for the Achilles tendon repair and ensure good matching for broken ends,and thus it is an effective repair method for closed Achilles tendon injury.

Footfall patterns of a runner with an Achilles tendon rupture

Purpose: This study aims to compare the load and the length of previously ruptured and healthy Achilles tendon(AT) of a recreational runner who used different footfall patterns on each limb during running.Methods: A 41-year-old recreational athlete with a ruptured AT participated in this report. Two force plates and a high-speed motion capture system were used to collect ground reaction force and kinematic data in shod and barefoot running conditions. AT length was measured using ultrasonography and an infrared camera system. AT force was estimated as the active plantar flexion moment divided by AT moment arm during stance phase.Results: The participant used a rearfoot pattern on the affected limb and a forefoot/midfoot pattern on the unaffected limb during shod running,and a forefoot/midfoot pattern during barefoot running. There was no difference between the length of the affected and the unaffected AT. During shod running, the maximal AT force and loading rate were lower in the affected AT versus the unaffected AT. During barefoot running, the affected maximal AT force and loading rate were greater than the unaffected AT.Conclusion: Footfall patterns can be an adaptation to reduce the loading on a previously injured AT. It appears that runners may consider using a rearfoot footfall pattern during running to reduce the stress on the AT.

Multi-omics analysis of human tendon adhesion reveals that ACKR1-regulated macrophage migration is involved in regeneration

Tendon adhesion is a common complication after tendon injury with the development of accumulated fibrotic tissues without effective anti-fibrotic therapies,resulting in severe disability.Macrophages are widely recognized as a fibrotic trigger during peritendinous adhesion formation.However,different clusters of macrophages have various functions and receive multiple regulation,which are both still unknown.In our current study,multi-omics analysis including single-cell RNA sequencing and proteomics was performed on both human and mouse tendon adhesion tissue at different stages after tendon injury.The transcriptomes of over 74000 human single cells were profiled.As results,we found that SPP1^(+)macrophages,RGCC^(+)endothelial cells,ACKR1^(+)endothelial cells and ADAM12^(+)fibroblasts participated in tendon adhesion formation.Interestingly,despite specific fibrotic clusters in tendon adhesion,FOLR2^(+)macrophages were identified as an antifibrotic cluster by in vitro experiments using human cells.Furthermore,ACKR1 was verified to regulate FOLR2^(+)macrophages migration at the injured peritendinous site by transplantation of bone marrow from Lysm-Cre;R26R^(tdTomato) mice to lethally irradiated Ackr1^(-/-)mice(Ackr1^(-/-)chimeras;deficient in ACKR1)and control mice(WT chimeras).Compared with WT chimeras,the decline of FOLR2^(+)macrophages was also observed,indicating that ACKR1 was specifically involved in FOLR2^(+)macrophages migration.Taken together,our study not only characterized the fibrosis microenvironment landscape of tendon adhesion by multi-omics analysis,but also uncovered a novel antifibrotic cluster of macrophages and their origin.These results provide potential therapeutic targets against human tendon adhesion.

Animal models of tendon calcification:Past,present,and future

Tendon calcification is a common clinical condition that frequently occurs as a complication after tendon injury and surgery,or as an expression of fibrodysplasia ossificans progressiva.This condition can be referred to by various names in clinical practice and literature,including tendon ossification,tendon mineralization,heterotopic ossification,and calcific tendonitis.The exact pathogenesis of tendon calcification remains uncertain,but current mainstream research suggests that calcification is mostly cell mediated.To further elucidate the pathogenesis of tendon calcification and to better simulate the overall process,selecting appropriate experimental animal models is important.Numerous animal models have been utilized in various clinical studies,each with its own set of advantages and limitations.In this review,we have discussed the advancements made in research on animal models of tendon calcification,with a focus on the selection of experimental animals,the sites of injury in these models,and the methods employed for modeling.

A tendon system to re-center steel moment frames with weak stories

A wide open bottom story of a frame building is often expected by owners for use as a garage or shops.However,this leads to weak stories due to abrupt changes in lateral stiffness and often results in unexpected story collapse as observed in many previous earthquakes.To retrofit frame buildings that have experienced weak story damage,a tendon system is proposed in this study,which consists of a set of swaying columns and tendons.The swaying columns are used to uniformly redistribute the lateral deformation along the height,while the tendons provide extra lateral stiffness and renders the entire structural system a re-centering capability.To avoid unnecessary forces to swaying columns,pin-connections are used at the bottom.Tendons are placed over the entire story to gain large elastic displacements.Parametric analysis reveals that the swaying column,with a stiffness of about 0.9 times that of the weak story,and the tendons attached at the roof,with a stiffness of 0.04 times that of the weak story,can provide the optimal performance with a maximum residual story drift angle of less than 0.5%.Online hybrid tests were carried out,which demonstrated that uniformly distributed story drifts and acceptable residual deformation could be achieved by the proposed tendon system.

Percutaneous versus Open Achilles Tendon Repair: A Case-Control Study

Purpose: We investigated whether percutaneous suturing of Achilles tendon ruptures showed better results and superiority in terms of clinical outcomes when compared to open suturing. Methods: We conducted a case-control study. Between 2009 and 2014, we performed surgical revisions of closed acute Achilles tendon ruptures in our hospital in 146 patients, of which 71 patients (2012-2014) received percutaneous suturing using Dresden instruments, and 75 patients (2009-2012) underwent open suturing. After a minimum period of 1 year post surgery, we performed clinical follow-up in 25 patients of each of the groups using the AOFAS hind foot score and the SF-12 questionnaire. Furthermore, we implemented a clinical questionnaire with a reference population of 200 healthy individuals. Results: Mean age in the total population of 146 patients was 47 years (range 21 to 83 years) at the time of surgery. The duration of the surgical procedure with percutaneous suturing was significantly shorter (24 versus 43 minutes, p < 0.0001), the complication rate was significantly lower (2.81% versus 10.7%, p < 0.0001), and the time of hospitalisation was significantly shorter (3 versus 4 days, p < 0.0001) when compared to open suturing. During follow-up, no significant differences between the two groups were observed in terms of descriptive parameters. Furthermore, ultrasound examinations of both follow-up populations did not show any significant difference. From a clinical perspective, the good to very good results achieved with open suturing (as measured with the AOFAS hind foot score and the SF-12 questionnaire) have not been significantly improved with percutaneous suturing. The additional use of a new clinical score (with the reference population) demonstrated good to very good consistency with the established scores. Conclusion: In our population, percutaneous Achilles tendon suturing showed significantly lower complication rates and significantly shorter procedure times when compared to open suturing. However, percutaneous suturing did not show clinical improvements of the good to very good results that were achieved with open suturing (as measured with the AOFAS back foot score and the SF-12 questionnaire). The implementation of a new and simple score for the clinical evaluation of Achilles tendon injuries resulted in good to very good consistency with the established questionnaires and, thus, offered a straightforward and rapid alternative when compared to the more elaborate scores.

Incidence and Predictors of Complications of Acute Achilles Tendon Rupture Repair at Hamad General Hospital, Doha, Qatar

Aim: The aims of this study were: 1) to estimate the prevalence and pattern of complications after Achilles tendon (AT) repair, and 2) to determine the significant predictors of post-operative infection. Methods: A retrospective cohort study of all patients who were operated at Hamad General Hospital (HGH) between June 2010 and June 2012 for AT rupture (n = 102), was conducted. Data was collected on 1) patient’ characteristics such as age, sex;2) disease characteristics such as mechanism of rupture, type of rupture (partial or complete), whether an anterior or posterior slab was applied, number of suture materials, number of antibiotics, surgical time, time to surgery and length of hospital stay (LOS), number of follow up visits, and 3) complications. Descriptive and analytical statistical analyses were applied. Receiver operating characteristic curve was applied to identify the validity of different LOS values, with a significance level at p ≤ 0.05. Results: Of the 102 patients with Achilles rupture, almost males (96.1%), with a mean age 31.07 ± 9.71 years, 52% with complete rupture, the majority were open ruptures (81.4%) and bathroom-related (70.6%). Anterior slab was applied to 58.2% and 2 types of suture materials to 71.6% of cases. Fifteen cases (14.7%, 95% CI: 7.8% - 21.6%) presented with one or more complications (9.8% post-operative infections, 5.9% stiffness and 2% re-rupture). Post-operative infections were significantly associated with: old age (z = 2.11, p = 0.035), longer LOS (z = 2.01, p = 0.04), and presence of diabetes (Fisher exact test: p = 0.003). After adjustment for age, LOS (p = 0.04) and diabetes (p = 0.017) remained as significant predictors of post-operative infections. LOS of 2.5 days was the optimum cut-off point above which post-operative infection is more likely to occur, with sensitivity of 80% and specificity of 54%. Conclusion: Achilles repair post operative infection ranks first as a complication of AT surgical repair, and its incidence is relatively higher in HGH than the counterpart figures in the literature. The