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.

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.

Bilateral Spontaneous Achilles Tendon Rupture without Any Predisposing Factors

Besides spontaneous rupture of achilles tendon is a rare condition which is usually associated with corticosteroid or fluoroquinolon usage, spontaneous rupture of Achilles tendon without any risk factors is extremely rare. In this report we aimed to present clinical features of a case of bilateral spontaneous achilles tendon rupture and tried to investigate potential etiologic factors. A 54 year old man was admitted to our emergency department as complaining bilateral ankle pain at the retrocalcaneal region. He had no trauma, any comorbidities or any drug consumption history. Painful achilles tendon gaps proximal to his ankles had been palpated and bilateral Thompson’s test positivity had been noted (Figures 1 and 2). He was unable to rise upon his toes however he was able to walk. American Orthopedic Foot and Ankle Society Hindfoot Scoring was calculated as 78 points. The rupture had been verified with a magnetic resonance imaging and his laboratory findings were all within normal limits (Figures 3 and 4).The patient did not approve an operation so conservative treatment with dorsiflexion limiting brace was applied and strengthening and stretching exercises of gastrosoleus was suggested. Atraumatic and bilateral cases with achilles rupture should be well investigated whether any systemic factors are coexistent. Besides well known corticosteroids or fluoroquinolone exposure, endocrinologic and rheumatological diseases, hypercholesterolaemia should be evaluated in terms of predisposing causes. Patients who have to use corticosteroids or fluoroquinolone, should be informed about achilles tendon rupture and be suggested do regular physical exercises in order to reduce the rupture risk. Despite predisposing factors, sometimes nothing can be associated with achilles tendon rupture as in our case. Genetic predisposition or a degenerative process of a tendon due to age may be underlying cause like in rotator cuff tears.

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.

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.

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.

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.

Anterior Compartment Syndrome after an Achilles Tendon Repair: A Case Report

Compartment syndrome may cause irreversible dysfunction if not treated correctly. The occurrence of compartment syndrome is not recognized as a potential complication after Achilles tendon rupture, and only a small number of such cases have been reported. We report the case of a 16-year-old girl with rupture of the right Achilles tendon. On postoperative day 4, she experienced severe anterior ankle pain. A blood test revealed a creatine kinase level of 7976 IU/L;the pressure in the distal anterior compartment was 90 mmHg and proximal compartment was 40 mmHg (needle manometer method). Magnetic resonance imaging (MRI) revealed a signal change in the anterior compartment. Anterior compartment syndrome was diagnosed on the basis of clinical findings, pressure measurements, and MRI findings. Emergency surgery was performed, and the anterior fascia was released. However, the dysfunction in the form of limited range of ankle motion remained. The cause of the compartment syndrome after Achilles tendon rupture was unclear. The patient’s involvement in basketball and positioning of the ankle in plantar flexion with a cast might have been contributing factors in our case. We need to consider the possibility that compartment syndrome may occur after Achilles tendon rupture.

Achilles Tendon Rupture with Isolated Medial Malleolar Fracture in Ipsilateral Ankle:A Case Report

Achilles tendon ruptures and malleol fractures are commonly seen injuries in orthopaedic and traumatology practice, but what is rare is their concomitant. In this report, we aimed to present a rare case of a patient who has isolated medial malleolar fracture and achilles tendon rupture in ipsilateral ankle after an ankle sprain due to a fall from stairs and mechanism of injury.

Enhanced recovery after surgery protocols for minimally invasive treatment of Achilles tendon rupture:Prospective single-center randomized study

BACKGROUND Achilles tendon rupture is a common orthopedic injury,with an annual incidence of 11-37 per 100000 people,significantly impacting daily life.Minimally invasive surgery,increasingly favored for its reduced risks and comparable fixation strength to open surgery,addresses these challenges.Despite advantages like accelerated recovery,perioperative care poses emotional support,pain management,and rehabilitation challenges,impacting treatment efficacy and patient experience.To address these gaps,this study investigated the efficacy of a rapid rehabilitation protocol in enhancing recovery outcomes for minimally invasive Achilles tendon surgery,aiming to develop personalized,standardized care guidelines for broader implementation.AIM To evaluate a nursing-led rapid rehabilitation program for minimally invasive Achilles tendon repair surgery,providing evidence-based early recovery indicators.METHODS This study enrolled 160 patients undergoing channel-assisted minimally invasive Achilles tendon repair randomized into experimental and control groups.The experimental group received perioperative rapid rehabilitation nursing care,while the control group received standard care.The primary outcome measure was the Oswestry disability index score,with secondary outcomes including quality of life,Barthel index,patient satisfaction with nursing,incidence of complications,and rehabilitation adherence.Statistical analysis included appropriate methods to compare outcomes between groups.The study was conducted in a specific setting,utilizing a randomized controlled trial design.RESULTS All 160 patients completed the follow-up.The experimental group showed significantly greater improvements in key efficacy indicators:Postoperative Oswestry disability index score(8.688 vs 18.88,P<0.0001),quality of life score(53.25 vs 38.99,P<0.0001),and Barthel index(70.44 vs 51.63,P<0.0001).The experimental group had a lower incidence of deep vein thrombosis(1.25%vs 10.00%,P=0.0339)with a relative risk of 0.1250(95%confidence interval:0.02050-0.7421).Infection rates were lower in the experimental group(2.50%vs 11.25%,P=0.0564).Hospital stay(5.40 days vs 7.26 days,P<0.0001)and postoperative bed rest(3.34 days vs 5.42 days,P<0.0001)were significantly shorter.Patient satisfaction was 100%in the experimental group vs 87.50%in the control group(P=0.0031).CONCLUSION The rapid rehabilitation intervention significantly reduced pain,shortened hospital stays,and lowered complication rates,improving joint function and patient satisfaction.

Outcomes and complications of operative versus non-operative treatment of acute Achilles tendon rupture： a meta-analysis

Background There is lack of consensus regarding the best option for the treatment of acute Achilles tendon rupture- operation or non-operation. The purpose of this meta-analysis was to identify and summarize the randomized controlled trials comparing the operative and non-operative lines of treatment of acute Achilles tendon ruptures. Methods We searched multiple databases in English （including EMBASE, PubMed, and OVID） and in Chinese （including CNKI, WANFANG, and VIP）, as well as reference lists of articles and main orthopaedic and sports medical journals. Two reviewers independently screened the studies for eligibility, evaluated the quality and extracted data from eligible studies, with confirmation by cross-checking. The major results and conclusions were concluded, and the different complication rates and functional outcomes were compared. Meta-analysis was processed by RevMan 5.0 software. Results Eight randomized controlled trials （RCTs） involving 777 patients met the inclusion criteria. The rerupture rate in non-operative group was significantly higher （Z=3.33, P 〈0.01）. However, the moderate （Z--4.27, P 〈0.01） and minor （Z--5.59, P 〈0.01） complication rate in the operative group were significantly higher. No significant difference in comparing the major and total complication rates. The return to work time in the operative group was shorter （Z=2.65, P 〈0.01）. The inability to return to previous level sporting rate and ankle joint decreased range of motion （ROM） rate showed no significant difference in the two groups. Other functional outcomes were similar in the two groups. Conclusions Operation could significantly reduce the risk of rerupture; however, it was associated with a higher risk of other complications. The functional outcomes were similar in two treatment methods except an earlier return to work in patients treated operatively. Thus operative treatment is preferable for patients with good physical condition. Non-operative treatment is an acceptable alternative especially for the older and patients with lower sporting requirements.

Concurrent arthroscopic bicruciate ligament reconstruction using Achilles tendon-bone allografts： experience with 15 cases

Objective： To evaluate the clinical outcome of arthroscopically assisted combined anterior and posterior cruciate ligament （ACL/PCL） reconstructions using Achilles tendon-bone allografts. Methods： Associated meniscus injuries were treated according to established methods prior to ligament reconstructions during arthroscopic surgery. Thirty Achilles tendon-bone allografts were used to reconstruct torn ACL and PCL in 15 knees. At postoperative follow-up, all knees were graded using the modified IKDC and the Lysholm scoring systems just as done preoperatively. Results were analyzed compared with the contralateral healthy knees. Results： Eleven men and 4 women with a minimum of 3-year follow-up （mean 38 months） were included in the study. Preoperatively, the group ratings by the modified IKDC standards were all severely abnormal. Twelvebicruciate reconstructions were performed in subacute or chronic stage （〉3-8 weeks）, 3 for acute ligamentous deficiencies （≤ 3 weeks）. The noticeable early complication was transitory local fever combined with joint effusion in one case. At postoperative follow-up, 9 knees were normal, 5 nearly normal and 1 abnormal. On Lysholm score the difference was statistically significant （ttest, P〈0.001） before and after operation. Conclusions： Achilles tendon-bone allograft offers an alternative for simultaneous arthroscopic ACL/PCL reconstructions. However, further investigation is needed to eradicate its potential immunogenicity for better use.

Gait analysis combined with the expression of TGF-β1,TGF-β3 and CREB during Achilles tendon healing in rat

Purpose:To observe the changes of gait behavior and the expression of wound healing factors of transforming growth factor-β1(TGF-β1),TGF-β3 and cAMP response element binding protein-1(CREB-1)during the healing of Achilles tendon in a rat model,and to investigate whether gait analysis can be used to evaluate the tendon healing.Methods:Achilles tendon of 40 healthy male Sprague-Dawley rats were transected and sutured to establish the Achilles tendon injury(ATI)model.They were randomly divided into 4 groups based on the observational time point at 1,2,4 and 6 weeks after injury(n=10 for each group).Before modeling,9 rats were randomly selected for CatWalk gait analysis,which contained step cycle,single stance time and average speed.Data were recorded as the normal controls.After then,ATI models were established in the left hind limbs of the all 40 rats(ATI group),while the right hind limbs were only cut and sutured without injury of the Achilles tendon(sham operation group).At 1,2,4 and 6 weeks after injury,the gait behavior of the corresponding group of rats(n=9)as observed and recorded by CatWalk platform.After then,the rats were sacrificed and Achilles tendon of both limbs was harvested.The tendon healing was observed by gross anatomy and histological examination,and the protein and mRNA expression of TGF-β1,TGF-β3,CREB-1 were observed by immunohistochemistry and qPCR.The results of tendon gross grading were analyzed by Wilcoxon rank sum test,and other data were analyzed by one-way analysis of variance among multiple groups.Results:Compared with normal controls,all gait indexes(step cycle,single stance time and average speed)were greatly affected following ATI,which however improved with time.The step cycle was significantly lower at 1,2 and 4 weeks after ATI(compared with normal controls,allp<0.05),but almost returned to the normal level at 6 weeks((0.694±0.102)vs.(0.503±0.094)s,p>0.05).The single stance time of the ATI group was significantly shorter at 1 and 2 weeks after operation((0.078±0.010)s at 1 week,(0.078±0.020)s at 2 weeks,allp<0.001)and revealed no significant difference at 4 weeks(p=0.120).The average speed of ATI group at 1,2,4,6 weeks was significantly lower than that in the normal control group(allp<0.001).Conclusion:Gait behavior indexes are associated with Achilles tendon healing.The study gives an insight of TGF-β1,TGF-β3,CREB-1 changes in the coursing of Achilles tendon healing and these cytokines may be able to be used to regulate the Achilles tendon healing.

Bi-pedicled V-Y gastrocnemius myocutaneous flap for repairing Achilles tendon and overlying skin defect： the anatomic basis and clinical application

Objective： To study the anatomic basis of the bipedicled V-Y gastrocnemins myocutaneons flap for repairing the composite Achilles tendon defect. Methods ： The pedicle anatomy of the bi-pedicled V-Y gastrocnemins myocutaneons flap was examined on 30 cadaver specimens. The sliding distances of the flap were measured at different knee flexion degrees. The bi-pedicled V-Y gastrocnemins myocutaneons flap was applied in 12 cases of Achilles tendon defect with simultaneous skin and soft tissue defect. Results： The surai arteries could be classified into four types. After cutting off the gastrocnemins origin with a ＂ Z-shaped＂ incision, the sliding distance of the flap reached （3. 7 ± 0. 5） cm when the knee flexed 0° ,（4.9 ± 0.7） cm when the knee flexed 30°, （ 6. 7 ±0.7 ） cm when the knee flexed 60°and （9.2 ±0.9） cm when the knee flexed 90°. All the defects healed. The patients recovered ambulation with satisfactory knee and ankle function. The follow-up was 4 months -12 years. Conclusions： Different sural artery types should be noticed during the harvest of the bi-pedicled V-Y gastrocnemins myocutaneons flap. With 90° knee flexion, this flap is suitable for one-stage repair of composite Achilles tendon defect within 9.2 cm ± 0.9 cm.

Collagen membrane alleviates peritendinous adhesion in the rat Achilles tendon injury model

Background Tendon adhesion is one of the most common causes of disability following tendon surgery. Therefore, prevention of peritendinous adhesion after surgical repair of tendon is a major challenge. The aim of this study was to explore the possible application of a collagen membrane for the prevention or attenuation of peritendinous adhesions. Methods Sprague-Dawley （SD） rat Achilles tendon was cut and sutured by a modified Kessler＇s technique with or without the collagen membrane wrapped. Macroscopic, morphological and biomechanical evaluations were applied to examine the recovery of the injured tendon at 4 and 8 weeks after surgery. Results The surgery group wrapped by collagen membranes had a better outcome than the group with surgery repair only. In the collagen membrane-treated group, less adhesion appeared, stronger tensile strength was detected, and more tendon fibers and collagen I expression were observed morphologically. Conclusion Wrapping the tendon with a collagen membrane may be an efficient approach for tendon repair and preventing tendon adhesion after its ruptures.

Differentially expressed proteins on postoperative 3 days healing in rabbit Achilles tendon rupture model after early kinesitherapy

Objectives： Surgical repair of Achilles tendon （AT） rupture should immediately be followed by active tendon mobilization. The optimal time as to when the mobilization should begin is important yet controversial. Early kinesitherapy leads to reduced rehabilitation period. However, an insight into the detailed mechanism of this process has not been gained. Proteomic technique can be used to separate and purify the proteins by differential expression profile which is related to the function of different proteins, but research in the area of proteomic analysis of AT 3 days after repair has not been studied so far. Methods： Forty-seven New Zealand white rabbits were randomized into 3 groups. Group A （immobilization group, n=l 6） received postoperative cast immobilization; Group B （early motion group, n= 16） received early active motion treatments immediately following the repair of AT rupture from tenotomy. Another 15 rabbits served as control group （Group C）. The AT samples were prepared 3 days following the microsurgery. The proteins were separated employing two- dimensional polyacrylamide gel electrophoresis （2D-PAGE）. PDQuest software version 8.0 was used to identify differentially expressed proteins, followed by peptide mass fingerprint （PMF） and tandem mass spectrum analysis, using the National Center for Biotechnology Information （NCBI） protein database retrieval and then for bioinformatics analysis. Results： Amean of 446.33,436.33 and 462.67 protein spots on Achilles tendon samples of 13 rabbits in Group A, 14 rabbits in Group B and 13 rabbits in Group C were suc- cessfully detected in the 2D-PAGE. There were 40, 36 and 79 unique proteins in Groups A, B and C respectively. Some differentially expressed proteins were enzyme with the gel, matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry （MALDI-TOF MS）. We successfully identified 9 and 11 different proteins in Groups A and B, such as GAPDH, phosphoglycerate kinase 1, pro-alpha-1 type 1 collagen, peroxiredoxin 1, alpha-l-antiproteinase E a-1 and MAD2L1 binding protein, etc. And some with the molecular chaperone, oxidative stress, energy metabolism, signal transduetion, coupled with the tendon cell expression and protein synthesis, proliferate, differentiate and are closely related to the AT healing. The GAPDH protein was further validated through Western blotting. It was indicated that some differentially expressed proteins were involved in various metabolism pathways and may play an important role in initial healing of AT rupture. Conclusion： Differentially expressed proteins in rabbit healing AT model may contribute to 3 days healing of AT rupture through a new mechanobiological mechanism due to the application of postoperative early kinesitherapy.

Achilles tendon thickening does not affect elasticity and functional outcome after surgical repair of Achilles rupture:A retrospective study

Purpose:Previous studies have confirmed that Achilles tendon occurs Achilles thickening after repair surgery of the rupture.Although this mechanism has been elucidated in the laboratory,there are few reports on its impact on clinical function.We designed a retrospective study to investigate the Achilles thickening after Achilles tendon rupture repair and its correlation between the elasticity and postoperative function.Methods:In this retrospective analysis,patients who underwent surgical treatment for acute Achilles tendon rupture from April 2016 to April 2020 were included.All the patients were regularly followed up at 3 months,1 year,and 2 years after surgery.American Orthopaedic Foot Ankle Surgeon(AOFAS)scale and Leppilahti score were used to evaluate functional outcomes.Achilles elasticity was measured by ultrasound shear wave of elasticity.Achilles thickening was calculated as maximal transverse and longitudinal diameter in cross-sectional plane of magnetic resonance scan.Sample t-tests was used for different follow-up periods.Correlation between Achilles thickening and other factors were analyzed using Pearson's method.p<0.05 indicates a statistically significant difference.Results:AOFAS scale and Leppilahti score at 1 year were significantly higher than at 3 months postoperatively(both p<0.001).These functional scales were also improved at 2-year follow-up significantly(both p<0.001).The dorsiflexion difference showed gradually recovery in each follow-up period(t=-17.907,p<0.001).The elasticity of the Achilles appeared to continuously decreases during the postoperative follow-up period in all position sets(p<0.001).In thickening evaluation,the cross-sectional area of the thickest plane of Achilles was significantly higher at 1 year postoperatively(310.5±25.2)mm^(2)than that at 3 months postoperatively((278.0±26.2)mm^(2),t=-8.219,p<0.001)and became thinner in 2-year magnetic resonance scan((256.1±15.1)mm^(2),t=16.769,p<0.001).The correlations between Achilles thickening,elasticity,and functional outcome did not show statistical significance(p>0.05)in every follow-up period.Conclusion:Achilles tendon thickens after surgery in the 1st year,but begins to gradually return to thinning about 2 years after surgery.There was no significant correlation between the increase and decrease of thickening and the patients'clinical function scores,Achilles elasticity,and bilateral ankle dorsiflexion difference.