Correlation of Hamstring Tendon Size in Pre-Operative MRI Measurement with Intra-Operative Graft Size in Primary Anterior Cruciate Ligament (ACL) Reconstruction

Background: The size of Hamstring autograft of less than 8.0 mm in ACL re-construction is one of the key factors that may contribute to the failure of the graft. In this study, we are going to assess the correlation of pre-operative MRI measurement of Hamstring tendons with the intra-operative ACL graft. Thus, it may help surgeons to anticipate the needs for graft augmentation should the final graft size be smaller than expected. Methods: We retrospectively re-viewed 41 cases of ACL reconstructions in which MRI were done pre-operatively, in Hospital Pakar Sultanah Fatimah (HPSF), Muar between January 2019 until December 2022. MRI measurements of Hamstring tendon (semitendinosus: ST, and gracilis) were done by a radiologist, and the in-tra-operative notes were reviewed for the final graft size. Pearson’s correlation coefficients were calculated to determine the relationship between graft size and tendon cross-sectional area. The intraclass correlation (ICC) by using two-way mixed model with type consistency, the reliability based on average measure was 0.41 (95% CI: ?0.10, 0.69). A p-value < 0.05 was considered sig-nificant. Results: Of 105 patients with primary ACL reconstruction done be-tween January 2019 to December 2022, only 41 patients were included in this study. There was fair correlation (p = 0.048) between pre-operative MRI measurement and the graft diameter intra-operatively. The mean of 17.0 mm of combined diameter of ST and gracilis tendon in MRI may results in graft diameter of 8.3 mm. There was also positive correlation between patients’ height and the intra-operative graft size. Conclusion: These results showed good correlation between pre-operative MRI measurement of Hamstring ten-don size with the intra-operative graft size, hence it is a reliable tool to predict the Hamstring autograft size in ACL reconstruction.

Recurrent cyclops lesion after primary anterior cruciate ligament reconstruction using bone tendon bone allograft:A case report

BACKGROUND Cyclops lesions are a known complication of anterior cruciate ligament(ACL)reconstruction,with symptomatic cyclops syndrome occurring in up to 11%of surgeries.Recurrent cyclops lesions have been rarely documented;this case study documents the successful treatment of a recurrent cyclops lesion.CASE SUMMARY A 28-year-old female presented following a non-contact injury to the right knee.Workup and clinical exam revealed an ACL tear,and arthroscopic reconstruction was performed.Two years later a cyclops lesion was discovered and removed via arthroscopic synovectomy.Seven months postoperatively,the patient presented with pain,stiffness,and difficulty achieving terminal extension.A smaller recurrent cyclops lesion was diagnosed,and a repeat synovectomy was performed.The patient recovered fully.CONCLUSION To the best of our knowledge,this is the first documented case of recurrent cyclops lesion after bone-patellar tendon-bone allograft ACL reconstruction presenting as cyclops syndrome.

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.

Go to the back before going forward:Addressing psychological responses in anterior cruciate ligament reconstruction rehabilitation

Helping athletes return to sports participation is a primary goal of anterior cruciate ligament(ACL)reconstruction rehabilitation.To facilitate the achievement of this goal,decades of research studies have sought to identify knee impairments that reduce knee function as well as interventions to resolve them.1Yet,over the past 10 years,research pertaining to psychological responses(i.e.,cognitions and emotions)after ACL reconstruction has grown exponentially—a phenomenon that can be visualized by entering the search terms"psychological"and"anterior cruciate ligament reconstruction"into the PubMed search engine.

Vitrification cryopreservation of ligaments based on zwitterionic betaine

Ligament cryopreservation enables a prolonged shelf life of allogeneic ligament grafts,which is fundamentally important to ligament reconstruction.However,conventional cryopreservation techniques fail to eliminate the damage caused by ice crystal growth and the toxicity of cryopreservation agents(CPAs).Here,we report a novel CPA vitrification formulation primarily composed of betaine for ligament cryopreservation.Comprehensive optimization was conducted on the methods for vitrification and rewarming,as well as the loading and unloading conditions,based on the critical cooling rate(CCR),critical warming rate(CWR),and permeation properties of the CPA.Using biomechanical and histological level tests,we demonstrate the superior performance of our method in ligament cryopreservation.After 30 days of vitrification cryopreservation,parameters such as the Young's modulus,tensile stress,denaturation temperature,and glycosaminoglycans content of the ligament remained essentially unchanged.This work pioneers the application of ice-free cryopreservation for ligament and holds great potential for improving the long-term storage of ligament,providing valuable insights for future cryopreservation technique development.

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.

Sorafenib inhibits ossification of the posterior longitudinal ligament by blocking LOXL2-mediated vascularization

Ossification of the Posterior Longitudinal Ligament(OPLL)is a degenerative hyperostosis disease characterized by the transformation of the soft and elastic vertebral ligament into bone,resulting in limited spinal mobility and nerve compression.Employing both bulk and single-cell RNA sequencing,we elucidate the molecular characteristics,cellular components,and their evolution during the OPLL process at a single-cell resolution,and validate these findings in clinical samples.This study also uncovers the capability of ligament stem cells to exhibit endothelial cell-like phenotypes in vitro and in vivo.Notably,our study identifies LOXL2 as a key regulator in this process.Through gain-and loss-of-function studies,we elucidate the role of LOXL2 in the endothelial-like differentiation of ligament cells.It acts via the HIF1A pathway,promoting the secretion of downstream VEGFA and PDGF-BB.This function is not related to the enzymatic activity of LOXL2.Furthermore,we identify sorafenib,a broad-spectrum tyrosine kinase inhibitor,as an effective suppressor of LOXL2-mediated vascular morphogenesis.By disrupting the coupling between vascularization and osteogenesis,sorafenib demonstrates significant inhibition of OPLL progression in both BMP-induced and enpp1 deficiency-induced animal models while having no discernible effect on normal bone mass.These findings underscore the potential of sorafenib as a therapeutic intervention for OPLL.

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.

Tendoscopic Surgery for Peroneal Tendons Instability: A Literature Review

Introduction: There has been a surge in the use of tendoscopic surgery for treating peroneal tendons instability. The novelty of this approach demanded a literature review of its indications, limitations, and clinical outcomes. Aim: a literature review of the clinical studies reporting on tendoscopic peroneal tendon stabilisation surgery along with its outcomes and complications. Methods: We carried out a comprehensive review of the literature up until September 2022 with an extensive search of the MEDLINE, Embase and Cochrane library databases. Results: Initial search resulted in 66 articles. Four duplicate articles were removed. Further 30 articles were excluded after title and abstract screening. Eight studies satisfied the inclusion criteria and were included in this review. Articles were analysed for outcomes and complications. Conclusion: The tendoscopic technique for peroneal tendon instability is an effective and safe surgical technique with very low failure rate. Levels of Evidence: Level IV.

Lateral femoral tunnel preparation and graft fixation for anterior cruciate ligament reconstruction–A discussion

This article provides a discussion and commentary around the recent advances in arthroscopic anterior cruciate ligament reconstruction(ACLR),with a focus on the aspects of lateral femoral tunnel preparation and graft fixation techniques.The paper explores and comments on a recently published review by Dai et al,titled"Research progress on preparation of lateral femoral tunnel and graft fixation in ACLR",while providing insight into its relevance within the field of ACLR,and recommendations for future research.

In vitro performance of a biodegradable zinc alloy adjustable-loop cortical suspension fixation for anterior cruciate ligament reconstruction

Anterior cruciate ligament(ACL)injuries of the knee are one of the most common and serious athletic injuries.The widely used cortical suspension fixation buttons for ligament reconstruction are permanent implants,particularly those made from conventional steel or titanium alloys.In this study,a biodegradable Zn-0.45Mn-0.2Mg(ZMM42)alloy with the yield strength of 300.4 MPa and tensile strength of 329.8 MPa was prepared through hot extrusion.The use of zinc alloys in the preparation of cortical suspension fixation buttons was proposed for the first time.After 35 d of immersion in simulated body fluids,the ZMM42 alloy fixation buttons were degraded at a rate of 44μm/a,and the fixation strength was retained(379.55 N)in the traction loops.Simultaneously,the ZMM42 alloy fixation buttons exhibited an increase in MC3T3-E1 cell viability and high antibacterial activity against Escherichia coli and Staphylococcus aureus.These results reveal the potential of biodegradable zinc alloys for use as ligament reconstruction materials and for developing diverse zinc alloy cortical suspension fixation devices.

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.

Recent research progress from biological perspective on the mechanism of formation of osteoarthritis after anterior cruciate ligament injury

The anterior cruciate ligament(ACL)mainly plays a role in stabilizing the knee joint by limiting the forward translation of tibial force and rotational force at the tibial joint,and if this ligament is damaged,it will cause joint pain,limited mobility,knee instability,etc.According to related studies,the incidence of traumatic osteoarthritis(PTOA)after ACL injury is as high as 87%,although many studies have shown that patients with ACL injury are susceptible to PTOA,but the exact mechanism is currently unknown.This may be related to biological,structural,and mechanical factors caused by the ligament injury.Previous studies have shown that elevated inflammatory mediators in the joint cavity following ACL injury can lead to chondrocytes necrosis and degradation of the cartilage matrix.These potential biochemical mediators contribute to PTOA formation,and early intervention can reduce future episodes of PTOA.In recent years,many scholars have devoted themselves to studying the potential important factors and signaling pathways involved in the formation of osteoarthritis after ACL injury,and exploring its molecular mechanism,which has led to great progress in this field.This paper mainly studies and discusses the mechanism of osteoarthritis formation after ACL injury from the biological perspective.

Spontaneous Paravesical and Broad Ligament Hematoma after Vaginal Delivery Had Uterine Artery Embolization after Evacuating the Hematoma

Broad ligament hematoma is typically seen during cesarean section due to rupture of branches of uterine and vaginal vessels and it’s rare to be seen post-normal vaginal delivery. Addressing puerperal hematomas postpartum presents considerable challenges for obstetric care providers. While hematomas such as those affecting the vulva, vulvovaginal region, or paravaginal area are frequently encountered, retroperitoneal hematomas are rare and notably pose a greater risk to the life of the patient. The medical literature contains scant case reports on retroperitoneal hematomas, with no consensus on a definitive treatment approach. Pelvic arterial embolization has emerged as both a sensible and increasingly preferred method for treating these hematomas recently, but its application is contingent upon the patient maintaining hemodynamic stability and the availability of a specialized interventional embolization unit. In our case, we are presenting a very rare case of a 31-year-old primigravida female with a history of in vitro fertilization pregnancy. She delivered a normal vaginal delivery at 31 weeks gestation. Unfortunately, she experienced multiple complications intrapartum, including preeclampsia and placental abruption. These complications increased her risk of developing a broad ligament hematoma.

Bipolar hip arthroplasty using conjoined tendon preserving posterior lateral approach in treatment of displaced femoral neck fractures

BACKGROUND Hip fractures account for 23.8%of all fractures in patients over the age of 75 years.More than half of these patients are older than 80 years.Bipolar hemiarthroplasty(BHA)was established as an effective management option for these patients.Various approaches can be used for the BHA procedure.However,there is a high risk of postoperative dislocation.The conjoined tendon-preserving posterior(CPP)lateral approach was introduced to reduce postoperative dislocation rates.AIM To evaluate the effectiveness and safety of the CPP lateral approach for BHA in elderly patients.METHODS We retrospectively analyzed medical data from 80 patients with displaced femoral neck fractures who underwent BHA.The patients were followed up for at least 1 year.Among the 80 patients,57(71.3%)were female.The time to operation averaged 2.3 d(range:1-5 d).The mean age was 80.5 years(range:67-90 years),and the mean body mass index was 24.9 kg/m^(2)(range:17-36 kg/m^(2)).According to the Garden classification,42.5%of patients were typeⅢand 57.5%of patients were typeⅣ.Uncemented bipolar hip prostheses were used for all patients.Torn conjoined tendons,dislocations,and adverse complications during and after surgery were recorded.RESULTS The mean postoperative follow-up time was 15.3 months(range:12-18 months).The average surgery time was 52 min(range:40-70 min)with an average blood loss of 120 mL(range:80-320 mL).The transfusion rate was 10%(8 of 80 patients).The gemellus inferior was torn in 4 patients(5%),while it was difficult to identify in 2 patients(2.5%)during surgery.The posterior capsule was punctured by the fractured femoral neck in 3 patients,but the conjoined tendon and the piriformis tendon remained intact.No patients had stem varus greater than 3 degrees or femoral fracture.There were no patients with stem subsidence more than 5 mm at the last follow-up.No postoperative dislocations were observed throughout the follow-up period.No significance was found between preoperative and postoperative mean Health Service System scores(87.30±2.98 vs 86.10±6.10,t=1.89,P=0.063).CONCLUSION The CPP lateral approach can effectively reduce the incidence of postoperative dislocation without increasing perioperative complications.For surgeons familiar with the posterior lateral approach,there is no need for additional surgical instruments,and it does not increase surgical difficulty.

DAPK2 promotes autophagy to accelerate the progression of ossification of the posterior longitudinal ligament through the mTORC1 complex

Background:Ossification of the posterior longitudinal ligament(OPLL)is a prevalent condition in orthopedics.While death-associated protein kinase 2(DAPK2)is known to play roles in cellular apoptosis and autophagy,its specific contributions to the advancement of OPLL are not well understood.Methods:Ligament fibroblasts were harvested from patients diagnosed with OPLL.Techniques such as real-time reverse transcriptasepolymerase chain reaction(RT-qPCR)and Western blot analysis were employed to assess DAPK2 levels in both ligament tissues and cultured fibroblasts.The extent of osteogenic differentiation in these cells was evaluated using an alizarin red S(ARS)staining.Additionally,the expression of ossification markers and autophagy markers was quantified.The autophagic activity was further analyzed through LC3 immunofluorescence and transmission electron microscopy(TEM).An in vivo heterotopic bone formation assay was conducted in mice to assess the role of DAPK2 in ossification.Results:Elevated DAPK2 expression was confirmed in both OPLL patient tissues and derived fibroblasts,in contrast to non-OPLL controls.Silencing of DAPK2 significantly curtailed osteogenic differentiation and autophagy in these fibroblasts,evidenced by decreased levels of LC3,and Beclin1,and reduced autophagosome formation.Additionally,DAPK2 was found to inhibit the mechanistic target of the rapamycin complex 1(mTORC1)complex’s activity.In vivo studies demonstrated that DAPK2 facilitates ossification,and this effect could be counteracted by the mTORC1 inhibitor rapamycin.Conclusion:DAPK2 enhances autophagy and osteogenic processes in OPLL through modulation of the mTORC1 pathway.

Arthroscopic M-shaped suture fixation for tibia avulsion fracture of posterior cruciate ligament:A modified technique and case series

BACKGROUND Tibial avulsion fractures of the posterior cruciate ligament(PCL)are challenging to treat and compromise knee stability and function.Traditional open surgery often requires extensive soft tissue dissection,which may increase the risk of morbidity.In response to these concerns,arthroscopic techniques have been evolving.The aim of this study was to introduce a modified arthroscopic tech-nique utilizing an M-shaped suture fixation method for the treatment of tibial avulsion fractures of the PCL and to evaluate its outcomes through a case series.AIM To evaluate the effects of arthroscopic M-shaped suture fixation on treating tibia avulsion fractures of the PCL.METHODS We developed a modified arthroscopic M-shaped suture fixation technique for tibia avulsion fractures of the PCL.This case series included 18 patients who underwent the procedure between January 2021 and December 2022.The patients were assessed for range of motion(ROM),Lysholm score and International knee documentation committee(IKDC)score.Postoperative complications were also recorded.RESULTS The patients were followed for a mean of 13.83±2.33 months.All patients showed radiographic union.At the final follow-up,all patients had full ROM and a negative posterior drawer test.The mean Lysholm score significantly improved from 45.28±8.92 preoperatively to 91.83±4.18 at the final follow-up(P<0.001),and the mean IKDC score improved from 41.98±6.06 preoperatively to 90.89±5.32 at the final follow-up(P<0.001).CONCLUSION The modified arthroscopic M-shaped suture fixation technique is a reliable and effective treatment for tibia avulsion fractures of the PCL,with excellent fracture healing and functional recovery.

Cyclops syndrome following anterior cruciate ligament reconstruction: Can relapse occur after surgery?

Symptomatic cyclops lesions are complications that can be seen at rates of up to approximately 10%after anterior cruciate ligament reconstruction.However,recurrent cyclops lesions have rarely been documented.There are case rare series in the literature regarding the treatment of recurrent cyclops lesion.Future large studies are needed to investigate factors contributing to the development of cyclops lesions and syndrome and treatment options.

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.