Optimization of Polycaprolactone and Type I Collagen Scaffold for Tendon Tissue Regeneration.

Introduction Collagen synthesis is vital for restoring musculoskeletal tissues, particularly in tendon and ligamentous structures. Tissue engineering utilizes scaffolds for cell adhesion and differentiation. Although synthetic scaffolds offer initial strength, their long-term stability is surpassed by biological scaffolds. Combining polycaprolactone (PCL) toughness with collagen in scaffold design, this study refines fabrication via electrospinning, aiming to deliver enduring biomimetic matrices for widespread applications in musculoskeletal repair. Methods Electrospinning employed four solutions with varied collagen and PCL concentrations, dissolved in chloroform, methanol, and hexafluoro-2-propanol. Solutions were combined to yield 60 mg/mL concentrations with different collagen/PCL ratios. Electrospinning at 12-14kV voltage produced scaffolds, followed by vacuum-drying. Collagen coating was applied to PCL and 15% collagen/PCL scaffolds using a 0.1% collagen solution. SEM characterized fiber morphology, tensile testing was conducted to determine the mechanical properties of the scaffold, and Fourier-transform infrared (FTIR) spectroscopy analyzed scaffold composition. Atomic force microscopy (AFM) analyzed the stiffness properties of individual fibers, and a finite element model was developed to predict the mechanical properties. Cell culture involved seeding human bone marrow mesenchymal stem cells onto scaffolds, which were assessed through Alamar Blue assay and confocal imaging. Results Various scaffolds (100% PCL, PCL-15% collagen, PCL-25% collagen, PCL-35% collagen) were fabricated to emulate the extracellular matrix, revealing collagen's impact on fiber diameter reduction with increasing concentration. Tensile testing highlighted collagen's initial enhancement of mechanical strength, followed by a decline beyond PCL-15% collagen. FTIR spectroscopy detected potential hydrogen bonding between collagen and PCL. A finite element model predicted scaffold response to external forces which was validated by the tensile test data. Cell viability and proliferation assays demonstrated successful plating on all scaffolds, with optimal proliferation observed in PCL-25% collagen. Confocal imaging confirmed stem cell integration into the three-dimensional material. Collagen coating preserved nanofiber morphology, with no significant changes in diameter. Coating of collagen significantly altered the tensile strength of the scaffolds at the macro scale. AFM highlighted stiffness differences between PCL and collagen-coated PCL mats at the single fiber scale. The coating process did not significantly enhance initial cell attachment but promoted increased proliferation on collagen-coated PCL scaffolds. Conclusion The study reveals collagen-induced mechanical and morphological alterations, influencing fiber alignment, diameter, and chemical composition while emphasizing scaffolds' vital role in providing a controlled niche for stem cell proliferation and differentiation. The optimization of each of these scaffold characteristics and subsequent finite element modeling can lead to highly repeatable and ideal scaffold properties for stem cell integration and proliferation.

Outcomes of 2,154 Endoscopic Trigger Finger Release Procedures.

BACKGROUND: Trigger finger is one of the most frequent causes of hand pain and disability. Recently, an endoscopic trigger finger release technique was developed, but outcomes have rarely been reported. Here, we present the outcomes of 2,154 endoscopic trigger finger release procedures in a single center. METHODS: In this retrospective study, 2,154 endoscopic trigger finger release procedures were performed on 2,034 patients. Outcome assessment at 90 days after surgery was classified as excellent, good, fair or poor according to a combination of patient satisfaction with the scar and pain at rest or under load on a numeric rating scale. RESULTS: The therapeutic outcomes were: 1,027 excellent, 607 good, 400 fair, and none poor. No major surgical complications were observed. Minor complications occurred in 231 fingers (10.7%). CONCLUSIONS: All patients were satisfied with their outcome after endoscopic trigger finger release. Endoscopic release can be an effective and efficient therapeutic method for the treatment of trigger finger.

Current and future advances in practice: tendinopathies of the hip.

Tendinopathy describes persistent tendon pain and loss of function related to mechanical loading. Two common hip tendinopathies seen in practice are gluteal tendinopathy and proximal hamstring tendinopathy. Both conditions can be frustrating for patients and clinicians due to the delay in diagnosis, significant disability caused and lack of response to common treatments. Tendinopathy is a clinical diagnosis and can most often be made using findings from the patient interview and pain provocation tests, without the need for imaging. Specific education and progressive exercise offer a low-risk and effective option for gluteal tendinopathy and result in greater rates of treatment success than corticosteroid injection, both in the short term (8 weeks) and at 1 year. Proximal hamstring tendinopathy is a common, but less researched, and under-recognized cause of persistent ischial pain. As research on proximal hamstring tendinopathy is limited, this review summarizes the available evidence on diagnosis and treatment following similar principles to other well-researched tendinopathies.

Distal hamstrings tendons mechanical properties at rest and contraction using free-hand 3-D ultrasonography.

Tendon properties impact human locomotion, influencing sports performance, and injury prevention. Hamstrings play a crucial role in sprinting, particularly the biceps femoris long head (BFlh), which is prone to frequent injuries. It remains uncertain if BFlh exhibits distinct mechanical properties compared to other hamstring muscles. This study utilized free-hand three-dimensional ultrasound to assess morphological and mechanical properties of distal hamstrings tendons in 15 men. Scans were taken in prone position, with hip and knee extended, at rest and during 20%, 40%, 60%, and 80% of maximal voluntary isometric contraction of the knee flexors. Tendon length, volume, cross-sectional area (CSA), and anteroposterior (AP) and mediolateral (ML) widths were quantified at three locations. Longitudinal and transverse deformations, stiffness, strain, and stress were estimated. The ST had the greatest tendon strain and the lowest stiffness as well as the highest CSA and AP and ML width strain compared to other tendons. Biceps femoris short head (BFsh) exhibited the least strain, AP and ML deformation. Further, BFlh displayed the highest stiffness and stress, and BFsh had the lowest stress. Additionally, deformation varied by region, with the proximal site showing generally the lowest CSA strain. Distal tendon mechanical properties differed among the hamstring muscles during isometric knee flexions. In contrast to other bi-articular hamstrings, the BFlh high stiffness and stress may result in greater energy absorption by its muscle fascicles, rather than the distal tendon, during late swing in sprinting. This could partly account for the increased incidence of hamstring injuries in this muscle.

Thin-slice elbow MRI with deep learning reconstruction: Superior diagnostic performance of elbow ligament pathologies.

PURPOSE: With the slice thickness routinely used in elbow MRI, small or subtle lesions may be overlooked or misinterpreted as insignificant. To compare 1 mm slice thickness MRI (1 mm MRI) with deep learning reconstruction (DLR) to 3 mm slice thickness MRI (3 mm MRI) without/with DLR, and 1 mm MRI without DLR regarding image quality and diagnostic performance for elbow tendons and ligaments. METHODS: This retrospective study included 53 patients between February 2021 and January 2022, who underwent 3 T elbow MRI, including T2-weighted fat-saturated coronal 3 mm and 1 mm MRI without/with DLR. Two radiologists independently assessed four MRI scans for image quality and artefacts, and identified the pathologies of the five elbow tendons and ligaments. In 19 patients underwent elbow surgery after elbow MRI, diagnostic performance was evaluated using surgical records as a reference standard. RESULTS: For both readers, 3 mm MRI with DLR had significant higher image quality scores than 3 mm MRI without DLR and 1 mm MRI with DLR (all P < 0.01). For common extensor tendon and elbow ligament pathologies, 1 mm MRI with DLR showed the highest number of pathologies for both readers. The 1 mm MRI with DLR had the highest kappa values for all tendons and ligaments. For reader 1, 1 mm MRI with DLR showed superior diagnostic performance than 3 mm MRI without/with DLR. For reader 2, 1 mm MRI with DLR showed the highest diagnostic performance; however, there was no significant difference. CONCLUSIONS: One mm MRI with DLR showed the highest diagnostic performance for evaluating elbow tendon and ligament pathologies, with similar subjective image qualities and artefacts.

Full-field strain distribution in hierarchical electrospun nanofibrous poly-L(lactic) acid/collagen scaffolds for tendon and ligament regeneration: A multiscale study.

Regeneration of injured tendons and ligaments (T/L) is a worldwide need. In this study electrospun hierarchical scaffolds made of a poly-L (lactic) acid/collagen blend were developed reproducing all the multiscale levels of aggregation of these tissues. Scanning electron microscopy, microCT and tensile mechanical tests were carried out, including a multiscale digital volume correlation analysis to measure the full-field strain distribution of electrospun structures. The principal strains (εp1 and εp3) described the pattern of strains caused by the nanofibers rearrangement, while the deviatoric strains (εD) revealed the related internal sliding of nanofibers and bundles. The results of this study confirmed the biomimicry of such electrospun hierarchical scaffolds, paving the way to further tissue engineering and clinical applications.

A histology guide for performing human cadaveric studies: SQIP 2024 what to look for with light microscopy.

Histological observation under light microscopy has long been used in human cadaveric studies. However, it can distort the interpretations of findings if not used appropriately; there is no guide for its proper use. The aim of this article is to revisit and discuss the correct use of histology in human cadaveric studies, following discussions with experts in multiple fields of medicine, and to create the first guide for such usage. We reached a consensus with the experts, agreeing that when this principle (structure, quantification, interaction, position: SQIP) is applied to histological observations, the findings will be interpreted correctly. Appropriate use of this recommendation can make human cadaveric studies more accurate and informative. This is the first histology guide for human cadaveric studies.

Investigation of the barriers to and functional outcomes of telerehabilitation in patients with hand injury.

BACKGROUND: Telerehabilitation is an approach that is growing in importance and rapidly becoming more prevalent. However, the potential barriers to this approach and its effectiveness relative to face-to-face treatment still need to be determined. PURPOSE: The aim of this study was to investigate the technology and access barriers, implementation and organizational challenges, and communication barriers faced by patients undergoing postoperative telerehabilitation after hand tendon repair surgery. It also aimed to investigate the effect of telerehabilitation on pain, kinesiophobia, and functional outcomes. STUDY DESIGN: Prospective, open-label, nonrandomized comparative clinical study. METHODS: The study was conducted with 44 patients who underwent tendon repair surgery due to tendon injuries of the extrinsic muscles of the hand. Participants were divided into two groups (face-to-face group and telerehabilitation group). All participants received three physiotherapy sessions per week for 8 weeks from their surgery (via video conference using mobile phones to the telerehabilitation group). An early passive motion protocol was applied for flexor tendon and zone 5-7 extensor tendon repairs. Mallet finger rehabilitation was performed for zone 2 extensor tendon repairs, while an early active short arc approach was used for zone 3-4 repairs. The telerehabilitation and face-to-face groups received the same treatment protocols three times a week. In the eighth week of treatment (in the 24th session), the Turkish version of the Arm, Shoulder, and Hand Injury Questionnaire (DASH-T) and Tampa Scale for Kinesiophobia were administered to all patients. The telerehabilitation group also underwent a barrier questionnaire. A pretreatment assessment could not be conducted. The independent-sample t-test was used for DASH-T data, and the Mann-Whitney U-test was used for Tampa Scale for Kinesiophobia to compare groups. RESULTS: In the study, there were 24 participants (age: 31.58 ± 12.02 years) in the face-to-face group and 20 participants (age: 39.25 ± 12.72 years) in the telerehabilitation group. The two groups were similar in terms of DASH-T and pain (p = 0.103, effect size = 0.647, and p = 0.086, effect size = 0.652, respectively) in the 8 weeks. However, the telerehabilitation group had a higher fear of movement (p = 0.017, effect size = 3.265). The most common barriers to telerehabilitation practices were the fear of damaging the tendon repair and the need for help during the treatment. CONCLUSIONS: We determined that face-to-face treatment in acute physiotherapy for patients who have undergone tendon repair may be more effective compared to telerehabilitation, as it appears to be less likely to induce kinesiophobia. However, in situations where face-to-face treatment is not possible (such as lockdown), telerehabilitation can also be preferred after at least one in-person session to teach and perform exercises.

Anatomical variations and developmental insights of tendons in the first extensor compartment of the hand: Cadaveric study with surgical implications.

Background: Anatomical variations in first extensor compartment play a role in the development of de Quervain's disease. This study delves into the detailed examination of these anatomical variations. Methods: 50 upper limbs (28 male and 22 female) from 25 for-malin-embalmed adult human cadavers were dissected to investigate variations in tendons of first extensor compartment. Results: Accessory tendons to main tendon of abductor pollicis longus (APL) were reported in 49 (98%) cases, with 34% having two accessory tendons, 52% having three, and 12% having four. Terminal ends of these accessory tendons were generally consistent, except in one case where it split into two tendinous bands at insertion site, which was most commonly at base of first metacarpal. Extensor pollicis brevis (EPB) was found as a single tendon in 48 cases, with one case each of duplication and absence. In 19 cases (38%), muscle belly of EPB was fused with that of APL to some extent and it typically inserted at base of the proximal phalanx of the thumb. Average length of muscle belly, tendon, and muscle tendon ratio (MTR) of APL was 15.99±0.62 cm, 5.91±0.76 cm and 2.71 and of EPB was 6.39±0.29 cm, 9.15±0.74 cm and 0.70 respectively. Conclusion: APL variations range from accessory tendons, splitting of tendons to various insertion points. Additionally, length and insertions points of these accessory tendons are key factors in deciding their usability as graft sources for tendon reconstruction and in surgical treatments of conditions like de Quervain's tenosynovitis.

Do False Tendons Prevent Adverse Left Ventricular Remodeling After Anterior Wall Myocardial Infarction? An Echocardiographic Strain Imaging Study.

The role of muscular left ventricular (LV) false tendons (FTs) is poorly understood. To gain insight into their pathophysiologic significance, we adapted echocardiographic LV strain imaging software to measure LVFT longitudinal strain in subjects with normal left ventricles and in patients who sustained previous anterior wall myocardial infarction (AWMI). GE EchoPAC software was used to measure longitudinal strain in LVFTs ≥0.3 cm in diameter. Tendinous strain was measured in 11 patients with LVFTs confined to the left anterior descending artery territory (connecting the anteroseptum or anterior wall to the apex) ≥6 months after AWMI (myocardial infarction [MI]+FT+ group) and in 25 patients with normal hearts containing LVFTs (MI-FT+ group). We also compared the indexed LV end-diastolic volumes in the MI+FT+ group to that of 25 patients with previous AWMI without LVFTs (MI+FT- group). The mean LVFT strain in MI+FT+ group was 5.5 ± 6.2% and -28.9 ± 4.7% in the MI-FT+ group (p <0.0001). The indexed LV end-diastolic volume in the MI+FT+ group did not differ from the MI+FT- group (88.4 ± 17.8 vs 87.9 ± 17 ml/m2, p = 0.90). In conclusion, the negative strain (contraction) developed by LVFTs in the MI-FT+ group may help maintain normal LV size and shape by generating inward restraining forces. The development of positive strain (stretch) in LVFTs in patients in the MI+FT+ group suggests they become infarcted after AWMI. This implies that they are incapable of generating inward restraining forces that might otherwise mitigate adverse remodeling. Of note, LV volumes after AWMI do not differ whether or not LVFTs are present.

FGF-stimulated tendon cells embrace a chondrogenic fate with BMP7 in newt tissue culture.

Newts can regenerate functional elbow joints after amputation at the joint level. Previous studies have suggested the potential contribution of cells from residual tendon tissues to joint cartilage regeneration. A serum-free tissue culture system for tendons was established to explore cell dynamics during joint regeneration. Culturing isolated tendons in this system, stimulated by regeneration-related factors, such as fibroblast growth factor (FGF) and platelet-derived growth factor, led to robust cell migration and proliferation. Moreover, cells proliferating in an FGF-rich environment differentiated into Sox9-positive chondrocytes upon BMP7 introduction. These findings suggest that FGF-stimulated cells from tendons may aid in joint cartilage regeneration during functional elbow joint regeneration in newts.

Reconstruction of the medial patellofemoral ligament through a double bundle of a single patellar tract and quadriceps tendons combined with medial displacement of lateral hemi-tibial tuberosity for treating low-grade recurrent patella dislocation.

PURPOSE: The present study aimed to assess the clinical efficacy and imaging results of reconstruction of the medial patellofemoral ligament through a double bundle of single patellar tract and quadriceps tendons combined with medial displacement of lateral hemi-tibial tuberosity for treating low-grade recurrent patella dislocation. METHODS: Twenty-three patients with recurrent patellar dislocation, including ten males and 13 females, with 23 knee joints were enrolled according to the relevant criteria. Reconstruction of the medial patellofemoral ligament was performed through a double bundle of a single patellar tract and quadriceps tendons combined with medial displacement of lateral hemi-tibial tuberosity. Knee function was evaluated using visual analog scale (VAS) score, International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner score, and Kujala score at pre- and postoperative stages. Patellar stability was assessed by CT scans measuring tibial tuberosity-trochlear groove (TT-TG) distance, lateral patella displacement (LPD), congruence angle (CA), and patellar tilt angle (PTA). RESULTS: All 23 patients were effectively followed up for 13-28 months (mean: 21.91 ± 4.14 months). At the last follow-up, the postoperative VAS score, IKDC score, Lysholm score, Tegner score, and Kujala score of 23 patients were 1.13 ± 0.82, 87.35 ± 3.17, 90.22 ± 1.28, 4.35 ± 0.65, and 89.26 ± 1.96, respectively, as compared to the preoperative values of 5.91 ± 1.13, 30.96 ± 5.09, 30.30 ± 2.98, 1.26 ± 0.62, and 27.87 ± 3.46, respectively, and these differences were statistically significant (P < 0.001). At the last follow-up, the postoperative TT-TG, LPD, CA, and PTA values of the 23 patients were 8.80 ± 1.85 mm, 6.01 ± 1.77 mm, 11.32 ± 6.18°, and 9.35 ± 2.88°, respectively, compared to the preoperative values of 18.77 ± 1.74 mm, 14.90 ± 4.07 mm, 37.82 ± 5.71°, and 23.58 ± 3.24°, respectively, and the differences were statistically significant (P < 0.001). No relevant complications were observed in the 23 patients. CONCLUSIONS: Reconstruction of the medial patellofemoral ligament through a double bundle of a single patellar tract and quadriceps tendons combined with medial displacement of lateral hemi-tibial tuberosity for treating low-grade recurrent patella dislocation showed satisfactory medium-term efficacy, and further investigations are required to confirm the long-term efficacy of this approach.

Comparison of efficacy of ultrasound-guided platelet rich plasma injection versus dry needling in lateral epicondylitis-a randomised controlled trial.

PURPOSE: To assess whether Ultrasound guided dry needling is adequate for both common extensor tendon tears and tendinosis or whether ultrasound guided platelet rich plasma (PRP) has a superior outcome when compared to dry needling when there are tears of the common extensor tendon. MATERIALS AND METHODS: This is a single-centre, single-blinded, randomised controlled trial conducted between November 2018 and April 2020. 40 patients diagnosed with lateral epicondylitis based on clinical and sonographic features and having comparable baseline characteristics were randomly assigned to the two study groups (dry needling and PRP). Inclusion criteria were patients aged 20 years or more who were symptomatic for at least 3 months with sonographic evidence of lateral epicondylitis. Exclusion criteria were complete tear of common extensor tendon confirmed on ultrasound and presence of other associated diseases like osteoarthritis of shoulder and elbow. RESULTS: There was significant improvement in the visual analogue scale pain score in PRP group compared to the dry needling group at 9 months. However, this difference was not evident at 3 and 6 months follow-up. Mean improvement in common extensor tendon thickness in PRP group (5.1 mm at 3 months and 4.3 mm at 6 months) was slightly better than dry needling (4.4 mm at 3 months and 4.0 mm at 6 months). There was no difference in tear (if present) healing between both groups at 3 months. However at 6 months follow up, PRP demonstrated significant (mean-2.5) healing in tear compared to dry needling (mean-3.1). CONCLUSION: Two injections of Ultrasound guided PRP are more beneficial non operative treatment compared to ultrasound guided dry needling, in lateral epicondylitis.

The pterygomandibular raphe: a comprehensive review.

The pterygomandibular raphe (PMR) is a tendinous structure connecting the bucinator and the superior pharyngeal constrictor muscles. With its implications in the spread of oral cancer, the proper treatment of obstructive sleep apnea, and dental procedures, it is important to obtain a thorough understanding of the PMR. We reviewed the existing literature to compile the published information regarding its anatomy, embryology, imaging, variations, functions, pathologies, and clinical relevance of the pterygomandibular raphe.

Outcome of Flexor Tendon Repair Using Eight-Strand Core Stitch Without Postoperative Finger Splinting.

BACKGROUND: There are no reports that detail clinical outcomes using the 8-strand suture techniques and early active mobilization. We aim to report the outcome of using an 8-strand double-cruciate core suture followed by early active motion without finger splinting. MATERIALS AND METHODS: Thirty-five patients with 41 affected digits were operated and followed up for at least 6 months. A double cruciate repair with 4 single cross-grasping stitches on either side was employed. Active full-range finger flexion/extension exercises were allowed from the third postoperative day with the wrist held in the neutral position. RESULTS: The total active motion (TAM) calculated for the proximal interphalangeal and distal interphalangeal joints averaged 151° ± 22°, and the TAM% averaged 86% ± 13%. Based on the original Strickland-Glocovac criteria, excellent and good outcomes were achieved in 25 of 29 fingers (86.2%). An average extension lag of 21° ± 11° (range 10°-40°) was observed in 11 (38%) fingers. The Buck-Gramcko scale showed excellent and good results in 10 (83.4%) thumbs. Active interphalangeal range of motion averaged 68° ± 23°. An average extension lag of 12° ± 4° (range 10°-20°) was observed in 7 (58%) thumbs. Complications occurred in 4 thumbs, including bowstringing (2), rupture (1), and flexion contracture of 60° (1). CONCLUSIONS: Using the 8-strand repair technique and active mobilization performed by the patient is both practical and cost-saving. Intensive supervision of a hand therapist is generally not required. Notably improved outcomes have been achieved while preventing adhesions at the repair site. Further clinical outcome studies devoted specifically to the flexor pollicis longus are recommended to validate early-phase active mobilization following the 8-strand repair.

Gellan gum-based bi-polymeric hydrogel scaffolds loaded with Rosuvastatin calcium: A useful tool for tendon tissue regeneration.

Statins have been long used in tissue engineering, besides their marketed hypolipidemic benefits. The aim of this research was to sustain the release of rosuvastatin calcium from bi-polymeric hydrogel scaffolds. A bi-polymer blend technique was used to enhance the mechanical properties of the fabricated hydrogels. Briefly, hydrogels were prepared via crosslinking gellan gum as the main polymer together with a secondary polymer in the presence of Ca2+. The fabricated hydrogels were assessed in terms of % swelling capacity, hydrolytic degradation and % drug released to determine the most efficient carrier system. The selected hydrogel exhibited a swelling capacity of 131.45±1.49 % following 3 weeks in an aqueous environment with a % weight loss of 15.73±1.86 % after 4 weeks post-equilibrium in aqueous medium. The results ensure a proper window for adequate drug diffusion and nutrient exchange. Sustained release was attained where 94.61±2.77 % of rosuvastatin was released at the 4-week mark. Later, FT-IR and DSC, were carried out and suggested the successful crosslinking and formation of new matrix. SEM images demonstrated the porous surface of the hydrogel while a Young's modulus of 888.558±73.549 kPa indicated the suitability of the hydrogel for soft tissue engineering. In-vivo testing involved implanting the selected hydrogel at precisely surgical cuts in the Achilles tendon of male Wistar Albino rats. Upon visual and microscopic evaluation, enhanced rates of fibrous tissue formation, vascularization and collagen expression were clearly noticed in the treatment group.

Advancements in scaffold for treating ligament injuries; in vitro evaluation.

Tendon/ligament (T/L) injuries are a worldwide health problem that affects millions of people annually. Due to the characteristics of tendons, the natural rehabilitation of their injuries is a very complex and lengthy process. Surgical treatment of a T/L injury frequently necessitates using autologous or allogeneic grafts or synthetic materials. Nonetheless, these alternatives have limitations in terms of mechanical properties and histocompatibility, and they do not permit the restoration of the original biological function of the tissue, which can negatively impact the patient's quality of life. It is crucial to find biological materials that possess the necessary properties for the successful surgical treatment of tissues and organs. In recent years, the in vitro regeneration of tissues and organs from stem cells has emerged as a promising approach for preparing autologous tissue and organs, and cell culture scaffolds play a critical role in this process. However, the biological traits and serviceability of different materials used for cell culture scaffolds vary significantly, which can impact the properties of the cultured tissues. Therefore, this review aims to analyze the differences in the biological properties and suitability of various materials based on scaffold characteristics such as cell compatibility, degradability, textile technologies, fiber arrangement, pore size, and porosity. This comprehensive analysis provides valuable insights to aid in the selection of appropriate scaffolds for in vitro tissue and organ culture.

Regeneration process of myotendinous junction injury induced by collagenase injection between Achilles tendon and soleus muscle in mice.

Recently, it has become clear that peri-muscular tissues play a significant role in the deterioration of muscle function. Understanding the function and regeneration of muscle, as well as its surrounding tissues, is crucial to determining the causes of muscular illnesses. However, the regeneration process of the myotendinous junction (MTJ), the most closely related peri-muscular tissue, is still unknown. Therefore, we generated a mouse model of MTJ injury by collagenase injection and searched for the process of regeneration of the MTJ and its adjacent regions. The MTJ region was damaged by collagenase injection, which greatly increased the tendon cross sectional area. Collagenase injections increased the proportion of myofibers with a central nucleus, which is a characteristic of regenerating muscle. The collagenase injection group had myofibers with central nuclei and expressing MTJ markers. Additionally, we measured the length of MTJs using serial cross sections of the soleus muscle and discovered that MTJs at 2 weeks after collagenase injection were shorter compared to the control group, with a propensity to progressively recover their length over time. The results showed that MTJs undergo morphological regeneration even when severely damaged, and that this regeneration occurs in conjunction with muscle regeneration. We anticipate that these findings will be valuable in upcoming research on motor unit regeneration.

[Calcific tendinitis]. / Tendinosis calcarea.

CLINICAL ISSUE: Calcific tendinitis (TC) is a common-usually self-limiting-musculoskeletal disease, histopathologically characterized by both deposition and subsequent inflammatory breakdown of calcium crystals in tendons. The disease can cause acute, sometimes excruciating pain and restricted movement in the shoulder joint. Furthermore, 10-30% of patients have a complicated course of the disease. STANDARD RADIOLOGICAL METHODS: Imaging-based assessment by X­ray and ultrasound is required to establish the initial diagnosis and differential diagnosis as well as for follow-up. METHODOLOGICAL INNOVATIONS: Magnetic resonance imaging (MRI) and, to a lesser degree, computed tomography (CT) complete the imaging work-up for establishing differential diagnoses and detecting complications. PRACTICAL RECOMMENDATIONS: The combined evaluation of clinical symptoms and imaging findings is crucial to assess prognosis, plan therapy and detect potential complications. This article provides an overview of imaging-based morphology as related to the different stages of TC, relevant complications and potential pitfalls with respect to comorbidities and differential diagnoses.

Cardiac ventricular false tendons: A meta-analysis.

Ventricular false tendons are fibromuscular structures that travel across the ventricular cavity. Left ventricular false tendons (LVFTs) have been examined through gross dissection and echocardiography. This study aimed to comprehensively evaluate the prevalence, morphology, and clinical importance of ventricular false tendons using a systematic review. In multiple studies, these structures have had a wide reported prevalence ranging from less than 1% to 100% of cases. This meta-analysis found the overall pooled prevalence of LVFTs to be 30.2%. Subgroup analysis indicated the prevalence to be 55.1% in cadaveric studies and 24.5% in living patients predominantly studied by echocardiography. Morphologically, left and right ventricular false tendons have been classified into several types based on their location and attachments. Studies have demonstrated false tendons have important clinical implications involving innocent murmurs, premature ventricular contractions, early repolarization, and impairment of systolic and diastolic function. Despite these potential complications, there is evidence demonstrating that the presence of false tendons can lead to positive clinical outcomes.