Normal Tendon Research Articles

Key imaging perspectives on Achilles tendon tears—A radiological roadmap: Pictorial essay

AbstractAchilles tendon tears (ATT) are commonly encountered in clinical practice although it is the strongest tendon in the body. ATT are reported to occur in 0.04% of the population annually. ATT may result from high impact sports trauma such as sudden dorsiflexion while weight bearing or repeated microtrauma to a compromised tendon. Multiple factors can decrease the tensile strength of the tendon predisposing it to rupture. The treatment approach for ATT is multifaceted, dependent on factors such as the degree of tear, distance between the retracted portions, tear location, and also on patient factors such as occupation and underlying predisposing factors. In this pictorial essay, we present the imaging features of normal Achilles tendon and in ATT across different modalities and outline essential reporting criteria for ATT.

Long-term Prognosis of Patellar Tendinopathy (Jumper’s Knee) in Young, Elite Volleyball Players: Tendon Changes 11 Years After Baseline

Background: The long-term prognosis of jumper's knee and whether structural changes in the patellar tendon persist is unknown. Purpose: To investigate whether limitations in knee function and structural changes persisted beyond the athletic career of young elite volleyball players. Study Design: Cohort study; Level of evidence, 2. Methods: Volleyball players (mean ± SD age, 18 ± 0.8 years) enrolled in 2006-2011 in a prospective cohort study were invited in 2020-2022 to a follow-up study. Participants rated their knee function with the Victorian Institute of Sport Assessment–Patellar Tendon (VISA-P) score (baseline and follow-up) and the International Knee Documentation Committee (IKDC) score (follow-up) and reported if jumper's knee had influenced their decision to retire from sport. Tendon thickness and structural changes were assessed with ultrasound (baseline) and magnetic resonance imaging (MRI) (follow-up) of both patellar tendons. Results: We included 138 of 143 former athletes (97%) 11.4 ± 1.6 years after their baseline examination. At baseline, 37 persons (52 knees) had developed jumper's knee. At follow-up, participants reported lower knee function scores in knees diagnosed with jumper's knee at baseline than healthy knees (VISA-P scores: jumper's knee, 81 [95% CI, 70-92]; healthy, 90 [95% CI, 86-94]; P < .001; IKDC scores: jumper's knee, 82 [95% CI, 75-89]; healthy, 92 [95% CI, 91-95]; P < .001). Jumper's knee problems directly caused 7 of the 37 athletes (19%) with jumper's knee at baseline to retire from competitive volleyball. Of the 138 players included, 97 (70%) completed a bilateral MRI examination (194 knees). At follow-up, 38 of the 54 abnormal tendons (70%) had no structural changes (P < .001 vs baseline) while 22 of the 140 normal tendons (16%) had developed structural changes. Clinical symptoms were not correlated with tendon structure at follow-up (VISA-P scores for normal tendons: 85 [95% CI, 73-87]; abnormal: 89 [95% CI, 85-92]; P = .48). Conclusion: Jumper’s knee is not a self-limiting condition; volleyball players who had developed jumper's knee during adolescence reported persistent reductions in knee function 11 years later, leading one-fifth to retire from competitive volleyball. Although approximately 70% of tendons with structural changes at baseline were normal at follow-up, there was no clear relationship between structure and function.

Patellar Tendon Reconstruction Using Hamstring Graft: A Case Report

Background: Patellar tendon ruptures presenting in a chronic setting are rare events that impose technical surgical challenges due to proximal retraction of the patella, quadriceps muscle atrophy and contracture, and peripatellar adhesions. Various reconstruction techniques have been described using different grafts and fixation methods; however, there is a paucity of reported out- comes and there is no consensus on standard of care. Indications: The patient is a young female of 18yrs who presented with a history of trauma to right knee and was diagnosed with chronic patellar tendon tear. The patient was indicated for patellar tendon reconstruction with autologous hamstring tendon graft due to chronicity of the injury. Method: Patellar tendon reconstruction using hamstrings graft and fixing with anchor suture and interference screw. Result: Achieving normal patella tendon height and complete range of motion with restoration of extensor mechanism of knee. Conclusion: Knee extensor mechanism disruptions necessitate prompt surgical correction. In patients with poor tendon quality and/or a history of knee arthroplasty, primary repair should be supplemented with autograft or allograft. Early repairs yield better results than late interventions, which necessitate intricate reconstructions to reestablish the extensor mechanism's continuity. Achieving early osteointegration of the graft is important in case of tendon reconstructive procedures such as in this case as it leads to better outcomes in terms of rehabilitation and early progress to daily activities. Keys Words: tendon injuries, patellar tendon reconstruction, chronic patellar tendon tear, hamstring graft, hamstring tendon autograft, interference screw

Shear-wave elastography of canine patellar tendons in healthy dogs and the influence of stifle joint angle.

Elastography is a sonographic modality that measures tissue stiffness, a mechanical property of tissues, and a biomarker for disease. Canine musculoskeletal application to the patellar tendon has been limited to semiqualitative strain elastography. This prospective study aimed to quantitatively evaluate patellar tendon stiffness using shear-wave elastography with a color map superimposed over the tendon, a propagation map for quality control, and measurements at specific regions of interest in 16 clinically normal sedated dogs weighing 25kg or greater. Tendon stiffness using shear-wave elastography (SWE) was assessed at different stifle angles and in three regions to determine if angle and location affected stiffness. All dogs were screened with general and orthopedic exams, lateral stifle radiographs, and patellar tendon 2D ultrasound. Shear-wave elastography was performed from a long axis at various stifle angles at the proximal, middle, and distal tendon segments. Quality diagnostic SWE results varied significantly with stifle angle, and 150° of extension was the only angle found to be clinically useful based on the ease of obtaining measurable results and a quality control propagation wave. Patellar tendons were primarily stiff with a red color elastogram. The proximal and middle segments, measured at various angles, had a mean SWE velocity of 7.32±0.90m/s. Tendon stiffness did not differ along tendon length when measured in greater extension. However, stiffness decreased in the middle segment of the tendon at 150° when compared with 120°. This study establishes a quantitative baseline of normal patellar tendon stiffness to compare with pathologic states.

Identification of age-related genes in rotator cuff tendon.

Rotator cuff tear (RCT) is the leading cause of shoulder pain, primarily associated with age-related tendon degeneration. This study aimed to elucidate the potential differential gene expressions in tendons across different age groups, and to investigate their roles in tendon degeneration. Linear regression and differential expression (DE) analyses were performed on two transcriptome profiling datasets of torn supraspinatus tendons to identify age-related genes. Subsequent functional analyses were conducted on these candidate genes to explore their potential roles in tendon ageing. Additionally, a secondary DE analysis was performed on candidate genes by comparing their expressions between lesioned and normal tendons to explore their correlations with RCTs. We identified 49 genes in torn supraspinatus tendons associated with advancing age. Among them, five age-related genes showed DE in lesioned tendons compared to normal tendons. Functional analyses and previous studies have highlighted their specific enrichments in biological functions, such as muscle development (e.g. myosin heavy chain 3 (MYH3)), transcription regulation (e.g. CCAAT enhancer binding brotein delta (CEBPD)), and metal ion homeostasis (e.g. metallothionein 1X (MT1X)). This study uncovered molecular aspects of tendon ageing and their potential links to RCT development, offering insights for targeted interventions. These findings enhance our understanding of the mechanisms of tendon degeneration, allowing potential strategies to be made for reducing the incidence of RCT.

Ultrasound Imaging in Diagnosis and Management of Lower Limb Injuries: A Comprehensive Review.

Medical imaging tests are widely used to diagnose a broad spectrum of lower-limb injuries. Among these modalities, ultrasound (US) imaging has gained significant traction as a valuable diagnostic instrument for assessing conditions primarily affecting muscles, tendons, ligaments, and other soft tissues. However, there are important dilemmas related to the indications and possibilities of US in lower-limb injuries. Conflicting findings and approaches raise questions regarding the validity, accuracy, and usefulness of the US in that area. This narrative review attempts to summarize the current state of knowledge regarding US imaging of lower-limb injuries. The study provides a detailed discussion of the existing literature and contemporary insights on the diagnosis of lower-limb injuries using US examination, and draws attention to the role of the US in interventional procedures and monitoring of the healing process. The characteristics of normal muscles, tendons, and ligaments in US imaging are presented, along with the most commonly documented conditions affecting these tissues. Furthermore, the benefits and justifications for employing US in interventional procedures are discussed, ranging from platelet-rich plasma injections to physiotherapeutic treatments like percutaneous electrolysis. The study was further augmented with US pictures depicting various lower-limb injuries, mainly affecting young athletes. This article aims to review the role of US imaging in the diagnosis and management of common lower-limb injuries.

Lateral plantar fasciopathy: An frequently overlooked cause of atraumatic pain at the fifth metatarsal base

BackgroundLateral cord plantar fasciitis (LCPF) causes atraumatic pain at the fifth metatarsal base. This study assesses the outcomes of a conservative treatment (PRP + casting) on LCPF. MethodsMedical history, clinical diagnosis, and ultrasound imaging were used to determine LPCF. All patients received a leucocyte-poor PRP injection at the proximal part of the fifth metatarsal base, followed by three weeks in a walking cast. Follow-up questionnaires, encompassing NRS, AOFAS, and Foot Functioning Index (FFI), were administered at 6 weeks, 12 weeks, and 2 years post-treatment. ResultsTen patients were enrolled in the study. Ultrasound findings revealed hyposonant and thickened lateral fascia plantaris at the MT 5 insertion point with normal peronei tendons. There was a notable reduction in pain from pre-treatment (NRSrest 55.1 ± 29.6, NRSactivity 79.20 ± 15.5) to 6 weeks post-treatment (NRSrest: 22.4 ± 23.6, p = 0.03; NRSactivity: 38.6 ± 30.3, p = 0.005). FFI indicated an improvement between 12 weeks (25.7 ± 25.7) and 2 years (9.1 ± 8.5) compared to pre-treatment (42.6 ± 16.7). ConclusionUltrasound stands out as the preferred diagnostic method for identifying LCPF. A PRP injection followed by a walking cast proves effective in relieving LCPF symptoms within six weeks with sustained relief up to two years. Level of evidenceLevel IV

Dual-Barb Microneedle with JAK/STAT Inhibitor-Loaded Nanovesicles Encapsulation for Tendinopathy.

Tendon stem/progenitor cells (TSPCs) are crucial for tendon repair, regeneration, and homeostasis. Dysfunction of TSPCs, due to aberrant activation of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway, contributes to tendinopathy. Unfortunately, the effectiveness of conventional subcutaneous injection targeting at suppressing JAK/STAT signaling pathway is limited due to the passive diffusion of drugs away from the injury site. Herein, a novel poly-gamma-glutamic acid (γ-PGA) dual-barb microneedle (MN) path loaded with TSPCs-derived nanovesicles (NVs) containing JAK/STAT inhibitor WP1066 (MN-WP1066-NVs) for tendinopathy treatment is designed. The dual-barb design of the MN ensures firm adhesion to the skin, allowing for sustained and prolonged release of WP1066-NVs, facilitating enhanced TSPCs self-renewal, migration, and stemness in tendinopathy. In vitro and in vivo experiments demonstrate that the degradation of γ-PGA patch tips facilitates the gradual release of WP1066-NVs at the lesion site. This release alleviates inflammation, suppresses extracellular matrix degradation, and restores normal tendon histological structure by inhibiting the JAK/STAT pathway. These findings suggest that the multifunctional dual-barb MN patch offers a novel and effective therapeutic strategy for tendinopathy treatment.

MRGPRX2-mediated mast cell activation by substance P from overloaded human tenocytes induces inflammatory and degenerative responses in tendons

Mast cells are immune cells minimally present in normal tendon tissue. The increased abundance of mast cells in tendinopathy biopsies and at the sites of tendon injury suggests an unexplored role of this cell population in overuse tendon injuries. Mast cells are particularly present in tendon biopsies from patients with more chronic symptom duration and a history of intensive mechanical loading. This study, therefore, examined the cross talk between mast cells and human tendon cells in either static or mechanically active conditions in order to explore the potential mechanistic roles of mast cells in overuse tendon injuries. A coculture of isolated human tenocytes and mast cells (HMC-1) combined with Flexcell Tension System for cyclic stretching of tenocytes was used. Additionally, human tenocytes were exposed to agonists and antagonists of substance P (SP) receptors. Mast cell degranulation was assessed by measuring β-hexosaminidase activity. Transwell and cell adhesion assays were used to evaluate mast cell migration and binding to tendon extracellular matrix components (collagen and fibronectin), respectively. Gene expressions were analyzed using real time qRT-PCR. Our results indicate that mechanical stimulation of human tenocytes leads to release of SP which, in turn, activates mast cells through the Mas-related G-protein-coupled receptor X2 (MRGPRX2). The degranulation and migration of mast cells in response to MRGPRX2 activation subsequently cause human tenocytes to increase their expression of inflammatory factors, matrix proteins and matrix metalloproteinase enzymes. These observations may be important in understanding the mechanisms by which tendons become tendinopathic in response to repetitive mechanical stimulation.

Current trends in the prevention of adhesions after zone 2 flexor tendon repair.

Treating flexor tendon injuries within the digital flexor sheath (commonly referred to as palmar hand zone 2) presents both technical and logistical challenges. Success hinges on striking a delicate balance between safeguarding the surgical repair for tendon healing and initiating early rehabilitation to mitigate the formation of tendon adhesions. Adhesions between tendon slips and between tendons and the flexor sheath impede tendon movement, leading to postoperative stiffness and functional impairment. While current approaches to flexor tendon repair prioritize maximizing tendon strength for early mobilization and adhesion prevention, factors such as pain, swelling, and patient compliance may impede postoperative rehabilitation efforts. Moreover, premature mobilization could risk repair failure, necessitating additional surgical interventions. Pharmacological agents offer a potential avenue for minimizing inflammation and reducing adhesion formation while still promoting normal tendon healing. Although some systemic and local agents have shown promising results in animal studies, their clinical efficacy remains uncertain. Limitations in these studies include the relevance of chosen animal models to human populations and the adequacy of tools and measurement techniques in accurately assessing the impact of adhesions. This article provides an overview of the clinical challenges associated with flexor tendon injuries, discusses current on- and off-label agents aimed at minimizing adhesion formation, and examines investigational models designed to study adhesion reduction after intra-synovial flexor tendon repair. Understanding the clinical problem and experimental models may serve as a catalyst for future research aimed at addressing intra-synovial tendon adhesions following zone 2 flexor tendon repair.

IDENTIFICATION OF HEALTHY AND TENDINOPATHIC CELL SUBTYPES IN FOOT AND ANKLE TENDONS USING SINGLE-CELL TRANSCRIPTOMICS

Tendinopathy can commonly occur around the foot and ankle resulting in isolated rupture, debilitating pain and degenerative foot deformity. The pathophysiology and key cells involved are not fully understood. This is partly because the dense collagen matrix that surrounds relatively few resident cells limits the ability of previous techniques to identify and target those cells of interest. In this study, we apply novel single cell RNA sequencing (CITE-Seq) techniques to healthy and tendinopathic foot/ankle tendons. For the first time we have identified multiple sub-populations of cells in human tendons. These findings challenge the view that there is a single principal tendon cell type and open new avenues for further study. Healthy tendon samples were obtained from patients undergoing tendon transfer procedures; including tibialis posterior and FHL. Diseased tendon samples were obtained during debridement of intractable Achilles and peroneal tendinopathy, and during fusion of degenerative joints. Single cell RNA sequencing with surface proteomic analysis identified 10 sub-populations of human tendon derived cells. These included groups expressing genes associated with fibro-adipogenic progenitors (FAPs) as well as ITGA7+VCAM1- recently described in mouse muscle but, as yet, not human tendon. In addition we have identified previously unrecognised sub-classes of collagen type 1 associated tendon cells. Each sub-class expresses a different set of extra-cellular matrix genes suggesting they each play a unique role in maintaining the structural integrity of normal tendon. Diseased tendon harboured a greater proportion of macrophages and cytotoxic lymphocytes than healthy tendon. This inflammatory response is potentially driven by resident tendon fibroblasts which show increased expression of pro-inflammatory cytokines. Finally, identification of a previously unknown sub-population of cells found predominantly in tendinopathic tissue offers new insight into the underlying pathophysiology. Further work aims to identify novel proteins targets for possible therapeutic pathways.

Tendinopathic Plantaris but Normal Achilles Tendon Found in About One-Fifth of Patients Not Responding to Conservative Achilles Tendon Management - Results from a Prospective WALANT Surgical Case Series on 105 Tendons.

Midportion Achilles tendinopathy is a relatively common condition. This study aimed to investigate the presence of a normal Achilles tendon, but a tendinopathic plantaris tendon, in a large and consecutive prospective sample of patients referred to a specialised tendon clinic for midportion Achilles tendon pain not responding to non-surgical treatment. A total of 105 consecutive tendons were operated on in 81 patients (62 males) suffering from painful midportion Achilles tendon pain. Clinical examination, ultrasound (US) and colour Doppler (CD) examination, and wide awake local anaesthetic no tourniquet (WALANT) surgery were performed in all patients. For 19/105 (18%) tendons from 14 patients, clinical examination suspected plantaris tendinopathy alone as there was a distinct tenderness on the medial side, but no thickening of the Achilles tendon. US examination followed by surgery confirmed the diagnosis. Midportion Achilles tendon pain is not always related to Achilles tendinopathy since pain related to the plantaris tendon alone was found in almost every fifth patient. Consequently, there is an obvious need for proper examination to identify the pain source and establish a correct diagnosis before treatment.

Tumefactive Multiple Sclerosis: A Mimicker of Intracranial Space-Occupying Lesions

Abstract: A chronic disease of CNS, Multiple sclerosis is characterized by inflammation and demyelination with axonal injury affecting upper motor neurons of brain or spinal cord. Tumefactive multiple sclerosis is a rare form of MS which mimics intracranial tumor-like space-occupying lesions on radiography. A 25-year old gentleman presented 2-month history of gradual onset difficulty in walking, slurring of speech and double vision. The patient had an ataxic gait accentuated by tandem walking with tendency to fall towards right and a negative Romberg’s sign. There was dysarthria and signs of cerebellar lesion present on the right side. Muscle tone was normal in upper limbs but increased (spasticity) in lower limbs bilaterally. Power was normal but deep tendon reflexes were exaggerated in all 4 limbs with bilateral up-going plantar reflex. MRI scan of the brain demonstrated tumour-like tumefactive lesions in the right cerebellum, right pons and the left subcortical region with no post-contrast enhancement of these lesions. MRI of whole spine demonstrated subtle hyperintense signals in the cervical spine. He had a past history of transverse myelitis 2 years ago with full clinical recovery with oral steroids. He was diagnosed with Tumefactive Multiple Sclerosis and started on corticosteroid therapy resulting in dramatic improvement.

Strength and Functional Outcomes Following Achilles Tendon Reconstruction With Hamstring Tendon Autograft Augmentation.

The proposed advantages of hamstring autograft reconstruction when compared to alternative procedures, such as flexor hallucis longus (FHL) transfer, V-Y lengthening, and allograft reconstruction, are improved healing and reproduction of normal tendon biomechanics and reduced morbidity within the foot and ankle. In this study, we examined the effect of Achilles tendon reconstruction using hamstring autografts on strength and functional outcomes. Patients who underwent Achilles repair with a hamstring autograft for insertional or midsubstance tendinopathy, delayed diagnosis of rupture, or infection after primary repair were evaluated for inclusion. Forty-six patients were identified; 12 further augmented with an FHL transfer are included in the analysis. Isokinetic testing was completed with a Biodex dynamometer under supervision of a physical therapist masked to surgical side. Pre- and postoperative Foot and Ankle Outcome Scores (FAOS, before March 2016) or Patient-Reported Outcomes Measurement Information System (PROMIS, after March 2016) surveys were collected. For knee flexion, peak torque was not significantly different when comparing operative and nonoperative sides at 180 degrees/second (45.38 Nm vs 45.96 Nm; P = .69) nor at 300 degrees/second (44.2 Nm vs 47.02 Nm; P = .069). Knee extension absolute peak torque was only found to be significantly weaker on the operative side at the faster testing (75.5 Nm vs 79.56 Nm; P < .05). Peak ankle plantarflexion torque was significantly weaker on the operative side at both the slower speed (60 degrees/second: 39.9 Nm vs 48.76 Nm; P < .005) and the faster speed (120 degrees/second: 31.3 Nm vs 40.7 Nm; P < .001). Average power for ankle plantarflexion did not differ significantly from the operative side to the nonoperative side in the slower test (26.46 W vs 27.48 W; P = .60) but did significantly differ on the faster test (32.13 W vs 37.63 W; P = .041). At an average of 19.9 months postoperation, all physical function and pain-related patient-reported outcome scores showed clinically and statistically significant improvement. Achilles reconstruction with a hamstring autograft ± FHL transfer allowed patients with severe Achilles pathology to return to good subjective function, with modest deficits in calf strength compared with the uninjured side. Overall knee flexion strength did not appear impaired. These results suggest that hamstring autograft reconstruction is a viable method to treat these complex cases involving a lack of healthy tissue, allowing patients to return to symptom-free physical function and athletic activity. Level IV, case series.

Contributions of collagen and elastin to elastic behaviours of tendon fascicle

Tendon exhibits the capacity to be stretched and to return to its original length without suffering structural damage in vivo, a capacity known as elastic recoil. Collagen fibres are aligned longitudinally and elastin fibres mostly run parallel to collagen fibres in tendon. However, their interactions and contributions to tendon elastic behaviours are not well understood. The present study examined functional roles of collagen and elastin in tendon elastic behaviours using a variety of mechanical tests. We prepared three types of fascicle specimens from mouse tail tendon: fascicles freshly isolated, those digested with elastase in PBS to selectively remove elastin, and those incubated in PBS without elastase. A quasi-static tensile test demonstrated that elastase-treated fascicles had higher tangent moduli and strength compared to fresh and PBS fascicles. Cyclic stretching tests showed that fresh and PBS fascicles could withstand cyclic strain at both small and large amplitudes, but elastase-treated fascicles could only behave elastically to a limited degree. Fibre-sliding analysis revealed that fresh fascicles could be elongated both through stretching of collagen fibers and through movement of the fibres. However, elastase-treated fascicles could be stretched only via fibre stretching. This evidence suggests that normal tendons can be extended through both fibre stretching and fibre sliding, whereas tendons without elastin can only extend as much as collagen fibers can withstand. Accordingly, collagen fibres mainly contribute to tendon elastic behaviours by furnishing rigidity and elasticity, whereas elastin provides tendon viscoelasticity and also enables sliding of collagen fibres during elastic behaviours. Statement of significanceThe present study revealed distinct mechanical functions of collagen and elastin fibres in elastic behaviours of mouse tail tendon fascicle using a variety of mechanical tests at both microscopic and macroscopic levels. It was demonstrated that collagen mainly governs tendon fascicle rigidity and elasticity, but only possesses limited extensibility, whereas elastin contributes to viscoelasticity and collagen fibre sliding, enabling elastic recoil behaviour against relatively large deformation. By their interactions, tendon can be elongated without suffering major structural damage and withstand a large magnitude of tensile force in response to mechanical loading. Such information should be particularly useful in designing collagen-based biomaterials such as artificial tendons, in that previous studies have merely considered collagen without incorporation of elastin.

Repair of chronic and large rotator cuff tears using extra-synovial autografts: An experimental study in rabbits.

To investigate whether and how extra-synovial autografts can enhance the reconstruction of chronic and large rotator cuff tears in a rabbit subscapularis model. Twenty rabbits were used to create a large subscapularis tear bilaterally. Six weeks later, the right shoulder of each rabbit was operated to repair the tear with an extra-synovial autograft, whereas the left shoulder did not undergo any surgery. At 6 and 12 weeks after the second procedure, the specimens underwent biomechanical and histological evaluation. Six more rabbits were used only as a normal reference. Biomechanical evaluation demonstrated that the ultimate load to failure of the Graft group (184.1 ± 35.7 N) was significantly higher (p = 0.04) than that of the Defect group (144.5 ± 32.2 N) at 12 weeks after repair, rising to 76% of the normal subscapularis tendon tensile strength. Histological analysis revealed an enhanced healing environment with neoangiogenesis and decreased inflammatory response at the repair site. Moreover, the tendon maturing score of the Graft group increased substantially from 6 (15.8 ± 0.9) to 12 (23.1 ± 0.6) weeks after repair (p = 0.01). In vivo data support the efficacy of extra-synovial autograft interposition in repairing chronic and large rotator cuff tears in a rabbit subscapularis model. The autografts were capable of enhancing the biomechanical properties of the repaired tendons, as evidenced by increased tensile strength, and forming new connective tissue simulating a fibrocartilage zone, as revealed by histological evaluation. N/A.

The effect of shear wave elastography in the diagnosis of delaminated partial-thickness rotator cuff tears.

To assess the effectiveness of shear wave elastography (SWE) in diagnosing delaminated partial-thickness rotatorcuff tears (DPT-RCT). A retrospective study was carried out on 137 patients with DPT-RCT. Thestudy included complete clinical data, including the images of conventional ultrasound (US), SWE, Magnetic Resonance Imaging (MRI) and shoulder arthroscopic surgery. The features of US, SWE, and MRI were evaluated. The study analysed theShear-Wave Velocity (SWV) among three types of DPT-RCT, and between the regions of tears, normal contralateral, and affected unilateral supraspinatus tendon. Furthermore, receiver operating characteristic (ROC) curves were evaluated. The SWE detection rate was significantly higher (91.2%) compared to US (73.7%) and MRI (87.6%) for the overall diagnosisof DPT-RCT. Similarly, SWE yielded higher rates of detection for types 1 (89.5%) and 2 (92.3%) of DPT-RCT as comparedto US (71.7%, 69.2%) and MRI (81.6%, 94.9%), respectively. However, there was no significant difference in the accuracy ofdiagnosing type 3 among the three methods. The SWV of the 137 supraspinatus tendon tears was 3.64±0.60 m/s, which was higher than that of the normal supraspinatus tendon (2.43±0.47 m/s, p<0.01) as well as the region of tears (1.61±0.54 m/s, p<0.01). Nevertheless, there was no significant difference in SWV among the three types of DPT-RCT. The cutoff thresholds ofSWV for identifying normal tendon from DPT-RCT and for identifying DPT-RCT from the region of tears were 2.96m/s and2.39m/s, respectively. SWE with SWV can provide both quantitative and qualitative diagnostic information for DPT-RCT, which can be used as a crucial supplement imaging method.

Acute disseminated encephalomyelitis following the COVID-19 Vaccine Sinopharm in low- and middle-income country: a case report

Introduction and importance: Coronavirus disease 2019 (COVID-19) is a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and various vaccines against it have been developed. Acute disseminated encephalomyelitis (ADEM) is a disease of the central nervous system that cause inflammation and demyelination and manifests as a multi-symptom acute neurological condition. Although infections are usually the cause of ADEM, vaccines may cause 5–10% of cases. Case presentation: A 40-year-old woman had received a second dose of the Sinopharm COVID-19 vaccine 4 months before her visit and experienced sudden gait imbalance and vertigo a day after her vaccination, which lasted for more than a month. On examination, no signs of skin bruising or bleeding were observed, and her vital signs were within the normal range. On neurological assessment, the patient had a Glasgow Coma Scale score of 14/15 (E4V5M5), had normal pupil size and light reaction, normal fundus, normal deep tendon reflexes and bilateral extensor plantar response. Meningeal symptoms were absent, and SARS-CoV-2 RNA tests using NAAT (Nucleic Acid Amplification Test) were negative. Development of central nervous system (CNS) manifestations during the recovery phase of fever, along with typical MRI findings; the diagnosis of para-infectious ADEM with COVID-19 vaccination was made. After the treatment with methylprednisolone sodium succinate injection, the patient showed improvement. Clinical discussion: ADEM associated with post-vaccinations is a rare condition. There has been growing evidence that shared epitopes between neuronal proteins and SARS-CoV-2 antigens may trigger autoimmune reactions against the CNS through molecular mimicry as its pathogenesis. Conclusion: We suggest the need for a strict vaccine safety monitoring system and post-vaccine monitoring and surveillance.

Collagen V haploinsufficiency in female murine patellar tendons results in altered matrix engagement and cellular density, demonstrating decreased healing.

Collagen V (Col5) is a quantitatively minor component of collagen fibrils comprising tendon, however, plays a crucial role in regulation of development and dynamic healing processes. Clinically, patients with COL5a1 haploinsufficiency, known as classic Ehlers-Danlos Syndrome (cEDS), present with hyperextensible skin, joint instability and laxity, with females more likely to be affected. Previous studies in Col5-deficient mice indicated that reduced Col5a1 expression leads to a reduction in stiffness, fibril deposition, and altered fibril structure. Additionally, Col5-deficient male tendons demonstrated altered healing compared to wild-type tendons, however female mice have not yet been studied utilizing this model. Along with clinical differences between sexes in cEDS patient populations, differences in hormone physiology may be a factor influencing tendon health. Therefore, the objective of this study was to utilize a Col5a1+/ - female mouse model, to determine the effect of Col5 on tendon cell morphology, cell density, tissue composition, and mechanical properties throughout healing. We hypothesized that reduction in Col5 expression would result in an abnormal wound matrix post-injury, resulting in reduced mechanical properties compared to normal tendons. Following patellar tendon surgery, mice were euthanized at 1, 3, and 6-weekpost-injury. Col5-deficient tendons demonstrated altered and decreased healing compared to WT tendons. The lack of resolution in cellularity by 6-weekpost-injury in Col5-deficient tendons influenced the decreased mechanical properties. Stiffness did not increase post-injury in Col5-deficient mice, and collagen fiber realignment was delayed during mechanical loading. Therefore, increased Col5a1 expression post-injury is necessary to re-establish matrix engagement and cellularity throughout tendon healing.

Superior Cluneal Nerve Entrapment Syndrome: Thought to Be Spondylolysis.

A rare but typically overlooked diagnosis in the orthopaedic surgery community is superior cluneal nerve (SCN) entrapment syndrome. The cluneal nerves function as purely sensory fibers, and the SCNs provide cutaneous innervation to the posterior parasacral, gluteal, and posterolateral thigh regions. When irritated, this syndrome can cause acute and chronic lower back pain and lower extremity symptoms. A 14-year-old adolescent girl presented to the clinic for an evaluation of pain in the right side of her lower back. The patient's physical examination showed tenderness to palpation on the right posterior iliac crest seven centimeters from the midline. Her neurologic examination demonstrated normal deep tendon reflexes, muscle strength, and sensation in the L2-S1 dermatomal distribution. Although imaging showed evidence of a left L5 spondylolysis, she responded positively to a steroid injection over the posterior iliac crest but negatively to one over the L5 pars defect. She later underwent a right SCN decompression surgery. After the procedure, she reported at least 90% improvement in her pain and rated it as a one in severity, on a scale of 0 to 10. Research regarding SCN entrapment syndrome has increased in the past several years. However, most of these studies are limited to the adult population. Therefore, more reports highlighting the potential for this syndrome in adolescents are needed as well.