Chronic Repetitive Injury Research Articles

Metabolism at the crossroads of inflammation and fibrosis in chronic kidney disease.

Chronic kidney disease (CKD), defined as persistent (>3 months) kidney functional loss, has a growing prevalence (>10% worldwide population) and limited treatment options. Fibrosis driven by the aberrant accumulation of extracellular matrix is the final common pathway of nearly all types of chronic repetitive injury in the kidney and is considered a hallmark of CKD. Myofibroblasts are key extracellular matrix-producing cells that are activated by crosstalk between damaged tubules and immune cells. Emerging evidence indicates that metabolic alterations are crucial contributors to the pathogenesis of kidney fibrosis by affecting cellular bioenergetics and metabolite signalling. Immune cell functions are intricately connected to their metabolic characteristics, and kidney cells seem to undergo cell-type-specific metabolic shifts in response to damage, all of which can determine injury and repair responses in CKD. A detailed understanding of the heterogeneity in metabolic reprogramming of different kidney cellular subsets is essential to elucidating communication processes between cell types and to enabling the development of metabolism-based innovative therapeutic strategies against CKD.

Role of geniculate artery embolization in the treatment of knee pain secondary to osteoarthritis

BackgroundOsteoarthritis (OA) is a leading cause of chronic knee pain and disability with a reported prevalence of 25–30% of the population. Knee OA has traditionally been thought as a degenerative disease only related to chronic repetitive injury “wear and tear” mechanism, yet it is now considered as a much more complex disease of inflammatory nature induced by cytokines and inflammatory mediators through abnormal neo-vascularization (angiogenesis). The rational of geniculate artery embolization (GAE) is based on the hypothesis that suggesting a direct relationship between the abnormal angiogenesis and the chronic knee pain. As a novel treatment option based on occlusion of these abnormal neo-vessels via geniculate artery embolization, we postulated that such a mechanism will relieve pain and improve the quality of life. GAE has been previously approved as a safe and effective treatment in cases of post-knee arthroplasty hemarthrosis.PurposeTo evaluate the feasibility, safety, and efficacy of geniculate artery embolization for OA-related knee pain.Materials and methodsSixteen patients with knee pain secondary to chronic OA refractory to conservative therapies for at least 6 months and not yet fit for total knee replacement were enrolled in a prospective single arm interventional study. GAE was performed using 150–300 μm microspheres. Patients were assessed and followed up using the visual analogue scale (VAS) for pain and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) for the overall knee function at baseline and at 1 week, 1, 3, and 6 months post-embolization.ResultsA total 16 patients presented by knee pain secondary to chronic OA were enrolled. All of them showed a remarkable improvement in the VAS and WOMAC scores, with better clinical outcome after GAE. Pre- versus post-embolization ± MDs in VAS score from 8.38 ± 0.81 (baseline) to 2.88 ± 1.54 after 6 months (post-embolization) equivalent to 66.66% improvement. There was also a satisfactory improvement in the WOMAC scores, with ± MDs drop from 77.94 ± 10.62 (baseline) to 49.69 ± 15.43 (post-embolization) equivalent to 37.41% improvement. No severe or life-threatening complications were reported.ConclusionsGAE holds promise as an effective minimally invasive procedure for the treatment of knee pain secondary to OA and could be introduced as a safe technique with no serious complications.

Heat shock proteins in pulmonary fibrosis: pawns of cell homeostasis.

Idiopathic pulmonary fibrosis (IPF) is a fatal disease that primarily affects the elderly. Up to date, the specific pathogenesis of IPF remains unknown. However, it is theorized to be caused by chronic repetitive injuries to the alveolar epithelium, eventually exhausting the stem cell capacity and activating pathological pathways. Heat shock proteins (HSPs), a category of stress response proteins, are also suggested to contribute to IPF pathogenesis. Furthermore, HSPs are key components in the regulation of cell homeostasis and act as chaperones for a multitude of new proteins. This review thoroughly evaluates the roles that specific HSPs, HSP90, HSP70, and HSP47, have in the fibrotic process. A close look into the roles of these HSPs in IPF pathogenesis will give valuable insight into the future of IPF treatment and prevention.

Microinstability characterised by small and easily overlooked anterior labral or Hill-Sachs lesions can be managed with arthroscopic anterior labral repair.

Some young individuals present with shoulder pain without a definite history or complaint of instability. However, careful history taking, physical examination, and high-quality magnetic resonance imaging may reveal evidence of instability of which the patient is unaware. Therefore, a clearer definition of these ambiguous patients is needed. This study aimed to report the characteristics and surgical outcomes of patients with microinstability compared to those of patients with classic recurrent anterior shoulder instability. From 2005 to 2018, 35 patients with microinstability (group M) underwent arthroscopic anterior labral repair (AALR) and were compared to 35 sex- and age-matched patients with classic recurrent anterior shoulder instability (group C) who also underwent AALR. Baseline characteristics, preoperative apprehension test findings, preoperative imaging for the presence of anterior labral and Hill-Sachs lesions, preoperative and postoperative (over 2years) range of motion (ROM) and functional scores, final complications, and patient satisfaction were analysed. The most common chief complaints in groups M and C were pain (29/35) and both pain and instability (27/35), respectively. Only pain during the apprehension test was predominant in group M (M vs. C, 27 vs. 1, p < 0.001). High incidence of chronic repetitive injuries (26/35) and acute trauma (28/35) were observed in groups M and C, respectively. Over half of the patients in group M showed anterior labral lesions on magnetic resonance arthrography (MRA, 18/35), and 21 patients had Hill-Sachs lesions on MRA/three-dimensional computed tomography. Finally, 29 patients showed either anterior labral or Hill-Sachs lesions on preoperative imaging. The lesion severity was higher in group C than that in group M. All patients underwent AALR with/without the remplissage procedure, with no significant differences in final clinical outcomes, complications, and patient satisfaction between the groups. Microinstability is diagnostically challenging and can be diagnosed in young patients with ambiguous shoulder pain during motion, without instability. Pain on anterior apprehension test and subtle labral and/or Hill-Sachs lesion on imaging study could be diagnostic clues. This condition can be managed with arthroscopic anterior labral repair with or without the remplissage procedure. The possibility of microinstability in young patients with shoulder pain should always be considered, and small anterior labral or Hill-Sachs lesions should be closely monitored. III.

Treatment of Osteochondral Lesions of the Talus: An Evidence-based Opinionated Review

Osteochondral lesions of the talus (OLTs) are a much-discussed topic in foot and ankle surgery due to their refractive nature to therapy. OLTs include fractures of the talar osteochondral surface from acute trauma or chronic repetitive injury, and their chronic subset in young patients conventionally referred to as osteochondritis dessicans. OLTs do not tend to heal well, and their treatments remain only moderately successful without an obvious superior method. The purpose of this review is to summarize the treatment of OLTs using current available literature and provide an opinionated preferred treatment algorithm. Level of Evidence: Diagnostic Level V. See Instructions for Authors for a complete description of levels of evidence.

Sequential inflammation model for Achilles tendinopathy by elastin degradation with treadmill exercise

Background & objectiveTendinopathy is a tendon disease with abnormal mechanical loading to induce chronic repetitive injury. However, lack of a comparable animal model to demonstrate clinical progressions has hindered the understanding of anatomical and pathological changes. The major extracellular matrix (ECM) in the tendon consists of abundant type I collagen (COL) and minimal amount of elastin (ELN). MethodsTo study the ECM breakdown and inflammation, rat Achilles tendon was harvested and ex vivo incubated with specific enzymes of elastase (ELNase) or collagenase (COLase). ResultsThe ELNase broke down ELN, loosened the tendon structure, and increased the COL composition. Increases in cyclooxygenase-2 expression levels in tenocytes were revealed to induce inflammation with either ELNase or COLase. However, incubation of COLase for 12 hours severely digested the tendon. To create a proper ELN degradation in rats, the present study used high-frequency ultrasound to guide the injection of ELNase at the paratendon tissue of the Achilles tendon. The effect of mechanically triggered inflammatory responses was investigated by applying treadmill exercise (15 m/min for 20 min per day). After ELNase injection for 14 and 28 days, a significant loss of ELN was observed, and exercise further facilitated the pathological transition of COL. The dynamics of inflammatory cell recruitments was revealed by specific staining of CD-11b (neutrophils) and CD-68 (macrophage) after in vivo injection of ELNase or COLase for 1, 3, 7, 14, and 28 days. The combination of ELNase and exercise caused early recruitment of neutrophil on day 1 and sequential expression of macrophage on day 7 in peritendinous tissue. ConclusionThese results suggested that ELN degradation with repetitive mechanical loading may present a suitable model for the pathogenesis of tendinopathy. The Translational potential of this articleThis discover the role of elastin degradation in tendinopathy and the interaction of exercise in the histological changes. The established the pathological model mimicking the pathogenesis to the human disease by injecting the elastase using ultrasound guidance and then applying treadmill exercise. The loss of elastin and change of collagen composition in clinical tendinopathy samples were observed in the rats. In addition, the sequential inflammation cascades were observed in the histological outcomes with combination of elastase injection and treadmill exercise. Thus, this model may be used to test the clinical treatment of tendinopathy in different stages.

Magnetic resonance imaging of impingement and friction syndromes around the knee

The knee is a complex joint with its function dependent on a combination of osseous and soft tissue structures. Alteration in the relationship of these tissues, due to either acute or chronic repetitive injury with possible underlying congenital predisposing factors, can result in impingement between the structures resulting in pain, particularly on activity. The purpose of this article is to provide a comprehensive review of the MRI features of various impingement syndromes around the knee.

Reconstruction of Chronic Boutonniere Deformity of the Thumb in a Golf Player

We present the case of a professional golf player who gradually developed a boutonniere deformity of the thumb due to chronic repetitive injury to the thumb and was treated with reconstruction of its insertion onto the proximal phalangeal base. The athlete showed an insertion variation of the extensor pollicis brevis, where some slips attached onto the extensor hood and the other slips ran along with the extensor pollicis longus to the distal phalanx, providing no slip to the proximal phalanx. The slips inserting to the distal phalanx were transferred to the base of the proximal phalanx and sagittal band reconstruction. As a result, the boutonniere deformity of the thumb fully recovered with satisfactory outcomes.Level of Evidence: Level V.

Symptomatic Intratendinous Ganglion Cyst of the Patellar Tendon

Ganglion cysts have been previously described throughout the body, most commonly about the wrist, hand, knee, ankle, and feet. When symptomatic, they may interfere with joint mechanics, resulting in snapping, catching, and locking. Intratendinous ganglion cysts lack a synovial epithelial lining and are thought to develop from the mucoid degeneration of connective tissue caused by chronic irritation, chronic repetitive injury, and chronic ischemia. On magnetic resonance imaging, ganglion cysts originating from tendons, ligaments, tendon sheaths, menisci, or joint capsules appear as well-defined lobulated masses that follow simple or complex fluid signal intensity on all pulse sequences, with enhancing walls and internal septations on post-contrast images. There may be appreciable degeneration and partial tearing of the structure of origin, particularly if associated with tendons. On ultrasonography, they present as hypoechoic masses, with internal septations and lobulations of varying sizes, without significant vascularity on power or color Doppler sampling. A thin fluid neck extending from the structure of origin (tail sign), when present, is a reliable sign of a ganglion cyst. This article describes a sonographically guided technique to treat symptomatic ganglion cysts within the patellar tendon. Complete evacuation of the ganglion cyst, with disappearance of the tail sign, is considered the determining factor for a successful procedure. A similar technique can be used for the treatment of other symptomatic intratendinous ganglion cysts elsewhere in the body. To our knowledge, symptomatic intratendinous ganglion cysts within the patellar tendon and their treatment have not been previously reported.

Knee Cartilage Patellofemoral Injuries

Cartilage injuries of the patellofemoral joint present a difficult challenge owing to the unique anatomy and high shear forces. Active duty military personnel commonly present with cartilage injuries of the patella and trochlea owing to acute trauma or chronic repetitive injury. The initial treatment for patellofemoral chondral injury is nonoperative modalities to include: rest, activity modification, anti-inflammatory medication, and physical therapy. Physical therapy predominantly focuses on strengthening the vastus medialis obliquus to improve patellofemoral alignment. Reconstructive cartilage procedures like fresh osteochondral allograft transplant and autologous chondrocyte implantation are used to restore articular congruity and minimize symptoms when nonoperative modalities and common first-line reparative techniques fail. Although there is currently no evidence-based algorithm for the management of cartilage lesions of the patellofemoral joint, there are trends in treatment that help guide the surgeon. The successful outcome of treatment for cartilage lesions depends on recognizing and addressing concomitant pathology with proximal or distal realignment and patellar unloading procedures. Outcomes also depend on appropriate patient selection with his/her commitment to an extended period of rehabilitation and the ability to modify their activities. The active duty patient does not always have the ability to participate in an extended period of rehabilitation and must be treated with the best treatment option that allows an effective return to duty. Therefore, the purpose of this article is to review the standard treatment options for chondral lesions of the patellofemoral joint and our preferred treatment options in the active duty patient.

Imaging of Articular Cartilage Injuries of the Lower Extremity

Imaging has become an important clinical tool in the evaluation of articular cartilage, both in the clinical and research setting. This article reviews the mechanisms of articular cartilage injury in the lower extremities and their implications. Specific examples of acute and chronic repetitive injuries in the hip, knee, and ankle are used to demonstrate the characteristics of articular cartilage lesions on magnetic resonance imaging and multidetector computed tomographic arthrography. Loss of meniscal function in the knee and femoroacetabular impingement in the hip represent sources of repetitive cartilage injury that predispose the joint to osteoarthritis. Acute cartilage injury is exemplified by osteochondral lesions of the talus, which may result in post-traumatic osteoarthritis. Recognition of early cartilage damage and associated lesions may help determine the proper treatment for the patient to delay or prevent progression to osteoarthritis.

Reprint of Imaging of the Elbow: A Review of Imaging Findings in Acute and Chronic Traumatic Disorders of the Elbow

Traumatic injuries of the elbow are frequent in patients of all ages but are particularly common in young children and adolescents engaged in normal play and athletic competition. Injury may result primarily due to direct trauma or may be secondary to transmission of forces through the elbow following a fall on an outstretched hand. In middle-aged and older individuals, chronic repetitive injuries tend to predominate. In all patients, radiographs remain the initial imaging study of choice. Many patients, however, may need advanced cross-sectional imaging (i.e. MRI, CT, or ultrasound) either at presentation or during the course of their treatment and follow-up. This article reviews the imaging appearance of common acute and chronic traumatic disorders of the elbow.

Comparison of Airway Remodeling in Acute, Subacute, and Chronic Models of Allergic Airways Disease

The relationship between airway inflammation and structural changes of airway remodeling, and their relative effects on airway function, are poorly understood. Remodeling is thought to result from chronic repetitive injury to the airway wall caused by airway inflammation; however, the mechanisms regulating remodeling changes have not been clearly defined. We examined the sequence of events in remodeling using three commonly used mouse models of allergic airways disease in which mice are exposed to nebulized ovalbumin for four consecutive days (acute), seven consecutive days (subacute), or three times a week for 6 wk (chronic). Surprisingly, we found that a very short period of exposure to ovalbumin was sufficient to elicit early changes of remodeling. Goblet cell hyperplasia and epithelial thickening were evident after just 4 d. In chronically challenged mice, these changes persisted and, in addition, subepithelial collagen deposition was significantly increased. This collagen deposition was associated with a failure to upregulate matrix metalloproteinase (MMP)-2, in conjunction with increased transforming growth factor-beta and MMP-9 expression. The relationship between inflammation, remodeling changes, and airway hyperresponsiveness (AHR) were examined. The acute and subacute models exhibited marked airway inflammation, whereas the chronic model had very modest inflammation. Conversely, airway fibrosis was only evident in the chronic model. AHR was present in all three models; however, it was significantly higher in the chronic model compared with the acute (P<0.05) and subacute (P<0.05) models. These data demonstrate that both airway inflammation and airway fibrosis may contribute to AHR, with airway fibrosis leading to the greatest increases in AHR.

Imaging of the Elbow: A Review of Imaging Findings in Acute and Chronic Traumatic Disorders of the Elbow

Traumatic injuries of the elbow are frequent in patients of all ages but are particularly common in young children and adolescents engaged in normal play and athletic competition. Injury may result primarily due to direct trauma or may be secondary to transmission of forces through the elbow following a fall on an outstretched hand. In middle-aged and older individuals, chronic repetitive injuries tend to predominate. In all patients, radiographs remain the initial imaging study of choice. Many patients, however, may need advanced cross-sectional imaging (i.e. MRI, CT, or ultrasound) either at presentation or during the course of their treatment and follow-up. This article reviews the imaging appearance of common acute and chronic traumatic disorders of the elbow.

Golf and Racquet Sports Injuries

There are specific injuries that are common in golf and racquet sports. These abnormalities have a predilection for specific structures as well and can be divided into two categories on the basis of etiology as either chronic repetitive injury or acute trauma. With golf injuries, upper extremity abnormalities prevail and include rotator cuff disease, epicondylitis, wrist tenosynovitis, and hamate hook fracture. Thoracolumbar spine pain can also occur. The order of frequency of these ailments is different for professional and recreational athletes. With racquet injuries, as in tennis, lower extremity injuries are more common and include medial gastrocnemius and Achilles tendon abnormalities, although shoulder, elbow, and wrist abnormalities may also occur. Knowledge of the biomechanics behind each sport is also helpful in understanding the pathophysiology of injury and in part explains the findings seen at imaging.