Therapeutic effect of intra-articular injection of ribbon-type decoy oligonucleotides for hypoxia inducible factor-1 on joint contracture in an immobilized knee animal model

Biomechanical outcomes of pharmacological therapies for post-traumatic arthrofibrosis in preclinical animal models: a systematic review and meta-analysis

PURPOSE/AIM OF THE STUDY

There is still no evidence of which drug has the greatest therapeutic potential for post-traumatic arthrofibrosis. The aim of this study is to systematically review the literature for quality evidence and perform a meta-analysis about the pharmacological therapies of post-traumatic arthrofibrosis in preclinical models.

MATERIALS AND METHODS

A comprehensive and systematic search strategy was performed in three databases (MEDLINE, EMBASE and Web of Science) retrieving studies on the effectiveness of pharmacological therapies in the management of post-traumatic arthrofibrosis using preclinical models in terms of biomechanical outcomes. Risk of bias assessment was performed using the SYRCLE's risk of bias tool. A meta-analysis using a random-effects model was conducted if a minimum of three studies reported homogeneous outcomes for drugs with the same action mechanism.

RESULTS

Forty-six studies were included in the systematic review and evaluated for risk of bias. Drugs from 6 different action mechanisms of 21 studies were included in the meta-analysis. Overall, the methodological quality of the studies was poor. Statistically significant overall effect in favor of reducing contracture was present for anti-histamines (Chi2 p = 0.75, I2 = 0%; SMD (Standardized Mean Difference) = -1.30, 95%CI: -1.64 to -0.95, p < 0.00001) and NSAIDs (Chi2 p = 0.01, I2 = 63%; SMD= -0.93, 95%CI: -1.58 to -0.28, p = 0.005).

CONCLUSIONS

Anti-histamines, particularly ketotifen, have the strongest evidence of efficacy for prevention of post-traumatic arthrofibrosis. Some studies suggest a potential role for NSAIDs, particularly celecoxib, although heterogeneity among the included studies is significant.

Preliminary investigation on the effect of extracorporeal shock wave combined with traction on joint contracture based on PTEN-PI3K/AKT pathway

To investigate the intervention effect of extracorporeal shock wave combined with manual traction on fixation-induced knee contracture and its influence on PTEN-PI3K/AKT signaling pathway. Thirty-six SD male rats were randomly divided into six groups. The left knee joints were not fixed in the control group (C group). Rats in other groups underwent brace fixation in the extended position of the left knee. After 4 weeks of bracing, it is randomly divided into five groups: Model group (M group), natural recovery group (NR group), extracorporeal shock wave treatment group (ET group), manual traction group (MT group), and extracorporeal shock wave combined with manual traction group (CT group). Joint range of motion (ROM) of left knee was carried out to assess joint function. Hematoxylin and eosin (HE) staining and Masson staining were respectively used to assess the cell number and collagen deposition expression. Immunohistochemical staining and Western blot were used to assess protein levels of phosphatase and tensin homolog (PTEN), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (AKT). The combined therapy was more effective than extracorporeal shock wave therapy or manual traction alone against the joint ROM, cell number and the collagen deposition, low-expression of PTEN, and overexpression of PI3K/AKT in the anterior joint capsule of rats with knee extension contracture. Extracorporeal shock wave combined with manual traction can promote the histopathological changes of anterior joint capsule fibrosis, upregulate the protein expression of PTEN and downregulate the protein expression of PI3K/AKT in the fibrotic joint capsule in a rat joint contracture model.

Knee immobilization reproduces key arthrofibrotic phenotypes in mice

AIMS

As has been shown in larger animal models, knee immobilization can lead to arthrofibrotic phenotypes. Our study included 168 C57BL/6J female mice, with 24 serving as controls, and 144 undergoing a knee procedure to induce a contracture without osteoarthritis (OA).

METHODS

Experimental knees were immobilized for either four weeks (72 mice) or eight weeks (72 mice), followed by a remobilization period of zero weeks (24 mice), two weeks (24 mice), or four weeks (24 mice) after suture removal. Half of the experimental knees also received an intra-articular injury. Biomechanical data were collected to measure passive extension angle (PEA). Histological data measuring area and thickness of posterior and anterior knee capsules were collected from knee sections.

RESULTS

Experimental knees immobilized for four weeks demonstrated mean PEAs of 141°, 72°, and 79° after zero, two, and four weeks of remobilization (n = 6 per group), respectively. Experimental knees demonstrated reduced PEAs after two weeks (p < 0.001) and four weeks (p < 0.0001) of remobilization compared to controls. Following eight weeks of immobilization, experimental knees exhibited mean PEAs of 82°, 73°, and 72° after zero, two, and four weeks of remobilization, respectively. Histological analysis demonstrated no cartilage degeneration. Similar trends in biomechanical and histological properties were observed when intra-articular violation was introduced.

CONCLUSION

This study established a novel mouse model of robust knee contracture without evidence of OA. This was appreciated consistently after eight weeks of immobilization and was irrespective of length of remobilization. As such, this arthrofibrotic model provides opportunities to investigate molecular pathways and therapeutic strategies.Cite this article: Bone Joint Res 2023;12(1):58-71.

Inflammation and Fibrosis Induced by Joint Remobilization, and Relevance to Progression of Arthrogenic Joint Contracture: A Narrative Review

Joint immobilization is frequently administered after fractures and ligament injuries and can cause joint contracture as a side effect. The structures responsible for immobilization-induced joint contracture can be roughly divided into muscular and articular. During remobilization, although myogenic contracture recovers spontaneously, arthrogenic contracture is irreversible or deteriorates further. Immediately after remobilization, an inflammatory response is observed, characterized by joint swelling, deposit formation in the joint space, edema, inflammatory cell infiltration, and the upregulation of genes encoding proinflammatory cytokines in the joint capsule. Subsequently, fibrosis in the joint capsule develops, in parallel with progressing arthrogenic contracture. The triggers of remobilization-induced joint inflammation are not fully understood, but two potential mechanisms are proposed: 1) micro-damage induced by mechanical stress in the joint capsule, and 2) nitric oxide (NO) production via NO synthase 2. Some interventions can modulate remobilization-induced inflammatory and subsequent fibrotic reactions. Anti-inflammatory treatments, such as steroidal anti-inflammatory drugs and low-level laser therapy, can attenuate joint capsule fibrosis and the progression of arthrogenic contracture in remobilized joints. Antiproliferative treatment using the cell-proliferation inhibitor mitomycin C can also attenuate joint capsule fibrosis by inhibiting fibroblast proliferation without suppressing inflammation. Conversely, aggressive exercise during the early remobilization phases is counterproductive, because it facilitates inflammatory and then fibrotic reactions in the joint. However, the adverse effects of aggressive exercise on remobilization-induced inflammation and fibrosis are offset by anti-inflammatory treatment. To prevent the progression of arthrogenic contracture during remobilization, therefore, care should be taken to control inflammatory and fibrotic reactions in the joints.

Low-frequency electrical stimulation alleviates immobilization-evoked disuse muscle atrophy by repressing autophagy in skeletal muscle of rabbits

BACKGROUND

The study aimed to investigate the effect of low-frequency electrical stimulation (LFES) on disuse muscle atrophy and its mechanism in a rabbit model of knee extension contracture.

METHODS

This study involved two experiments. In the time-point experiment, 24 rabbits were randomly divided into 4 groups: Control 1 (Ctrl1 group), immobilization for 2 weeks (I-2 group), immobilization for 4 weeks (I-4 group), and immobilization for 6 weeks (I-6 group). In the intervention experiment, 24 rabbits were randomly divided into 4 groups: Control 2 (Ctrl2 group), electrical stimulation (ESG group), natural recovery (NRG group), and electrical stimulation treatment (ESTG group). All intervention effects were assessed by evaluating the knee joint range of motion (ROM), cross-sectional area (CSA) of the rectus femoris muscle, and expression of autophagy-related proteins.

RESULTS

The time-point experiment showed that immobilization reduced the knee ROM, reduced the rectus femoris muscle CSA, and activated autophagy in skeletal muscle. The levels of five autophagy-related proteins [mammalian target of rapamycin (mTOR), phosphorylated mTOR (p-mTOR), autophagy-related protein 7 (Atg7), p62, and microtubule-associated protein light chain 3B-II (LC3B-II)] were significantly elevated in the skeletal muscle of the I-4 group. The intervention experiment further showed that LFES significantly improved the immobilization-induced reductions in ROM and CSA. Additionally, LFES resulted in a significant decrease in the protein expression of mTOR, p-mTOR, Atg7, p62, and LC3B-II in the rectus femoris muscle.

CONCLUSIONS

LFES alleviates immobilization-evoked disuse muscle atrophy possibly by inhibiting autophagy in the skeletal muscle of rabbits.

Development of a novel knee contracture mouse model by immobilization using external fixation

AIMS

Several studies have used animal models to examine knee joint contracture; however, few reports detail the construction process of a knee joint contracture model in a mouse. The use of mouse models is beneficial, as genetically modified mice can be used to investigate the pathogenesis of joint contracture. Compared to others, mouse models are associated with a lower cost to evaluate therapeutic effects. Here, we describe a novel knee contracture mouse model by immobilization using external fixation.

METHODS

The knee joints of mice were immobilized by external fixation using a splint and tape. The passive extension range of motion (ROM), histological and immunohistochemical changes, and expression levels of fibrosis-related genes at 2 and 4 weeks were compared between the immobilized (Im group) and non-immobilized (Non-Im group) groups.

RESULTS

The extension ROM at 4 weeks was significantly lower in the Im group than in the Non-Im group (p < 0.01). At 2 and 4 weeks, the thickness and area of the joint capsule were significantly greater in the Im group than in the Non-Im group (p < 0.01 in all cases). At 2 weeks, the mRNA expression levels of the fibrosis-related genes, except for the transforming growth factor-β1, and the protein levels of cellular communication network factor 2 and vimentin in the joint capsule were significantly higher in the Im group (p < 0.01 in all cases).

CONCLUSION

This mouse model may serve as a useful tool to investigate the etiology of joint contracture and establish new treatment methods.

Imperatorin alleviated NLR family pyrin domain-containing 3 inflammasome cascade-induced synovial fibrosis and synovitis in rats with knee osteoarthritis

We aimed to clarify the therapeutic effects of imperatorin (IMP) on knee osteoarthritis (KOA). Thirty 3-month-old SD male rats were randomly divided into Normal, monosodium iodoacetate (MIA) and MIA+IMP groups. Their synovial tissues were subjected to histopathological analysis. Primary synovial fibroblasts obtained from additional normal rats were treated by lipopolysaccharide (LPS) and then IMP. The mRNA and protein expressions of factors related to synovitis and synovial fibrosis were detected by qRT-PCR and Western blotting, respectively. The concentrations of inflammatory factors IL-1β and IL-18 were measured by ELISA. IMP reduced HIF-1α, NLR family pyrin domain-containing 3 inflammasome expression and IL-1β, IL-18 production in synovial fibroblasts induced by LPS. IMP also downregulated synovial fibrosis markers. In vitro study revealed that MIA-induced synovitis and synovial fibrosis were relieved by IMP. IMP relieves the inflammation associated with synovitis and synovial fibrosis. It reduces the production of pro-inflammatory mediators and cytokines and inhibits TGF-β1, TIMP-1 and VEGF expressions that promote synovial fibrosis.

Acupotomy treatment for finger joint contracture after immobilization: Case report

INTRODUCTION

Contractures frequently occur in the finger joints after immobilization. This report describes the effect of acupotomy treatment in patients with joint contracture due to immobilization of the finger joints.

PATIENT CONCERNS AND CLINICAL FINDINGS

Case 1 was of a 39-year-old male patient who had flexion limitation of the left thumb and difficulty in grasping. Case 2 was of a 41-year-old female patient who had flexion limitation of the right index finger and difficulty in typing. Stiffness occurred after tendon repair surgery and cast immobilization in both cases. In Case 1, the patient had limited flexion movement of the first metacarpophalangeal and interphalangeal joints after 5 weeks of immobilization of the left thumb in a cast. In Case 2, the patient had limited flexion movement after 3 weeks of immobilization of the second proximal interphalangeal joint of the left hand in a cast.

DIAGNOSIS, INTERVENTIONS, AND OUTCOMES

We diagnosed both patients with finger joint contracture due to immobilization. Conservative treatment for approximately 4 weeks did not lead to improvement in either patient. Acupotomy is the key treatment for improving movement in Korean Medicine. Therefore, acupotomy was performed, and joint stiffness markedly improved without adverse events. Both patients reported that the daily use of the damaged fingers became comfortable.

CONCLUSION

We found that acupotomy may be effective for finger joint contracture due to improper immobilization. We suggest it as a simple and safe treatment for joint contracture.

Mechanisms involved in the arthrofibrosis formation and treatments following bone fracture

Arthrofibrosis is a common complication for patients with bone fracture following external and internal fixation. In this review, we summarize the related factors and significant pathways for joint adhesion following fracture surgery. Moreover, the different types of treatments and related preventive measures are also discussed. Many factors related to the development and treatment of arthrofibrosis are discussed in this review in order to provide possible clues for the prospective targets to develop new medication or treatments for preventing or reducing the joint adhesion following orthopedic surgery.

Nitric oxide synthase inhibitor L-NG-nitroarginine methyl ester (L-NAME) attenuates remobilization-induced joint inflammation

Shortly after joint remobilization, inflammation is induced in the joint and aggravates joint contracture via subsequent fibrosis. However, the mechanisms involved in remobilization-induced inflammation are not yet fully understood. We hypothesized that joint immobilization followed by remobilization induces hypoxia/reoxygenation, initiating inflammatory reactions through nitric oxide (NO) production via NO synthase 2 (NOS2). This study aimed to investigate whether: 1) administration of the NOS inhibitor L-NG-nitroarginine methyl ester (l-NAME) can attenuate remobilization-induced joint inflammation; and 2) hypoxia/reoxygenation is induced by joint immobilization and followed by remobilization. Unilateral knee joints of rats were immobilized using external fixators for three weeks. After removal of the fixation device, knees were allowed to move freely for one day (remobilization) with or without l-NAME administration. Without l-NAME administration, inflammatory reactions including joint swelling and inflammatory cell infiltration, edema, and upregulation of inflammatory mediator genes in the joint capsule were detected following upregulation of the NOS2 gene after remobilization. These remobilization-induced inflammatory reactions were partially attenuated by administration of l-NAME. Therefore, NOS2/NO elevation has potential as a novel treatment for remobilization-induced joint inflammation. Gene expression of the hypoxia marker hypoxia inducible factor-1α was upregulated after one day of remobilization, rather than after immobilization. These results suggest that upregulation of NOS2 by remobilization might be not due to hypoxia/reoxygenation.

Effects of losartan and atorvastatin on the development of early posttraumatic joint stiffness in a rat model

BACKGROUND

After a trauma, exuberant tissue healing with fibrosis of the joint capsule can lead to posttraumatic joint stiffness (PTJS). Losartan and atorvastatin have both shown their antifibrotic effects in different organ systems.

OBJECTIVE

The purpose of this study was the evaluation of the influence of losartan and atorvastatin on the early development of joint contracture. In addition to joint angles, the change in myofibroblast numbers and the distribution of bone sialoprotein (BSP) were assessed.

STUDY DESIGN AND METHODS

In this randomized and blinded experimental study with 24 rats, losartan and atorvastatin were compared to a placebo. After an initial joint injury, rat knees were immobilized with a Kirschner wire. Rats received either losartan, atorvastatin or a placebo orally daily. After 14 days, joint angle measurements and histological assessments were performed.

RESULTS

Losartan increased the length of the inferior joint capsule. Joint angle and other capsule length measurements did not reveal significant differences between both drugs and the placebo. At cellular level both losartan and atorvastatin reduced the total number of myofibroblasts (losartan: 191±77, atorvastatin: 98±58, placebo: 319±113 per counting field, p<0.01) and the percentage area of myofibroblasts (losartan: 2.8±1.8% [p<0.05], atorvastatin: 2.5±1.7% [p<0.01], vs control [6.4±4%], respectively). BSP was detectable in equivalent amounts in the joint capsules of all groups with only a trend toward a reduction of the BSP-stained area by atorvastatin.

CONCLUSION

Both atorvastatin and losartan reduced the number of myofibroblasts in the posterior knee joint capsule of rat knees 2 weeks after trauma and losartan increased the length of the inferior joint capsule. However, these changes at the cellular level did not translate an increase in range of motion of the rats´ knee joints during early contracture development.

Molecular Pharmacological Approaches for Treating Abdominal Aortic Aneurysm

Abdominal aortic aneurysm (AAA) is considered to be a potent life-threatening disorder in elderly individuals. Although many patients with a small AAA are detected during routine abdominal screening, there is no effective therapeutic option to prevent the progression or regression of AAA in the clinical setting. Recent advances in molecular biology have led to the identification of several important molecules, including microRNA and transcription factor, in the process of AAA formation. Regulation of these factors using nucleic acid drugs is expected to be a novel therapeutic option for AAA. Nucleic acid drugs can bind to target factors, mRNA, microRNA, and transcription factors in a sequence-specific fashion, resulting in a loss of function of the target molecule at the transcriptional or posttranscriptional level. Of note, inhibition of a transcription factor using a decoy strategy effectively suppresses experimental AAA formation, by regulating the expression of several genes associated with the disease progression. This review focuses on recent advances in molecular therapy of using nucleic acid drugs to treat AAA.

Endoplasmic reticulum stress-dependent ROS production mediates synovial myofibroblastic differentiation in the immobilization-induced rat knee joint contracture model

Joint contracture is a common complication for people with joint immobility that involves fibrosis structural alteration in the joint capsule. Considering that endoplasmic reticulum (ER) stress plays a prominent role in the promotion of tissue fibrosis, we investigated whether the unfolded protein response (UPR) contributes to the fibrotic development in immobilization-induced knee joint contractures. Using a non-traumatic rat knee joint contracture model, twelve female Sprague-Dawley rats received knee joint immobilization for a period of 8 weeks. We found that fibrosis protein markers (type I collagen, α-SMA) and UPR (GRP78, ATF6α, XBP1s) markers were parallelly upregulated in rat primary cultured synovial myofibroblasts. In the same cell types, pre-treatment with an ER stress inhibitor, 4-phenylbutyric acid (4-PBA), not only abrogated cytokine TGFβ1 stimulation but also reduced the protein level of UPR. Additionally, high reactive oxygen species (ROS) generation was detected in synovial myofibroblasts through flow cytometry, as expected. Notably, TGFβ1-induced UPR was significantly reduced through the inhibition of ROS with antioxidants. These data suggest that ER stress act as a pro-fibrotic stimulus through the overexpression of ROS in synovial fibroblasts. Interestingly, immunohistochemical results showed an increase in the UPR protein levels both in human acquired joint contractures capsule tissue and in animal knee joint contracture tissue. Together, our findings suggest that ER stress contributes to synovial myofibroblastic differentiation in joint capsule fibrosis and may also serve as a potential therapeutic target in joint contractures.

Intra-articular collagenase injection increases range of motion in a rat knee flexion contracture model

Objectives

A knee joint contracture, a loss in passive range of motion (ROM), can be caused by prolonged immobility. In a rat knee immobilization flexion contracture model, the posterior capsule was shown to contribute to an irreversible limitation in ROM, and collagen pathways were identified as differentially expressed over the development of a contracture. Collagenases purified from Clostridium histolyticum are currently prescribed to treat Dupuytren’s and Peyronie’s contractures due to their ability to degrade collagen. The potential application of collagenases to target collagen in the posterior capsule was tested in this model.

Materials and methods

Rats had one hind leg immobilized, developing a knee flexion contracture. After 4 weeks, the immobilization device was removed, and the rats received one 50 µL intra-articular injection of 0.6 mg/mL purified collagenase. Control rats were injected with only the buffer. After 2 weeks of spontaneous remobilization following the injections, ROM was measured with a rat knee arthrometer, and histological sections were immunostained with antibodies against rat collagen types I and III.

Results/conclusion

Compared with buffer-injected control knees, collagenase-treated knees showed increased ROM in extension by 8.0°±3.8° (p-value <0.05). Immunohistochemical analysis revealed an increase in collagen type III staining (p<0.01) in the posterior capsule of collagenase-treated knees indicating an effect on the extracellular matrix due to the collagenase. Collagen I staining was unchanged (p>0.05). The current study provides experimental evidence for the pharmacological treatment of knee flexion contractures with intra-articular collagenase injection, improving the knee ROM.

Effects of joint immobilization on changes in myofibroblasts and collagen in the rat knee contracture model

The purpose of this study was to examine the time-dependent changes in the development of joint capsule fibrosis and in the number of myofibroblasts in the joint capsule after immobilization, using a rat knee contracture model. Both knee joints were fixed in full flexion for 1, 2, and 4 weeks (immobilization group). Untreated rats were bred for each immobilization period (control group). Histological analysis was performed to evaluate changes in the amount and density of collagen in the joint capsule. The changes in type I and III collagen mRNA were examined by in situ hybridization. The number of myofibroblasts in the joint capsule was assessed by immunohistochemical methods. In the immobilization group, the amount of collagen increased within 1 week and the density of collagen increased within 2 weeks, as compared with that in the control group. Type I collagen mRNA-positive cell numbers in the immobilization group increased at all time points. However, type III collagen mRNA-positive cell numbers did not increase. Myofibroblasts in the immobilization group significantly increased compared with those in the control group at all time points, and they increased significantly with the period of immobilization. These results suggest that joint capsule fibrosis with overexpression of type I collagen occurs and progresses within 1 week after immobilization, and an increase in myofibroblasts is related to the mechanism of joint capsule fibrosis. The findings suggest the need for a treatment targeting accumulation of type I collagen associated with an increase in myofibroblasts. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1998-2006, 2017.