Prevention of arthrofibrosis during knee repair by extracorporeal shock wave therapy: Preliminary study in rabbits

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.

Outcome of eight working dogs with fibrotic myopathy following extracorporeal shockwave and rehabilitation therapy: a case series

Introduction

Fibrotic myopathy of the gracilis, semitendinosus, and semimembranosus is described primarily in working German Shepherd dogs. The purpose of this case series is to describe the rehabilitation modalities and treatments utilized in working dogs with fibrotic myopathy and the time frame they were able to continue working.

Methods

Medical records of patients with hindlimb lameness that were presented to the Schwarzman Animal Medical Center in New York City from 2012 to 2023 were retrospectively searched. Signalment, history, clinical evaluation, gait analysis, goniometry of stifles, and follow-up evaluation were compared among patients. Ten male working dogs met inclusion criteria. Extracorporeal Shockwave Therapy (ECSWT) was administered under sedation or general anesthesia. Rehabilitation therapy (RT), including massage, hamstring stretch, photobiomodulation, pulsed electromagnetic field therapy, warm compress, therapeutic ultrasound, underwater treadmill, and therapeutic exercises, were performed once every one to 3 weeks with varying protocols according to patient assessments. Follow-up phone calls and emails were conducted to determine long-term outcome.

Results

On average, dogs were able to work full-time for 32.1 months (range 6-82; SD 23.6) from the time of diagnosis. No activity limitation was reported by the owners/handlers.

Discussion

This report is the first to describe non-invasive medical treatments that may extend the working ability of dogs diagnosed with fibrotic myopathy. Further prospective randomized controlled studies are needed to demonstrate the efficacy of ECSWT and RT for treating fibrotic myopathy.

Conclusion

The results of this retrospective study suggest that the combination of ECSWT and RT may allow working dogs with fibrotic myopathy to continue their working capacity for an extended period of time.

The effect of extracorporeal shock wave on joint capsule fibrosis based on A2AR-Nrf2/HO-1 pathway in a rat extending knee immobilization model

Joint capsule fibrosis, a common complication of joint immobilization, is mainly characterized by abnormal collagen deposition. The present study aimed to investigate the effect of extracorporeal shock wave therapy (ESWT) on reduced collagen deposition in the joint capsule during immobilization-induced joint capsule fibrosis. Additionally, the potential involvement of the adenosine A2A receptor (A2AR)-Neurotrophic factor e2-related factor 2 (Nrf2)/Haem oxygenase-1 (HO-1) pathway was explored. Thirty 3-month-old male Sprague-Dawley rats were randomly assigned to five groups: control (C), immobilization model (IM), natural recovery (NR), ESWT intervention (EI), and ESWT combined with A2AR antagonist SCH 58261 intervention (CI). After the left knee joints of rats in the IM, NR, EI and CI groups were immobilized using a full-extension fixation brace for 4 weeks, the EI and CI groups received ESWT twice a week for 4 weeks. The CI group was also treated with ESWT following intraperitoneal injection of SCH 58261 (0.01 mg/kg) for 4 weeks. The range of motion of the left knee joint was measured, and the protein levels of collagens I and III, A2AR, phosphorylated-protein kinase A/protein kinase A (p-PKA/PKA), p-Nrf2/Nrf2, and HO-1 were analysed by Western blotting. The IM and NR groups showed significantly greater arthrogenic contracture than the C group (P < 0.05). Compared to the NR group, the EI and CI groups exhibited significant improvement in arthrogenic contracture (P < 0.05). Conversely, the EI group showed lower contracture than the CI group (P < 0.05). Similar results were observed for collagen deposition and the protein levels of collagens I and III. The intervention groups (EI and CI groups) showed higher levels of p-Nrf2/Nrf2 and HO-1 than the NR group (P < 0.05). Moreover, the EI group exhibited higher levels of p-PKA/PKA, p-Nrf2/Nrf2, and HO-1 than the CI group (P < 0.05). However, no significant difference was found in the A2AR levels among the five groups (P > 0.05). ESWT may activate A2AR, leading to the phosphorylation of PKA. Subsequently, Nrf2 may be activated, resulting in the upregulation of HO-1, which then reduces collagen deposition and alleviates immobilization-induced joint capsule fibrosis.

The effect of extracorporeal shock wave on joint capsule fibrosis in rats with knee extension contracture: a preliminary study

The purpose of this study was to observe the therapeutic effect of extracorporeal shock wave (ESW) on extensional joint contracture of knee joint in rats and its mechanism on articular capsule fibrosis. Thirty-two SD rats were randomly divided into blank control, immobilization, natural recovery, and ESW intervention groups. Except for the control group, the left knee joints of other rats were fixed with external fixation brace for 4 weeks when they were fully extended to form joint contracture. The effect of intervention was assessed by evaluating joint contracture, total cell count and collagen deposition in joint capsule, and protein expression levels of TGF-β1, p-Smad2/3, Smad2/3, p-JNK, JNK, I and III collagen in joint capsule. ESW can effectively reduce arthrogenic contracture, improve the histopathological changes of anterior joint capsule, inhibit the high expression of target protein and the excessive activation of TGF-β1/Smad2/3/JNK signal pathway. Inhibition of excessive activation of TGF-β1/Smad2/3/JNK pathway may be one of the potential molecular mechanisms by which extracorporeal shock wave can play a role.

Extracorporeal Shock Wave Therapy Improves Nontraumatic Knee Contracture in a Rat Model

BACKGROUND

Joint contractures occur frequently after trauma or immobilization, but few reliable treatments are available. Extracorporeal shock wave therapy (ESWT) is often used for various musculoskeletal conditions, but whether it is effective for treating joint contractures and the mechanisms through which it might work for that condition remain unclear.

QUESTIONS/PURPOSES

Using a rat model, we asked, does ESWT (1) inhibit the progression of knee contracture, (2) ameliorate histopathologic joint changes, and (3) improve serum and myofascial fibrosis-related factors? We also asked, (4) what is the possible mechanism by which ESWT inhibits knee contracture?

METHODS

Thirty-two male Sprague-Dawley rats (12 weeks old and weighing 300 to 400 g) were randomly separated into two groups: control group (eight rats) and noncontrol group (24) in the first week. Rats in the control group were kept free in cages for 4 weeks, and the right lower limbs of the rats in the noncontrol group were immobilized in plaster for 4 weeks. ROM was then measured for each rat with or without 4 weeks of immobilization. After ROM measurement, rats in the noncontrol group were randomly separated into three groups: immobilization group (eight rats), remobilization group (eight rats), and remobilization with ESWT group (eight rats) at Week 4. Knee contracture was induced in rats by fixing the right knee with a plaster cast as in a previous study. The plaster cast was removed after 4 weeks; knee contracture was established when passive ROM was decreased and dysfunction such as abnormal gait occurred. Subsequently, rats with a remobilized joint contracture were treated with or without ESWT for 15 days (on Days 5, 10, and 15). The therapeutic effect was examined using ROM, joint diameter (as an indication of swelling), histopathologic changes, and the levels of fibrosis-related extracellular matrix component factors (hyaluronic acid, serum procollagen peptide, and laminin). The effect of ESWT on fibrosis protein was also evaluated using immunohistochemistry, quantitative polymerase chain reaction (qPCR), and Western blot. The expressions of factors in the TGF-β/SMADs pathway were also determined using Western blot and qPCR.

RESULTS

ESWT mitigated immobilization-induced knee contracture in rats by improving ROM (immobilization versus remobilization with ESWT: 53° ± 8° versus 32° ± 8° [95% confidence interval 13° to 30°]; p < 0.001) and joint swelling (immobilization versus remobilization with ESWT: 8 ± 0.8 cm versus 6 ± 0.3 cm [95% CI 0.4 to 2.2 cm]; p = 0.01). Histopathologic features of remission were alleviated after ESWT (immobilization versus remobilization with ESWT: thickness of the knee space: 0.2 ± 0.03 mm versus 0.6 ± 0.01 mm [95% CI -0.49 to -0.33 mm]; p < 0.001. On Masson staining, the positive expression area, which indicates collagen fiber deposition, was 24% ± 5% versus 9% ± 2% ([95% CI 10% to 21%]; p < 0.001). ESWT improved the serum fibrosis factors of hyaluronic acid, procollagen peptide, and laminin (immobilization versus remobilization with ESWT: hyaluronic acid: 412 ± 32 versus 326 ±15 ng/mL [95% CI 29 to 144 ng/mL]; p = 0.003; serum procollagen peptide: 19 ± 1 versus 12 ±1 ng/mL [95% CI 3 to 11 ng/mL]; p < 0.001; laminin: 624 ± 78 versus 468 ±9 ng/mL [95% CI 81 to 231 ng/mL]; p = 0.006) and myofascial factors of α-SMA and Type I collagen associated with immobilization-induced contractures.

CONCLUSION

The findings suggest that ESWT improved joint contracture by inhibiting the TGF-β1/SMADs signaling pathway in rats.

CLINICAL RELEVANCE

This work suggests ESWT may be worth exploring in preliminary research in humans to determine whether it may be a treatment option for patients with nontraumatic knee contractures. If the mechanism of ESWT can be confirmed in humans, ESWT might be a therapy for diseases involved in the TGF-β1/SMADs signaling pathway, such as hypertroic scarring and scleroderma.

Identification of novel biomarkers for arthrofibrosis after total knee arthroplasty in animal models and clinical patients

Background

Arthrofibrosis is a debilitating complication after total knee arthroplasty (TKA) which becomes a considerable burden for both patients and clinical practitioners. Our study aimed to identify novel biomarkers and therapeutic targets for drug discovery.

Methods

Potential biomarker genes were identified based on bioinformatic analysis. Twelve male New Zealand white rabbits underwent surgical fixation of unilateral knees to mimics the joint immobilization of the clinical scenario after TKA surgery. Macroscopic assessment, hydroxyproline content determination, and histological analysis of tissue were performed separately after 3-days, 1-week, 2-weeks, and 4-weeks of fixation. We also enrolled 46 arthrofibrosis patients and 92 controls to test the biomarkers. Clinical information such as sex, age, range of motion (ROM), and visual analogue scale (VAS) was collected by experienced surgeons

Findings

Base on bioinformatic analysis, transforming growth factor-beta receptor 1 (TGFBR1) was identified as the potential biomarkers. The level of TGFBR1 was significantly raised in the rabbit synovial tissue after 4-weeks of fixation (p<0.05). TGFBR1 also displayed a highly positive correlation with ROM loss and hydroxyproline contents in the animal model. TGFBR1 showed a significantly higher expression level in arthrofibrosis patients with a receiver operating characteristic (ROC) area under curve (AUC) of 0.838. TGFBR1 also performed positive correlations with VAS baseline (0.83) and VAS after 1 year (0.76) while negatively correlated with ROM baseline (-0.76) in clinical patients.

Interpretation

Our findings provided novel biomarkers for arthrofibrosis diagnosis and uncovered the role of TGFBR1. This may contribute to arthrofibrosis prevention and therapeutic drug discovery.