Imaging of Osteoarthritis of the Knee

Infrapatellar fat pad as a source of biomarkers and therapeutic target for knee osteoarthritis

BACKGROUND AND OBJECTIVE

Osteoarthritis (OA) is a multifactorial and highly prevalent disease in elderly adults; however, its pathogenesis, diagnosis, and treatment are unmet needs nowadays. Research efforts have focused on elucidating the molecular mechanisms involved in the pathogenesis, onset, and progression of OA to facilitate early detection and effective therapeutic approaches. Infrapatellar fat pad (IPFP) represents a promising novel source of OA biomarkers given that it is an active player in OA. This review aims to investigate the current literature regarding the potential of the IPFP as a source of diagnostic and prognostic biomarkers for OA as well as potential target for novel therapies.

METHODS

A literature search was conducted in the PubMed database in June 2024. We included cross-sectional and longitudinal studies based on IPFP from human OA patients, oriented in the identification of imaging, biochemical, and molecular biomarkers in the IPFP.

RESULTS

After screening and evaluation, we included a total of 61 studies. Most of the imaging publications (n = 47) on IPFP are based on magnetic resonance imaging (MRI) that revealed potential semiquantitative and quantitative imaging biomarkers linked to inflammation, fibrosis, pain, and joint degeneration imaging parameters. Biochemical and molecular studies (n = 14) pointed out an increase in interleukin-6 (IL-6), fatty acid-binding protein 4 (FABP4), adiponectin, and lysophosphatidylcholine (LysoPC) in the IPFP during OA progression.

CONCLUSIONS

Imaging, biochemical, and molecular studies indicate OA potential biomarkers in the IPFP related to inflammation, lipid dysregulation, and fibrosis. The combination of imaging and biochemical biomarkers could provide a better prediction of OA onset and the identification of OA progressors at an early stage. The IPFP study could also reveal potential therapeutic targets with the vision of better precision medicine.

Sodium hyaluronate and acupotomy bone decompression alleviates inflammatory responses in patients with knee osteoarthritis

OBJECTIVE

Knee osteoarthritis (KOA), predominantly affecting middle-aged and elderly populations, induces localized joint pain and functional impairment. It was to evaluate the effectiveness of acupotomy bone decompression (ABD) combined with sodium hyaluronate (SH) intra-articular injection on inflammatory responses in treating KOA.

METHODS

Clinical data from 128 patients with KOA were retrospectively collected, categorized into SH group (n = 55) and ABD + SH group (n = 73). Pain was assessed using the visual analogue scale (VAS), knee joint function was evaluated, and knee joint balance and gait parameters were measured. The status of articular cartilage and bone marrow edema was evaluated using quantitative magnetic resonance imaging (MRI). Interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, matrix metalloproteinase (MMP)-3, MMP-9, and hypersensitive C-reactive protein (hs-CRP) were detected.

RESULTS

ABD + SH group showed drastic reductions in VAS scores, decreased indices of different axial balances, and increased stride length and walking speed versus the SH group (P < 0.05). Quantitative MRI examination revealed that relative to the SH group, ABD + SH group exhibited increased thickness of articular cartilage and reduced area of bone marrow edema post-treatment (P < 0.05). Post-treatment levels of hs-CRP, IL-6, IL-1β, TNF-α, MMP-3, and MMP-9 were markedly lower in the ABD + SH group versus SH group (P < 0.05). Moreover, the clinical effective rate in the ABD + SH group was drastically superior to the SH group (95.9% vs. 78.2%, P < 0.05).

CONCLUSION

Combining ABD with SH treatment for KOA effectively alleviates patient pain and inflammatory responses.

Serum CXCL12 and S100A12 levels in peripheral blood fluid and their correlation with severity in patients with knee osteoarthritis

Background

This paper aimed to investigate the expression of CXCL12 and S100A12 in peripheral blood (PB) and synovial fluid (SF) of patients with knee osteoarthritis (OS) and to analyze the correlation between them and the severity of knee OS.

Methods

Sixty patients with knee OS treated in our hospital from January 2020 to December 2022 were selected as the experimental group, and 60 healthy knee joints with similar ages were selected as the control group. The fasting venous blood of 120 subjects was drawn in the early morning, and the SF was extracted during joint operation or sodium hyaluronate injection. Put the collected PB and SF in the refrigerator at -80 °C. The levels of CXCL12 and S100A12 in PB and SF were detected by enzyme-linked immunosorbent assay (Elisa).

Results

The correlation between the levels of CXCL12 and S100A12 in PB and SF and Kmurl L grade and WOMAC score. The levels of CXCL12 and S100A12 in PB and SF in the observation group were higher than those in the control group. There were significant differences in the levels of CXCL12 and S100A12 in PB and SF in the experimental group. The higher the Kmurl grade of knee OS, the higher the concentration of CXCL12 and S100A12 in PB and SF. The levels of CXCL12 and S100A12 in PB of knee OS were positively correlated with WOMAC score (r=0.767, 0.521, respectively, P<0.05); see Figure 1. The levels of CXCL12 and S100A12 in SF of knee OS were positively correlated with WOMAC score (r=0.663, 0.357 respectively, P<0.05). The levels of CXCL12 and S100A12 in PB and SF are positively correlated with the severity of knee OS.

Conclusions

The levels of CXCL12 and S100A12 in PB and SF can provide the basis for the evaluation and prognosis of knee OS.

Blood flow signals through the bone cortex on ultrasonography can be used as a screening test for detecting bone marrow lesions on magnetic resonance imaging in patients with early knee osteoarthritis

PURPOSE

Blood flow signals (BFSs) through the bone cortex on ultrasonography (US) and bone marrow lesions (BMLs) detected on magnetic resonance imaging (MRI) can be used to assess bone lesions; however, no studies have reported their relationship. Therefore, this study aimed to assess whether BFSs through the bone cortex on US can serve as a screening test for detecting BMLs on MRI in patients with early knee osteoarthritis (OA).

METHODS

This study enrolled patients with knee joint pain who were diagnosed with early knee OA between January 2018 and January 2024. We targeted 77 patients who underwent MRI and in whom the presence or absence of BFSs through the bone cortex was confirmed on US. The association between BFSs and BMLs was evaluated using the chi-square test, and the sensitivity and specificity of BFSs for detecting BMLs on MRI were calculated.

RESULTS

The chi-square test showed that BFSs and BMLs were significantly associated in the femur and tibia (femur: χ2 [1] = 52.9, p < 0.001; Tibia: χ2 [1] = 44.8, p < 0.001). The sensitivity, specificity, positive predictive value, and negative predictive value of BFSs for detecting BMLs on MRI were 85.0%, 96.5%, 89.5%, and 94.8%, respectively, for the femur, and 84.0%, 92.3%, 84.0%, and 92.3%, respectively, for the tibia.

CONCLUSION

BFSs through the bone cortex on US can be used as a screening test for detecting BMLs on MRI in patients with early knee OA.

[Clinical guideline for the interventional treatment of gonarthrosis: Consensus and algorithms]

Osteoarthritis is a major health problem due to its high prevalence. It is a very common cause of consultation in both primary care and hospitals, implying a high care burden and health costs. Current treatment recommendations are based on a conservative approach, based mainly on physical exercise and ultimately on prosthetic surgery. Between both therapeutic measures there is a wide range of interventional possibilities with disparate evidence, aimed at patients in whom medical treatment does not achieve sufficient symptomatic control and their osteoarthritis is not indicated for surgery. Due to the observed need for analysis and summary of knowledge in this field, and as a result of this forum of experts, this guide has been developed to help decision-making on some areas of gloom that we find in daily clinical practice for the interventional therapeutic approach to gonarthrosis.

Does MRI alter management in patients 60 years and older with chronic knee pain: correlation with radiographs and clinical parameters

OBJECTIVE

To determine if MRI altered management in patients ≥ 60 years old with chronic knee pain.

MATERIALS AND METHODS

Consecutive patients ≥ 60 years old with knee MRI and radiographs within 90 days were included. Exclusion criteria included mass/malignancy, recent trauma, and infection. Standing AP and PA flexion views were evaluated using Kellgren-Lawrence (KL) and International Knee Documentation Committee (IKDC) scales. Pertinent clinical history was recorded. MRIs were considered to alter management if subchondral fracture was identified or subsequent arthroscopy was performed due to an MRI finding.

RESULTS

Eighty-five knee MRI/radiograph exams were reviewed; mean 68.2 years (60-88), 47:38 F:M. Twenty knee MRIs (24%) had either a subchondral fracture (n = 9) or meniscal tear (n = 11) prompting arthroscopy. On PA flexion view, 0/20 of these studies had KL grade 4 and 70% (14/20) had KL grade 0-1 compared to the remaining MRIs having 15.4% (10/65) KL grade 4 and 38.5% (25/65) KL grade 0-1 (p = 0.03). A 10-pack-year tobacco history, 38% vs 18%, was associated with a subchondral fracture or arthroscopy (p = 0.06). Subchondral fractures were more prevalent in older patients (mean 72.4 vs 67.7 years; p = 0.03).

CONCLUSION

In patients ≥ 60 years old with chronic knee pain, MRI altered management in ~ 24% of cases; 70% in patients with KL grade 0-1, and none in patients with KL grade 4. MRI may benefit older patients with minimal osteoarthritis but not those with end-stage disease. Patients with ≥ 10 pack years of smoking may also benefit from MRI.

Classification Criteria For Early Knee Osteoarthritis: A Review Article

Objective The aim of this systematic review (SR) was to define the “state of the art” on classification criteria for early knee osteoarthritis (EKOA).

Methods A systematic review was performed using MEDLINE (Pubmed), Web of Science, Scopus, EMBASE, PEDro, CINAHL and Google scholar databases. Two independent reviewers conducted the eligibility review. Any type of study that proposed diagnostic criteria of EKOA was included.

Results Seven articles were included according to the inclusion criteria. The evidence presented in this SR shows that there is still no consensus regarding definition and classification of EKOA. At present, there are seven different proposals in the scientific literature, and they only agree on including knee pain and radiographic evaluation in their criteria, but they do not even consider the same situations for including these two factors.

Conclusion There is still no consensus regarding definition and classification of EKOA. Knee pain and radiological assessment seem to be the most commonly used criteria, but due to the variability encountered, it is not possible to reach a consensus on a clear definition and diagnosis of EOKA.

Radiological Approach to Assessment of Lower-Limb Alignment-Coronal and Transverse Plane Analysis

Lower-limb alignment deformities constitute a significant clinical concern, as they can lead to serious complications, including progressive degenerative diseases and disabilities. Rotational deformities may give rise to conditions such as joint arthrosis, patellar instability, and the degeneration of the patellofemoral cartilage. Therefore, a comprehensive evaluation of lower-limb alignment is essential for the effective patient management, preoperative planning, and successful correction of these deformities. The primary assessment method employs full-length standing radiographs in the anteroposterior (AP) projection, which facilitates accurate measurements of the anatomical and mechanical axes of the lower limb, including angles and deviations. The outcomes of this analysis are vital for the meticulous planning of osteotomy and total knee arthroplasty (TKA). In addition, computed tomography (CT) provides a specialized approach for the precise evaluation of femoral and tibial rotation. In this area, there are potential opportunities for the implementation of AI-based automated measurement systems.

Is Magnetic Resonance Imaging Overused Among Patients Undergoing Total Knee Arthroplasty?

INTRODUCTION

With increasing healthcare costs, it is important to quantify the number of total knee arthroplasty (TKA) patients who have MRIs that are not considered clinically necessary. The purpose of this study was to determine the number of unnecessary preconsultation MRIs done among TKA patients at our institution.

METHODS

Eight hundred and sixty-nine patients who underwent a primary TKA were identified. Review of medical records and imaging results was conducted to determine which patients had received preconsult MRIs and whether they were necessary or unnecessary.

RESULTS

Of the 869 TKA, 177 (20.4%) presented with a preconsultation MRI, of which, 112 met the study inclusion criteria. Of the 112 MRIs, 18 (20.7%) were done without radiographic imaging, and 69 (79.3%) were completed after radiographically evident moderate-to-severe arthritis. Overall, 87 MRIs (10.0%) were deemed clinically unnecessary.

CONCLUSIONS

Referring physicians are overusing MRIs before consultation with an orthopaedic surgeon. The 87 patients who had unnecessary MRIs at our institution over a one-year period represented a cost of $20,706. Extrapolating that number to the scale of patients affected by arthritis each year is potentially a staggering amount of money. Evidence-based guidelines should be put into place to optimize healthcare utilization.

Ultrasound Imaging in Knee Osteoarthritis: Current Role, Recent Advancements, and Future Perspectives

While conventional radiography and MRI have a well-established role in the assessment of patients with knee osteoarthritis, ultrasound is considered a complementary and additional tool. Moreover, the actual usefulness of ultrasound is still a matter of debate in knee osteoarthritis assessment. Despite that, ultrasound offers several advantages and interesting aspects for both current clinical practice and future perspectives. Ultrasound is potentially a helpful tool in the detection of anomalies such as cartilage degradation, osteophytes, and synovitis in cases of knee osteoarthritis. Furthermore, local diagnostic and minimally invasive therapeutic operations pertaining to knee osteoarthritis can be safely guided by real-time ultrasound imaging. We are constantly observing a growing knowledge and awareness among radiologists and other physicians, concerning ultrasound imaging. Ultrasound studies can be extremely useful to track the response to various therapies. For this specific aim, tele-ultrasonography may constitute an easy tool aiding precise and repeated follow-up controls. Moreover, raw radio-frequency data from US backscattering signals contain more information than B-mode imaging. This paves the way for quantitative in-depth analyses of cartilage, bone, and other articular structures. Overall, ultrasound technologies and their rapid evolution have the potential to make a difference at both the research and clinical levels. This narrative review article describes the potential of such technologies and their possible future implications.

Evaluating the reliability of the lateral femoral condyle measuring methods by different modalities for patients with lateral patellar dislocation

BACKGROUND

A variety of measurement methods and imaging modalities are in use to quantify the morphology of lateral femoral condyle (LFC), but the most reliable method remains elusive in patients with lateral patellar dislocation (LPD). The purpose of this study was to determine the intra- and inter-observer reliability of different measurement methods for evaluating the morphology of LFC on different imaging modalities in patients with LPD.

METHODS

Seventy-three patients with LPD were included. Four parameters for quantifying the morphology of LFC were retrospectively measured by three observers on MRI, sagittal CT image, conventional radiograph (CR), and three-dimensional CT (3D-CT). The intra-class correlation coefficient was calculated to determine the intra- and inter-observer reliability. Bland-Altman analysis was conducted to identify the bias between observers.

RESULTS

The lateral femoral condyle index (LFCI) showed better intra- and inter-observer reliability on MRI and 3D-CT than on CR and sagittal CT images. The mean difference in the LFCI between observers was lowest on 3D-CT (0.047), higher on MRI (0.053), and highest on sagittal CT images (0.062). The LFCI was associated with the lateral femoral condyle ratio (ρ = 0.422, P = 0.022), lateral condyle index (r = 0.413, P = 0.037), and lateral femoral condyle distance (r = 0.459, P = 0.014). The LFCI could be reliably measured by MRI and 3D-CT.

CONCLUSION

The LFCI could be reliably measured by MRI and 3D-CT. The LFCI was associated with both the height and length of LFC and could serve as a comprehensive parameter for quantifying the morphology of LFC in patients with LPD.

Exploring biomarkers associated with severity of knee osteoarthritis in Southern China using widely targeted metabolomics

BACKGROUND

Metabolomics is a tool to study the pathogenesis of diseases and their associated metabolites, but there are still insufficient metabolomic studies on severe knee osteoarthritis.To investigate the differences in serum metabolites between healthy populations and knee osteoarthritis (KOA) patients in Southern China using widely targeted metabolomics, and to explore biomarkers and their metabolic pathways that could be associated with the severity of KOA.

METHODS

There were 10 healthy individuals in the control group and 32 patients with KOA. According to the Kellgren-Lawrence (KL) grading system, KOA was further divided into mild (n = 13, KL grade 1 and 2) and severe (n = 19, KL grade 3 and 4). Serum samples from all participants were collected and analyzed metabolomics based on ultra-performance liquid chromatography/electrospray ionization/tandem mass spectrometry. We screened for differential metabolites between patients and controls, and between mild and severe KOA. We explored the metabolic pathways involved in differential metabolism using the Kyoto Encyclopedia of Genes and Genomes database.

RESULTS

Sixty-one metabolites were differentially expressed in the sera of the patient group compared with the control group (45 upregulated and 16 downregulated). Analysis of the mild and severe KOA groups showed a total of 12 differential metabolites. Receiver operating characteristic curve analysis showed N-alpha-acetyl-L-asparagine was a good predictor of advanced osteoarthritis(OA).Differential metabolites are enriched in multiple pathways such as arachidonic acid metabolism.

CONCLUSION

Widely targeted metabolomics found that upregulation of the amino acid metabolite N-α-acetyl-L-asparagine was significantly associated with severe KOA and could be a biomarker for predicting severity of KOA. Arachidonic acid metabolism may play an important role in patients with severe KOA.

Knee osteoarthritis: Current status and research progress in treatment (Review)

Knee osteoarthritis (KOA) is a common chronic articular disease worldwide. It is also the most common form of OA and is characterized by high morbidity and disability rates. With the gradual increase in life expectancy and ageing population, KOA not only affects the quality of life of patients, but also poses a burden on global public health. OA is a disease of unknown etiology and complex pathogenesis. It commonly affects joints subjected to greater loads and higher levels of activity. The knee joint, which is the most complex joint of the human body and bears the greatest load among all joints, is therefore most susceptible to development of OA. KOA lesions may involve articular cartilage, synovium, joint capsule and periarticular muscles, causing irreversible articular damage. Factors such as mechanical overload, inflammation, metabolism, hormonal changes and ageing serve key roles in the acceleration of KOA progression. The clinical diagnosis of KOA is primarily based on combined analysis of symptoms, signs, imaging and laboratory examination results. At present, there is no cure for KOA and the currently available therapies primarily focus on symptomatic treatment and delay of disease progression. Knee replacement surgery is typically performed in patients with advanced disease. The current study presents a review of epidemiological characteristics, risk factors, histopathological manifestations, pathogenesis, diagnosis, treatment modalities and progress in KOA research.

Differential Metabolites in Osteoarthritis: A Systematic Review and Meta-Analysis

(1) Many studies have attempted to utilize metabolomic approaches to explore potential biomarkers for the early detection of osteoarthritis (OA), but consistent and high-level evidence is still lacking. In this study, we performed a systematic review and meta-analysis of differential small molecule metabolites between OA patients and healthy individuals to screen promising candidates from a large number of samples with the aim of informing future prospective studies. (2) Methods: We searched the EMBASE, the Cochrane Library, PubMed, Web of Science, Wan Fang Data, VIP Date, and CNKI up to 11 August 2022, and selected relevant records based on inclusion criteria. The risk of bias was assessed using the Newcastle-Ottawa quality assessment scale. We performed qualitative synthesis by counting the frequencies of changing directions and conducted meta-analyses using the random effects model and the fixed-effects model to calculate the mean difference and 95% confidence interval. (3) Results: A total of 3798 records were identified and 13 studies with 495 participants were included. In the 13 studies, 132 kinds of small molecule differential metabolites were extracted, 58 increased, 57 decreased and 17 had direction conflicts. Among them, 37 metabolites appeared more than twice. The results of meta-analyses among four studies showed that three metabolites increased, and eight metabolites decreased compared to healthy controls (HC). (4) Conclusions: The main differential metabolites between OA and healthy subjects were amino acids (AAs) and their derivatives, including tryptophan, lysine, leucine, proline, phenylalanine, glutamine, dimethylglycine, citrulline, asparagine, acetylcarnitine and creatinine (muscle metabolic products), which could be potential biomarkers for predicting OA.

An auxiliary diagnostic technology and clinical efficacy evaluation in knee osteoarthritis based on serum surface-enhanced Raman spectroscopy

Knee osteoarthritis (KOA), a progressive joint disease, is a leading source of chronic pain and disability, and its diagnosis mainly depends on medical imaging findings and clinical symptoms. This study aimed to explore an auxiliary diagnostic technology and clinical efficacy evaluation in KOA based on surface-enhanced Raman scattering (SERS). Three sequential experiments were performed: 1) preliminary observation of the therapeutic effects of icariin (ICA); 2) using serum SERS spectra obtained from rat models belonging to sham group, KOA group and icariin treatment group, respectively, to analyze the KOA-related expression profiles; 3) employing partial least squares (PLS) and support vector machines (SVM) algorithms to establish KOA diagnosis model. Pathological changes verified the efficacy of icariin in KOA. Raman peak assignment combined with spectral difference analysis reflected the biochemical changes associated with KOA, including amino acid, carbohydrates and collagen. ICA intervention significantly reversed these changes, although full recovery could not be achieved. Based on PLS-SVM approach, the sensitivity, specificity and accuracy of 100%, 98.33% and 98.89%, respectively, were obtained for screening KOA. This work proves that SERS has great potential to be used as an auxiliary diagnostic technology for KOA, and is also helpful for the exploration of novel KOA treatment agent.

Effects of Modified Duhuo Jisheng Decoction Combined with Arthroscopic Surgery on Bone Metabolism, Oxidative Stress, and Serum TLR4 and TGF-β1 in Patients with Knee Osteoarthritis

Objective

To analyze the effects of modified Duhuo Jisheng Decoction combined with arthroscopic surgery on bone metabolism, oxidative stress, and serum TLR4 and TGF-β1 in patients with knee osteoarthritis (KOA).

Methods

Prospectively select 82 patients with KOA from January 2020 to January 2022 in our hospital and divide them into the control group and observation group according to the random number table method, with 41 patients in each group. The control group was treated with arthroscopic surgery alone and routine anti-infection after operation. The observation group was treated with Duhuo Jisheng Decoction on the basis of the treatment of the control group. The patients in the two groups were treated continuously for 4 weeks. The improvement of patients' symptoms was evaluated by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Before treatment and 4 weeks after treatment, the scores of traditional Chinese medicine (TCM) symptoms, bone metabolism indicators (cartilage oligomeric matrix protein (COMP), collagen type II carboxy terminal peptide (ctx-II), and matrix metalloproteinase-3 (MMP-3)), oxidative stress indicators (superoxide dismutase (SOD), glutathione peroxidase (GSHPx), malondialdehyde (MDA), nitric oxide (NO)), serum Toll-like receptor 4 (TLR4), and transforming growth factor β (TGF-β) level were compared between the two groups.

Results

After treatment, the WOMAC score of the two groups decreased (42.45 ± 10.83) in the observation group and (67.81 ± 14.63) in the control group. The WOMAC score of the observation group was lower than that of the control group (P < 0.05). After treatment, the levels of COMP, CTX-II, and MMP-3 in the two groups decreased, and the levels of COMP, CTX-II, and MMP-3 in the observation group were lower than those in the control group (P < 0.05). After treatment, the levels of SOD and GSHPx increased, while the levels of MDA and NO decreased in the two groups. The levels of SOD and GSHPx in the observation group were higher than those in the control group, while the levels of MDA and NO were lower than those in the control group (P < 0.05). After treatment, the TLR4 level in the observation group was lower than that of the control group, and the level of TGF-β in the observation group was higher than that of the control group (P < 0.05).

Conclusion

Compared with arthroscopic surgery alone, combined with modified Duhuo Jisheng Decoction can better alleviate the clinical symptoms of patients with KOA, improve their bone metabolism, oxidative stress indicators, and serum TLR4 and TGF-β 1 level, and reduce the inflammatory injury of knee joint.