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Schematic diagram of the position of cysts and bursae assessed in the present study. (a) Sagittal plane showing cruciate ligaments. (b) Coronal plane. (c) Sagittal plane showing tibiofibular joint. (d) and (e) Axial planes at the level of distal femur and menisci, respectively. These illustrations are intended to be a rough guide for readers to show approximate locations of these lesions and do not represent precise anatomical details. P, patella; H, Hoffa's fat pad; F, femur; T, tibia; ACL, anterior cruciate ligament; PCL, posterior cruciate ligament; IT, iliotibial band; LM, lateral meniscus; MM, medial meniscus; PA, pes anserinus; MCL(s), superficial layer of medial collateral ligament; MCL(d), deep layer of medial collateral ligament; Fi, fibula; Po, popliteus tendon; BF, biceps femoris tendon; SM, semi-membranosus tendon; GN, medial head of gastrocnemius muscle; S, sartorius muscle. Lesions: (1) prepatellar bursa; (2) superficial infrapatellar bursa; (3) deep infrapatellar bursa; (4) Hoffa's fat pad ganglion cyst; (5) ACL ganglion cyst; (6) PCL ganglion cyst; (7) iliotibial bursitis; (8) lateral meniscal cyst; (9) medial collateral ligament bursitis; (10) anserine bursa; (11) proximal tibiofibular joint cyst; (12) popliteal cyst; (13) subgastrocnemius bursa; (14) semi-membranous medial collateral ligament bursa; (15) medial meniscal cyst.
Source publication
The purpose of the present study was to determine the prevalence of cystic lesions and cyst-like bursitides in subjects with frequent knee pain and to assess their relation to radiographic osteoarthritis (OA) severity; to describe bilaterality and size fluctuation of the lesions over 6 months; and to assess relations between the prevalence of synov...
Contexts in source publication
Context 1
... may result in a cyst-like appearance, how- ever, due to accumulation of fluid within the bursa and thickening of the synovial membrane [8]. Locations of various bursae and cystic lesions of the knee are shown schematically in Figure 1. ...Context 2
... types of lesions were studied, including popliteal cysts (Figure 2), proximal tibiofibular joint (PTFJ) cysts, medial and lateral meniscal cysts, and anterior and pos- terior cruciate ligament (ACL and PCL) and Hoffa's fat pad ganglion cysts. In addition, the following bursitides with cyst-like appearances were included: anserine, prepatellar, superficial and deep infrapatellar, iliotibial, SM-MCL, medial collateral ligament, and subgastrocne- mius bursitides [7] (Figures 1 and 2). ...Similar publications
Background
Previous studies showed that among persons with radiographic knee OA, periarticular lesions were significantly more common among participants with knee pain than those without. However, data were derived mostly from persons with knee OA, and there were few normal participants without knee OA in the data analyses. The objectives of this s...
Introduction: A great number of people all over the world suffer from knee joint
problems. The benefits of ultrasound (US) when compared to magnetic resonance
imaging (MRI) are that the US is noninvasive, freely available, well‑accepted by
patients, cheap and that it has the advantage of dynamic evaluation and real‑time
imaging. In this study, ther...
Tuberculosis of the musculoskeletal system is uncommon and constitutes 1% to 5% of all forms of tuberculosis. In total, 30% of skeletal tuberculosis involves the joints, the knee being the third most commonly affected after the spine and the hip. Knee tuberculosis commonly presents as synovitis or arthritis, and infected Baker’s cyst is a rather ra...
Evidence for the validity of US in detecting structural joint pathology in OA is increasing. However, despite the rapidly emerging field of US in OA, few studies have reported on the inter-observer reliability of US to date. The objective of this study was to assess inter-observer reliability of ultrasonography (US) in the evaluation of specificall...
Background
Symptoms of knee osteoarthritis (KOA) vary according to many factors mainly degree of KOA and degree of inflammatory features.The primary goal of treatment the patients with KOA is to maximize long-term health-related quality of life through control of symptoms. Understanding ultrasonographic characteristics of KOA in asymptomatic patien...
Citations
... The exclusion criteria were as follows: (1) studies involving cadaver subjects or non-human research; (2) duplicate publications (if multiple published studies were retrieved from the same database, the largest or the most complete one was included); (3) reviews; or (4) abstract or title publication only. ...
Background
Baker’s cyst is the most common cystic disease of the knee, and a fast and accurate diagnosis of Baker’s cyst is essential for a better management. Ultrasound is a rapid, portable, widely available, inexpensive and noninvasive imaging modality. However, the diagnostic accuracy of ultrasound on Baker’s cyst still remains undetermined. We conducted the first meta-analysis to comprehensively assess the accuracy of ultrasound for the detection of Baker’s cyst.
Methods
PubMed, Embase and Web of Science were searched from inception to July 14, 2022, without language restrictions. Studies providing cross-tabulations of ultrasound versus pathology (gold standard) or MRI (standard imaging technique) for diagnosis of Baker’s cyst were included. Indicators for the diagnostic accuracy of ultrasound, including sensitivity, specificity and area under the curve, were calculated using a bivariate model. Sensitivity analysis was conducted to evaluate the heterogeneity and robustness of the results.
Results
A total of 13 studies with 1,011 subjects (mean age 32.2 years; men 53.5%) met the inclusion criteria. The pooled sensitivity, specificity and area under the curve of ultrasound for diagnosis of Baker’s cyst, compared with pathology, were 0.97 (95% confidence intervals: 0.73–1.00), 1.00 (0.98–1.00) and 1.00 (0.99–1.00), respectively. The pooled estimates of ultrasound versus MRI were 0.94 (0.87–0.98) for sensitivity, 1.00 (0.83–1.00) for specificity and 0.97 (0.95–0.98) for area under the curve. Sensitivity analysis did not change the results materially.
Conclusion
Ultrasound shows excellent diagnostic accuracy for the assessment of Baker’s cyst and provides similar diagnostic information (absent or present) compared to MRI. Because of its advantages of low cost, portability and accessibility, ultrasound is likely to be a choice of imaging technique for screening Baker’s cyst in clinical and population settings as well as in follow-ups.
... According to the literature, arthroscopic excision is the most commonly used procedure for intra-articular ganglion cysts 12,18,[31][32][33][34][35][36] (Table IV). In a study by Brown and Dandy, 6,500 knee arthroscopies were evaluated 37 . ...
:
Magnetic resonance imaging (MRI) without contrast is sufficient to diagnose an intra-articular ganglion cyst of the knee. MRI with intravenous contrast may be considered for cysts in the infrapatellar fat pad, which are not a typical presentation.
➢:
The current literature supports treating symptomatic cases or those discovered accidently during knee arthroscopy with arthroscopic excision.
➢:
Although aspiration of these cysts results in a higher recurrence rate than excision, it is associated with quicker recovery. Thus, aspiration might be chosen as an initial treatment for anyone who would like to avoid surgery or requires a rapid recovery, including professional athletes.
➢:
Open excision may be considered for infrapatellar fat pad cysts that are >4.5 cm in size.
... Popliteal cysts (Baker cysts) constitute the most common cystic lesions around the knee joint in adults [1]. Cystic lesions around the knee can be classified into primary, not associated with intra-articular pathology, and secondary, often associated with concomitant intra-articular lesions, especially meniscal tears [2]. ...
Popliteal cysts represent one of the commonest knee pathologies in the adult population. The vast majority of cases may be treated conservatively as symptoms tend to resolve spontaneously. However, few patients may experience persistent pain and nerve-related symptoms not responding to conservative management. We present a case of a 46-year-old patient who suffered from tibial nerve palsy due to a popliteal cyst that was treated successfully with a combined open and arthroscopic procedure. It is important to understand that popliteal cysts rarely may lead to tibial nerve entrapment, and in selected cases, operative management may be indicated.
... MRI can help delineate the location of lesions concerning anatomic structures and, with the application of contrast, determine if lesions are cystic or solid (6). Typically, cysts located around the knee are encapsulated fluid collections with low T1-weighted signals and high T2weighted signals on MR scans, similar to benign intra-articular fluid collections, effusions, or certain types of soft-tissue tumors (7)(8)(9)(10). Radiologists and clinicians must familiarize themselves with the MRI features of the cyst and cyst-like lesions to accurately diagnose the disease, develop treatment plans, and manage patients more effectively. ...
Background
Cystic lesions are frequently observed in knee joint diseases and are usually associated with joint pain, degenerative disorders, or acute injury. Magnetic resonance imaging-based, artificial intelligence-assisted cyst detection is an effective method to improve the whole knee joint analysis. However, few studies have investigated this method. This study is the first attempt at auto-detection of knee cysts based on deep learning methods.
Methods
This retrospective study collected data from 282 subjects with knee cysts confirmed at our institution from January to October 2021. A Squeeze-and-Excitation (SE) inception attention-based You only look once version 5 (SE-YOLOv5) model was developed based on a self-attention mechanism for knee cyst-like lesion detection and differentiation from knee effusions, both characterized by high T2-weighted signals in magnetic resonance imaging (MRI) scans. Model performance was evaluated via metrics including accuracy, precision, recall, mean average precision (mAP), F1 score, and frames per second (fps).
Results
The deep learning model could accurately identify knee MRI scans and auto-detect both obvious cyst lesions and small ones with inconspicuous contrasts. The SE-YOLO V5 model constructed in this study yielded superior performance (F1 = 0.879, precision = 0.887, recall = 0.872, all class mAP0.5 = 0.944, effusion mAP = 0.945, cyst mAP = 0.942) and improved detection speed compared to a traditional YOLO model.
Conclusion
This proof-of-concept study examined whether deep learning models could detect knee cysts and distinguish them from knee effusions. The results demonstrated that the classical Yolo V5 and proposed SE-Yolo V5 models could accurately identify cysts.
... Therefore, studying the effect of the slant angle of the target on the results is important to emulate real scenarios, especially for the injuries that are based on the accumulation of blood/fluid/water after the abnormality happens. MRI and ultrasound images [264][265][266][267][268] show that the fluid can be accumulated in arbitrary/slant shapes. ...
The knee is prone to injuries more often than other joints in the body due to its complexity and weight-bearing role. These injuries are not only inherent to sports fields but also to everyday lifestyles. Connective tissue injuries are the most prevalent knee diagnoses, accounting for 50% of musculoskeletal injuries. They are the most critical knee injuries because they can require surgical intervention and prolonged rehabilitation. In the United States, roughly 17 million ligamentous injuries necessitate medical care each year, at an estimated cost of over $40 billion. Early detection of a partial tear for knee ligaments without obstructing natural activity reduces the severity of the injury and its transformation into a complete tear, which can only be treated using interventional surgery. Besides, the treatment period is shortened from nearly one year in complete tears to several weeks in the case of mild or moderate tears. Moreover, early detection decreases the risk of other injuries that are associated with complete ligament tears, such as meniscal and tendon tears, posttraumatic osteoarthritis, and dislocation. Therefore, onsite diagnostic tools are required because the current scanning modalities, such as MRI and CT, are not suitable for use outside the hospital.
Meanwhile, Electromagnetic imaging (EMI) has undergone rapid development and has become one of the promising biomedical imaging modalities because of its unique features, such as low cost, simple structure, portability, and non-ionization. EMI modality is based on the significant changes in dielectric characteristics of tissues due to abnormality or injuries. When the ligament tear happens for knee injuries, the synovial fluid increases inside the knee joint, which can be detected using EMI. Thus, EMI is an attractive solution to address the mentioned limitations.
Implementing a complete EMI system that includes antenna array designs, hardware platforms, and microwave imaging algorithms is of significant interest in this context. In order to test and validate new EMI systems for knee injuries, a realistic durable knee phantom is required. Therefore, the first contribution of this thesis is to introduce knee phantom with realistic dielectric and anatomical properties fabricated using proper molds and equivalent mixtures. The fabricated phantom is based on a composite material of polymer and additive materials such as aluminium-oxide and graphite.
In the second part of this thesis, a portable EMI system for knee injuries is designed, fabricated, tested, and validated for the first time in the literature. Specifically, design an eight-element wide band biconical antenna array at 0.7-2.2 GHz with a unidirectional radiation pattern to improve penetration into the knee. To reconstruct knee images, a modified multi-static confocal algorithm is used. Since humans' left and right knees are mirror-symmetrical, the modified algorithm uses a differential approach to remove signal clutters, muti-static coherence factor to improve the quality of channels, and applies dielectric mapping to reduce detection error. The images indicate the ability of the system to detect different types of ligament tears with an accurate localization. The third contribution in this thesis is presented as an essential step to verify the proposed system on the ex-vivo pig knee joint before clinical trials. Six healthy hind legs from three dead adult pigs were removed at the hip, suspended in the developed system, and scanned. Then, ligament tear was emulated by injecting distilled water into the middle of the left knee joint of each pig for early and mid-stage injuries. The injured knees were re-scanned. Furthermore, all knee’s connective tissues are extracted from a healthy hind leg along with collected synovial fluid. The extracted tissues and fluid were characterized and modelled, then imported to build an equivalent model for pig knee of 1 mm3 resolution in a realistic simulation environment to be used in the numerical studies by the researchers.
The last part of this thesis focuses on introducing textile brace systems to be more conformable with the knee and can be worn for knee imaging and daily monitoring. The two braces are designed to match the human knee for enhanced electromagnetic wave penetration. The antennas in two braces achieve wide bandwidth and unidirectional radiation. The first brace consists of a simple 12-element textile slot loop antenna array. In contrast, the second brace consists of 8-element dual-polarized octagonal aperture antenna array. The dual-polarized brace system demonstrates a high capability to detect accumulated fluid with an arbitrary shape, slant angle, small size or deeper than the center of the brace. The reconstructed knee images in this section are based on a modified double-stage delay multiply and sum algorithm.
The presented results in this context demonstrate the capability of detecting and monitoring knee injuries. The introduced systems break the hospital boundaries to real-time onsite scanning for knee injuries, can be used at home, sports fields, and clinics, making it easy to detect and manage early injuries and avoid serious consequences.
... Therefore, studying effect of slant angle of the target on the results is important to emulate real scenarios, especially for the injuries that are based on the accumulation of blood/fluid/water after the abnormality happens. Varieties of MRI and ultrasound images [45][46][47][48][49] show that the fluid can be accumulated in arbitrary/slant shapes. ...
With the increasing uptake of sport activities, onsite detection of associated knee injuries at early stages is in high demand to avoid severe ligament tear and long treatment period. Portable electromagnetic imaging (EMI) systems have the potential to meet that demand, but there are challenges. For example, EMI is based on the contrast in the dielectric properties due to the accumulated fluid after knee injury. However, that fluid can be in any shape and orientation. Therefore, to capture enough data for processing, EMI should operate as a dual-polarized wearable system with compact antennas. Thus, the proposed system is a textile brace worn on the knee and consists of an 8-element dual-polarized aperture antenna array, which is matched with the knee. Each of the utilized antennas is fed by two orthogonal coaxial feed, occupies a small size of
$36 \times 36 \times 3.1\ {\rm{m}}{{\rm{m}}^3}$
, and is backed by a full ground plane for unidirectional radiation. The antenna covers the band 0.7-3.3 GHz (130%), with front to back ratio of more than 10 dB. The textile wool-felt is used as the substrate to enable building flexible brace system. The system's capability to reconstruct knee images with different injuries is verified on realistic knee models and phantoms. The double stage delay, multiply and sum algorithm (DS-DMAS) is used to reconstruct those images, which demonstrate the efficiency of the dual-polarized system and its superiority over single-polarized systems.
... This hypothetical pathway assumes meniscal pathology to be an early event leading to biomechanical failure of the knee joint. The assumptions are based on previous knowledge and derived logic (10,(13)(14)(15)(16)(17)(18). In this model, we did not adjust for mediators; that is, the causal effects estimated could be interpreted as total causal effects that could not be confounded or mediated through other MRI features if our DAG is correct (Figure 1). ...
Objective
To explore whether magnetic resonance imaging (MRI) features suggestive of knee osteoarthritis (OA) are associated with presence of knee pain in possible early‐stage OA development.
Methods
We included 294 participants from the Osteoarthritis Initiative (mean ± SD age 50 ± 3 years; 50% women) with baseline Kellgren/Lawrence grade of 0 in both knees, all of whom had received knee MRIs at 4 different time points over 6 years (baseline, 24, 48, and 72 months). Using a linear mixed model (knees matched within individuals), we studied whether MRI features (meniscal body extrusion [in mm], cartilage area loss [score 0–39], cartilage full thickness loss [range 0–16], osteophytes [range 0–29], meniscal integrity [range 0–10], bone marrow lesions [BMLs] including bone marrow cysts [range 0–20], Hoffa‐ or effusion‐synovitis [absent/present], and popliteal cysts [absent/present]) were associated with knee‐specific pain as reported on the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire using a 0–100 scale (worst to best).
Results
The differences in KOOS knee pain score for a knee with a 1 unit higher score on MRI were the following: meniscal extrusion –1.52 (95% confidence interval [95% CI] –2.35, –0.69); cartilage area loss –0.23 (95% CI –0.48, 0.02); cartilage full thickness loss –1.04 (95% CI –1.58, –0.50); osteophytes –0.32 (95% CI –0.61, –0.03); meniscal integrity –0.28 (95% CI –0.58, 0.02); BMLs including potential cysts –0.19 (95% CI –0.55, 0.16); synovitis 0.23 (95% CI –1.14, 1.60); and popliteal cysts 0.86 (95% CI –0.56, 2.29).
Conclusion
Meniscal extrusion, full thickness cartilage loss, and osteophytes are associated with having more knee pain. Although these features may be relevant targets for future trials, the clinical relevance of our findings is unclear because no feature was associated with a clinically important difference in knee pain.
... It may be detected incidentally in the general population but is more fre-quently found in patients suffering from knee osteoarthritis (KOA) [1][2][3][4][5][6]. In these patients the prevalence ranges from 20% to 40%, and increases with age, severity of OA, and duration of disease [7][8][9][10][11][12][13]. This figure is not surprising given that in almost 30-50% of cases a connection is present between the knee articular space and the gastrocnemio-semimembranosus bursa. ...
... So, it is debated whether and to what extent each condition contributes to the patient's discomfort. Besides authors who claim that the presence of the enlarged bursa may increase the symptoms of KOA [10,12,13,[17][18][19], others have not observed any relationship with pain and other discomfort [8,9,11,20]. In order to disentangle this complex issue, the aims of the present study were to evaluate the burden of symptoms in patients with different Kellgren-Lawrence (K-L) degree of KOA, comparing those with and without BC, and to assess the outcomes after conservative treatments in both groups. ...
... Literature data are conflicting. Some authors found that the presence of the bursa may play a role in exacerbating pain due to KOA [10,12,13,[17][18][19], whereas others have not observed any relationship with pain and other symptoms [8,9,11,20]. These discrepancies can be explained by several factors: patients selection (community dwelling or subjects seen in rheumatologic services), demographic differences, different degree KOA, methods of investigation, and others. ...
Objective:
Several symptoms are common to knee osteoarthritis and Baker's cyst. To what extent each condition contributes to the patient's discomfort is still a matter of debate. The aim of the present study was twofold: first, to compare the burden of symptoms in patients with isolated knee osteoarthritis and patients with knee osteoarthritis associated with Baker's cyst; second, to assess the outcomes after conservative treatments.
Subject and methods:
Patients suffering from monolateral idiopathic knee osteoarthritis were enrolled. Demographic, anthropometric and clinical data (KOOS scale) were collected. Ultrasound evaluation was performed according to standard protocols. On the basis of the clinical presentation different therapeutic options were used (fluid withdrawal, hyaluronic acid and/or steroids injections).
Results:
One-hundred and thirty patients were included in the study (97 with isolated knee osteoarthritis, 33 with knee osteoarthritis and Baker's cyst). In basal conditions, lower scores in KOOS sub-scales were observed in patients with knee osteoarthritis associated with Baker's cyst and in patients with effusion compared with patients without effusion. At 3 months after therapy significant higher scores were observed in both groups. At 6 months the scores were unchanged in the patients without Baker's cyst, but worsened in those with Baker's cyst.
Conclusions:
The study shows that Baker's cysts associated with knee osteoarthritis contribute to the burden of symptoms. The conservative treatment of both conditions allows significant improvements, but in the medium term (6 months) the efficacy of the therapy declines in patients with knee osteoarthritis associated with Baker's cyst.
... The current study revealed that the most commonly prevalent cysts were Baker's cysts (36.7%) followed by ganglion cysts (20%) followed by geods cyst ( [18]. ...
Background: Cystic knee lesions (synovial cysts, bursae, ganglia, and meniscal cysts) are frequently discovered and can be divided into real cysts and lesions that simulate cysts (hematomas, seromas, abscesses and vascular lesions). Aim of the Work: The aim of this study was to assess the role of magnetic resonance imaging in evaluation of cysts and cyst like lesions in and around the knee. Subjects and Methods: From January 2018 to August 2019, 30 patients were referred from outpatient clinics and orthopedic surgery department to MRI unit of radiodiagnosis and medical imaging department at Tanta University Hospitals, for MRI evaluation of suspected knee cystic lesions. Results: MRI was able to detect all clinically suspected cystic lesions within the knee. It also helped to describe morphology and it’s relation to surrounding tissues. 16.7% and 3.3% of the studied cystic lesions had fine and thick septa respectively, and 67 % of the studied cystic lesions had communication with the joints. MRI could identify the associated pathology of most of the detected cystic lesions (80%). The most common pathology were meniscal degeneration (26.7%) followed by meniscal tear and osteoarthritis (23.3%) and (20%) respectively. Ligament tear / sprain formed 6.7% of the total cysts while bone contusion forms 3.3%. Conclusion: The findings of this study confirm that In spite of its high cost, limited availability and the need for highly expert radiologists, MRI remains the method of choice for both diagnosis, characterization and uncovering the associated pathology and cause of cystic lesions around the knee. The high ability of MRI to image soft tissues plays a key role.
... In the popliteal fossa, six bursae can be identified 1 . Even though all six can undergo inflammation, the Baker's cyst (BC) is the most frequently involved in the inflammatory process 2,3 . It was described in 1877 by Baker as a distention of the popliteal bursa 4 . ...
