Tophaceous gout of the knee: revisiting MRI patterns in 30 patients

Correlations of characteristics with tissue involvement in knee gouty arthritis: Magnetic resonance imaging analysis

Objective

This study investigates the MRI features of knee gouty arthritis (KGA), examines its relationship with the extent of tissue involvement, and assesses whether risk factors can predict KGA.

Materials and methods

Patients diagnosed with KGA underwent MRI examinations, and two independent observers retrospectively analyzed data from 44 patients (49 knees). These patients were divided into mild and severe groups based on tissue involvement observed during arthroscopy. MRI features were summarized, and the intraclass correlation coefficient evaluated interobserver reproducibility. Single-factor analysis compared clinical indicators and MRI features between groups, while Cramer's V coefficient assessed correlations. Multivariate logistic regression identified predictors of tissue involvement extent, and a ROC curve evaluated diagnostic performance.

Results

Among 49 knees, 18 had mild and 31 had severe tissue involvement. Key MRI features included ligament sketch-like changes, meniscal urate deposition, irregularly serrated cartilage changes, low-signal signs within joint effusion, synovial proliferation, Hoffa's fat pad synovitis, gouty tophi, bone erosion, and bone marrow edema. The interobserver reliability of the MRI features was good. Significant differences (P < 0.05) were observed between the groups for anterior cruciate ligament (ACL) sketch-like changes, Hoffa's fat pad synovitis, and gouty tophi. ACL sketch-like changes (r = 0.309), Hoffa's fat pad synovitis (r = 0.309), and gouty tophi (r = 0.408) were positively correlated with the extent of tissue involvement (P < 0.05). ACL sketch-like changes (OR = 9.019, 95 % CI: 1.364-61.880), Hoffa's fat pad synovitis (OR = 6.472, 95 % CI: 1.041-40.229), and gouty tophi (OR = 5.972, 95 % CI: 1.218-29.276) were identified as independent predictors of tissue involvement extent (P < 0.05). The area under the ROC curve was 0.862, with a sensitivity of 67.70 %, specificity of 94.40 %, and accuracy of 79.14 %.

Conclusion

This comprehensive analysis of MRI features identifies ligament sketch-like changes, meniscal urate deposition, and low-signal signs within joint effusion as characteristic MRI manifestations of KGA. Irregular cartilage changes are valuable for differential diagnosis in young and middle-aged patients. ACL sketch-like changes, Hoffa's fat pad synovitis, and gouty tophi correlate with tissue involvement severity and are critical in predicting and assessing the extent of tissue involvement in KGA.

Neoplastic and Non-neoplastic Soft Tissue Lesions Around the Knee

Neoplastic and non-neoplastic soft tissue masses around the knee are often incidental findings. Most of these lesions are benign with typical imaging characteristics that allow a confident diagnosis. However, some of these incidental neoplastic masses are characterized by morbidity and potential mortality. This review highlights the typical aspects of these lesions, facilitating a correct diagnosis.

Gouty Arthropathy: Review of Clinical Manifestations and Treatment, with Emphasis on Imaging

Gout, a crystalline arthropathy caused by the deposition of monosodium urate crystals in the articular and periarticular soft tissues, is a frequent cause of painful arthropathy. Imaging has an important role in the initial evaluation as well as the treatment and follow up of gouty arthropathy. The imaging findings of gouty arthropathy on radiography, ultrasonography, computed tomography, dual energy computed tomography, and magnetic resonance imaging are described to include findings of the early, acute and chronic phases of gout. These findings include early monosodium urate deposits, osseous erosions, and tophi, which may involve periarticular tissues, tendons, and bursae. Treatment of gout includes non-steroidal anti-inflammatories, colchicine, glucocorticoids, interleukin-1 inhibitors, xanthine oxidase inhibitors, uricosuric drugs, and recombinant uricase. Imaging is critical in monitoring response to therapy; clinical management can be modulated based on imaging findings. This review article describes the current standard of care in imaging and treatment of gouty arthropathy.

Intraosseous Tophaceous Gout in Hallux Mimicking a Bone Tumor in a Young Patient: A Case Report

CASE

A 17-year-old man experienced night pain in his right hallux. Radiographs revealed a lytic lesion in the proximal phalanx of the right hallux. Magnetic resonance imaging showed a low-signal intensity mass on T1-weighted sequences and isointense-high-signal intensity on T2-weighted sequences. We suspected a benign bone tumor such as osteoid osteoma or a bone cyst and consequently performed biopsy and surgical treatment. The lesion was filled with a whitish chalk-like substance, and pathologic examination revealed tophaceous gout.

CONCLUSIONS

It can be difficult to distinguish intraosseous tophaceous gout from other diseases, including bone tumors, using imaging; hence, pathological examination may be necessary for the diagnosis.

Limited Knee-Joint Range of Motion in Patients With Tophaceous Gout Improved With Medical Treatment: A 18-Months Follow Up

Objectives: Tophi may occur within the knee joint causing limited knee-joint range of motion (knee motion). We investigated the relationships between knee motion, total intra-articular tophi size (tIA-tophi), and total subcutaneous tophi size (tSC-tophi) and determined knee motion improvement after continual urate-lowering therapy (ULT). Methods: A total of 26 patients with tophaceous gout and limited knee motion were enrolled. Inclusion criteria were age ≤ 60 years and preserved knee joint space on a plain radiograph. tSC-tophi were measured using a Vernier caliper and tIA-tophi were measured using magnetic resonance imaging software. All patients were re-evaluated after 12-24 months of continual ULT. Upon initial visit, knee motion was related to tIA-tophi and tSC-tophi. Results: After an average of 18.2 months of ULT, the reduction in tSC-tophi was correlated with the reduction in tIA-tophi (P = 0.014, r = 0.395) and improvement in knee motion (P = 0.038, r = 0.408). Knee motion can be eventually improved even in cases of poor initial knee motion (P = 0.000, r = -0.911) or large initial tIA-tophi (P = 0.014, r = 0.476). Tophi can occur in any location within the knee joint. In multiple lineal regression, knee motion was predicted to improve 8.39° for every 10cm of tIA-tophi reduction. Conclusions: Limited knee motion in patients with intra-articular tophi improved with medical treatment, regardless of initial severity. Furthermore, tSC-tophi can be used as an indicator of limited knee motion and their improvement as a predictor of knee motion improvement.

Arthroscopic Management of Intra-articular Tophaceous Gout of the Knee: A Case Report and Review of the Literature

Introduction:

Surgical management of intra-articular tophaceous gout has been previously described but not widely reported in the literature. Therefore, when faced with clinical decision-making regarding this entity, the surgeon may be unfamiliar with the diagnosis, appropriate management, and outcomes related to treatment.

Case Report:

A 42-year-old male oil field worker who presented with the right knee intra-articular tophaceous gout deposits resulting in mechanical symptoms. The pathology was diagnosed intraoperatively while performing knee arthroscopy for what was presumed to be a meniscal tear. The patient underwent arthroscopic debridement of the tophi and partial meniscectomy. The tophaceous gout deposits were debrided with an arthroscopic liberator which allowed for the protection of the underlying articular cartilage. Postoperatively, he was begun with aggressive range of motion exercises and was referred to a rheumatologist for gout medical management. The patient improved significantly in regard to pain and range of motion and was able to return to full duty by 6weeks postoperatively.

Conclusions:

Tophaceous gout of the knee can mimic intra-articular pathology and may be encountered unexpectedly when performing a knee arthroscopy. The treating surgeon should be aware of the potential for this condition and understand that surgical intervention, when combined with appropriate medical management, can yield favorable clinical results.

The popliteal groove region: A new target for the detection of monosodium urate crystal deposits in patients with gout. An ultrasound study

OBJECTIVES

To determine the prevalence of the ultrasound findings indicating monosodium urate crystal deposits at the popliteal groove region in patients with gout; to evaluate the diagnostic accuracy of ultrasound in detecting monosodium urate crystal deposits at the popliteal groove region, patellar tendon and the knee hyaline cartilage; to investigate the correlation between the ultrasound findings at the popliteal groove region and the clinical features.

METHODS

Bilateral ultrasound assessment of the popliteal groove region, patellar tendon and femoral condyles' hyaline cartilage was performed on 47 consecutive patients with gout and 37 controls. The ultrasound findings indicating monosodium urate crystals (aggregates, tophi and "double-contour" sign) were identified according to the Outcome Measures in Rheumatology definitions.

RESULTS

One or more ultrasound abnormalities (aggregates and/or tophi) were found in at least one popliteal groove region in 23 out of 47 patients with gout (48.9%) and in 4 out of 37 controls (10.8%) (P < 0.001). Sensitivity, specificity and diagnostic odds ratio of the ultrasound findings at the popliteal groove region, patellar tendon and at the femoral condyles' hyaline cartilage were 0.49/0.89/7.9, 0.62/0.81/6.9 and 0.30/1.0/32.0, respectively. There was a significant correlation between the ultrasound findings at the popliteal groove region and history of knee inflammatory involvement (P < 0.001, V = 0.644) and number of gouty "attacks" in the previous year (P = 0.012, V = 0.434).

CONCLUSIONS

This study provides new insights into the ultrasound assessment of patients with gout, highlighting the clinical relevance of the popliteal groove region as an area of collection of otherwise undetectable monosodium urate crystals.

Intraarticular calcifying aponeurotic fibroma of the wrist: mimicking gout or calcium pyrophosphate dihydrate deposition disease

Calcifying aponeurotic fibroma is a rare, benign fibroblastic tumor that typically occurs in the palms of the hands and soles of the feet in children and adolescents. We report an unusual case of a calcifying aponeurotic fibroma with diffuse intra-articular involvement of the carpal joints in a 59-year-old female. Radiographs and computed tomography scans revealed a large lobulated soft tissue mass with multiple stippled calcifications around the carpal joints and numerous erosions of the second to fifth carpometacarpal and intercarpal joints. Magnetic resonance imaging showed diffuse multinodular synovial proliferation with inhomogeneous hypo- to isointense signal intensity on T1-weighted images, inhomogeneous hypointense to hyperintense signal intensity on T2-weighted images, and inhomogeneous intense enhancement on fat-suppressed contrast-enhanced T1-weighted images. Radiologic diagnosis included gout, calcium pyrophosphate dihydrate deposition disease, and tenosynovial giant cell tumor. Surgical excision was performed, and the mass was diagnosed on pathologic examination as a calcifying aponeurotic fibroma. There has been no reported case of a calcifying aponeurotic fibroma with diffuse intra-articular involvement of the carpal joints in the literature.

Pathological Fracture of the Proximal Tibia from an Intraosseous Gouty Tophus: A Rare Presentation of Gout

Intraosseous gouty tophus as the cause of pathological fracture is a seldom encountered condition. Not only does the tophus lesion affect the bone, but recent literature has also demonstrated a correlation between bone health in relation to gout as a disease entity, and showed the importance of medical treatment to improve the bone quality in patients with gout. We present a rare case of a pathological fracture due to an intraosseous gouty tophus as the presentation of gout, which imposed a diagnostic challenge, and illustrates the importance of multidisciplinary management in such conditions.

Solitary subcutaneous sarcoidosis with massive chronic prepatellar bursal involvement

A 56-year-old man presented with a painless prepatellar mass of the left knee. MR images demonstrated a large, well-defined mass with heterogeneous intermediate signal intensity on T1- and proton density-weighted images. Mild, heterogeneous enhancement was noted after the intravenous administration of gadolinium. Diagnostic imaging included atypical soft-tissue infection, fibrogranulomatous reaction, gouty tophus, rheumatoid nodule and xanthoma or possibly malignancy. The histopathological examination revealed sarcoidosis involving the prepatellar bursa.

Cross-sectional imaging of adult crystal and inflammatory arthropathies

This article highlights the key aspects and current perspectives of the role of cross-sectional imaging in adult crystal and inflammatory arthropathies in adults, briefly discussing CT, and particularly focusing on MRI and US imaging as it supplements the conventional radiography. The role of conventional and advanced MR imaging techniques and imaging findings in this domain is discussed and illustrated with case examples. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This article contains images and data, which were collected from patients as a part of a retrospective IRB from the institutional teaching files and informed consent was waived.

Tophaceous gout with rare involvement of the patella

Gout arthritis is an inflammatory arthritis caused by hyperuricemia from various etiologies. It is typically a polyarticular arthritis with the most common joint involved being the first metatarsophalangeal joint. We present a case of gout of the knee with characteristic magnetic resonance imaging findings and rare involvement of the patella. Radiographic findings of gout are diagnostic; however, they manifest many years after the onset of the disease process. Control of symptoms and progression of the disease is possible with correct treatment made possible by early diagnosis.

Intrameniscal Gouty Tophi in the Knee: A Case Report

CASE

We report a case of recurrent acute arthritis and restricted range of motion in the knee joint, with magnetic resonance imaging subsequently detecting a nodular lesion within the lateral meniscus. Knee arthroscopy and histology revealed that the lesion was intrameniscal gouty tophi. After arthroscopic synovectomy and excision of the tophi, the symptoms resolved and the patient remained symptom-free at two years of follow-up.

CONCLUSION

Surgeons should be aware of the presence of such pathology and consider arthroscopic surgery if the mechanical symptoms persist.

The radiographic and MRI features of gout referred as suspected soft tissue sarcoma: a review of the literature and findings from 27 cases

Gout has been termed the "great mimicker", for its ability to resemble other pathological conditions. Whilst the typical imaging features of gout are well described, there is a relative paucity of literature describing more challenging cases of gout, where a malignant tumour has been considered in the differential diagnosis. The aim of this article is to provide an overview of the radiographic and MRI features of 27 cases of gout that were initially referred to our centre as suspected soft tissue sarcoma, alongside a review of the literature.

Imaging as an Outcome Measure in Gout Studies: Report from the OMERACT Gout Working Group

OBJECTIVE

The gout working group at the Outcome Measures in Rheumatology (OMERACT) 12 meeting in 2014 aimed to determine which imaging modalities show the most promise for use as measurement instruments for outcomes in studies of people with chronic gout and to identify the key foci for future research about the performance of these imaging techniques with respect to the OMERACT filter 2.0.

METHODS

During the gout session, a systematic literature review of the data addressing imaging modalities including plain radiography (XR), conventional computed tomography (CT), dual-energy computed tomography (DECT), magnetic resonance imaging (MRI), and ultrasound (US) and the fulfillment of the OMERACT filter 2.0 was presented.

RESULTS

The working group identified 3 relevant domains for imaging in gout studies: urate deposition (tophus burden), joint inflammation, and structural joint damage.

CONCLUSION

The working group prioritized gaps in the data and identified a research agenda.

First metatarsophalangeal joint arthrodesis for the treatment of tophaceous gouty arthritis

In tophaceous gouty arthritis, surgeons face the choice between preservation of the involved joint and arthrodesis after tophi excision. Magnetic resonance imaging (MRI) can allow evaluation of the distribution of tophaceous deposits, which can be difficult to visualize on radiography. The goal of this study was to evaluate the characteristic MRI features of tophaceous lesions and to compare the clinical outcomes of arthrodesis after tophi excision with those of simple tophi excision. The authors reviewed 16 feet in 15 consecutive patients diagnosed with tophaceous gouty arthritis of the first metatarsophalangeal (MTP) joint who underwent surgery. Nine feet (group A) were treated with simple tophi excision, whereas the other 7 (group B) underwent first MTP joint arthrodesis after tophi excision. For clinical evaluation, the visual analog scale (VAS) for pain, American Orthopaedic Foot and Ankle Society (AOFAS) score, Tegner activity scale, and patient satisfaction assessments were used. Magnetic resonance imaging was performed to evaluate the characteristics of tophaceous deposits in the first MTP joint. Mean VAS and AOFAS scores and patient satisfaction significantly differed between the 2 groups at final follow-up (P=.007, .005, and .002, respectively). In group A, progression of arthritis of the first MTP joint was observed in 6 of 9 cases at final follow-up. The tophaceous lesions of these 6 cases were found to be located intra-articularly on MRI. Arthrodesis after tophi excision should be considered for treating tophaceous gouty arthritis of the first MTP joint when tophi are located intra-articularly and loss of cartilage involved is greater than 50% of the entire joint.

Advanced imaging in gout

OBJECTIVE

The purpose of this article is to describe the role of advanced imaging using ultrasound, CT, and MRI in the assessment and diagnosis of gout.

CONCLUSION

Dual-energy CT can quantitatively identify monosodium urate crystal deposits with high sensitivity and specificity within joints, tendons, and periarticular soft tissues. There are several characteristic ultrasound imaging findings, which include visualization of echogenic monosodium urate crystal deposition, tophus, and adjacent erosions. MRI is sensitive in showing soft-tissue and osseous abnormalities of gout, although the imaging findings are not specific. Gout commonly involves specific joints and anatomic structures, and knowledge of these sites and imaging appearances are clues to the correct diagnosis.

Imaging in gout: insights into the pathological features of disease

PURPOSE OF REVIEW

Imaging has the potential to assess various pathological manifestations of gout, including monosodium urate (MSU) crystal deposition, tophus formation and cartilage, soft tissue, and bone pathology. This review discusses recent research examining the role of imaging to assess the manifestations of disease.

RECENT FINDINGS

Various imaging techniques are used in the assessment of gout, including plain radiography, ultrasonography, conventional computed tomography (CT), dual energy computed tomography (DECT), and MRI. Potential roles for ultrasonography are MSU crystal detection, measurement of tophi, and assessment of disease complications. Ultrasonography may allow detection of MSU crystals in patients with hyperuricaemia, prior to development of clinically apparent gout. Conventional CT allows excellent visualization of tophi and bone erosion. DECT is a promising method of noninvasive MSU crystal detection. MRI allows assessment of tophi, synovial and soft tissue disease, and bone pathology. The relative absence of MRI bone marrow oedema in gout suggests that the mechanisms of bone erosion in gout are quite different from those in other erosive arthropathies.

SUMMARY

Imaging modalities have provided important insights into the pathology of gout. The role of various imaging techniques in gout diagnosis, monitoring, and prediction of outcome is rapidly developing.

Pseudotumoural soft tissue lesions of the foot and ankle: a pictorial review

In the foot and ankle region, benign neoplasms and pseudotumoural soft tissue lesions are significantly more frequent than malignant tumours. The pseudotumoural lesions constitute a heterogeneous group, with highly varied aetiology and histopathology. This article reviews the imaging features of the most common pseudotumours of the soft tissues in the foot and ankle. Although the imaging characteristics of several of the lesions discussed are non-specific, combining them with lesion location and clinical features allows the radiologist to suggest a specific diagnosis in most cases.

Pseudotumoural soft tissue lesions of the hand and wrist: a pictorial review

Mimickers of soft tissue tumours in the hand and wrist are more frequent than true neoplastic lesions. Pseudotumours belong to a large and heterogeneous group of disorders, varying from normal anatomical variants, cystic lesions, post-traumatic lesions, skin lesions, inflammatory and infectious lesions, non-neoplastic vascular lesions, metabolic disorders (crystal deposition disease and amyloidosis) and miscellaneous disorders. Although the imaging approach to pseudotumoural lesions is often very similar to the approach to “true” soft tissue tumoral counterparts, further management of these lesions is different. Biopsy should be performed only in doubtful cases, when the diagnosis is unclear. Therefore, the radiologist plays a pivotal role in the diagnosis of these lesions. Awareness of the normal anatomy and existence and common imaging presentation of these diseases, in combination with relevant clinical findings (clinical history, age, location and skin changes), enables the radiologist to make the correct diagnosis in most cases, thereby limiting the need for invasive procedures.