Volumetric reduction and dissolution prediction of monosodium urate crystal during urate-lowering therapy - a study using dual-energy computed tomography.

METHODS: Baseline and follow-up DECTs were performed under a standard ULT protocol. Monthly dissolution rates were calculated by simple and compound methods. Correlations with average SU were compared and analyzed. Best-fit regression model was identified. MSU dissolution times were plotted against SU at different endpoints. RESULTS: In 29 tophaceous gout patients, MSU volume reduced from baseline 10.94 ± 10.59 cm3 to 2.87 ± 5.27 cm3 on follow-up (p = .00). Dissolution rate had a stronger correlation with SU if calculated by compound method (Pearson's correlation coefficient r= -0.77, p = .00) and was independent of baseline MSU load. The ensuing dissolution model was logarithmic and explained real-life scenarios. When SU > 0.43 mmol/l, dissolution time approached infinity. It improved to 10-19 months at SU = 0.24 mmol/l. When SU approximated zero (as with pegloticase), dissolution flattened and still took 4-8 months. CONCLUSION: MSU dissolution is better described as a logarithmic function of SU, which explains, predicts, and facilitates understanding of the dissolution process.

Beyond Medical Treatment: Surgical Treatment of Gout.

PURPOSE OF REVIEW: Medical treatment with urate-lowering therapy (ULT) is efficacious. A recent publication suggested that surgery in gout is more prevalent than previously reported. This revelation led us to review what is known about surgical treatment of gout. RECENT FINDINGS: The Google Scholar database (January 1, 2014-January 1, 2020) found 104 publications with a total of 169 gout patients, with an average disease duration of 6.7 years. Most (68%) were not on ULT. The mean pre-operative serum urate levels were 9.19 mg/dL. One hundred thirteen patients underwent tophi excision, while in 33 patients, tophi were found during surgery. The majority of the surgeries were performed in Asia and Europe. Most patients were not taking ULT at the time of surgery, leading to hyperuricemia. This can result in tophi reformation post-surgery. The role of surgery should be a last-line treatment and until recently has only been demonstrated through case reports.

Tophaceous gout of the lumbar spine mimicking a spinal meningioma.

PURPOSE: Although gout is a common metabolic disorder, it usually affects distal joints of the appendicular skeleton. Axial spine involvement is rare, with only 131 cases reported in the literature. The authors report a rare case of lumbar spinal gout mimicking a spinal meningioma. METHODS: A 77-year-old man with a history of gout presented with chronic low back pain and progressive paraparesis. Imaging revealed a lumbar spine compressive mass lesion with a dural tail signal. The differential diagnosis was thought to be straightforward favoring a spinal meningioma. Tophaceous gout was never considered. The presence of a dural tail associated with the lesion is an interesting detail of this case, that strongly misguided it and to the best of our knowledge it is the first one reported in the literature. RESULTS: The patient underwent surgery and intra-operative findings were surprisingly different from those expected, revealing a chalky white mass lesion firmly adherent and compressing the dural sac. It was completely excised, leaving the dura intact. Histopathology confirmed the diagnosis of tophaceous gout. The patient was sent to physical therapy and had a complete remission of pain and neurological deficit, regaining his walking capacity. CONCLUSION: Although spinal gout is rare, it should be considered in the differential diagnosis for patients presenting with symptoms of spinal stenosis, a suspicion of neoplastic lesion of the spine, and a previous history of gout. Early diagnosis can ensure proper and timely medical management, perhaps avoiding neurological compromise and the need for surgery.

[Tophaceous gout of the lumbar spine in a patient without systemic gout or normouricaemia]. / Tofo gotoso en la columna lumbar como inicio de gota en un paciente con normouricemia.

Gout is a common metabolic disorder typically diagnosed in peripheral joints. Tophaceous deposits in the lumbar spine is a very rare condition with very few cases reported in the literature. We present a case of tophaceous gout that originated in the lumbar spine in a patient with normal uric acid blood levels. The following case report concerns a 52-year-old patient with low back pain, left sciatica and numbness in the left leg. Serum uric acid levels were within normal range. MRI and bone scan images suggested an inflammatory-infectious process focussed at L4. After an L4-L5 decompressive laminectomy, histological examination revealed tissue infiltrated with mature plasma cells with negatively birefringent crystals using polarised light consistent with urate deposits.

Spinal gout with intervertebral foramen infiltration: A rare case perfectly mimicking degenerative lumbar disc disease.

Spinal gout is a relatively rare disease characterized by significant clinical symptoms. In the current study, the first case of spinal gout with tophus in the intervertebral foramen, which perfectly mimicked degenerative lumbar disc disorders, was presented. The patient was a 57-year-old man with a medical history of gout who had suffered from progressive neurological deterioration for the last 12 months. Imaging examination revealed bilateral stenosis in the L5/S1 intervertebral foramen, mimicking degenerative lumbar disc disease. Nerve root radiculography and blocking were performed and the neurological symptoms were completely relieved. Open surgery was further performed and unexpectedly, the intra-operative findings were amorphous chalky white lesions. Histopathology confirmed the diagnosis of spinal gout. After surgery, the patient was prescribed a medication and achieved complete remission of clinical symptoms. No deterioration was found at the 1-year follow-up. To the best of our knowledge, this is the first report of spinal gout tophus in intervertebral foramen in the literature. It was concluded that, although intraspinal tophaceous gout is relatively rare, orthopedic surgeons should take it into consideration as a differential diagnosis, particularly if the patient has a medical history of gout. Early diagnosis and timely medical management may possibly be able to avoid neurological compromise and the need for surgery.

Tophaceous Gout at the Popliteal Sulcus.

Teaching point: Popliteal sulcus erosion with soft tissue mass: when in doubt, think of gout.

Gout Affecting the Nail Unit: Report of Two Cases and Literature Review.

Background: Gout is a depositional, inflammatory disorder that is rarely reported to affect the nail unit. Cases of gout involving the nail unit are likely under-recognized and therefore underreported. We present two cases of tophaceous gout affecting the nail unit and a literature review of the various presentations. Summary: Five cases of gout were identified to affect the nail unit. In all cases, these presented as white hyperkeratotic papulonodules with associated nail dystrophy. Chalky discharge was seen in three of the five cases. Nine cases were identified to have demonstrated pseudocarcinomatous changes that histopathologically mimic squamous cell carcinoma (SCC). Literature review highlights a range of findings including subclinical deposits of uric acid in the nail, onychoschizia, onychorrhexis, and Beau's line. Key Messages: Physicians should be aware of the subtle and nonspecific clinical findings of gout, which may be easily misconstrued for other pathological entities.

Foraminal stenosis and radiculopathy secondary to tophaceous gout: illustrative case.

BACKGROUND: Tophaceous gout is a severe form of gout that results in the formation of large nodules, or tophi, in the affected joints and surrounding tissues. Gouty tophi in the spine have a constellation of presentations that often mimic other pathologies and may not be easily discernable from more common pathologic processes. OBSERVATIONS: A 47-year-old female with a history of chronic renal disease, obesity, gout, inflammatory polyarthritis, and multiple sclerosis presented with 6 months of low-back pain and lumbar radiculopathy affecting the right lower extremity. A lumbar magnetic resonance imaging study revealed right foraminal stenosis and spondylolisthesis at levels L4-5. An intraspinal extradural mass was noted adjacent to the traversing right L5 and exiting right L4 nerve roots. A bilateral decompressive laminectomy, facetectomy, and foraminotomy of L4-5 was performed. A calcific, chalky-white mass was discovered in the foramen, and pathology determined the specimen to be a gout tophus. Postoperatively, the patient endorsed the resolution of her preoperative symptoms, which have not returned on follow-up. LESSONS: Reports of gouty depositions compressing the spinal cord in the current literature are relatively rare. Although the diagnosis of gouty tophi can only be confirmed histologically, patient history may serve as a helpful diagnostic tool.

A unique presentation of acute tophaceous gout in the lumbar spine causing cauda equina syndrome.

Gout is a common metabolic disease characterized by the deposition of monosodium urate (MSU) crystals and typically affects the peripheral joint, rarely involving the axial skeleton. We present a rare case of acute tophaceous gout in the lumbar spine causing cauda equina syndrome. A 60-year-old man with a history of gout and prior admissions for polyarticular gout flare presented with acute onset of bilateral lower limb numbness and weakness. He underwent surgical decompression with drainage of the epidural collection, with histology consistent with tophaceous gout. The patient made a full recovery postoperatively and was discharged uneventfully. Due to the high initial suspicion for gout, early spinal decompression surgery was performed, and the patient was started on medical therapy. Spinal tophaceous should be considered in the list of different diagnoses of spinal epidural masses especially in the context of a history of gouty arthritis.

Carpal tunnel syndrome caused by tophi in the superficial flexor tendon: a case report.

Carpal tunnel syndrome (CTS) is the most common disease among peripheral nerve entrapment diseases. CTS is often caused by the hyperplasia of the transverse carpal ligament and edema of tissue in the carpal tunnel, resulting in compression of the median nerve. Specific manifestations of CTS include numbness, loss of skin sensation in the palm and three and a half fingers on the radial side, and decreased muscle strength; however, CTS caused by wrist tophi is very rare. To our knowledge, CTS with median nerve compression caused by tophi in the superficial flexor tendon of the index finger of the wrist has not been reported before. Here, we will report a case of CTS caused by tophi in the wrist in a 37-year-old patient with no history of gout. CTS caused by tophi is uncommon, but if the patient has high uric acid, CTS may be due to tophi.

Spontaneous Fracture of the Fifth Metatarsal Secondary to Gout Tophus in a Young Patient: A Case Report.

Gout is a common disease, and its prevalence is increasing. After several years of untreated gout, in very rare cases tophi may cause a spontaneous fracture. This type of fracture may be difficult to distinguish from others, especially when gout is not yet diagnosed. We present a case of a pathological fracture caused by tophus in a young man, which led to the diagnosis of gout.

A 55-Year-Old Male With Systemic Gout Complicated by Septic Shock.

Tophaceous gout is the systemic deposition of uric acid which can induce cutaneous ulceration. We present the case of a 55-year-old male with chronic tophaceous gout whose initial presentation was complicated by septic shock due to methicillin-sensitive Streptococcus aureus bacteremia and superinfection of many of his affected joints. The case and discussion will focus on the extent of his infections and approaches to preventative care.

Bilateral carpal tunnel syndrome and motor dysfunction caused by gout and type 2 diabetes: A case report.

BACKGROUND: Carpal tunnel syndrome (CTS) has been associated with gout and type 2 diabetes mellitus (T2DM). However, due to insufficient clinical understanding of gout-related CTS and reliance on the diagnostic importance of elevated serum uric acid levels, such cases are prone to missed diagnosis, misdiagnosis, and delayed treatment. In addition, the effect of T2DM on gout - induced carpal tunnel syndrome has not been reported. CASE SUMMARY: Herein, we present an unusual case of CTS and motor dysfunction caused by miliary tophaceous gout and T2DM. The patient presented to the hand and foot clinic with paresthesia of the fingers of both hands, especially at night. The patient was diagnosed with type 2 diabetes a month ago. Ultrasonography revealed bilateral transverse carpal ligament thickening with median nerve compression during hospitalization. The patient was successfully treated with carpal tunnel decompression and tendon release. The postoperative pathological examination revealed typical gout nodules. This case suggests that the presence of T2DM could accelerate tophi formation and worsen CTS symptoms, although no definitive proof in this regard has been described previously. CONCLUSION: Tophi formation may most likely cause the co-occurrence of CTS and flexor dysfunction in gout and incipient diabetes patients.

Rare Case of Gout Leading to Septic Arthritis, Osteomyelitis, and Septic Shock in an Elderly Patient.

Gout is a common, chronic inflammatory arthritis that oftentimes accompanies an initial acute and painful attack characterized by intense pain and swelling. Although it may present in different sites such as the ankles, wrists, knees, elbows, and fingers, the lower extremities are the most common site of involvement. The pathophysiology of gout is complex, but typically, the deposition of monosodium urate crystals within the joint space and the subsequent acute inflammatory response play an important role. Following an acute attack, chronic gout can present with tophi or nests of monosodium urate crystals surrounded by macrophages and multinucleated giant cells that trigger granulomatous inflammation. Progressively, chronic gout can lead to several other complications including joint destruction, gout nephropathy, spinal compression, and secondary infections. In this case report, we present an elderly female patient with chronic gout and multiple tophi formations in all digits of both of her hands. The tophi led to an ulceration and secondary septic arthritis and osteomyelitis of the right second digit. By the time the patient presented and was admitted to the hospital, she was in septic shock. We will review the pathogenesis of gout and other cases of concomitant septic arthritis and gout, as well as medical management and necessary surgical intervention as a means of treatment.

Ulcerated Tophaceous Gout.

Gout is a disease that occurs in response to the presence of monosodium urate (MSU) crystals typically within joints. Patients with gout may develop a chronic deposition of monosodium urate crystals within or around joints, cartilage, tendons, peri-articular, and subcutaneous tissue. This condition is termed "tophaceous gout." Ulceration of the skin by tophi is very uncommon. Literature regarding the clinical course and the management of ulcerated tophi is limited and, therefore, treatment options are not well established. We hereby present a case of a 46-year-old male who presented to our facility with poorly controlled polyarticular tophaceous gout complicated by ulcerated tophi. Our hope is to contribute to the limited knowledge of this rare disease process and to contribute toward formulating the best management approach.

Operative management of gouty tophi in the region of the olecranon: a case series.

Background: Tophaceous gout affecting the olecranon region can result in local discomfort, skin ulceration, secondary infection, and considerable disability if left untreated. However, there are limited reports of outcomes, including postoperative complications and recurrence after surgical excision of tophaceous gout deposits at the elbow. The aim of this study is to present our surgical technique and minimum one-year outcomes after surgical excision of tophaceous gout involving the elbow. Methods: A retrospective chart review was performed on all patients from a single surgeon's practice who underwent surgical excision of gouty tophi of the elbow between January 2016 and December 2019. The indications for surgical excision of tophi included failure of medical management, presence of skin ulceration, and/or large gouty tophi. The relevant data pertaining to patient demographics, preoperative findings, intraoperative findings, surgical pathology reports, and short-term postoperative complications were collected through retrospective chart review. Patients were subsequently contacted for a follow-up telehealth visit to assess recurrence of gouty tophi, functional outcomes, and range of motion (ROM) measurements. Results: Six male patients underwent 7 total procedures (1 bilateral elbow) during the study period. The mean age of the cohort at the time of surgery was 56.0 ± 7.1 years (range: 45.3-63.5). The mean size of the swelling in 2 maximum dimensions was 5.8 × 3.4 cm. There were no intraoperative or immediate postoperative wound complications. There was no recurrence of gouty tophi at a mean follow-up time of 30.8 months (range: 14.0-43.5). Patients reported physiologic ROM (mean flexion-extension arc of 2°-134°) with no pain at final follow-up. Conclusion: Surgical treatment of tophaceous gout of the elbow is associated with a low risk of wound complication and recurrence.

2021 Asia-Pacific League of Associations for Rheumatology clinical practice guideline for treatment of gout.

BACKGROUND: Gout is the most prevalent inflammatory arthritis in the Asia-Pacific region and worldwide. This clinical practice guideline (CPG) aims to provide recommendations based on systematically obtained evidence and values and preferences tailored to the unique needs of patients with gout and hyperuricemia in Asia, Australasia, and the Middle East. The target users of these guidelines are general practitioners and specialists, including rheumatologists, in these regions. METHODS: Relevant clinical questions were formulated by the Steering Committee. Systematic reviews of evidence were done, and certainty of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation methodology. A multi-sectoral consensus panel formulated the final recommendations. RESULTS: The Asia-Pacific League of Associations for Rheumatology Task Force developed this CPG for treatment of gout with 3 overarching principles and 22 recommendation statements that covered the treatment of asymptomatic hyperuricemia (2 statements), treatment of acute gout (4 statements), prophylaxis against gout flare when initiating urate-lowering therapy (3 statements), urate-lowering therapy (3 statements), treatment of chronic tophaceous gout (2 statements), treatment of complicated gout and non-responders (2 statements), treatment of gout with moderate to severe renal impairment (1 statement), and non-pharmacologic interventions (5 statements). CONCLUSION: Recommendations for clinically relevant scenarios in the management of gout were formulated to guide physicians in administering individualized care.

A rare case of tophaceous gout manifesting as an osteolytic lesion of the acromioclavicular joint.

An osteolytic lesion on imaging can be considered malignancy until proven otherwise. However, advanced stages of gout have presented with sclerotic rims and lytic lesions thought to be due to overexpression of osteoclasts. Patients have been found to demonstrate osteolytic lesions in patellar regions, which are common locations for gout to manifest; however, to our knowledge, no other cases of osteolytic gout in the acromioclavicular joint have been reported at this time. We report a rare case of a 56-year-old male who presented with acute-on-chronic left upper extremity pain and was found to have an osteolytic lesion of the shoulder on imaging. This lesion was later biopsied and found to be histologically consistent with gout. This case report aims to elucidate further understanding of the various ways that gout can present, to diagnose and treat these patients more effectively.

Tophaceous gout in thoracic spine mimicking meningioma: A case report and literature review.

BACKGROUND: Gout is a common metabolic disorder of purine metabolism, causing arthritis in the distal joints of the appendicular skeleton. Spine involvement is rare, and very few cases of spinal gout have been reported. The authors present a rare case of axial gout with tophaceous deposits in the thoracic spinal canal resulting in cord compression and mimicking a meningioma. CASE DESCRIPTION: A 33-year-old male presented with chronic mid back pain and a progressive paraparesis. The presumed diagnosis was meningioma based on MR imaging with/without contrast that showed a posterolateral, right-sided, and T10-T11 intradural extramedullary lesion. Notable, was hyperuricemia found on hematological studies. The patient underwent a decompressive laminectomy (T9-T11) for excision of the lesion, intraoperatively, an intraspinal, chalky, white mass firmly adherent to and compressing the dural sac was removed. The histopathology confirmed the diagnosis of a gouty tophus. Postoperatively, the patient's pain resolved, and he regained the ability to walk. CONCLUSION: A gouty tophus should be included among the differential diagnostic considerations when patients with known hyperuricemia present with back pain, and paraparesis attributed to an MR documented compressive spinal lesion.

Tophaceous Gout in the Lumbar Spine Causing Radiculopathy. / Gota tofácea en la columna lumbar causando radiculopatía.

Tophaceous deposits in lumbar spine is considered a rare condition. We report the case of a 44-year-old patient with low back pain and radiculopathy. Radiographs revealed lytic spondylolisthesis in L5. Magnetic resonance imaging showed hypointense signal on T1 and a heterogeneous signal on T2 located in the L4-L5 interspinous space and in the left facet joint that invades left neuroforamen. The left knee ultrasound showed «double contour¼ of the medial femoral condyle. Decompressive laminectomy with arthrodesis at the level of L5-S1 was performed. The histological examination revealed amorphous material with a foreign body giant cell reaction.