Chronic multiarticular tophaceous gout with abnormally large tophi, case of surgical intervention: a case report from Nepal

Introduction and importance: Gout is an inflammatory disease caused by the deposition of monosodium urate monohydrate crystals around the synovial joints, affecting the first metatarsophalangeal joints followed by ankle and knees. It is found to be more prevalent among men and older women. Tophi tends to develop if the acute phase of the disease is not controlled. In contrast, our patient had an unusual presentation of multiple tophi affecting several joints accompanied by deformities. Case presentation: Here, the authors present a case of a 63 years old male with chronic multiarticular tophaceous gout with a history of more than 30 years. He presented with multiple joint deformities and prior surgical history of excision of tophi. Laboratory reports revealed elevated serum uric acid, and X-ray showed joint deformities with tophi. However, the parameters of renal function test were normal. Surgical excision of the tophi was done. Clinical discussion: Gout is one of the most common inflammatory arthritis, which if untreated can progress to tophi formation. The diagnosis can be made clinically and by several investigations including serum uric acid estimation and aspiration of the joint to reveal monosodium urate monohydrate crystals. A long standing case of multiarticular tophi causing joint deformities does require surgical intervention. Conclusion: Early treatment and diagnosis of hyperuricemia prevent the progression to gouty arthritis and tophi formation. Long history of multiple tophaceous gout is an unusual presentation, which we intend to present here as a novel case report. Nevertheless, such cases require surgical interventions.


Introduction and importance
Gout is a metabolic disorder characterized by the deposition of monosodium urate monohydrate crystals in the synovial joints and soft tissues due to increased serum uric acid level resulting in the repeated episodes of inflammatory arthritis [1] .Gout is the most prevalent inflammatory arthritis [2] .It is more common in men and older women, usually affecting the first metatarsophalangeal joint, followed by the ankle, knee, and small joints of hands and wrist.Patients present with symptoms in the acute phase, is managed medically.However, tophi develop in 12-35% of the total gout patients [3] .This specifically occurs if the acute phase is not treated.Surgical intervention is required typically for the patients with chronic multiple tophaceous gout causing multiple joints deformities [4] .Here, we intend to present a case of chronic multiple tophaceous gout, first of its kind reported from Nepal who had undergone a surgical intervention.This case has been reported in line with 2023 Surgical CAse REport (SCARE) criteria [5] .

Case presentation
A 62-year-old male from Kathmandu, Nepal, had presented to the Orthopedic Out Patient Department of our institution with a long standing history of gout for the past 30 years without significant and similar family history.Initially, he started developing early morning stiffness and burning type of pain on the left knee that was aggravated on drinking beer and consuming red meat

HIGHLIGHTS
• The pathogenesis of gout involves a long standing history of hyperuricemia due to either overproduction or under excretion which ultimately leads to the development of tophi around the soft tissues.Long history of multiple tophaceous gout with normal renal function test is unusual which is demonstrated in our case report.• Treatment ranges from controlling acute flares to surgical resection of gouty tophi.• Surgical treatment is rarely required unless there is a presence of extensive joint destruction, and deformities.
which lasted for a few hours.The pain was relieved on cold compression.He then visited the nearby tertiary health care center, where colchicine along with NSAIDs were prescribed and was further advised for conservative management of reducing consumption of purine rich diet.However, he did not take the medications regularly which were discontinued after 2 years.Gradually, painful swelling appeared around the left knee joint associated with the redness and shining of the overlying skin for which he visited the hospital and was advised for serum uric acid estimation that was found to be elevated.Allopurinol was prescribed, along with colchicine but was not taken on regular basis.Then, he had no medical interventions for next 6 years that resulted in an increase in swelling involving bilateral first metatarsophalangeal joint, the right knee joint and the elbow joint of both sides.This caused a limitation on his daily activities.
Radiological investigation followed by diagnostic aspiration of the left knee swelling depicted white a chalky material with the presence of sodium urate crystals on the joint space and surrounding soft tissues.A diagnosis of gouty tophi with a chronic history of hyperuricemia was made.According to him, a surgical intervention to remove the tophi on the left knee joint and the bilateral first metatarsophalangeal joint was undertaken.After 2 years, he had another surgery to remove tophi from his right knee joint and the third metacarpal of right hand.Despite receiving medication, he remained symptomatic as tophi continued to increase in size with frequent relapses on those surgically removed sites which was either due to poor response or poor compliance to the treatment.Recently he visited our institution due to gross deformities in bilateral first interphalangeal and knee joints [Fig.1].
On the physical examinations, flexion deformities involving both knees joints along with painful tophaceous swelling in the right third metacarpophalangeal joint and right proximal phalanx and distal phalanx of index finger were found [Fig.2].
Renal Function Test revealed serum urea of 37 mg/dl and serum creatinine of 1 mg/dl implying the normal values.X-ray of bilateral foot showed joint destruction due to tophi [Fig.3].
Recently, a revision surgery to remove the tophi on the right first metatarsophalangeal joint was accomplished by the orthopedic team at our institution under local anesthesia, where chalky white tophi was excised [Fig.4], and the wound was thoroughly closed by suture.No intraoperative surgical complications were encountered.The patient was then discharged on the same day with an advice of special care of the surgical wound site with regular dressing on every alternate day.He is still on close follow up.No diagnostic tests are used on the follow up and oral febuxostat is continued till now.The patient is satisfied with the treatment he received.

Clinical discussion
Gout is the most common inflammatory arthritis, a disorder of purine metabolism resulting from long standing hyperuricemia led by deposition of urate crystals in various joints and tissues.The four phases of gout are asymptomatic hyperuricemia, acute gouty arthritis, intercritical gout, and finally chronic tophaceous gout [6] .It mainly affects older men and postmenopausal women particularly involving the first metatarsophalangeal joint.The subsequent other sites are joints of the tarsal, ankle, knee, and upper limb [7] .The upper limit of serum uric acid level is 7 mg/dl in men and 6 mg/dl in women, and level above the solubility ( > 6.8 mg/dl) results in super saturation, hence hyperuricemia, that leads to urate crystal deposition from supersaturated serum [7,8] .If hyperuricemia remains untreated for a prolonged period, clinical presentation may progress from arthritis to development of tophi in the bone, surrounding soft tissues, ligaments, and even organs, characteristically called chronic  tophaceous gout [9] .Consumption of huge quantity purine-rich food with heavy alcohol intake are the principal risk factors for the flare up of acute gout.The gout risk is high with consuming beer followed by spirits' consumption [10] .Alcohol helps to increase uric acid production whereas uric acid excretion is decreased.Metabolism of alcohol produces adenosine triphosphate that later degrades to adenosine monophosphate which is ultimately converted into uric acid [11] .From a genetic point, of view, mutation in the uricase gene leads to deficiency of the same enzyme which functions to convert uric acid to a more soluble excretable compound called allantoin [8] .
The gout's diagnosis is made by thorough clinical history along with supporting investigations like serum uric acid estimation and the demonstration of monosodium urate crystals from the affected joint aspirate.Although radiographs are not useful in acute cases, they can show characteristic findings in chronic tophi cases [12] .According to Wallace et al. [13] (1977), about 84% of the total gout patients studied were found to have monosodium urate crystals in the synovial joint.Different treatment modalities range from prophylaxis of acute flares, treating the acute attack, to surgical intervention for deformities and joint destruction [14,15] .The acute attacks of gout are treated with painkillers, colchicine, and corticosteroids.However, relapses of acute flares and progression to chronicity do occur due to lack of patient compliance, availability of medication and cost related reasons.This was vital in progression of tophaceous disease in our case.Urate excreting drugs like probenecid aim to lower serum uric acid level to at least 6 mg/dl.Drugs like allopurinol and febuxostat decrease production of uric acid by inhibiting the enzyme xanthine oxidase.Newer agents like pegloticase oxidize uric acid to allantoin [14] .Surgical treatment is rarely required for gout unless there is joint destruction with recurrent deformity [4] .Other indications are painful tophi, impairment of tendon function, nerve compression, and overlying skin necrosis [16] .

Learning points
• Although gout is regarded as a common disease entity, the clinical diagnosis of multiarticular tophaceous with a long standing chronic history of hyperuricemia remains quite uncommon, especially being under reported in developing countries like Nepal.Here, we have highlighted such uncommon case.• As mentioned above, surgical intervention was undertaken at our institution to remove the tophi involving the right first meta-tarsophalengeal joint, and the patient was satisfied with the treatment he had received.However, recurrent tophi may develop in the mere future as indicated by several episodes of recurrence of tophi in the patient despite past surgical removal.Similarly, our patient will probably have to undergo several other surgical procedures to remove the remaining tophi on his other joints and soft tissues.Such cases of recurrence of multiarticular tophaceous gout whilst undergoing therapeutic management has not been reported in other existing literature.Therefore, we would also like to emphasize on this fact.• Although, our patient had a chronic history of hyperuricemia and tophaceous gout involving several soft tissues and joints, the laboratory reports indicated a normal renal function test.This is also quite interesting because two third of uric acid excretion occurs via the kidney, and chronic hyperuricemia can affect the renal function.• Chronic multiarticular tophaceous gout leading to impairment of daily activities leading to worsened the quality of life of the patient is also uncommon despite gout being a common disease.This has been stated in our case presentation.• The genetic profile of the patient could not be explored due to the limited respective experimental facilities at our institution.Therefore, the genetic etiology of multiarticular tophaceous gout and its subsequent recurrence could not be ruled out.

Conclusion
Hyperuricemia can lead to acute gouty arthritis but if left untreated can progress to chronicity particularly with the formation of tophi.Long history of multiple tophaceous gout is unusual.This may lead to multiple joint deformities, impairing the patient daily activities and hence requiring surgical intervention.

Figure 1 .
Figure 1.Gross deformities on bilateral first interphalangeal and knee joints with multiple tophi around the soft tissues involving the right and left leg.

Figure 2 .
Figure 2. Painful tophi involving right proximal and distal phalanx of index finger and third metacarpophalangeal joint.

Figure 3 .
Figure 3. X-ray of bilateral foot showing destruction by tophi.