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The Unique Macroscopic Appearance of Gouty Arthritis of the Knee
Abstract:
Patients with significant gouty arthritis can develop disabling joint pain secondary to monosodium urate (MSU) articular deposition. We report a case of white, chalky MSU crystal deposition covering the articular surfaces of the knee as discovered by total knee arthroplasty. A 65-year-old male with a history of gout presented with bilateral knee pain. His radiographic imaging was negative for gouty tophi, and he elected to undergo left total knee arthroplasty. Intraoperatively a distinct chalky, white paste consistent with MSU deposition was observed covering the articular surfaces of the knee consistent with the diagnosis of gouty arthritis. Gout is the most common inflammatory arthritis affecting more than 3 million people in the USA. The inflammation results from the phagocytosis of monosodium urate crystals (MSU) and the release of inflammatory cytokines within the joint. Gout progresses from acute to chronic over many years and frequently causes chronic arthropathy. When significant knee pain and disability is associated with gouty arthropathy, total knee arthroplasty is certainly an option. The pathological appearance of gouty joints is characteristic. Macroscopic examination of joints affected by gout reveals a nodular, white, chalky appearance. Polarized microscopy of gout demonstrates negative birefringent needle-shaped MSU crystals. In this case report, we describe the characteristic chalky, white MSU deposit that covers the articular surfaces of a knee joint in a patient with a history of gout undergoing total knee arthroplasty. The investigators have obtained the patient's informed written consent for print and electronic publication of the case report.
Insights
Gout patients can experience severe knee pain from monosodium urate (MSU) crystal buildup. This case highlights chalky MSU deposits found during knee replacement surgery, confirming a characteristic pathological finding.
Area of Science:
- Rheumatology
- Orthopedic Surgery
- Pathology
Background:
- Gouty arthritis, caused by monosodium urate (MSU) crystal deposition, is a common inflammatory condition leading to joint pain and disability.
- Chronic gout can result in significant arthropathy, often necessitating surgical intervention such as total knee arthroplasty for severe cases.
- Diagnosis of gout typically involves identifying MSU crystals, but macroscopic presentation can be characteristic.
Observation:
- A 65-year-old male with a history of gout presented with debilitating bilateral knee pain.
- Radiographic imaging did not reveal gouty tophi, and the patient proceeded with a left total knee arthroplasty.
- Intraoperative findings revealed a chalky, white paste covering the articular surfaces of the knee.
Findings:
- The intraoperative observation of chalky white deposits was consistent with extensive monosodium urate (MSU) crystal deposition.
- This macroscopic finding aligns with the known pathological appearance of chronic gouty arthropathy affecting the knee joint.
- The case demonstrates a characteristic, though perhaps less commonly reported, intraoperative visual of MSU deposition in severe gout.
Implications:
- This case underscores the importance of recognizing the macroscopic appearance of MSU deposition during orthopedic procedures.
- It highlights that even without visible tophi on imaging, significant MSU crystal burden can be present in gouty arthropathy.
- The findings reinforce total knee arthroplasty as a viable option for managing disabling knee pain from chronic gouty arthritis.
