Case Report of Gouty Arthritis Complicated by Septic Arthritis

Summary

This protocol describes combined medical and surgical management for diagnosing and treating gouty arthritis complicated by septic arthritis.

Abstract

Gouty knee arthritis shares numerous clinical similarities with septic knee arthritis. Core overlapping manifestations include sudden onset of unilateral knee symptoms such as redness, swelling, heat, and pain, accompanied by significant functional impairment and restricted mobility. Inflammatory markers like erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are often markedly elevated in both conditions. Early imaging studies typically fail to reveal bone destruction. Due to highly overlapping clinical presentations, misdiagnosis between the two conditions is common, often requiring joint aspiration and synovial fluid analysis for definitive diagnosis. This report describes a case of gouty arthritis complicated by suppurative arthritis. The patient presented with a sudden onset of swelling and pain in the right knee lasting 2 days, accompanied by increased skin temperature and limited mobility. The patient had no prior history of gout and was otherwise in good health. Routine synovial fluid analysis showed a white blood cell count of 4+ and a red blood cell count of 1+. Culture identified Staphylococcus aureus (MRSA) in the sample. After vancomycin treatment, symptoms significantly improved, and the patient was discharged 1 week later. However, 2 days post-discharge, the patient returned with recurrent knee swelling and pain. Following a multidisciplinary consultation, arthroscopic debridement was performed. Intraoperative findings revealed extensive chalky crystal deposits within the joint cavity. Postoperative pathology confirmed gouty arthritis. The patient was discharged after symptom resolution following postoperative allopurinol therapy to reduce uric acid levels. This case underscores the importance of early differentiation between gouty arthritis and septic arthritis in clinical practice, as well as the necessity of scientific management.

Introduction

Gouty arthritis (GA) is an inflammatory disease caused by the deposition of monosodium urate (MSU) crystals in the joints, surrounding soft tissues, tendons, and other sites. Clinically, it manifests as acute joint redness, swelling, and pain, initially affecting a single joint, with 50% of cases occurring in the first metatarsophalangeal joint¹. Gout predominantly affects the lower extremities, such as the dorsum of the foot, heel, ankle, and knee joints, though the fingers, elbows, wrists, and shoulders may also be involved^2,3. Statistics indicate that the prevalence of gout in Wester....

Protocol

Written informed consent for the use of medical history and clinical images was obtained from patients in accordance with institutional guidelines. Patient identifiers are anonymized in all documentation. This study was reviewed and approved by the Ethics Committee, approval number: 2025-KLS-511-01. This case report and any accompanying images have been published with the patient's written informed consent.

1. Patient preparation

1. The study included a 46-year-old male patient presenting with acute swelling and pain of the right knee. Upon admission, demographic information, detailed medical history, and prior....

Results

On initial admission, the patient exhibited right knee swelling, warmth, erythema, and pain rated 10/10. MRI revealed joint effusion and synovial thickening without bone destruction. Synovial fluid appeared turbid yellow, with a markedly elevated leukocyte count. Culture identified MRSA. Empirical antibiotics were adjusted to vancomycin, resulting in a gradual improvement of symptoms and normalization of inflammatory markers. The patient was discharged after 1 week of treatment.

At 2 weeks pos.......

Discussion

This case lacks the typical symptoms and signs of GA, which commonly affects the first metatarsophalangeal joint and is often associated with elevated serum uric acid levels¹⁷. This case presented with knee swelling and pain, normal serum uric acid levels, and although no urate crystals were identified in the joint aspirate, elevated white blood cells (WBC), CRP, and procalcitonin suggested infection. Antibiotic therapy was effective but incomplete, as persistent intra-articular inflammation persi.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
1.5-Tesla MRI Scanner	Siemens Healthineers	MAGNETOM Essenza
Allopurinol Tablets	GlaxoSmithKline	500790
Antinuclear Antibody (ANA) Assay	Thermo Fisher Scientific	2401-0001
Antistreptolysin O (ASO) Test	Abbott Laboratories	7D55-20
Arthroscopy Shaver	Stryker Corporation	272-300-100
Blood Agar Plate	BD Diagnostics	221261
Blood Culture Bottle (Aerobic)	BD Diagnostics	442020
Blood Culture Bottle (Anaerobic)	BD Diagnostics	442021
CCP ELISA	Axis-Shield Diagnostics	FCCP600
Chocolate Agar Plate	bioMérieux	43101
Complete Blood Count Reagent Kit	Sysmex Corporation	XN-9000 series
C-Reactive Protein (CRP) Assay	Roche Diagnostics	4628918190
Drainage Tube (Surgical)	Medtronic	8888173031
Erythrocyte Sedimentation Rate (ESR) Kit	Streck	107760
Etoricoxib Tablets	Merck & Co.	100 mg, NDC 0006-0372
Formalin Solution (10%)	Sigma-Aldrich	HT501128
Gram Stain Kit	Hardy Diagnostics	G100
Hematoxylin and Eosin (H&E) Stain	Sigma-Aldrich	HHS128 & HT110116
HLA-B27 Antibody Reagent	BD Biosciences	340183
Levofloxacin Injection	Janssen Pharmaceuticals	NDC 50458-050-01
Linezolid Injection	Pfizer	NDC 0009-4992-01
Medication Catheter (Intra-articular)	Smith & Nephew	72202866
Paraffin Wax	Leica Biosystems	3801310
Procalcitonin (PCT) Assay	Brahms GmbH	KRYPTOR PCT
Rheumatoid Factor (RF) Test	Beckman Coulter	467858
Synovial Fluid Collection Tube	Sarstedt	82.1190.001
Tuberculosis Antibody Test	Standard Diagnostics	TB Ab Rapid 11FK10
Ultrasound Machine	GE Healthcare	LOGIQ E10
Vancomycin Hydrochloride	Mylan Pharmaceuticals	NDC 67457-156-60
Xpert MTB/RIF Assay	Cepheid	GXMTB/RIF-10