Gout in the knee

Knee joint and inflammation in gout – briefly explained

The knee is the largest joint in the body. Bones (femur, shinbone, kneecap) are guided by stable ligaments, menisci distribute the load and a synovial membrane (synovial membrane) produces lubricating fluid. It is precisely this mucous membrane that reacts sensitively to uric acid crystals in gout.

• Articular surfaces with cartilage for low-friction movement
• Menisci as shock absorbers and load distributors
• Joint capsule and mucous membrane (synovia) as the “inner skin” of the joint

If uric acid crystals are deposited in the synovial fluid, the body recognizes them as a foreign substance. Immune cells react - acute synovitis occurs with redness, warmth, swelling and massive pain.

What is gout in the knee?

Gout is an inflammatory and metabolic joint disease. The cause is prolonged elevated uric acid in the blood (hyperuricemia). When the solubility limit is exceeded, crystals (monosodium urate) are formed and deposited in joints and soft tissues. A gout attack occurs when the immune system reacts to these crystals - often at night, abruptly and very painfully.

• Acute gout: sudden, very severe joint pain with swelling, heat, redness
• Intercritical phase: symptom-free period between attacks
• Chronic gout: repeated attacks result in joint damage, visible tophi (nodules), and persistent discomfort

The knee is often affected, along with the big toe, ankle and metatarsal. Triggers can be a food rich in purines, alcohol, dehydration, an infection or medication.

Typical symptoms of gout in the knee

• Sudden, severe knee pain – often at night or early in the morning
• Clearly visible swelling, overheating and redness of the joint
• Restriction of movement to the point of being unable to bear weight
• Pain when touched (even the blanket is uncomfortable)
• Sometimes slight fever, fatigue

Warning signs: If a high fever, severe signs of illness or recent, very painful joint swelling occur without known gout, a bacterial joint infection must be urgently ruled out - this is an orthopedic emergency.

Causes and risk factors

The basis of gout is permanently elevated uric acid. This may be due to increased production, decreased renal excretion, or both. Lifestyle and comorbidities often play together.

• Diet: foods rich in purines (offal, sardines, anchovies), plenty of meat and seafood
• Drinks: Alcohol (especially beer and spirits), sugar-sweetened drinks/fructose
• Dehydration and fasting/crash diets, rapid weight loss
• Medications: diuretics (thiazides, loop diuretics), low doses of aspirin; Losartan can lower uric acid
• Kidney disease, metabolic syndrome, high blood pressure, diabetes, lipid metabolism disorder
• Genetic predisposition, older age, male gender; in women, especially after menopause
• Mechanical stress/minor trauma to the knee, operations, acute illness/infections

Not everyone with elevated uric acid develops gout. Whether seizures occur depends on the individual crystal formation and triggers.

Diagnosis: This is how we proceed

The aim is to reliably differentiate gout from other causes of joint inflammation - especially a bacterial infection. The combination of history, examination, laboratory, imaging and, if necessary, joint puncture leads to the diagnosis.

The gold standard is the detection of needle-shaped, strongly negatively birefringent monosodium urate crystals from the synovial fluid using a polarization microscope. At the same time, the sample is examined microbiologically to rule out bacterial arthritis if clinically doubtful.

Differential diagnoses: What else is possible

• Septic arthritis (bacterial joint infection) – emergency, must be ruled out
• Pseudogout (chondrocalcinosis, calcium pyrophosphate crystals)
• Rheumatoid arthritis of the knee – chronic inflammatory, often bilateral
• Psoriatic arthritis – inflammatory joint disease associated with psoriasis
• Activated knee osteoarthritis – wear and tear with inflammatory activation
• Torn meniscus or dislocation of the kneecap with irritating effusion
• Baker's cyst with tear and swelling of the calf

The distinction is made through a combination of clinical picture, crystal analysis, laboratory and imaging.

Acute treatment of gout attack in the knee

In an acute attack, the focus is on rapid inflammation and pain inhibition. We prefer conservative measures and drug therapy after an individual assessment of the benefits and risks.

• Relieve, elevate and cool (ice pack with cloth, 10–15 minutes, several times a day)
• Non-steroidal anti-inflammatory drugs (e.g. ibuprofen, naproxen, diclofenac) - only if tolerated and after consultation with a doctor, be careful with stomach/kidney/heart diseases
• Colchicine in low doses at the beginning of the attack - note dosage and contraindications; Check interactions (e.g. with certain antibiotics/statins) with a doctor
• Glucocorticoids: briefly orally or as an intra-articular injection if NSAID/colchicine are not an option - only after ensuring that there is no infection
• Drink enough fluids (if medically permitted), remain calm and temporarily immobilize the knee

A joint puncture can be diagnostic and therapeutic at the same time: the effusion is relieved and the pain often noticeably decreases. If necessary, an ultrasound-guided corticosteroid injection is carried out into the knee joint under sterile conditions - only if infection has been reliably ruled out.

Joint puncture and injection – when does it make sense?

• Unclear diagnosis: crystal evidence and exclusion of bacterial arthritis
• Severe effusion with tenderness: relief by puncture
• Contraindications to painkillers/colchicine: local steroid injection as an option

We usually carry out the puncture using ultrasound. This increases safety, protects tissue and enables targeted medication administration when indicated.

Long-term strategy: Prevent relapses

The aim of long-term therapy is to permanently lower uric acid so that no new crystals form and existing deposits are gradually broken down. This reduces the risk of further attacks and protects the knee joint.

• Indications for long-term urate-lowering therapy (ULT): ≥2 attacks/year, visible tophi, gouty arthropathy, uric acid stones, chronic kidney disease or very high uric acid levels
• First choice drug: Allopurinol (creep, dose adjustment according to kidney function); Alternative in case of intolerance: Febuxostat
• Target values: Uric acid < 6 mg/dl (360 µmol/l), for tophi < 5 mg/dl (300 µmol/l)
• If possible, start ULT only after the acute attack has subsided; In the first 3-6 months, concomitant prophylaxis against seizures (e.g. low-dose colchicine or NSAID, if tolerated)
• Regular laboratory checks (uric acid, blood count, liver and kidney values) and dosage adjustment

Long-term drug therapy is often accompanied by a family doctor or internist. In terms of orthopedics, we pay attention to joint protection, provide injections/punctures and coordinate physiotherapy and aids.

Exercise and physiotherapy

During an acute attack: rest and take it easy. As soon as the inflammation subsides, a measured return to exercise helps to maintain knee function and prevent subsequent damage.

• Gentle mobilization and stretching, then gradual strengthening (quadriceps, hips, core)
• Joint-friendly endurance: cycling (light), swimming, aqua jogging, walking
• Short-term bandage or soft orthosis for pain relief and stability
• Avoiding jumping/contact stress in the first few weeks after a severe attack

A physiotherapeutic program is individually adapted - the aim is low-pain everyday movement, better stress tolerance and relapse prevention through weight management and muscle balance.

Diet and Lifestyle: Evidence-Based Tips

• Low-purine, Mediterranean-style diet: lots of vegetables, whole grains, legumes (in moderation), nuts, olive oil
• Prefer protein sources: low-fat dairy products, eggs, plant-based alternatives; Meat in moderation, avoid offal
• Fish 1-2 times per week, but reduce the consumption of varieties high in purines (sardines/anchovies).
• Drink enough (water/unsweetened tea), avoid sugar-sweetened drinks and fructose sodas
• Reduce alcohol, especially beer and spirits - wine in small quantities can be more tolerable, check individually
• Sustainable weight loss if you are overweight (5-10% reduces the risk of gout), avoid crash diets
• Coffee and foods rich in vitamin C can be cheap; Cherry products show evidence in studies, but are not a substitute for ULT

Nutrition does not replace medical therapy, but it is a strong pillar of prevention and supports the reduction of uric acid with medication.

Course and possible complications

Without treatment, seizures may occur more frequently and last longer. Over time, tophi (gout nodules) develop in soft tissues, tendons and bones. The knee can be permanently damaged.

• Chronic gouty arthropathy with cartilage and bone erosion
• Mechanical problems caused by tophi (blockages, friction, tendon involvement)
• Kidney stones and kidney damage with persistent hyperuricemia
• Higher cardiometabolic risk (high blood pressure, cardiovascular disease)

Consistent uric acid reduction and lifestyle changes significantly reduce these risks.

When is an operation necessary?

Surgery is rarely necessary for gout in the knee and is only considered if there is a clear indication. The focus is on conservative measures.

• Surgical removal of disturbing tophi if they mechanically block, repeatedly inflame or endanger skin
• Arthroscopic restoration in individual cases to remove free crystal nests/tophi
• Knee endoprosthesis (artificial joint) in cases of advanced joint destruction that can no longer be controlled - the indication is determined carefully and in an interdisciplinary manner

The risk of a gout attack increases before and after surgery. Perioperative prophylaxis is planned individually.

When should you seek medical advice?

• First severe knee pain with swelling/overheating
• Fever, severe signs of illness or suspected infection
• Persistent discomfort despite immobilization, cooling and over-the-counter painkillers
• Repeated seizures or visible nodules (tophi)
• Comorbidities (kidney, heart, metabolism) and new medications that could affect gout

An early diagnosis prevents complications and enables targeted, gentle therapy.

Your orthopedist in Hamburg: our approach

In our practice at Dorotheenstraße 48, 22301 Hamburg, we clarify acute and chronic knee swelling in a structured manner. We rely on clear diagnostics, conservative therapy and individual prevention plans.

• Thorough examination and ultrasound of the knee, if necessary, puncture and laboratory analysis
• Conservative acute treatment with graduated pain and anti-inflammatory drugs
• Ultrasound-assisted injections only if there is a confirmed indication and infection has been ruled out
• Coordination with family doctors or internists for long-term urate-lowering therapy
• Physiotherapy recommendations, aids and sports return planning
• Advice on nutrition and lifestyle with everyday measures

We take the time to provide information and make a decision on an equal level - without blanket promises, with a clear, evidence-based plan.