M00.069 Staphylococcal arthritis, unspecified knee

Name of the Condition

• Staphylococcal Arthritis, Unspecified Knee

Summary

Staphylococcal arthritis, unspecified knee, is a bacterial infection affecting the knee joint, caused by Staphylococcus bacteria. It results in rapid inflammation, pain, and potential joint damage if not treated promptly. This condition requires immediate medical attention to prevent complications.

Causes

Staphylococcal arthritis, unspecified knee, is primarily caused by infection with Staphylococcus bacteria, most commonly Staphylococcus aureus. The bacteria can enter the knee joint through direct inoculation (e.g., injury or surgery), spread from nearby infections, or via the bloodstream from a distant site.

Risk Factors

• Recent knee surgery or invasive procedures.
• Immunocompromised states (e.g., diabetes, HIV, chemotherapy).
• Intravenous drug use.
• Pre-existing knee conditions (e.g., rheumatoid arthritis).
• Skin infections or bacteremia.

Symptoms

• Severe knee pain, swelling, and warmth.
• Fever and chills.
• Reduced range of motion in the affected knee.
• Fatigue and malaise.
• Redness over the knee.

Diagnosis

Diagnosis involves knee joint aspiration to analyze synovial fluid for bacteria, blood cultures to identify systemic infection, and imaging (e.g., X-rays, MRI) to assess joint damage. Clinical evaluation and patient history are also critical.

Treatment Options

• Antibiotics: Intravenous antibiotics are crucial to eliminating the bacterial infection.
• Joint Drainage: Repeated needle drainage, arthroscopy, or open surgery may be necessary to remove infected fluid and reduce pressure.
• Supportive Care: Pain management, rest, and immobilization of the knee to promote healing.

Prognosis and Follow-Up

With prompt treatment, most patients recover without long-term joint damage. Follow-up care includes monitoring for recurrence, assessing joint function, and adjusting antibiotics based on culture results. Delayed treatment increases the risk of permanent joint damage or systemic infection.

Complications

• Permanent joint damage or arthritis.
• Sepsis (systemic infection).
• Osteomyelitis (bone infection).
• Septic shock.

Lifestyle & Prevention

• Practice good hygiene to reduce infection risk.
• Properly clean and care for wounds near the knee.
• Manage underlying conditions (e.g., diabetes) to support immune function.
• Avoid intravenous drug use to lower infection risk.

When to Seek Professional Help

Seek immediate medical attention if you experience severe knee pain, swelling, fever, or reduced mobility, as these may indicate a serious infection requiring urgent treatment.

Tips for Medical Coders

Document the affected knee (unspecified) and confirm the presence of staphylococcal infection. Ensure clinical notes support the diagnosis and specify the joint involved. Use this code when the knee is affected but not specified as left or right.