M71.169 Other infective bursitis, unspecified knee

Name of the Condition

• Other infective bursitis, unspecified knee

Summary

Other infective bursitis, unspecified knee refers to an infection of the bursa in the knee region that is not classified under more specific infective bursitis codes. This condition involves microbial invasion of the bursa, leading to inflammation, pain, and potential functional impairment of the knee joint.

Causes

Other infective bursitis, unspecified knee typically results from bacterial infection, often introduced through direct trauma, skin breakdown, or spread from adjacent tissues. Common causative organisms include Staphylococcus aureus. Non-bacterial infections or secondary infection of a pre-existing bursitis may also occur, though the exact etiology varies by case.

Risk Factors

• Recent injury or surgery near the knee bursa
• Skin infections or open wounds in the knee area
• Immunocompromised states (e.g., diabetes, HIV)
• Chronic inflammatory conditions (e.g., rheumatoid arthritis)
• Repetitive motion or pressure on the knee bursa

Symptoms

• Localized pain, swelling, and warmth over the knee bursa
• Redness or erythema at the site
• Fever or systemic signs of infection
• Limited range of motion in the knee joint
• Pus drainage if the infection progresses

Diagnosis

Diagnosis involves a physical examination to assess bursal characteristics, including tenderness, warmth, and swelling. Imaging studies or fluid aspiration may be used to confirm infection and identify causative organisms. Laboratory tests, such as blood work or culture of aspirated fluid, help determine the microbial cause and guide treatment.

Treatment Options

Treatment typically includes antibiotic therapy targeted at the identified pathogen, often initiated empirically before culture results. Drainage of the infected bursa may be necessary for severe cases. Rest, elevation, and anti-inflammatory measures can help reduce symptoms. Surgical intervention is rare but may be required for persistent or complicated infections.

Prognosis and Follow-Up

With prompt and appropriate treatment, most cases resolve without long-term complications. Follow-up care ensures infection resolution and monitors for recurrence. Chronic or untreated infections may lead to persistent pain or functional limitations. Regular assessments help adjust treatment plans as needed.

Complications

Potential complications include abscess formation, spread of infection to surrounding tissues, or chronic bursitis. Delayed treatment may result in joint damage or systemic infection. Rarely, sepsis can occur in severe cases.

Lifestyle & Prevention

Avoiding trauma to the knee, maintaining skin integrity, and managing underlying conditions (e.g., diabetes) can reduce risk. Proper wound care and hygiene help prevent infection. Ergonomic adjustments may minimize repetitive pressure on the knee bursa.

When to Seek Professional Help

Seek care if symptoms worsen, persist despite home care, or include fever, pus drainage, or severe pain. Prompt evaluation is necessary for signs of spreading infection or systemic illness.

Tips for Medical Coders

Use M71.169 for unspecified knee when the site is not further specified. Ensure documentation supports the infective nature and knee location. Differentiate from other bursitis codes (e.g., non-infective or site-specific) based on clinical details.