M71.161 Other infective bursitis, right knee

Name of the Condition

• Other infective bursitis, right knee

Summary

Other infective bursitis, right knee refers to an infection of the bursa (a small fluid-filled sac that reduces friction between tissues) in the right 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, right 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 right knee bursa
• Skin infections or open wounds in the right knee area
• Immunocompromised states (e.g., diabetes, HIV)
• Chronic inflammatory conditions (e.g., rheumatoid arthritis)
• Repetitive motion or pressure on the right knee bursa

Symptoms

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

Diagnosis

Diagnosis involves a physical examination to assess bursal characteristics, including tenderness, warmth, and swelling in the right knee. Imaging (e.g., ultrasound or MRI) may be used to evaluate the bursa and surrounding tissues. Aspiration of the bursa for fluid analysis (e.g., culture, Gram stain) helps identify the causative organism 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 or persistent cases. Rest, elevation, and anti-inflammatory medications can help manage symptoms. Surgical intervention is rare but may be required for abscess formation or refractory infections.

Prognosis and Follow-Up

With appropriate treatment, most cases resolve without long-term complications. Follow-up care involves monitoring for symptom improvement and ensuring the infection is fully cleared. Physical therapy may be recommended to restore knee function and mobility. Recurrence is possible, especially if underlying risk factors persist.

Complications

Untreated or severe infections may lead to abscess formation, spread to adjacent tissues, or septic arthritis. Chronic bursitis or persistent pain can occur if the infection is not adequately managed. Rarely, systemic infection (sepsis) may develop.

Lifestyle & Prevention

• Avoid repetitive knee strain or pressure (e.g., prolonged kneeling)
• Maintain skin integrity and treat wounds promptly
• Manage chronic conditions (e.g., diabetes) to reduce infection risk
• Use protective gear during activities that stress the knee

When to Seek Professional Help

Seek care if symptoms worsen (e.g., increasing pain, swelling, or fever), if pus drainage occurs, or if knee function is significantly impaired. Prompt evaluation is critical to prevent complications.

Tips for Medical Coders

Document the specific site (right knee) and confirm infective bursitis is not classified under a more specific code. Ensure clinical documentation supports the diagnosis and site specificity. Code M71.161 is used when the right knee is the affected site and no more detailed code applies.