M70.40 Prepatellar bursitis, unspecified knee

Name of the Condition

• Prepatellar bursitis, unspecified knee

Summary

Prepatellar bursitis is inflammation of the prepatellar bursa, a fluid-filled sac located in front of the kneecap (patella). This condition typically causes localized pain, swelling, and tenderness over the kneecap, often resulting from repetitive pressure or trauma to the area. It is a common soft tissue disorder affecting the knee joint.

Causes

Prepatellar bursitis commonly develops due to repetitive mechanical stress, such as frequent kneeling or direct trauma to the kneecap. Prolonged pressure from activities like gardening, construction work, or sports can irritate the bursa. In some cases, infection or underlying inflammatory conditions may contribute to inflammation.

Risk Factors

• Repetitive kneeling or prolonged pressure on the kneecap.
• Occupational activities requiring frequent kneeling (e.g., flooring, plumbing).
• Participation in sports or activities with direct knee impact.
• History of knee trauma or injury.
• Pre-existing inflammatory conditions (e.g., rheumatoid arthritis).

Symptoms

• Localized pain, swelling, or tenderness over the kneecap.
• Visible swelling or a soft, fluctuant mass in the anterior knee.
• Discomfort worsened by kneeling or pressure on the kneecap.
• Stiffness or limited range of motion in the knee.

Diagnosis

Diagnosis is typically based on clinical evaluation, including a physical examination to assess swelling, tenderness, and range of motion. Patient history helps identify potential causes or risk factors. Imaging (e.g., X-ray, ultrasound) may be used to rule out fractures, arthritis, or other structural issues. Aspiration of the bursa may be performed if infection is suspected.

Treatment Options

Treatment focuses on reducing inflammation and relieving symptoms. Initial management often includes rest, ice, compression, and elevation (RICE). Nonsteroidal anti-inflammatory drugs (NSAIDs) may help alleviate pain and swelling. In severe or persistent cases, corticosteroid injections or physical therapy may be recommended. Surgical intervention is rarely needed but may be considered for chronic or infected bursitis.

Prognosis and Follow-Up

Most cases of prepatellar bursitis resolve with conservative treatment within a few weeks. Prognosis is generally favorable, especially when the underlying cause (e.g., repetitive pressure) is addressed. Follow-up may involve monitoring symptoms and adjusting activity levels to prevent recurrence. Severe or recurrent cases may require ongoing management.

Complications

Complications are uncommon but may include chronic bursitis, infection (septic bursitis), or limited knee function. Untreated infection can spread to surrounding tissues, requiring prompt medical attention. Rarely, persistent inflammation may lead to bursal thickening or calcification.

Lifestyle & Prevention

• Avoid prolonged kneeling or use protective padding when kneeling is necessary.
• Maintain proper ergonomics during work or sports to reduce knee pressure.
• Gradually increase activity levels to prevent overuse injuries.
• Strengthen surrounding knee muscles through targeted exercises.
• Address underlying conditions (e.g., arthritis) to reduce bursal stress.

When to Seek Professional Help

Seek medical attention if symptoms worsen, persist beyond a few weeks, or are accompanied by fever, redness, or warmth (signs of infection). Prompt evaluation is recommended if knee function is significantly impaired or if there is a history of trauma.

Tips for Medical Coders

When coding for prepatellar bursitis, ensure documentation supports the diagnosis, including clinical findings (e.g., swelling, tenderness) and any contributing factors (e.g., repetitive kneeling). Note whether the condition is acute or chronic, as this may impact coding specificity. Verify that the code M70.40 is appropriate for unspecified knee involvement and aligns with the patient’s clinical presentation.