M70.42 Prepatellar bursitis, left knee

Name of the Condition

• Prepatellar bursitis, left 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. It is a common soft tissue disorder affecting the knee and may limit mobility or worsen with activity.

Causes

Prepatellar bursitis commonly develops due to repetitive pressure on the kneecap, such as frequent kneeling (e.g., in occupations like gardening, construction, or cleaning). Direct trauma, such as a fall or blow to the knee, can also trigger inflammation. Underlying conditions like rheumatoid arthritis or infection may contribute in some cases, though trauma or overuse are the most frequent causes.

Risk Factors

• Repetitive kneeling or prolonged pressure on the kneecap.
• Occupations or activities involving frequent kneeling (e.g., carpet laying, plumbing).
• History of knee trauma or injury.
• Pre-existing inflammatory conditions (e.g., arthritis).
• Advanced age, as bursae may degenerate over time.

Symptoms

• Localized pain, tenderness, or swelling over the kneecap.
• Warmth or redness in the affected area.
• Stiffness or reduced range of motion in the knee.
• Discomfort worsened by kneeling, bending, or pressure on the kneecap.

Diagnosis

Diagnosis is typically based on clinical evaluation, including a physical examination to assess pain, swelling, and tenderness over the prepatellar bursa. A healthcare provider may inquire about the patient’s history of repetitive kneeling, trauma, or underlying conditions. Imaging studies like X-rays or ultrasound are rarely needed but may be used to rule out other knee disorders or assess for infection if suspected.

Treatment Options

Treatment often includes rest, ice, and avoiding activities that aggravate the knee. Nonsteroidal anti-inflammatory drugs (NSAIDs) may help reduce pain and inflammation. In some cases, a healthcare provider may aspirate fluid from the bursa or inject corticosteroids to relieve symptoms. Physical therapy may be recommended to improve mobility and strengthen surrounding muscles.

Prognosis and Follow-Up

Most cases of prepatellar bursitis resolve with conservative treatment within a few weeks. Follow-up may involve monitoring symptoms and adjusting activity levels. If symptoms persist or worsen, further evaluation may be needed to address underlying causes or complications.

Complications

Untreated or severe cases may lead to chronic inflammation, limited knee function, or infection of the bursa (septic bursitis). Rarely, persistent swelling or pain may require surgical intervention to remove the bursa.

Lifestyle & Prevention

• Avoid prolonged kneeling or use protective padding when kneeling is necessary.
• Maintain a healthy weight to reduce stress on the knee.
• Engage in regular exercise to strengthen knee muscles and improve flexibility.
• Use proper techniques during activities that involve knee movement to minimize strain.

When to Seek Professional Help

Seek medical attention if symptoms worsen, do not improve with rest, or are accompanied by fever, redness, or drainage, which may indicate infection. Prompt evaluation is also recommended for severe pain or inability to bear weight on the knee.

Tips for Medical Coders

When coding for prepatellar bursitis of the left knee, use ICD-10-CM code M70.42. Ensure documentation specifies the left knee and confirms the diagnosis, as the code is site-specific. Note any contributing factors (e.g., trauma, overuse) or complications (e.g., infection) that may impact coding accuracy.