Clergyman's Knee (Prepatellar Bursitis): Causes, Symptoms, Diagnosis, and Treatment

What is a clergyman's knee?

Clergyman's knee, scientifically known as prepatellar bursitis, is an inflammation of the prepatellar bursa, a small fluid-filled sac located in front of the kneecap (patella). It is characterized by pain, swelling, and tenderness over the front of the knee, often resulting from repetitive kneeling or direct trauma.

Understanding Clergyman's Knee: The Anatomy of Prepatellar Bursitis

To comprehend clergyman's knee, it's essential to understand the role of bursae in the body. Bursae are small, slippery sacs filled with synovial fluid, strategically positioned near joints where tendons and muscles glide over bone. Their primary function is to reduce friction and provide cushioning, allowing smooth movement.

The prepatellar bursa is one of the more than 150 bursae found throughout the body. It lies just beneath the skin and in front of the patella (kneecap). While typically thin and unnoticeable, this bursa can become inflamed and swollen, a condition known as prepatellar bursitis. The historical term "clergyman's knee" arose because individuals who spent significant time kneeling, such as clergy during prayer, were commonly affected. Other common names include "housemaid's knee" or "carpenter's knee," reflecting its prevalence in occupations requiring frequent kneeling.

What Causes Clergyman's Knee?

Prepatellar bursitis can develop due to a variety of factors, primarily involving irritation or injury to the bursa:

• Repetitive or Prolonged Kneeling: This is the most common cause. Continuous pressure and friction on the prepatellar bursa irritate its lining, leading to inflammation and increased fluid production. Occupations like plumbing, roofing, gardening, carpet laying, and even sports that involve frequent kneeling (e.g., wrestling, volleyball) are high-risk activities.
• Direct Trauma: A sudden impact or fall directly onto the kneecap can injure the bursa, causing acute inflammation and swelling.
• Infection (Septic Bursitis): The prepatellar bursa's superficial location makes it susceptible to infection. Bacteria can enter the bursa through a cut, scrape, or puncture wound over the kneecap. Septic bursitis is a more serious condition requiring prompt medical attention.
• Systemic Inflammatory Conditions: Less commonly, prepatellar bursitis can be a manifestation of underlying systemic inflammatory diseases such as rheumatoid arthritis, gout, or pseudogout.
• Overuse and Biomechanical Factors: While less direct, repetitive activities that strain the knee joint or imbalances in muscle strength and flexibility can contribute to overall knee stress, potentially exacerbating bursa irritation.

Signs and Symptoms

The symptoms of clergyman's knee typically develop gradually, but can also appear suddenly after an acute injury. Key indicators include:

• Pain: Localized pain over the front of the kneecap, which often worsens with kneeling, direct pressure, or bending the knee deeply.
• Swelling: A noticeable, often soft and spongy, lump or swelling directly over the kneecap. In some cases, the swelling can be quite significant, resembling a "golf ball" under the skin.
• Tenderness: The affected area will be tender to the touch.
• Warmth and Redness: If the bursa is acutely inflamed or, more importantly, infected (septic bursitis), the skin over the kneecap may feel warm to the touch and appear red. This warrants immediate medical evaluation.
• Restricted Range of Motion: While not always present, severe swelling and pain can limit the ability to fully bend or straighten the knee.

Diagnosis

Diagnosing clergyman's knee typically involves a comprehensive approach by a healthcare professional:

• Medical History: The doctor will inquire about the onset of symptoms, activities that exacerbate the pain, any history of trauma, and relevant medical conditions.
• Physical Examination: A thorough examination of the knee will assess for localized tenderness, swelling, warmth, redness, and range of motion. The doctor may also check for signs of infection or other knee pathologies.
• Imaging Studies:
  • X-rays: Primarily used to rule out other conditions such as fractures or arthritis, as bursitis itself is not visible on X-ray.
  • MRI (Magnetic Resonance Imaging): Can provide detailed images of soft tissues, confirming bursal inflammation and ruling out other causes of knee pain.
• Fluid Aspiration (Bursa Aspiration): If infection (septic bursitis) is suspected, a small needle may be used to withdraw fluid from the bursa. This fluid is then sent to a laboratory for analysis to identify bacteria and guide antibiotic treatment. This procedure also helps relieve pressure and pain.

Treatment Options

Treatment for clergyman's knee aims to reduce inflammation, alleviate pain, and restore normal knee function. The approach depends on the severity of symptoms and whether an infection is present.

Conservative Management

Most cases of prepatellar bursitis respond well to non-surgical treatments:

• Rest and Activity Modification: Avoiding activities that aggravate the knee, especially kneeling, is crucial.
• Ice Application: Applying ice packs to the affected area for 15-20 minutes several times a day helps reduce swelling and pain.
• Compression: Using an elastic bandage or compression sleeve can help minimize swelling.
• Elevation: Elevating the leg above heart level, especially when resting, can help drain fluid from the area.
• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Over-the-counter medications like ibuprofen or naproxen can help reduce pain and inflammation.
• Protective Padding: Wearing kneepads during activities that involve kneeling can prevent recurrence.
• Physical Therapy: A physical therapist can provide exercises to improve knee flexibility, strengthen surrounding muscles (quadriceps, hamstrings), and address any biomechanical imbalances that may contribute to the condition. They may also use modalities like ultrasound or phonophoresis.

Medical Interventions

If conservative measures are insufficient, other medical treatments may be considered:

• Corticosteroid Injections: A corticosteroid, a powerful anti-inflammatory medication, can be injected directly into the bursa to reduce inflammation and pain. This is typically done in conjunction with fluid aspiration if significant swelling is present.
• Antibiotics: If septic bursitis is diagnosed, a course of oral or intravenous antibiotics is necessary to clear the infection.

Surgical Intervention

Surgical removal of the bursa (bursectomy) is rarely needed for prepatellar bursitis and is typically reserved for chronic, severe cases that do not respond to other treatments, or for recurrent septic bursitis. The bursa usually regrows normally over time.

Prevention Strategies

Preventing clergyman's knee primarily involves protecting the prepatellar bursa from excessive pressure and trauma:

• Use Kneepads: Always wear appropriate kneepads when performing activities that involve prolonged or repetitive kneeling, such as gardening, plumbing, or sports.
• Take Breaks: If your occupation or hobby requires kneeling, take frequent breaks to stand, stretch, and relieve pressure on your knees.
• Improve Body Mechanics: Learn and practice proper techniques for lifting and moving to minimize stress on your knees.
• Maintain a Healthy Weight: Excess body weight puts additional stress on all joints, including the knees.
• Address Underlying Conditions: If you have a systemic inflammatory condition, work with your doctor to manage it effectively.
• Promptly Treat Skin Wounds: Clean and cover any cuts or scrapes over the kneecap to prevent bacterial entry and potential infection of the bursa.

When to See a Doctor

While many cases of clergyman's knee can be managed with self-care, it's important to seek medical attention if you experience:

• Severe pain or swelling that doesn't improve with rest and ice.
• Significant redness or warmth around the kneecap.
• Fever or chills, which could indicate an infection.
• Inability to bend or straighten your knee fully.
• Symptoms that persist or worsen despite conservative treatment.

Early diagnosis and appropriate management are key to preventing chronic issues and ensuring a full recovery from clergyman's knee.