Bursal Impingement: Understanding Its Causes, Symptoms, and Treatment

What is Bursal Impingement?

Bursal impingement refers to the painful compression or irritation of a bursa, a small, fluid-filled sac that reduces friction between tissues, often occurring when surrounding structures repeatedly rub against or squeeze it, leading to inflammation.

Understanding Bursae

To comprehend bursal impingement, one must first understand the role of bursae. Bursae (plural of bursa) are thin, slippery sacs found throughout the body, strategically positioned at points where tendons, muscles, or skin glide over bones. They contain a small amount of synovial fluid, acting as cushions and lubricants to minimize friction during movement. This critical function allows for smooth, pain-free motion across joints.

What is Bursal Impingement?

Bursal impingement occurs when a bursa becomes inflamed, a condition known as bursitis, and is subsequently compressed or "pinched" by adjacent anatomical structures, such as bones, tendons, or ligaments. This compression typically happens during specific movements or activities, exacerbating the inflammation and pain. The underlying bursitis makes the bursa swollen and sensitive, rendering it more susceptible to impingement. Impingement syndromes are common in areas of high movement and friction, particularly around major joints.

Common Locations of Bursal Impingement

While bursal impingement can occur in any joint with a bursa, certain areas are more prone due to their anatomical structure and movement patterns:

• Shoulder (Subacromial Impingement): This is perhaps the most common site. The subacromial bursa lies between the rotator cuff tendons and the acromion (a bony projection of the shoulder blade). Impingement occurs when the bursa and rotator cuff tendons get pinched in the subacromial space, often during overhead arm movements.
• Hip (Trochanteric Impingement): The trochanteric bursa is located on the outer side of the hip, cushioning the greater trochanter (a bony prominence of the femur) from the IT band and gluteal muscles. Impingement here causes pain on the outer hip, often worsened by lying on the affected side or walking.
• Knee: Several bursae around the knee can be affected:
  • Prepatellar bursa: In front of the kneecap ("housemaid's knee").
  • Infrapatellar bursa: Below the kneecap ("clergyman's knee").
  • Pes anserine bursa: On the inner side of the knee, below the joint line.
• Elbow (Olecranon Impingement): The olecranon bursa is located at the tip of the elbow. Impingement or direct trauma can lead to swelling and pain, sometimes referred to as "student's elbow."

Causes and Risk Factors

Bursal impingement typically results from a combination of factors that increase friction or pressure on a bursa:

• Repetitive Motion and Overuse: Engaging in activities that involve repeated movements, especially those that compress a bursa (e.g., throwing, cycling, kneeling, overhead lifting).
• Trauma or Direct Impact: A sudden blow or fall onto a bursa can cause immediate inflammation and lead to impingement.
• Poor Biomechanics and Posture: Incorrect movement patterns, postural imbalances (e.g., rounded shoulders, excessive pronation), or gait abnormalities can alter joint mechanics and increase stress on bursae.
• Muscle Imbalances: Weakness or tightness in surrounding muscles can disrupt normal joint kinematics, leading to increased friction or impingement. For example, weak rotator cuff muscles can contribute to shoulder impingement.
• Anatomical Variations: Some individuals may have bone spurs, abnormal bone shapes, or structural anomalies that naturally narrow the space around a bursa, making it more susceptible to impingement.
• Underlying Medical Conditions: Certain systemic diseases, such as rheumatoid arthritis, gout, or diabetes, can predispose individuals to bursitis and subsequent impingement.

Signs and Symptoms

The symptoms of bursal impingement are primarily related to inflammation and mechanical irritation:

• Localized Pain: Typically sharp or aching pain directly over the affected bursa. The pain often worsens with specific movements that compress the bursa.
• Tenderness: The area around the bursa will be tender to the touch.
• Swelling and Redness: The bursa may visibly swell, and the overlying skin might appear red or feel warm due to inflammation.
• Reduced Range of Motion: Pain and swelling can limit the ability to move the affected joint through its full range.
• Weakness: Pain during movement can make it difficult to exert full strength in the affected limb.
• Pain at Rest or Night: As inflammation progresses, pain may become constant, even at rest, and can be particularly disruptive at night, especially if lying on the affected side.

Diagnosis

Diagnosing bursal impingement involves a thorough clinical assessment:

• Medical History: The doctor will inquire about the onset of pain, aggravating and alleviating factors, activity levels, and any previous injuries or medical conditions.
• Physical Examination: A physical therapist or physician will assess the affected joint's range of motion, muscle strength, and palpate the area to pinpoint tenderness and swelling. Specific orthopedic tests may be performed to reproduce the impingement symptoms.
• Imaging Studies:
  • X-rays: Primarily used to rule out bone spurs, fractures, or arthritis that might contribute to impingement.
  • Ultrasound: Can visualize fluid within the bursa and assess soft tissue structures, helping to confirm bursitis.
  • Magnetic Resonance Imaging (MRI): Provides detailed images of soft tissues, including the bursa, tendons, and muscles, helping to identify inflammation, tears, or other pathologies contributing to impingement.

Treatment and Management

Treatment for bursal impingement typically begins with conservative approaches, aiming to reduce inflammation and relieve pressure on the bursa:

• Rest and Activity Modification: Avoiding activities that aggravate the bursa is crucial for reducing inflammation.
• Ice Application: Applying ice packs to the affected area can help reduce swelling and pain.
• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Over-the-counter or prescription NSAIDs (e.g., ibuprofen, naproxen) can help manage pain and inflammation.
• Physical Therapy: A cornerstone of treatment, focusing on:
  • Pain Management: Modalities like ultrasound or electrical stimulation.
  • Range of Motion Exercises: Gentle movements to restore flexibility without aggravating the bursa.
  • Strengthening Exercises: Targeting weak muscles to improve joint stability and biomechanics, especially around the affected joint.
  • Stretching: Addressing muscle tightness that may contribute to impingement.
  • Postural Correction and Ergonomics: Educating on proper body mechanics during daily activities and sports.
• Corticosteroid Injections: In cases of persistent pain and inflammation, a corticosteroid injection directly into the bursa can provide significant, though often temporary, relief.
• Aspiration: If the bursa is significantly swollen with fluid, the fluid may be drained with a needle to relieve pressure.
• Lifestyle Modifications: Adjusting activity levels, modifying sports techniques, and using ergonomic aids can prevent recurrence.
• Surgical Intervention: Rarely needed, but in chronic, severe cases that do not respond to conservative treatment, surgical removal of the bursa (bursectomy) may be considered.

Prevention Strategies

Preventing bursal impingement involves addressing the underlying causes and adopting healthy movement habits:

• Proper Warm-up and Cool-down: Prepare muscles and joints for activity and aid recovery.
• Gradual Progression: Increase the intensity, duration, or frequency of activities slowly to allow tissues to adapt.
• Correct Biomechanics and Form: Pay attention to posture and technique during exercise, work, and daily activities. Seek professional guidance from a fitness expert or physical therapist if unsure.
• Strength and Flexibility Balance: Maintain balanced strength and flexibility in muscles surrounding major joints to optimize joint mechanics.
• Ergonomics: Adjust your workspace and equipment to promote neutral joint positions and reduce repetitive stress.
• Listen to Your Body: Avoid pushing through pain. If an activity causes discomfort, modify it or take a break.
• Appropriate Footwear: Wear supportive shoes, especially for activities involving impact or prolonged standing.

When to Seek Medical Attention

It is advisable to consult a healthcare professional if you experience:

• Persistent pain that does not improve with rest and basic self-care.
• Significant swelling, redness, or warmth around a joint.
• Inability to move a joint or bear weight.
• Fever or signs of infection (e.g., pus, spreading redness).
• Symptoms that worsen despite conservative measures.

Early diagnosis and appropriate management can effectively resolve bursal impingement and prevent chronic issues.