### Date : 2024-06-16 10:40 ### Topic : subacromial impingement syndrome #medicine #orthopedic ---- ### Shoulder Impingement Syndrome (충돌증후군) Overview **Shoulder impingement syndrome (SIS)** is a common condition affecting the shoulder, where the tendons of the rotator cuff or the subacromial bursa are compressed against the acromion. This compression can lead to pain, inflammation, and restricted movement.  ### Pathophysiology Shoulder impingement occurs when the space between the acromion (part of the scapula) and the rotator cuff tendons narrows, causing the tendons and bursa to be pinched or compressed during shoulder movements. Over time, this can lead to tendinitis, bursitis, and even rotator cuff tears. ### Causes and Risk Factors - **Anatomical Variations:** A hooked or curved acromion can reduce the subacromial space. - **Repetitive Overhead Activities:** Common in athletes (e.g., swimmers, baseball players) and certain occupations (e.g., painters, carpenters). - **Age:** Degenerative changes and calcium deposits in older adults can contribute to impingement. - **Poor Posture:** Forward head posture and rounded shoulders can alter the mechanics of the shoulder joint. ### Clinical Features - **Pain:** Typically felt in the front and side of the shoulder, especially when lifting the arm overhead, reaching, or lying on the affected side. - **Weakness:** Particularly in the muscles of the rotator cuff, leading to difficulty with activities that require lifting or rotating the arm. - **Limited Range of Motion:** Stiffness and reduced ability to move the shoulder, particularly during activities that involve overhead movement. - **Night Pain:** Pain that can disrupt sleep, often worsening when lying on the affected shoulder. ### Diagnosis Diagnosis is based on clinical history, physical examination, and imaging studies: - **Clinical History:** Detailed history of symptoms, including pain characteristics, activities that exacerbate symptoms, and any history of shoulder injuries. - **Physical Examination:** - **Neer Test:** Pain with passive forward flexion of the arm while the scapula is stabilized. - **Hawkins-Kennedy Test:** Pain with internal rotation of the arm when the shoulder is flexed to 90 degrees and the elbow is bent. - **Empty Can Test:** Pain or weakness when resisting downward pressure on the arm positioned in the scapular plane with the thumb pointing down. - **Imaging:** - **X-rays:** To check for bony abnormalities or acromial spurs. - **MRI or Ultrasound:** To visualize soft tissue structures, including the rotator cuff tendons and subacromial bursa, and to detect tears or inflammation. > **Subacromial impingement syndrome** is often considered a part of the broader category known as **rotator cuff syndrome**. Rotator cuff syndrome encompasses various conditions that affect the rotator cuff tendons and the structures surrounding them. Here’s how subacromial impingement fits into the spectrum of rotator cuff disorders: ### Relationship with Rotator Cuff Syndrome **Rotator Cuff Syndrome** refers to a group of conditions involving the rotator cuff tendons, which include: - **Tendinitis:** Inflammation of the rotator cuff tendons. - **Bursitis:** Inflammation of the subacromial bursa. - **Partial or Full-Thickness Tears:** Damage or tears to the rotator cuff tendons. - **Impingement Syndrome:** Compression of the rotator cuff tendons and subacromial bursa between the acromion and the head of the humerus.  <Photo from: https://my.clevelandclinic.org/health/body/rotator-cuff> ### Subacromial Impingement Syndrome as Part of Rotator Cuff Syndrome Subacromial impingement syndrome occurs when the rotator cuff tendons and/or the subacromial bursa are compressed in the subacromial space, particularly during overhead activities. This compression can lead to inflammation (tendinitis or bursitis), pain, and eventually tendon degeneration or tears if left untreated. ### Key Points on the Relationship: 1. **Impingement Leads to Tendinitis and Bursitis:** - The repeated compression of the tendons and bursa under the acromion can cause inflammation, leading to tendinitis and bursitis, which are core components of rotator cuff syndrome. 2. **Progression to Rotator Cuff Tears:** - Chronic impingement can weaken the rotator cuff tendons over time, making them more susceptible to partial or full-thickness tears. This progression links impingement directly to more severe rotator cuff injuries. 3. **Overlapping Symptoms:** - Symptoms of subacromial impingement (pain, weakness, limited range of motion) overlap significantly with other rotator cuff disorders, making it a key part of the rotator cuff syndrome spectrum. ### Example Case Study **Patient Profile:** - **Name:** Jee Hoon Ju - **Age:** 45 - **Gender:** Male - **Occupation:** Painter **Medical History:** - **Symptoms:** Jee Hoon Ju reports a gradual onset of shoulder pain over the past few months, particularly when reaching overhead or lifting objects. He experiences sharp pain at night when lying on his right shoulder and has noticed some weakness when trying to lift his arm. - **Lifestyle:** His job involves repetitive overhead painting tasks. **Physical Examination:** [[Shoulder Joint Specific Physical Examination Tests]] - **Neer Test:** Positive, with pain during passive forward flexion. - **Hawkins-Kennedy Test:** Positive, with pain during internal rotation at 90 degrees of shoulder flexion. - **Empty Can Test:** Positive, with pain and weakness during resistance. **Imaging:** - **X-ray:** Shows a hooked acromion. - **MRI:** Reveals inflammation of the subacromial bursa and a partial thickness tear of the supraspinatus tendon. **Diagnosis:** Based on Jee Hoon Ju’s symptoms, physical examination, and imaging results, he is diagnosed with subacromial impingement syndrome. ### Management 1. **Non-Surgical Treatment:** - **Rest and Activity Modification:** Avoid activities that exacerbate symptoms, particularly repetitive overhead movements. - **Physical Therapy:** Focused on strengthening the rotator cuff muscles, improving scapular mechanics, and enhancing shoulder flexibility. - **Medications:** NSAIDs to reduce pain and inflammation. - **Steroid Injections:** Corticosteroid injections into the subacromial space to reduce inflammation and pain. 2. **Surgical Treatment:** Considered if conservative measures fail to relieve symptoms after several months. - **Arthroscopic Subacromial Decompression:** Removal of inflamed bursa and any acromial bone spurs to increase the subacromial space. - **Rotator Cuff Repair:** If there is a significant tear in the rotator cuff tendons. 3. **Rehabilitation:** - Post-surgery or during conservative treatment, a structured rehabilitation program is essential to restore shoulder function and prevent recurrence. ### Conclusion Subacromial impingement syndrome is a common cause of shoulder pain and dysfunction, particularly in individuals who perform repetitive overhead activities. Early diagnosis and a combination of conservative treatments, including physical therapy and activity modification, can often manage the condition effectively. In more severe cases, surgical intervention may be necessary to relieve symptoms and restore shoulder function. Regular follow-up and adherence to a rehabilitation program are crucial for successful recovery.