Definition of subacromial impingement syndrome DeSeze and Robinson et al. studied the specific configuration of the subacromial and the trajectory of the greater tuberosity and proposed the nomenclature of the second shoulder joint. It is also referred to as the subacromial joint. The impingement syndrome is one of the most common causes of shoulder pain. Etiology Abnormal morphology of the anterolateral end of the acromion, osteophyte formation, osteophyte formation in the greater tuberosity of the humerus, hypertrophy of the acromioclavicular joint, and other possible causes of decreased acromioclavicular-humeral head spacing can cause compression and impingement of the subacromial structures. The majority of this impingement occurs in the anterior 1/3 of the acromion and below the acromioclavicular joint. Repeated impingement can lead to bursa and tendon damage, degeneration, and even tendon rupture. Clinical Presentation Impingement syndrome can occur from the age of 10 to the elderly. Some patients have a history of shoulder trauma, and a significant number are associated with chronic overuse of the shoulder joint. The symptoms are caused by repeated injury to the rotator cuff and bursa, resulting in tissue edema, hemorrhage, degeneration and even tendon rupture. Early rotator cuff hemorrhage and edema are similar to the clinical manifestations of rotator cuff rupture, making the diagnosis easily confused. The impingement sign should be differentiated from other causes of shoulder pain. The pain usually appears in the anterolateral aspect of the shoulder joint and the patient will localize this specific area. The pain may radiate to the deltoid stop. Patients will often complain that the pain is aggravated by pressure on the affected side of the shoulder joint at night or by abduction and supination of the upper arm during sleep. A complete history and physical examination are the basis for the diagnosis of acromioclavicular impingement syndrome. Diagnosis 1. Signs and symptoms are as previously described. 2. X-rays. The supraspinatus outlet position can sometimes be seen as a small bone spur at the anterior border of the acromion. 3. MRI can reveal effusion or bursitis. In some cases, a partial tear of the rotator cuff can be found. 4. 3D CT combined with MIMICS digital technology is used to reconstruct the acromion to achieve more accuracy. 5. The acromion impingement injection test can also assist in the diagnosis Treatment 1.Conservative treatment: For patients with definite subacromial impingement syndrome, I would generally first advise the patient to take rest and avoid exercises such as supination and abduction. In case of pain, oral NSAIDs can be taken. The conservative rehabilitation exercises for patients with subacromial impingement syndrome are different from those for patients with frozen shoulder. Since the symptoms are similar to those of frozen shoulder, patients with undefined diagnosis can be allowed to perform some slow supination movements first without adjuvant examination, and continue the exercises if the symptoms are relieved, or suspend the exercises if the symptoms worsen. For some patients, local seal treatment is feasible. The doctor may also suggest some physical therapy. 2.Surgical treatment For patients whose conservative treatment is ineffective for more than 3-6 months or even aggravated, I would recommend arthroscopic minimally invasive surgical treatment. The goal of surgical treatment is to remove the impingement and create a larger space for the rotator cuff. This allows the humeral head to move freely in the subacromial space and lift the upper arm without pain. The most common procedures are subacromial decompression and acromioplasty. This can be done through arthroscopic surgery or open surgery. The subacromial impingement syndrome is treated more precisely using digitally assisted shoulder arthroscopy techniques, which require 3-4 small incisions of about 6 mm during the arthroscopic procedure. The shoulder joint is examined with a fiber-optic camera system, and a number of small, fine instruments dedicated to arthroscopy are used to perform the surgical operation within the shoulder joint. Incisional surgery: In some areas where arthroscopic surgery is not available, a small incision can be made on the anterolateral aspect of the shoulder joint to perform decompression and plication surgery. Most patients with impingement of the acromion have some bone removed at the anterior border of the acromion with some bursal tissue attached. Some concomitant conditions such as acromioclavicular arthritis, biceps tendonitis or partial rotator cuff tears can also be managed along with the treatment of acromioclavicular impingement. 3. Rehabilitation Post-operative surgery patients do not need to brake, and rehabilitation exercises are carried out under the guidance of a specialized rehabilitation physician from the first day after surgery. Depending on the patient, the rehabilitation physician will provide a rehabilitation program based on your needs and the findings from the surgery. This includes exercises to restore range of motion and strength to the shoulder joint. It usually takes 2-6 months to obtain complete pain relief, and the degree of pain relief may not vary from patient to patient.