Brief overview
- Definition: painful entrapment of tissue in the joint space of the shoulder that permanently restricts mobility
- Symptoms: The main symptom is pain, especially with certain movements and heavier loads; later, there is often restricted movement of the shoulder joint
- Causes: Primary impingement syndrome is caused by a change in the bone structure; secondary impingement syndrome is triggered by another disease or injury
- Treatment: Conservative therapy consists of physical therapy, pain medication, and rest; surgery is used to treat the cause
- Diagnosis: After a history and physical examination, imaging studies are used, especially X-ray, MRI, and ultrasound
- Course of disease and prognosis: Depends on the exact cause and duration of symptoms before treatment begins
- Prevention: avoidance of incorrect posture and monotonous continuous stress, sufficient sport and exercise
Impingement syndrome of the shoulder: Description
Four cuff-like muscles surround the shoulder joint (rotator cuff). The tendons of the rotator cuff muscles no longer slide freely in the joint space due to compression. The condition is also called shoulder impingement syndrome or shoulder tightness syndrome because of the “lack of space” in the joint.
Two forms of impingement shoulder syndrome
Impingement shoulder syndrome is divided into primary “outlet impingement syndrome” and secondary “non-outlet impingement syndrome.”
Primary outlet impingement syndrome of the shoulder is caused by a change in the bony structures. In this case, a possible cause of narrowing of the joint space is degenerative structural changes or a bone spur.
In contrast, secondary non-outlet impingement syndrome of the shoulder is due to a non-bony change. In such cases, inflammation of the bursa (bursitis) and muscle or tendon damage reduce the joint space and cause movement restrictions and pain.
Impingement shoulder syndrome: frequency
Symptoms
In the early stages, impingement shoulder syndrome is noticeable by an acute onset of pain. It manifests itself only discreetly at rest, but intensifies during stressful activities, especially when performed over the head. In many cases, patients identify a triggering event. Extraordinary strain during overhead activities or the influence of cold are often associated with the onset of the pain.
The pain of impingement shoulder syndrome is described as being deep in the joint. In addition, lying on the affected side is described as extremely uncomfortable, as it increases the pain.
When the arm hangs loosely down the body and then is raised laterally in an extended position (abduction), patients with impingement shoulder syndrome report severe pain at an angle of about 60 degrees or greater. Abduction between 60 and 120 degrees is impossible because the supraspinatus tendon is pinched in the process. This phenomenon is described as a painful arc and is an important clinical sign of impingement shoulder syndrome.
Causes and risk factors
The shoulder joint is the most mobile joint in the body. It is formed by the head of the upper arm (caput humeri) and the articular surface of the scapula. The scapula has a bony prominence, the acromion, which is the highest point of the shoulder joint. Compared to the hip joint, the shoulder joint is much less protected by bony structures. It is surrounded by four cuff-like muscles (rotator cuff).
The tendons of the rotator cuff run under the acromion through the so-called subacromial space and contribute far more to the stability of the shoulder joint than the surrounding ligaments. In shoulder impingement syndrome, the narrowing of the joint space results from either bony changes in the acromion or damage to the surrounding soft tissues.
In non-outlet impingement shoulder syndrome, the surrounding soft tissues cause the discomfort, such as bursitis. It is usually accompanied by swelling, which narrows the joint space.
Treatment
Impingement syndrome of the shoulder is treated with various treatment approaches. Initially, attempts are made to treat the symptoms conservatively through physical rest, pain medication or physiotherapy. However, for a complete cure, shoulder impingement syndrome usually requires surgery (causal therapy).
Conservative therapy of shoulder impingement
Conservative therapy initially includes sparing the shoulder joint and avoiding stressful factors such as sports or physically demanding overhead work.
Drug treatment provides for anti-inflammatory painkillers such as ibuprofen or acetylsalicylic acid. However, they usually only relieve the discomfort and do not eliminate the triggering cause.
The exercises serve primarily to strengthen that muscle group of the shoulder joint that is needed for the joint rotation to the outside (external rotation): Targeted training of the so-called external rotators (rotator cuff) increases the joint space, which brings relief.
Since muscles dwindle (muscle atrophy) with prolonged restraint, impingement shoulder exercises also help to maintain the strength of the muscles. However, the affected shoulder joint should not be overloaded in the process. Only correctly performed, regular physiotherapy allows to reduce the pain. Try to incorporate the learned exercises firmly into your daily routine to achieve the best possible therapeutic success.
Causal therapy of shoulder impingement
Meanwhile, in contrast to open surgery, arthroscopy (joint endoscopy) is normally used. Arthroscopy is a minimally invasive surgical technique in the joint area that is particularly recommended for young patients in order to minimize the risk of joint stiffening.
A camera with an integrated light source and special surgical equipment are inserted into the joint through two to three small skin incisions. In this way, the physician examines the joint from the inside and obtains a precise overview of the causative changes.
The joint space is then exposed, for example by grinding away a bone spur or removing any cartilage damage. If the shoulder impingement syndrome has already caused tendon tears in the advanced stage, these are sutured during the arthroscopy. The skin incisions require only a few sutures for closure and leave only very inconspicuous scars compared to open surgery.
Since patients often automatically adopt a protective posture even after surgery, physiotherapeutic exercises are always recommended afterwards to counteract impingement syndrome in the shoulder.
Examinations and diagnosis
The right person to contact if impingement syndrome of the shoulder is suspected is a specialist in orthopedics and trauma surgery. He or she will first take your medical history (Anamnesis) by asking you various questions, such as:
- How long has the pain been present?
- Was there a severe strain or injury at the time the pain began?
- Does the pain increase with exertion, at night or when you lie on the affected side?
- Do you suffer from restricted movement in the affected joint?
- Does the pain radiate from the joint and is it of a dull quality?
- Do you do any sports, and if so, what kind?
- What do you do for a living?
Physical examination
The strength level of the shoulder joint muscles is measured by movement against resistance. There are various clinical tests to check the individual muscles of the shoulder joint for damage. In addition, neck grip and apron grip can be used to check which movements cause pain.
In the neck grip, the patient places both hands on the neck with the thumb pointing downwards, and in the apron grip, the patient grasps his back with both hands as if he were tying on an apron. In shoulder impingement syndrome, patients complain of pain when doing this and are unable to comply with the prompts.
Jobe test
The Jobe test is an orthopedic test used as part of the clinical examination for impingement syndrome of the shoulder to confirm or rule out the involvement of the supraspinatus muscle and its tendon. For this purpose, the patient is asked by the physician to spread the arms at shoulder level (90 degrees) with the elbow joint extended and to turn the hands together with the forearms inwards (internal rotation).
Impingement test according to Neer (Neer test)
The impingement test according to Neer is another clinical test for suspected impingement shoulder syndrome. In this test, the patient is asked to extend the arm forward for a long time and to turn the hand and forearm inward to the maximum extent possible (pronation position). The physician fixes the patient’s shoulder blade with one hand and raises the patient’s arm with the other hand. The Neer test is positive if there is pain when the arm is raised above 120 degrees.
Hawkins test
The Hawkins test is also a clinical test that helps confirm or rule out shoulder impingement syndrome. However, it is far less specific than the Jobe and Neer tests because it does not pinpoint individual muscles as the cause. The shoulder joint is passively rotated inward by the examiner during the Hawkins test. If pain is experienced, the physician evaluates the test as positive.
Impingement shoulder syndrome: imaging
X-ray examination
X-ray examination is the diagnostic imaging tool of choice for diagnosing impingement syndrome of the shoulder. It can detect bony changes and provide an overview of the joint.
Ultrasound
In the context of an inflammation of the shoulder joint, fluid accumulations often occur within the bursa. They can be easily and inexpensively detected by ultrasound examination (sonography). Sonography can also be used to visualize other bursa changes, the muscular structures of the shoulder joint, and any thinning of the muscles.
While all of this provides evidence of shoulder impingement syndrome, sonography is used primarily to identify associated pathology.
Magnetic resonance imaging
Course of the disease and prognosis
The prognosis for shoulder impingement syndrome cannot be generalized because it depends on the triggering cause. In most cases, the symptoms can be alleviated by anti-inflammatory painkillers (anti-inflammatory drugs). However, this is not a permanent solution. Physiotherapeutic treatment must be carried out over a longer period of time in many cases before satisfactory results are achieved.
It is not possible to make a blanket prediction of how long a patient with shoulder impingement syndrome will be ill. Since the course of the disease depends on the duration of the symptoms, it is important to start therapy as soon as possible. After all, if the symptoms persist untreated for more than three months, there is a chance that the shoulder pain will become chronic and treatment will become more difficult.
