Brief overview
- Definition: entrapment of tissue in narrowed joint space; permanent restriction of mobility
- Forms: Primary impingement syndrome based on change in bone structure; secondary impingement syndrome triggered by other disease or injury
- Diagnosis: Medical history, physical examination, imaging procedures (X-ray, MRI, ultrasound)
- Treatment: Depending on the type and severity of impingement, conservative therapy (physiotherapy, pain medication) or surgery
- Symptoms: Pain in the affected joint; in the long term, there is often limited mobility; the joint as well as the surrounding tissue are partially damaged
- Causes and risk factors: Bony changes or injuries to the joint; extreme stress often also contributes to the development of the disease
- Course of disease and prognosis: Depends on the type of impingement and the type of treatment; more severe joint damage possible
What is impingement syndrome?
Impingement syndrome manifests itself mostly in the shoulder joint. It affects about ten percent of the population, men and women around the age of 50 about equally often. Impingement syndrome often also occurs in the hip joint. More rarely, patients suffer from impingement syndrome of the ankle joint.
You can read more about this topic in our articles Impingement – Shoulder and Impingement – Hip.
Forms of impingement syndrome
Impingement syndrome of the shoulder can be divided into two forms, depending on which structures are compressed:
Primary outlet impingement syndrome is due to a change in bony structures, such as a bone spur or an excessively tilted bone roof.
Secondary non-outlet impingement syndrome is the result of another condition or injury that reduces the joint space. This includes, for example, inflammation of the bursa (bursitis) and damage to tendons or muscles.
The right person to contact if you suspect impingement syndrome is a specialist in orthopedics and trauma surgery. The detailed description of your symptoms already provides the doctor with valuable information about your current state of health. The doctor will ask you the following questions, for example:
- Do you remember a severe strain or injury at the time the pain began?
- Is the pain dull and radiating from the joint?
- Does the pain intensify at night or when you lie on the affected side?
- Do you have limited range of motion in the affected joint?
An X-ray of the affected joint, an ultrasound examination (sonography), and a magnetic resonance imaging (MRI) support a reliable diagnosis.
X-ray examination
X-ray examination is the diagnostic tool of first choice for impingement syndrome. If your treating orthopedist does not have his own X-ray equipment, he will refer you to a radiology practice and then discuss the findings with you. Typical bony structural changes can be detected on the X-ray.
Ultrasound (sonography)
Magnetic resonance imaging (MRI)
Magnetic resonance imaging (MRI) is far superior to ultrasound examinations because it allows much more precise images of the soft tissues (muscles, tendons, bursa). Cartilage and bone bulges are also very accurately depicted. An MRI image is therefore always taken before any planned surgery to reconstruct the joint in order to make a reliable diagnosis.
In addition, the good overview image of the soft tissues enables more precise planning of the surgical intervention.
Does impingement require surgery?
Conservative therapy
In the early stages, the focus is on so-called conservative therapy. If possible, the affected joint is spared, and pain-increasing stress factors (sports, physically strenuous work) are largely avoided.
Anti-inflammatory painkillers (ibuprofen or acetylsalicylic acid) usually relieve the pain, but do not affect the triggering cause.
Physiotherapy usually also helps well to reduce the pain. In some cases, these measures (especially in shoulder impingement) are sufficient to allow patients to live mostly symptom-free lives without surgery.
Causal therapy
Impingement syndrome – Arthroscopy
Arthroscopy is a minimally invasive surgical method in which a camera with an integrated light source and special surgical instruments are inserted into the joint through two to three small incisions in the skin. This surgical method allows the physician to examine the joint for damage and obtain an overview of the entire joint.
This is often followed directly by surgical treatment, during which any bony prominences that restrict the joint’s freedom of movement are ground off. If cartilage damage is already present, the doctor usually removes this as well.
In advanced stages of impingement syndrome, tendons are sometimes already torn: they can be sutured and reconstructed during arthroscopy. The skin incisions are then sutured closed with a few stitches and leave far more discreet scars than open surgery.
Impingement syndrome cannot necessarily be “trained away.” However, depending on the severity and type of impingement, it is possible to prevent further damage to the joint and reduce pain. Have a physical therapist show you exercises to strengthen the muscles. Strengthening those muscles that are needed to rotate the joint outward (external rotators) should definitely be targeted for hip impingement.
The external rotators help to effectively increase the joint space. Stretching of the relevant muscles is also important. In addition, muscle-building exercises should definitely be performed after surgery has been performed to counteract muscle atrophy.
What are the symptoms of impingement syndrome?
Symptoms in the shoulder joint
When impingement syndrome occurs at the shoulder joint, patients report an acute onset of pain in the early stages that is discrete at rest and intensifies with exertion (especially overhead activities). Patients often specify a triggering situation (exertion, exposure to cold, injury). The pain is described as deep in the joint and often intensifies at night, making lying on the affected side almost impossible.
Symptoms in the hip joint
Impingement syndrome often shows a very insidious onset of symptoms at the hip joint. Initially, pain of the hip joint occurs only sporadically and is often described by the patient as groin pain. However, the pain intensifies during physical activity and then often radiates into the thigh. In most cases, they intensify when the leg, which is bent at 90 degrees, is turned inward (internal rotation with 90 degrees of flexion).
Causes and risk factors
Impingement syndrome has several causes. These are divided into bony structural changes as well as damage to the soft tissues (muscles, tendons, bursa). The risk of impingement syndrome increases with age, although hip impingement syndrome sometimes also occurs in young athletes due to increased stress on the mobile joints.
Impingement syndrome of the shoulder: Causes
In impingement syndrome of the shoulder, the narrowing of the joint space results either from bony changes in the acromion or from damage to the surrounding soft tissues.
So-called outlet impingement shoulder syndrome results from narrowing of the subacromial space due to bony changes in the shoulder such as joint wear (osteoarthritis).
Non-outlet impingement shoulder syndrome, on the other hand, is caused by damage to the surrounding soft tissues. Inflammation of the bursa (bursitis subacromialis) often causes swelling and thus narrows the joint space.
Impingement syndrome of the hip: Causes.
In most cases, impingement syndrome of the hip results from a deformity of the acetabulum. The acetabulum is part of the pelvic bone and presents as a cup-shaped socket that, together with the femoral head, forms the hip joint.
When bone spurs form at the edge of the acetabular roof or the femoral head (bite deformity), a painful restriction of movement often results, especially when turning inward (internal rotation) and when bending (flexion) the hip joint. The bony changes occur, for example, as a result of increased physical exertion, which is why young athletes more often suffer from hip impingement syndrome.
Course of the disease and prognosis
Impingement syndrome leads more frequently to inflammation and signs of wear if the tightness is severe. Furthermore, with continued compression of nerves and tendons, the risk of tears and tissue death (necrosis) increases.
Both immobilization for too long and surgery carry the risk of joint stiffness. Even after impingement syndrome has been successfully operated on, patients should perform physiotherapy exercises afterwards.
Impingement syndrome cannot be completely prevented, but general fitness and regular exercise are recommended to balance the load on the joints and keep them mobile.
It also makes sense to adjust the desk workstation to allow for better posture.
