Shoulder Impingement syndrome

What’s that?

Impingement syndrome is the compression of soft tissue by the denser structures of the joint, resulting in pain.

About the disease

Most often, concerning impingement syndrome, we mean a subacromial lesion of the shoulder joint. However, similar changes can develop in other joints.

Impingement syndrome of the shoulder is a pathologic condition in which the head of the shoulder hits the acromial process and the acromial-clavicular ligament, which is thrown over the top. As a result of prolonged trauma to the rotator cuff of the shoulder, over time, it weakens and ceases to fulfill its function.

The term “impingement-syndrome” was first implemented by physician C. S. Neer, the first descriptions date back to 1972. The scientist described this pathology in the example of shoulder impingement. Thus, in this syndrome, there is a mechanical compression of the rotator cuff of the humerus. It is characterized by compression of the tendon of the supraspinous muscle between the large tubercle and part of the acromion adjacent to the clavicle. Impingement of the right shoulder joint is more common in right-handed people, and left shoulder joint impingement in left-handed people is due to the unequal load on these musculoskeletal joints.

Impingement syndrome is a dynamic process and is always accompanied by inflammation. Inflammation proceeds in stages. Dynamics implies the presence of a trigger mechanism and variability over time. Thus, traumatization triggers degenerative changes, which then lead to deformity. Increasing stenosis further promotes traumatic injury, which closes the vicious circle.

The main symptom of the pathological condition is pain in the projection of the affected joint, which sharply increases with movement. It leads to compensatory limitation of mobility in the joint. At the initial stage of the process, as the inflammatory changes subside, the amplitude of movements is restored.

X-rays of the affected area can help diagnose impingement syndrome, but magnetic resonance imaging provides the most information. MRI primarily allows to assess the condition of soft tissues.

Treatment of pathology is determined by the stage of the disease. When there are no organic changes in the joint, only conservative therapy is sufficient. When secondary fibrosis and other organic changes develop, orthopedic surgery is indicated.

Types

According to Neer’s theory, there are three successive stages in the course of impingement syndrome:

• Stage I (initial) reversible stage, manifested by edema and hemorrhages;
• Stage II – corresponds to the phenomena of fibrosis and tendonitis (inflammatory process in the tendon);
• Stage III – characterized by bone spur formation and rotator tendon rupture.

Given the localization, other variants besides subacromial impingement syndrome are possible:

• Impingement of the wrist joint – compression of the carpal bones by the head of the ulna;
• ischiofemoral (iliofemoral) impingement – compression of soft tissue structures between the sciatic tuberosity and the small acetabulum of the femur (usually the quadriceps muscle is pinched);
• Hip impingement – develops as a result of a congenital or acquired (post-traumatic) abnormality that causes the joint structures to hit each other;
• Ankle impingement – compression of soft tissue structures in the anterior or posterior ankle;
• Impingement of the knee joint – impingement of the suprapatellar fat body located in the hamstring fossa.

Symptoms of impingement syndrome

The main symptom of impingement syndrome is pain of varying intensity in the shoulder joint. They occur or intensify during the shoulder joint’s active and passive movements (flexion, extension, rotation, and abduction). Pain sensations can also bother me at night. Pain syndrome limits the volume of movement in the affected joint. An important distinguishing feature is that the pain increases significantly when trying to move.

Causes of impingement Syndrome

The causes of impingement syndrome can be classified into two categories:

• intrinsic or intratendinous factors, which are emphasized within the endogenous theory;
• external or extra-tendinous factors that are associated with traumatization.

The endogenous theory is that excessive loading of the joint and degenerative tendon damage may contribute to impingement syndrome. The mechanical theory includes bone spurs, joint instability, and dysfunctional surrounding muscles.

Diagnosis of impingement syndrome

To diagnose pathological changes in the shoulder joint, specific scales-questionnaires are used at the initial stage, based on assessing the level of pain syndrome, the degree of restriction of motor activity, and the reduction in the amplitude of movement and strength. Specialized scales are considered more sensitive than general tests.

The following tests are performed to visualize possible causes and assess the condition of the joint:

• X-rays of the affected area (e.g., foot and ankle) – allows detection of bone deformities;
• magnetic resonance imaging – primarily aimed at assessing the condition of soft tissue structures, which are almost invisible in radiographic examination.

Additional examinations are ordered as indicated. Sometimes, a diagnostic arthroscopy may be performed to view the joint from the inside.

Treatment of impingement Syndrome

According to clinical guidelines, the treatment of impingement syndrome is determined by the stage and severity of the pathologic process. Thus, at the stage when there is only edema and hemorrhage, conservative symptomatic therapy is sufficient. If there is joint fibrosis and adjacent tendon inflammation, the question is decided in favor of plastic surgery. The presence of bone spurs and traumatic ruptures is an absolute indication for surgical intervention.

Conservative treatment

In the period of acute inflammation, highly selective non-steroidal drugs, which have the most pronounced analgesic effect, are prescribed. Improving the therapeutic result requires modification of lifestyle – a proportional rate of physical activity, proper nutrition, and excess weight reduction.

Surgery for impingement syndrome.

Surgical treatment is indicated in patients with a long disease course as the only method that affects the pathogenetic link and promotes a complete cure. Surgery for impingement syndrome consists of soft tissue decompression and one-stage removal of dense calcinates.

In the postoperative period, short courses of non-steroids from the group of cyclooxygenase type 2 blockers are usually prescribed. It helps to accelerate the control of chronic inflammation after removing the causative factor.

All these treatment options are available in more than 790 hospitals worldwide (https://doctor.global/results/diseases/shoulder-impingement-syndrome). For example, Mumford procedure is performed in 29 clinics across Turkey for an approximate price of $3.0 K (https://doctor.global/results/asia/turkey/all-cities/all-specializations/procedures/mumford-procedure). 

Prevention

To reduce the likelihood of the risk of impingement syndrome in different localizations, it is recommended:

• avoid excessive weight-bearing exercise, but maintain a moderate pace of physical activity (mostly aerobic);
• periodically carry out courses in therapeutic massage and physiotherapy;
• timely treat pathologies of the musculoskeletal system.

Rehabilitation

After surgical intervention on the structures of the musculoskeletal system, plaster immobilization is performed. After the cast is removed, the therapeutic physical training of the operated limb begins. 

Shoulder Impingement Syndrome: Insights into Relief and Recovery FAQ