ISG syndrome

The collective term ISG syndrome covers pain of the sacroiliac joint (ISG), which can arise from a variety of causes.

The sacroiliac joint, one of the largest joints in the human body, provides the connection between the sacrum (Os sacrum) and the left or right ilium (Os ilium) . It is responsible for transmitting power from the spine to the pelvis and legs. Sufficient stability is provided by a strongly developed ligamentous apparatus and a tight joint capsule. However, this also leads to a low mobility of the joint, which is limited to a few millimeters and a few degrees.

The sacroiliac joint is often the source of discomfort due to the daily force of walking upright and the associated shear forces. In up to 25% of patients with back pain, the actual origin of the pain is in the sacroiliac joint. Nevertheless, ISG syndrome presents a diagnostic challenge.

Signs of ISG syndrome may include:

• Lower back pain
• Radiation in buttocks and/or leg
• Intensification of pain during exertion, e.g. climbing stairs, sitting for long periods of time

The symptomatology of ISG syndrome can vary from person to person in terms of location, severity, and triggers.

Usually, there is unilateral pain in the lower back that radiates to the buttocks and/or leg. In only a quarter of cases is the pain bilateral. In most cases, these complaints are intensified in an attack-like manner during exertion, especially when climbing stairs or sitting for long periods of time.

Causes of ISG syndrome include:

• Overload, e.g. due to anatomical peculiarities, competitive sports
• Incorrect loading, e.g. due to muscular imbalances
• Weakness of connective tissue, especially in women and during pregnancy

The causes of pain in the sacroiliac joint are manifold. The focus is on overloading and incorrect loading.

Overloading of the sacroiliac joint can be caused by anatomical peculiarities, e.g. by a scoliosis or a difference in leg length. These lead to a unilateral pelvic obliquity, resulting in overloading of the sacroiliac joint on the opposite side. Painful wear and tear of the joint cartilage, osteoarthritis, can be the result.

Similarly, competitive sports can lead to overstressing of the sacroiliac joint. The constantly recurring high loads can result in small bone fractures, so-called stress fractures, which in turn lead to pain in the sacroiliac joint.

Furthermore, incorrect loading due to muscular imbalances can disrupt the cooperation between muscles, ligaments and the sacroiliac joint and thus cause typical complaints of the ISG syndrome.

Weakness of the connective tissue can also trigger ISG syndrome, as it leads to a loosened ligamentous apparatus around the joint. The insufficient stability leads to over-movement of the joint, which results in pain. Women and especially pregnant women are often affected by connective tissue weakness. Accordingly, they are predestined for ISG syndrome.

Despite the frequency of ISG syndrome, the diagnosis is often made too late or not at all. This is due, among other things, to the fact that ISG syndrome is not recognized by some physicians as an independent clinical picture. In addition, the risk of confusion with other diseases that cause lower back pain is high. In general, ISG syndrome should be considered in all patients who complain of lower back pain and appropriate diagnostic procedures should be initiated.

Our spine specialist Priv.-Doz. Dr. Pestka will ask you about your pain in a detailed consultation. This is followed by a physical examination of the spine, pelvis and legs. Palpation of the sacroiliac joint can typically trigger a pressure pain.

In most cases, the medical history and physical examination are already sufficient to make the diagnosis of ISG syndrome. If there is a suspicion of a specific cause of the pain, e.g. inflammation of the joint or osteoarthritis, imaging is performed.

X-rays can be used to assess bony changes in the context of osteoarthritis or bone fractures. If inflammation of the joint is suspected, on the other hand, a magnetic resonance imaging (MRI) examination is preferred.

The most reliable indication of an ISG syndrome can be provided by means of so-called ISG infiltration . In this procedure, pain-relieving drugs are injected into the joint space. A temporary improvement in symptoms confirms the suspicion of ISG syndrome.

Conservative therapy:

Multimodal therapy of ISG syndrome is composed of medicinal, physiotherapeutic and interventional approaches.

The following conservative therapies are available:

• Drug therapy: analgesics
• Physical therapy: heat
• Physiotherapy, manual therapy
• Auxiliary means: pelvic orthosis, insoles
• ISG Infiltration

In addition to local analgesics, oral analgesics can be used. Painkillers from the group of non-steroidal anti-inflammatory drugs (NSAIDs) play a particularly important role here. These not only help to relieve pain, but also inhibit inflammatory processes. If these drugs do not lead to sufficient improvement of the symptoms, opioids can be considered.

Heat applications, such as the application of a hot water bottle or a warm bath, can also improve the symptoms by releasing muscle tension. In addition, it is essential to get enough exercise in everyday life.

Another important therapy component is physiotherapy. Physiotherapeutic exercises are used to stretch the ligaments of the sacroiliac joint and strengthen the surrounding muscles. In addition, pelvic orthoses can help stabilize the sacroiliac joint. In the case of a leg length difference, shoe insoles create the necessary compensation.

In cases of persistent pain and unsuccessful pain and physiotherapy, local infiltration of pain and anti-inflammatory preparations near the joint or directly into the joint can bring about an improvement in the symptoms. Infiltration treatments are carried out precisely with the aid of ultrasound or X-ray.

Operation:

In the treatment of ISG syndrome, the numerous conservative therapeutic measures lead in the vast majority to a satisfactory improvement of symptoms. In the case of chronic complaints lasting more than 6 months and after conservative therapies have been exhausted, surgery, a so-called minimally invasive permanent joint fusion, may be considered in exceptional cases.