Symptoms | Sacroiliitis

Symptoms

The leading symptom of sacroiliitis is inflammatory pain in the back or buttocks, which classically occurs either only at night or in the morning or at least becomes less severe during the day. Typically, there is a knocking pain or a pain of displacement over the altered sacroiliac joints. In some patients, the pain radiates into the thighs.

In addition, there is stiffness in the affected region, which can be improved by movement. Unilateral sacroiliitis is rather the exception. However, it can happen that initially only the left or right side is affected and in the course of time the opposite side also becomes inflamed.

In addition, sacroiliitis can be more pronounced on the left or right side, so that the corresponding side is also more affected. If the symptoms are strictly one-sided, the diagnosis of sacroiliitis should be reconsidered. Often there is another cause for the complaints, such as irritation of the sciatic nerve or a herniated disc.

The sacrum (Os sacrum) is connected to the iliac bones on the right and left by the sacroiliac joint, which is not very flexible. Sacroiliitis typically affects both sides. However, one side may be more severely affected than the other, so that the symptoms are also more pronounced on each side.

Diagnosis of Sacroiliitis

For the diagnosis of sacroiliitis, it is first of all important to take the patient’s medical history (anamnesis). This is followed by a clinical examination, which checks the extent of movement of the lower spine. There are also some tests that make the presence of sacroiliitis very likely.

These include the stool test and a positive Mennell’s sign: The patient lying on his side bends the lower leg to the maximum while the other is retro-reflected (bent backwards). This triggers the typical low back pain in sacroiliitis. The diagnosis is confirmed by imaging techniques.

With an X-ray image, sacroiliitis can be simultaneously classified into grades 1 to 4 using the New York criteria. In X-rays, however, changes can only be detected after an average of eight years of the disease. An earlier diagnosis allows for magnetic resonance imaging (MRI of the sacroiliac joint or MRI of the lumbar spine).

The MRI of the lumbar spine reliably shows the inflammation of the ISG ́s.The MRI of the LWS pelvis can also reliably show the condition of the joint (ISG arthrosis). If sacroiliitis is diagnosed without any of the above-mentioned basic diseases being known beforehand, further diagnostics should be carried out in order not to overlook these sometimes serious diseases and to be able to treat them quickly. Important differential diagnoses are: Tuberculous or bacterial inflammation of the spine can also occasionally cause symptoms similar to those of sacroiliitis.

  • First-degree sacroiliitis has suspicious changes,
  • In one degree two, circumscribed erosions and/or subchondral sclerosis are found, although the joint space is still normally wide.
  • If a grade three is present, there is significant erosion or sclerosis and the joint space is either widened or narrowed. In addition, ankylosing buds may already be present here.
  • The fourth degree sacroiliitis is characterized by ankylosis, i.e. a bony stiffening of the joint.
  • Osteoporosis
  • Slipped discs of the lumbar spine and
  • Spinal disorders caused by tumors

In some cases of sacroiliitis and the suspected presence of sacroiliitis, it is useful to perform imaging by means of MRI (magnetic resonance imaging). However, at the beginning of every diagnosis is the physical examination and the medical consultation.

If, for example, abnormalities are found in the so-called stool rising test or the mennell sign, the suspicion of sacroiliitis should be clarified. However, the standard procedure is a conventional x-ray of the sacroiliac joints. Depending on the result, an additional MRI of the pelvis can now be performed.

While x-rays can show good bony changes in the sense of sacroiliitis that has been present for some time, MRI is the only method that offers the possibility of imaging acute inflammatory changes. Inflammatory processes can be visualized either by the administration of a contrast medium or by special computer calculations in which the imaging of fatty tissue is suppressed and thus contrast is achieved. Although contrast medium is used in most cases, it is not absolutely necessary.

In addition, the contrast agents used differ from those given in computer tomography (CT). Contrast media used in MRI can usually be given despite a “contrast medium allergy“. In contrast to CT with contrast medium, kidney or thyroid diseases do not pose a problem either.

The great advantage of an MRI of the pelvis is that even sacroiliitis in its early stages, which has not yet caused any bony changes, can be detected. However, the interpretation is very demanding and not always clearly possible. Major disadvantages are the high costs of the examination and the limited availability.

If there is a suspicion of sacroiliitis or if it has already been detected by an imaging procedure, a blood test is usually also performed in the laboratory. Typically, an inflammatory reaction can be detected. This means that values such as blood sedimentation or CRP may be elevated.

However, these values are very unspecific and an increase can have a variety of possible causes. A very specific value, however, which is determined in the case of sacroiliitis in the blood, is HLA B27. If this marker can be detected, there is a high probability that Bekhterev’s disease or a related disease is present. It is also typical for these diseases that other laboratory values such as rheumatoid factors or antibodies, which would indicate an autoimmune disease, are in the normal range. The determination of these values is therefore carried out to exclude other diseases if necessary.