Ankylosing spondylitis M45.09

Ankylosing spondylitis, also known as ankylosing spondylitis, is a chronic inflammatory disease that mainly affects the spine (sclerosis and ossification of the spinal apparatus/bamboo rod spine) and the large joints (ankylosis of the sacroiliac joints and intervertebral joints). This disease belongs to the group of spondylarthritides (axial spondylarthrtis - M46.89) and is basically characterized by inflammation of the joints and the enthesis. Frequent associations with HLA-B27, iritis or iridocyclitis, mesaortitis, cardiac conduction disorders; possibly amyloidosis.

Genetic disposition: 90% of patients are HLA-B27 positive (frequency in the normal population: 8%). The HLA-B27 protein plays a significant pathogenetic role due to its particularly slow and complicated folding. Ultimately, the triggering factors are unknown.

Ankylosing spondylitis (Bekhterev's disease) shows a variety of symptoms that can develop over the course of the disease. The main symptom is "chronic inflammatory back pain".

• Back pain: The pain is often localized in the lower back. The pain often occurs at night or in the early hours of the morning and can be so severe that it disturbs sleep. The pain usually improves with movement and worsens at rest. It may be associated with radiating pain into the thighs, tapping pain and pain on displacement of the sacroiliac joints (chair-rise test, Mennel's sign: low back pain when the lower leg is bent to the maximum and the other leg is retroflexed when the patient is lying on his side.
• Stiffness: Especially in the morning or after long periods of rest. The stiffness can last for several hours and usually improves with movement.
• Painful inflammation of the joints: Inflammation can occur in large joints such as the hip, knee or shoulder. The joints of the spine are also affected.
• Reduced mobility: As the disease progresses, the mobility of the spine can decrease, which can lead to a stooped posture. The ability to bend or twist may be limited. Finger-floor distance increased (normal=0); chin-sternum distance increased (normal=0)
• Possible chest pain (synchondritis of the sternomanubrial synchondrosis); possible pubic bone pain (symphysitis).
• Chest stiffness: The inflammation can also affect the thoracic spine, which can lead to restricted mobility of the chest and breathing difficulties.
• Possible inflammatory enthesiopathies: painful inflammation of the tendon insertions: Achilles tendon, plantar aponeurosis, trochanter, ischium, iliac crest.
• Possibly anterior uveitis (25%) with iritis, iridocyclitis. The symptoms are red, painful eyes and blurred vision. Uveitis may occur in episodes and should be treated immediately.
• Fatigue: Many patients report severe tiredness or fatigue that is not improved by sleep or rest.
• Postural changes: In advanced stages, there may be stiffening of the spine and thorax, fixed kyphosis, osteoporosis (18%), rarely amyloidosis (1%), increased cardiovascular risk.

Imaging techniques: MRI (gold standard); X-ray: signs of sacroilitis, signs of spondylarthritis. Bony ankylosis of the intervertebral joints. Entesiopathies with ossifying periostitis (e.g. heel spur).

Clinic, laboratory, assessment of the Basdai Index (Bath Anykylosing Spondylitis Disease Activity Index with 6 standardized questions on fatigue, pain sensitivity, morning stiffness. Alternative: ASDAG index.

Psoriatic spondylarthritis (see psoriatic arthritis below)

Reiter's syndrome (reactive arthritis)

Tuberculous and bacterial spondylitis and spondylodiscitis

Enteropathic arthritis with sacroiliitis (patients with chronic inflammatory bowel disease/CED - ulcerative colitis, Crohn's disease develop arthritis in 25% and sacroiliitis in 15%)

Wipple's disease