Ankylosing Spondylitis: Visual Explanation for Students — Transcript

Hi, this is Tom from zeroanoise.com. In this video, I'm going to be going through ankylosing spondylitis. You can find written notes on this topic at zerodefines.com/ankylosing-spondylitis or in the rheumatology section of the zeroD finals medicine book. Let's jump straight in. Ankylosing spondylitis is an inflammatory condition that mainly affects the spine and causes progressive stiffness and pain. It's part of the seronegative spondyloarthropathies, a group of conditions that are related to the HLA-B27 gene.

Other conditions in this group are things like reactive arthritis and psoriatic arthritis. The key joints that are affected in ankylosing spondylitis are the sacroiliac joints and the joints of the vertebral column. The inflammation causes pain and stiffness in these joints.

Progression leads to fusion of the joints, so fusion of the spinal column and the sacroiliac joints. Fusion of the spine leads to the classical finding on the x-ray of a bamboo spine, and this is something that will often appear in your medical exams.

There's a strong link with the HLA-B27 gene, and around 90% of patients who have ankylosing spondylitis will have this HLA-B27 gene. However, only around 2% of people who have the gene will develop ankylosing spondylitis. This number goes

up to around 20% if they have a first-degree relative that's affected. So, if you have a first-degree relative and the HLA-B27 gene, there is around a 20% chance of developing the condition. So, how do these patients present? The tip

especially in your exams is a young adult male in their late teens or twenties. It affects males about three times more often than females, and symptoms usually develop gradually over more than three months. The main presenting features are low

back pain and stiffness and sacroiliac pain, which occurs in the buttock region. The pain and stiffness are worse with rest and improve with movement. The pain is worst at night and in the morning, and it may even wake them up

from sleep in the early hours of the morning. When you take a history, the patient will describe how it takes at least 30 minutes for the stiffness to improve in the morning, and then that stiffness seems to get progressively

better throughout the day as they do more and more activities. The symptoms can fluctuate with periods of flares of worsening symptoms and other periods where the symptoms seem to improve. One of the key complications of ankylosing spondylitis is vertebral fractures.

So, what associations are there between ankylosing spondylitis and other affected areas in the body? Ankylosing spondylitis doesn't just affect the spine; it can affect other organ systems and cause things like systemic symptoms such as weight loss and fatigue. It can present with chest

pain related to the costovertebral joints and the costosternal joints. Enthesitis is inflammation of the entheses, and this is where the tendons or the ligaments insert into the bone. This can cause problems like plantar

fasciitis and Achilles tendonitis. Dactylitis is a condition where there's inflammation of an entire finger or toe. It can cause anemia, anterior uveitis, aortitis, which is inflammation of the aorta, the large blood vessel coming out of the

heart. It can cause heart block when there's fibrosis of the heart's conduction system. Restrictive lung disease can be caused by restricted movement in the chest wall, and ankylosing spondylitis can also be associated with pulmonary fibrosis, particularly at the upper lobes of the

lungs, and this occurs in about 1% of patients. The condition that's also associated with ankylosing spondylitis is inflammatory bowel disease. There's a test called the Schober test, which you're expected to know about in medical school, and this is a test that's used as

part of a general examination of the spine to assess how much mobility there is, particularly in the lumbar spine. You might be asked to do this in your OSCE examinations. So, how do you do it? Well, you have the patient stand straight. You

find approximately where their L5 vertebra is, and then you mark a point 10 centimeters above the L5 vertebra and 5 centimeters below, so the points are 15 centimeters apart. Then you ask the patient to bend forward as far as they can, and you measure the

distance between the two points. If the distance between them when they're bending forwards is less than 20 centimeters, this indicates there's a restriction in the lumbar movement, and it would help to support a diagnosis of ankylosing spondylitis. What investigations can you do? Well, you

can start with some basic inflammatory markers like CRP and ESR. They might go up with increased disease activity. You can send off a genetic test to look for the HLA-B27 gene. You can do x-rays of the spine and the sacrum, and

if the x-rays are normal, an MRI of the spine can show early changes. This shows up as bone marrow edema in the vertebral bodies, and this is something that will appear before there are any changes on the x-ray.

So, what x-ray changes do you get? Well, this bamboo spine is the typical exam description of the x-ray appearance of the spine in later stages of ankylosing spondylitis, and it's worth remembering this term in case it appears in your MCQ

exams. X-ray images in ankylosing spondylitis can show squaring of the vertebral bodies, subchondral sclerosis, and subchondral erosions. Syndesmophytes are areas of bone growth where the ligament normally inserts into the bone, and this occurs relating to the

ligaments that support the intervertebral joints, so where the ligaments insert into the vertebra to hold the vertebra together. You can get these developments of bony growth called syndesmophytes. Ossification can occur in the ligaments or discs and the joints,

and this is where the structures like the ligaments start to turn into bone-like tissue. You can get fusion of the facet joints, the sacroiliac joints, and the costovertebral joints, so there's no longer any movement at all in those

joints. So, let's move on to the management of ankylosing spondylitis. Let's first start with the medical management of the condition. So, the first step would be non-steroidal anti-inflammatory medication like ibuprofen or naproxen, and these can be used to help with the pain related to

the inflammation. If the improvement in the pain and the symptoms aren't adequate after two to four weeks of the maximum dose, you can consider switching to another non-steroidal anti-inflammatory, and simply switching medication can sometimes lead to an improvement in

symptoms. Steroids can be used during flares of the condition to help control the symptoms, and this could be oral steroids or intramuscular slow-release injections or steroid injections directly into the affected joints. The next step is medications that target

tumor necrosis factor, anti-TNF medications like etanercept or monoclonal antibodies against TNF such as infliximab, adalimumab, and certolizumab are known to be effective in treating the disease activity in ankylosing spondylitis. If these don't work, so if

you get no adequate response from NSAIDs, steroids, and TNF inhibitors, then there's a monoclonal antibody against interleukin-17 called secukinumab, and this is a relatively new medication that shows promising results in ankylosing spondylitis. Then you need to move on to

additional management to support the medical management. Physiotherapy is really important to give them exercise and encourage them to mobilize the spine to keep that flexibility and mobilization. Avoiding smoking is important. Bisphosphonates can be used to treat osteoporosis if it occurs. You need

to offer treatment for other complications such as the heart block or the restrictive lung disease, and then surgery may be required if there are deformities to the spine or vertebral fractures or deformities develop in other joints. So, thanks for watching. I hope you found

this video helpful. If you did, don't forget there's plenty of other resources on the zero to finals website including...

this video helpful if you did don't forget there's plenty of other resources on the zero to finals website including loads and loads of notes on various different topics that you might cover in medical school with specially made illustrations there's also a whole test

section where you can find loads of questions to test your knowledge and see where you're up to in preparation for your exams there's also a blog where I share a lot of my ideas about a career in medicine

and tips on how to have success as a doctor and if you want to help me out on YouTube you can always leave me a thumbs up give me a comment or even subscribe to the channel so that you can find out

when the next videos are coming out so I'll see you again soon