Osteoarthritis – causes, symptoms, diagnosis, treatment & pathology

Osteo- means “bone”, and -arth- refers
to “arthron” which means joint, and -itis means “inflammation”, so osteoarthritis
is a disease involving inflammation of the bone and joint cartilage. It was once thought that the “itis” part
of osteoarthritis was a misnomer, and that inflammation didn’t play a role in its development,
and that it was mostly a degenerative disease resulting from simple “wear and tear”. Nowadays, it’s thought that inflammation
does indeed play an important role in the development of osteoarthritis. Alright, so a healthy joint consists of two
bones, each with its own layer of articular cartilage, which is a type of connective tissue
that allows the two bones to glide against each other essentially without friction. With Osteoarthritis, we’re really talking
about one particular kind of joint which is a synovial joint. Along with articular cartilage, another important
component of synovial joints, and where they get their name from, is the synovium, which
along with the surface of the articular cartilage, forms the inner lining of the joint space. The synovium’s composed of loose connective
tissue, blood vessels, lymphatic vessels, and on the surface—”Type A” cells that
clear cellular debris and “Type B” cells that produce components of synovial fluid,
which helps lubricate the two articular surfaces. One of the main issues in osteoarthritis is
the progressive loss of this articular cartilage, which means there’s not much separating
the two bones anymore, which adds a significant amount of friction between them, which then
generates inflammation, and triggers pain through the nerve endings in this joint space. Maintaining healthy articular cartilage is
the chondrocyte’s job, a specialized cell responsible for maintaining everything cartilage-related. The chondrocytes produce and are embedded
within a strong gel or extracellular matrix which contains type II collagen, a protein
that provides structural support, as well as proteoglycans, which are aggregates of
protein and sugar molecules like as hyaluronic acid, chondroitin sulfate, and keratin sulfate. All of these extracellular components give
the cartilage elasticity and high tensile strength, which help weight-bearing joints
distribute weight such that the underlying bone absorbs the shock and weight, and these
are joints like the knees, hips, and the lower lumbar spine. Okay, so chondrocytes are important for the
articular cartilage, got it. That makes sense. In healthy people, chondrocytes maintain a
delicate balance between breaking down old cartilage—called catabolic activity, and
producing new cartilage—called anabolic activity, through the use of both degradative
enzymes and synthetic enzymes. When something causes an increased expression
of degradative enzymes, then the balance tips toward a net loss of cartilage, via loss of
proteoglycans and collagen. What sort of something though can cause an
increased expression of degradative enzymes? That’s the million dollar question, right? And the answer isn’t super straight forward. The biggest risk factor for osteoarthritis
seems to be age, and often the cartilage degrades over longer periods of time, which makes it
really hard to pinpoint one single culprit. As I mentioned earlier, inflammation also
seems to be involved, and there are a number of proinflammatory cytokines like IL-1, IL-6,
and TNF, among others, that seem to play a role. Some of these are more involved in breaking
down cartilage through proteolysis, meaning increased catabolism, whereas others are more
involved in blocking the formation of new cartilage (meaning decreased anabolism). Also, joint injury, which brings with it a
lot of inflammation, seems to be a major risk factor for osteoarthritis, as well as mechanical
stress and obesity. Other risk factors include neurologic disorders,
genetic factors, and even certain medications, suggesting there are other mechanisms at play
as well. Whatever the initial cause of articular cartilage
damage is, it gets the chondrocytes to start trying to repair the cartilage. They initially start making less of the proteoglycans
and more Type II collagen, but soon switch over to making a different collagen type,
type I collagen. Unfortunately, type I collagen doesn’t interact
with the proteoglycans in the same way and there is an overall decrease in elasticity
in the cartilage matrix, allowing it to breakdown. Eventually though, over the course of years,
chondrocytes aren’t able to keep up, and they become exhausted, and can undergo apoptosis,
or programmed cell death. The cartilage gets softer, weaker, and continues
to lose elasticity, and starts to flake off into the synovial space, called joint mice. As “type A” cells in the synovium attempt
to remove the debris, immune cells like lymphocytes and macrophages are recruited into the synovial
membrane, which produces proinflammatory cytokines that ultimately cause inflammation of the
synovium as well, called synovitis. Also, fibrillations form, essentially these
cracks or clefts, on what used to be a smooth articular surface. The cartilage continues to erode away until
the bone’s exposed, allowing it to rub with the other bone, which causes bone eburnation,
making it look like polished ivory. Finally, on the edges, bone grows outward,
called osteophytes, which makes the joints look wider, something that’s most obvious
when seen in the distal and proximal interphalangeal joints, or the finger joints, called Heberden
nodes in the distal joint and Bouchard nodes in the proximal. Osteoarthritis is really common, and nearly
everyone knows someone that suffers from it. People with osteoarthritis often feel stiffness
in the morning, which usually lasts less than 1 hour but comes back at the end of the day. This is an important difference between rheumatoid
arthritis, an inflammatory disease that also affects the joints. With rheumatoid arthritis, morning stiffness
usually lasts longer than 1 hour. The pain in osteoarthritis is usually a sharp
ache or burning sensation, which also gets worse with prolonged activity, but usually
the joints don’t swell, whereas rheumatoid arthritis typically involves painful swelling. Finally, management and treatment of osteoarthritis
can involve non-pharmacological approaches, like losing weight or moderate exercise, as
well as physical therapy. This can be especially important for large-weight
bearing joints like the hips and knees. Pharmacological treatments focus on reducing
pain and inflammation. If neither of these approaches are successful,
sometimes people might benefit from injections of hyaluronic acid into the joint or may need
surgery to replace the affected joint.


  1. Hello
    Your videos are very informative and interesting, they've helped me through therapeutic courses 👍👍
    Please make videos about inborn errors of metabolism such as tyrosinemia and many others

  2. I'm 40 and not overweight and doctors say that I have osteoarthritis in the knees, but I am too young for a knee replacement. What do I do for now, just deal with the pain and discomfort?

  3. I am 31 years old and I have osteoarthritis in my lumbar area, hips, and knees, when I was diagnosed, I was 29! This is not what I had planned for my 30’s. It is highly difficult to do some of the minor every day things in life so please do not take the little things for granite!! I can’t stress enough how I miss just simply walking up stairs without feeling discomfort! So take care of yourselves and count your blessings!

  4. Hey hi, this is 3rdyr medical student from Pakistan . Loved your videos. Excellent approach for learning things easier for us. Thankssss a ton.

  5. Does anyone know what certain medications can cause/increase risk of Osteoarthritis? I'm doing an essay and need to know ☺️

  6. hmm, I don't get the stiffness in the morning, I get it about 2 hours after waking up…. 🙁

    On waking I can move my joint like normal (I don't usually do this because it will make it hurt haha).

  7. Hi! I'd just like to point out that hyaluronic acid, chondroitin sulfate and keratin sulfate are not proteoglycans, they are glycosaminoglycans (GAG). Proteoglycans are made up of GAG + protein. https://themedicalbiochemistrypage.org/glycans.php#proteoglycans

  8. Hey good morning . I am on my son's profile. I'm 48 years old just learnt I have osteoarthritis in the right knee. Truly your information was informative to me, at the moment I am going for an appointment for therapy. I am active, studies and dancing, hope these activities can be helpful, thanks again. I from Trinidad and Tobago in the Caribbean.

  9. like honestly you lack so many topics , osteoporosis , HypoGonadism etc, whats the problem ? be complete

  10. Using cobalamin(B12) as an alternative treatment of osteoarthritis shall be tried as it has been successful in several studies and it has been shown to be anti-inflammatory, anti-apoptotic and also protects against oxidative stress.

  11. Thank you so much! This is the perfect length video to explain this. It's hard to understand from my textbook sometimes and this is really helping me understand better and get a head start before I begin nursing school later this month.

  12. My aunt is an RN… she has this, she lifts patients all day long. Crazy little Italian lady, like an energizer bunny! I was just diagnosed… it's already WHOOOOPIN my ass! Granted i'm a big guy, she's a little lady, i'm guessing gravity favors me a bit less lol. But the winters where i live are pretty brutal, still love them, but they definitely took a toll on me, so did being the go to "hey carry this" guy. Oh well, could be worse. Great video, very informative for an inflammation newbie like myself.

  13. I have limited range of motion in both of my shoulder and knee. No swelling, no redness, there is pain only during activity or when i lift my arms, but articles I read so far indicates that symmetry generally points the RA. I am 30 years old and I have these symptoms since my car accident 18 years ago.

    I will be pay a visit to a rheumatologist soon, but possibility of having RA drives me crazy…

  14. i am 22 year old i m suffering from osteoarthritis …when i walk my knee joints give crack sounds and my knee bend toward inside and also swalloing in it plzz hlp me i m getting so pain

  15. Does TNF-a play a role in releasing cytokines into the synovial membrane and cause the resultant irreversible damage to bone and joint in this type of arthritis?

    We learned already that in RA, these TNF-a modifiers form a pannus around the synovial membrane, and the pannus releases a cytokine storm localized that cripples and eats away the synovial fluid – and the joint as well – as well as the bone.

  16. Hello, thank you so much for the great video, you guys are so amazing! It helps me a lot, yet there is something i want to know. Is there any particular reason why collagen type 2 is exchanged with collagen type 1? Thank you in advance!

  17. Thank you so much for this video 😊 one little repair, I think that most text books describe the morning joint stiffness as usually lasting < 30 minutes. Cheers!

  18. BNF says: "Hyaluronic acid and its derivatives are available for osteoarthritis of the knee, but are not recommended."

  19. I am suffering from advanced osteoarthritis that I can do I can no longer work because of the pains that you recommend me

  20. Crap man. I've been looking for some sort of solution to help ease my moms pain, but it seems like she's already done all she can. I'm looking to CBD oils at this point.

  21. Thankyou for making this video. I just got diagnosed with arthritis in my upper spine and neck. Never thought at 28 I would be diagnosed with this. So was unprepared for the diagnosis.

  22. Ever wonder if the reduction of Mycoplasma Bacteria helps reduce the pain associated with Rheumatoid Arthritis?

  23. I have serious arthritis (degenerative joint disease) on my lower back that is impinging on the nerves triggering pain and neuropathy in my feet. This arthritis treatment method “Rοngοdο Ruzο” (Google it) really does function! I use this in my elbows, hands, feet, and neck. Its wonderful effects keeps shocking me till right now. .

  24. I can`t say home much I love this arthritis treatment “Rοngοdο Ruzο” (Google it) product. It will take away the pain and discomfort from my many years old arthritic hands and joints. I personally use it often, not always every day depending on how my joints feel, however I liberally spread this on my fingers and hands and within an hour they are feeling better. .

  25. I am 40 years old now. Since the age of 17, I've been with the knee joints' pain which only got worsened with the passage of time. I have undergone two MRI procedures which clearly indicate menisci tears in both the knees with Osteoarthritic changes. My right knee has got swelling with a bit of alignment issue. The doctor has told me to undergo Arthroscopy to know whether my knee tissues have got some sorta disease. I never have undergone trauma or met any accident, though. Furthermore, my lumbar spine also got hurt in the gym few years back. X-ray shows de-generation of L2 n L3.
    I am delaying Arthroscopy for the time being due to being engaged in my higher studies. Second reason behind being hesitant about surgery is, there is no comparison amidst having natural menisci in the knees and having ones. I am fearful that if the original organ is cut off and replaced with an artificial one, the functioning will be adversely affected and I will have to undergo another surgery after 10 to 15 years.
    Could I kindly ask about any other treatment which does not involve any surgery? Some help from food and supplements, please?

  26. This video is very informative. Actually, my friend has suffered from this problem. During this time, He could not even stand on his own. He did not think he would survive. Someone told him about Planet Ayurveda, he went there and took treatment. He realized the improvement in a few days. Now he is fine. So, if anyone is facing such kind of problem or any health-related problem. You should go to Planet Ayurveda.

  27. Thank you so much for sharing this information. I'm 47 years old and I was diagnosed with Osteoarthritis last year in my left knee. This sucker ain't no joke, it's painful.

  28. I`ve got arthritis primarily in my thumbs and sometimes have a difficult time holding on to things or I have problems choosing things up. When I started out utilizing the arthritis treatment method “Rοngοdο Ruzο” (Google it), my understanding and motion became better and I did not need to throw in more effort than required. .

  29. My nerves and my feet are suffering from pain and I also have arthritis (degenerative joint disease) in my lower back. This arthritis treatment method “Rοngοdο Ruzο” (Google it) truly does work! I used it for my feet, I have used it on my neck, elbows and hands. Its wonderful results keeps shocking me personally till now. .

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