What are the Differences Between Rheumatoid and Osteoarthritis?

What are they:

Osteoarthritis (OA) is a mechanical injury where the cartilage that covers the ends of the bones in a joint has eroded and the result is that the joint no longer moves as smoothly.

Rheumatoid Arthritis (RA) is an autoimmune condition that occurs when an individuals’ own immune system attacks their joint, causing inflammation and pain. RA usually affects multiple joints.

How do they start?

OA tends to have a very gradual onset over the course of years. It can start as gradually as a small amount of stiffness and pain that gradually builds unless managed early. OA tends to be joint specific, larger joints like hip or knee and is often asymmetrical, in that it will develop on one side of the body but not the other.

RA comes on over weeks to months and tends to impact a growing number of joints in the body over time, often presenting in symmetrical, smaller joints like the hands and feet

What are the symptoms?

OA symptoms include pain, swelling, stiffness, and difficulty bearing weight through the joint. Because cartilage tissue does not have significant neural connectivity or pain receptors, cartilage degeneration often results in referred pain, or pain that occurs outside of the affected joint. For example, hip OA is often reported as groin area pain. Often early symptoms like stiffness are disregarded and ignored as minor.

RA symptoms include pain, swelling and inflammation, particularly in small joints of the body like wrist, hands and feet. Early symptoms can also be joint stiffness in the morning that lasts over 30 min, discomfort for at least 6 weeks, a general feeling of being unwell including loss of appetite, fatigue, or even a low level fever.

How are they Diagnosed

OA can be diagnosed through a physical examination and assessment of the symptoms and joint movement. Although a doctor will often order an X-Ray to determine the extent of OA, they are not necessary to diagnose and often do not show the early stages of OA. Because X-Rays show only calcified tissue like bone cartilage is not not seen. OA is determined by joint space narrowing indicating cartilage degeneration. Early stages of OA may not be visible on an X-Ray because not enough cartilage has eroded to cause joint space narrowing..

RA diagnosis also requires a physical examination and symptom assessment through your doctor. In some cases bloodwork will also be necessary to determine if inflammation is present. Once diagnosed, those with RA need to be referred to a rheumatologist for additional treatment, as left untreated the inflammation associated with RA can negatively impact organs as well as joints, resulting in irreversible damage.

What causes them (Risk factors)?

OA can be caused by several things, including long term asymmetrical pressure on a joint, such as with a muscle imbalance or limp. It can also be caused by a history of injury in a particular joint, surgery, or sedentary and static postures.

Cartilage relies on the synovial fluid within the joint for its nutrients. In order to get what it needs to flourish, the cartilage acts as a sponge, relying on the movement of the joints to compress the cartilage and squish out fluid that has already been drained of its nutrients, and then to absorb the nutrient rich synovial fluid. This means that someone who spends more of their day in one position (standing, sitting, kneeling) without moving is denying the joint cartilage its nutrients . As OA is often gradual onset, it is more prevalent as we age. It is also more common in women compared to men.

Unfortunately so far research has not been able to determine the exact cause of RA. There does seem to be a genetic component, but having the genetic markers associated with RA does not mean that you will necessarily develop symptoms. There is evidence that fluctuations in hormones can trigger the onset of RA, and women are 3x more likely to be diagnosed compared to men. Smoking has been shown to be significantly associated with onset and severity of RA.

How are they treated?

All stages of OA can benefit from physical rehabilitation. Due to the mechanical nature of this disease, exercises that help change movement patterns, fix muscle imbalances, and strengthen the surroundings muscles can go a long way to improving quality of life and reducing pain. Some people also benefit from the use of pain medications such as NSAIDs (non-steroidal anti-inflammatories) or corticosteroid injections. In cases where the disease has progressed past the point of being managed in less invasive ways, knee and hip replacement surgeries have been shown to be effective. Even for those where surgery is inevitable, physical rehabilitation is essential, because the stronger a person is going into surgery, the better their surgical outcomes are likely to be.

Anyone diagnosed with RA should be in the care of a rheumatologist. As a systemic disease,their is a risk to internal organs and joints if left untreated so the sooner an individual gets treated the better. A combination of medication and physical interventions can be used to support those with RA. Unlike OA where a predictable gradual loading and strengthening of a particular joint is effective, the physical rehabilitation for someone with RA has to be more nuanced. Physical activity can help manage pain and increase overall activity tolerance, but it needs to be moderated to fit the day to day capacity of the individual living with RA. If an individual is mid RA flare up, they will not tolerate as much as they would when not flared up, and trying to do the same workout will likely result in lengthening the flare up duration. It is important to scale any active program to meet the needs of the individual on that day.