Osteoarthritis: Causes and Treatment Options

What is osteoarthritis?

Osteoarthritis is a joint disease in which various causes lead to often progressive and partly irreversible damage (wear and tear) to the hyaline articular cartilage .

This leads to changes in the joint (subchondral bone) and its surrounding structures (capsule and ligaments, muscles).

J. Lengerke 21:37, May 27, 2009 (CEST), Roe-heberden, CC BY-SA 3.0 DE

Common symptoms, which usually increase gradually, include start-up pain and pain during exertion that worsens over time, movement restrictions, and stiffness, as well as possible contour enlargement, thickening, and swelling. Later, this can potentially lead to misalignments and instabilities.

We distinguish and refer to:

Primary osteoarthritis: The development is idiopathic (meaning without a tangible cause), so without additional influencing factors

Secondary osteoarthritis: As a result of another illness or cause (e.g., due to arthritis, trauma with joint injury)

Polyarthrosis: When multiple joints in your body are affected

Activated osteoarthritis: A "silent" osteoarthritis can suddenly cause Conditions due to an event (usually trauma, overloading). This is usually accompanied by signs of inflammation (swelling, effusion, overheating, resting pain). 

Development of osteoarthritis

There are various hypotheses for the development of degenerative changes in articular cartilage and osteoarthritis. It appears that osteoarthritis can arise and begin from both sides of the joint: on the one hand from the cartilage surface (especially with trauma, underloading, and overloading) and on the other hand simultaneously originating from the bone (shift in the growth zone).

The main causes are presumed to be:

• Reduced alternation between loading and unloading

• Increasing ossification of the articular cartilage

• Trauma

Reduced alternation between loading and unloading

We include underloading as well as age-related degeneration and overloading in this group.

As often mentioned, underloading is perhaps one of the greatest threats to hyaline articular cartilage in our Western world. Because we sit so much, our articular cartilage is no longer properly nourished. In the long run, this inadequate supply has negative effects on the structure and stability of hyaline cartilage! Cartilage cells are not sufficiently stimulated to synthesize activity due to the lack of pressure changes. And due to inadequate fluid transport from the subchondral bone into the cartilage, they also receive too few nutrients. As a result, the cells produce too little matrix, especially ground substance! Due to the missing ground substance, less water can be bound within the cartilage, which decreases the tension of the collagen network. The deformability of the cartilage increases. And due to this greater deformability, the stress on the individual collagen fibrils increases! This makes damage to them possible.

Age also plays a role here: as you age, you tend to move even less. And older cells produce less matrix and ground substance. Which intensifies this problem even further…

Overloading

If an undernourished and untrained cartilage is suddenly subjected to heavy loading, the limit of load capacity is quickly reached and exceeded.

The resulting overload has a traumatizing effect on the collagen network: the first area where damage frequently occurs is the transitional zone (see Blog Articular Cartilage Zone II). Through damage in this area, the transitional zone can suddenly bind more water (since it is no longer prevented from doing so by the now-defective collagen network). Due to this larger accumulation of water in Zone II, the tension on the superficial cartilage zone from below also increases and pushes it toward the joint surface. The cartilage becomes soft and deformable in this area, and it is only a question of time before damage manifests.

If cartilage material, even tiny wear particles, enters the joint fluid (synovia) and thus comes into contact with the capsule, your body perceives it as foreign material. The capsule reacts with inflammation (synovitis).

If pieces of cartilage detach, the holes and cracks known in osteoarthritis develop. Increasingly, the cartilage can no longer adequately perform its protective function, and the subchondral bone is exposed to increased stress. This also causes further damage and increasing exertion pain in these zones further down.

All these factors bring about changes in the cartilage itself. As a result, the collagen network in the articular cartilage can suffer damage and be qualitatively reduced. Through any reduced synthesis activity, matrix production can be diminished or disrupted, but changes can also originate from the bone or the vascular and nervous system. Or following accidents involving compression and heavy impacts with injuries and joint involvement: 

Ossification

Another cause of osteoarthritis can originate from changes in the bone. On X-rays, a narrowing of the joint space can be seen as the first sign. An enlargement of the mineralized cartilage zone with a decrease in the softer cartilage zone is also visible.

Due to this reduction of the soft area of the articular cartilage, which is supposed to absorb the pressure load on the underlying bone, the strain during mechanical stress is correspondingly greater. As a result, the load limit can be reached or exceeded more quickly, which in turn leads to damage to the collagen network.

Due to this thickening of the mineralized zone, the osmosis and diffusion processes between the bone and the cartilage zones are also reduced, which in turn leads to poorer synthesis activity—with the mentioned consequences and outcomes. 

Trauma

In addition to the above-mentioned, usually slow changes that lead to damage, trauma during sports or everyday life can naturally also injure and damage hyaline cartilage. These resulting injuries can lead to premature osteoarthritis.

Treatment options

The extent to which complete healing and regeneration of injured cartilage is possible depends on the size and progression of the injury.

In osteopathy and Physiotherapy at BodyLab Zurich, the focus lies—depending on the current status and phase—on analgesia, mobilization, unloading, and exercise. The often restricted joints and shortened muscles are treated and stretched using manual techniques, improving your range of motion. Through targeted exercises, muscle building, stability, and load capacity are improved.

Orthopedic insoles are another helpful tool to potentially improve your body mechanics and thus achieve pain reduction. Walking sticks can provide acute relief.

Patient education and instruction with home exercises and behavioral guidelines are also an essential part of therapy.

Special forms of osteoarthritis and their medical names

• Spondylarthrosis: facet joint osteoarthritis, osteoarthritis of the vertebral joints

• Omarthrosis:  shoulder joint (glenohumeral)

• Rhizarthrosis:  carpometacarpal joint of the thumb (CMC joint I)

• Bouchard osteoarthritis: proximal interphalangeal joint (PIP joint)

• Heberden osteoarthritis: distal interphalangeal joint (DIP joint)

• Coxarthrosis:  hip joint

• Gonarthrosis:  knee joint

Whenever you need us, we are here for you!

Your BodyLab team, your specialists for movement and Conditions of the body

Osteopathy and Physiotherapy | Rehabilitation and Training

Zurich Altstetten

You can find more on this on our page knee osteoarthritis.

Cover photo credit

J. Lengerke 21:37, May 27, 2009 (CEST), Roe-heberden, CC BY-SA 3.0 DE

"}