Degenerative Joint Disease (DJD) is the medical term for osteoarthritis (OA), the most common form of arthritis. This chronic, progressive disorder primarily attacks the joints, involving the entire joint structure. DJD is characterized by the slow, irreversible deterioration of the joint’s protective tissues. It is a leading cause of chronic pain and mobility limitations, especially in older adults.
Understanding Degenerative Joint Disease
DJD is fundamentally a mechanical failure of the joint, triggered by the breakdown of articular cartilage. This smooth tissue covers the ends of bones within a joint, allowing them to glide frictionlessly. In DJD, chondrocytes, the cells responsible for maintaining this cartilage, fail to keep up with the damage, leading to the tissue becoming frayed, thin, and eventually eroded.
The loss of cartilage exposes the underlying bone surfaces, creating painful bone-on-bone friction during movement. The body attempts to stabilize the compromised joint by growing extra bone tissue at the margins, forming bony projections known as osteophytes, or bone spurs. These structural changes—cartilage loss, joint space narrowing, and osteophyte formation—are the hallmarks of DJD seen on X-rays.
DJD is classified as a non-inflammatory or “wear-and-tear” condition, though secondary inflammation occurs as a response to mechanical damage. This distinguishes it from inflammatory arthropathies, such as Rheumatoid Arthritis. Inflammatory arthritis is a systemic, autoimmune disorder where the immune system attacks the joint lining, or synovium, leading to widespread inflammation and joint destruction.
What Factors Lead to DJD
The development of DJD is a complex process driven by a combination of non-modifiable and modifiable factors. Advanced age is the primary non-modifiable risk, as the body’s natural capacity for cartilage repair declines over time. Genetic predisposition also plays a substantial role, with specific inherited traits potentially affecting the quality of collagen within the cartilage.
Gender is another non-modifiable factor, as women over the age of 50 are more commonly affected by DJD than men, particularly in the knees and hands. Prior joint injury or trauma, such as a ligament tear or fracture, significantly increases the risk of developing post-traumatic arthritis years later. This initial trauma disrupts the joint’s biomechanics, accelerating the degenerative process.
Excess body weight is a major modifiable risk factor, impacting joints through both mechanical and biochemical pathways. For example, each pound of excess weight translates to approximately four pounds of additional pressure on the knee joint when walking. Adipose tissue also produces inflammatory chemicals called adipokines, which can contribute to cartilage breakdown even in non-weight-bearing joints. Repetitive stress from certain occupations or high-impact sports can also contribute to DJD by continually overloading the joint structure.
Common Indicators of Joint Degeneration
The primary indicator of joint degeneration is a deep, aching joint pain that typically worsens with activity and lessens with rest. While early pain is activity-dependent, as the condition progresses, pain may become persistent, even occurring at night or during rest. This pain results from irritation to the joint capsule and underlying bone, which contain nerve endings, since cartilage itself is devoid of nerves.
Joint stiffness is also common, often most noticeable upon waking up or after prolonged periods of inactivity. This stiffness is generally short-lived, resolving within 30 minutes of moving the joint, which distinguishes it from the longer-lasting stiffness associated with inflammatory arthritis. A tell-tale sign of DJD is crepitus, a grinding, cracking, or crunching sensation or sound heard during joint movement.
Crepitus results from the rough, irregular surfaces of the damaged cartilage and exposed bone ends rubbing against each other. The condition most frequently affects large, weight-bearing joints—specifically the knees, hips, and spine—but is also common in the small joints of the hands. Patients may also observe a loss of flexibility or a reduced range of motion, which can impede daily activities.
Approaches to Managing DJD
Management strategies for DJD focus on controlling pain, improving function, and slowing the progression of joint damage. Lifestyle modifications form the basis of treatment, with weight reduction being highly recommended to decrease the mechanical load on weight-bearing joints. Low-impact exercises like swimming, cycling, or Tai Chi are encouraged to maintain joint flexibility and strengthen the surrounding muscles without causing excessive stress.
Physical therapy plays a significant role in improving strength, range of motion, and joint stability. Pharmacological treatments manage pain and inflammation, including over-the-counter pain relievers like acetaminophen for mild pain. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, can be taken orally or applied topically to reduce inflammation.
In cases of localized pain and swelling, healthcare providers may recommend injectable treatments. Corticosteroid injections deliver powerful anti-inflammatory medication directly into the joint for short-term pain relief, though the effects are temporary. Viscosupplementation involves injecting hyaluronic acid, a substance similar to the joint’s natural lubricating fluid, into the joint space, a procedure primarily approved for the knee.
For severe, end-stage DJD where conservative measures have failed, surgical intervention may be necessary to restore mobility. Arthroscopy is a minimally invasive procedure used to clean out the joint or remove loose cartilage fragments. For advanced disease involving significant bone damage, arthroplasty, or total joint replacement, is the definitive solution, replacing damaged joint surfaces with artificial components made of metal, plastic, or ceramic.