An Osteochondral defect is an area of damage involving joint cartilage and the bone directly beneath it. In plain terms, it is a “pothole” in the smooth joint surface, sometimes with weakened or injured underlying bone. It is most commonly discussed in the knee, but it can also occur in other joints such as the ankle. Clinicians use the term in orthopedic and sports medicine settings to describe a specific type of joint surface injury and to guide evaluation and treatment planning.

Loose bodies are free-floating pieces of tissue inside a joint. They most often involve small fragments of cartilage, bone, or a mix of both. They are commonly discussed in knee care, especially when symptoms feel “mechanical,” like catching or locking. Clinicians use the term to describe a finding that can help explain pain, swelling, or intermittent loss of motion.

A Degenerative meniscus tear is a wear-related tear in the knee’s meniscus cartilage. It often develops gradually rather than from a single twist or impact. It is a common clinical term used in orthopedics, sports medicine, and physical therapy when evaluating knee pain in adults.

Meniscal degeneration is gradual wear-and-tear change within the knee’s meniscus tissue. It is commonly described on MRI reports and in orthopedic clinic notes for knee pain. It can occur with aging, repetitive loading, or alongside osteoarthritis. It helps clinicians explain symptoms and choose an appropriate evaluation and care pathway.

A Bone marrow lesion is an MRI finding in the bone near a joint. It often appears as a “bone marrow edema–like” signal change rather than a true fluid pocket. In knee care, it is commonly discussed in osteoarthritis, overuse injuries, and trauma. Clinicians use it to help explain pain patterns and to guide further evaluation.

Bony edema is a medical term that describes extra fluid within bone marrow. It is most commonly identified on MRI scans rather than on X-rays. In the knee, it often appears near areas of impact, overload, or cartilage wear. Clinicians use it as a clue to what may be causing pain or inflammation.

Subchondral cysts are small cavities in the bone just beneath joint cartilage. They are most often seen on imaging in joints affected by wear-and-tear arthritis. In the knee, they commonly appear near the ends of the femur or tibia. Clinicians use the term to describe an imaging finding that helps characterize joint disease.

Subchondral sclerosis is a term used to describe increased bone density just beneath a joint’s cartilage surface. It is most often reported as an imaging finding on X-ray, CT, or MRI. It commonly appears in joints affected by osteoarthritis, including the knee. It helps clinicians describe how a joint is responding to stress, cartilage loss, or altered load-bearing.

Osteophytes are bony outgrowths that form along the edges of a joint. They are often called “bone spurs,” although they are part of the bone itself. They most commonly develop in joints affected by osteoarthritis, including the knee. Clinicians use the presence and location of Osteophytes as a clue to joint stress and degeneration.

Joint space narrowing is a term used in medical imaging reports to describe a reduced gap between two bones in a joint. It is most commonly discussed when reviewing weight-bearing X-rays of the knee, hip, or hand. In simple terms, it can suggest that the “cushion” of cartilage or meniscus in that joint is thinner or less effective. Clinicians use it as one piece of information when evaluating arthritis, injury effects, and joint degeneration.