Which feature distinguishes Kellgren-Lawrence grade 4 from grade 3?

Which feature distinguishes Kellgren-Lawrence grade 4 from grade 3?

• A. Large osteophytes
• B. Definite narrowing of joint space
• C. Some sclerosis
• D. Moderate multiple osteophytes

Answer: (A)

Kellgren-Lawrence grading uses radiographic features to stage knee osteoarthritis by severity. Grade 3 shows multiple osteophytes with definite joint space narrowing and some sclerosis, sometimes with deformity. Grade 4 represents more advanced disease, characterized by large osteophytes, marked joint space narrowing, severe sclerosis, and deformity. The feature that clearly distinguishes grade 4 from grade 3 is the presence of large osteophytes. Definite narrowing can occur in both grades, some sclerosis is more in grade 3, and moderate multiple osteophytes fit grade 3 rather than grade 4.

Kellgren-Lawrence grading uses radiographic features to stage knee osteoarthritis by severity. Grade 3 shows multiple osteophytes with definite joint space narrowing and some sclerosis, sometimes with deformity. Grade 4 represents more advanced disease, characterized by large osteophytes, marked joint space narrowing, severe sclerosis, and deformity. The feature that clearly distinguishes grade 4 from grade 3 is the presence of large osteophytes. Definite narrowing can occur in both grades, some sclerosis is more in grade 3, and moderate multiple osteophytes fit grade 3 rather than grade 4.