Knee Osteoarthritis: A Primer

Abstract

The purpose of this article is to provide a synopsis of the current medical understanding of knee osteoarthritis. We describe the prevalence, causes and associated risk factors, symptoms, diagnosis and classification, and treatment options. A quiz serves to assist readers in their understanding of the presented material.

Conflict of interest statement

Disclosure Statement

The author(s) have no conflicts of interest to disclose.

Figures

Figure 1A

Anterior-posterior (AP) radiograph of a left knee with mild osteoarthritis (OA; Kellgren and Lawrence Grade 1). The arrow indicates doubtful joint space narrowing and possible osteophytic lipping.

Figure 1B

AP radiograph of a left knee with moderate OA (Kellgren and Lawrence Grade 2). The arrow indicates definite osteophytes and possible joint space narrowing.

Figure 2A

Anterior-posterior (AP) radiograph of a left knee with moderate to severe osteoarthritis (OA; Kellgren and Lawrence Grade 3). The arrows indicate multiple osteophytes, definite joint space narrowing, sclerosis, and possible bony deformity.

Figure 2B

AP radiograph of a left knee with severe OA (Kellgren and Lawrence Grade 4), showing large osteophytes (downward arrow at right), marked joint space narrowing (upward arrow at left), severe bone sclerosis (asterisk), and definite bony deformity in medial tibial plateau.