Symptoms of Knee Osteoarthritis
The primary symptoms of knee osteoarthritis are joint pain, stiffness (particularly brief morning or inactivity stiffness), and functional limitations in joint movement, often accompanied by coarse crepitus and bony enlargement on examination. 1, 2
Core Symptomatic Features
Pain Characteristics
- Pain is typically activity-related or "pain on usage" rather than constant, though in severe cases rest pain and night pain may develop 1, 2
- Pain severity is variable and often fluctuates over time, with symptoms frequently being intermittent rather than continuous 1
- The pain serves as a major barrier to maintaining physical activity and is a leading cause of disability globally 3
Stiffness Pattern
- Morning stiffness or inactivity stiffness is present but characteristically mild and of limited duration (unlike inflammatory arthritis which causes prolonged morning stiffness) 1
- This brief stiffness pattern helps distinguish osteoarthritis from inflammatory conditions like rheumatoid arthritis 1
Functional Impairment
- Reduced joint mobility and limitations in movement are hallmark features, with patients experiencing decreased ability to perform daily activities 2, 4
- Functional impairment can be severe enough to significantly impact quality of life, work capacity (affecting 66% of US patients), and increase absenteeism 3
- Loss of valued activities such as walking for exercise and dancing commonly occurs 4
Physical Examination Findings
Observable Signs
- Coarse crepitus (grinding sensation) with joint movement is a characteristic finding on examination 2
- Bony enlargement at the joint is commonly present and palpable 2
- Tenderness at the joint line can be elicited on palpation 2
Advanced Disease Features
- In severe cases, joint deformity may develop as the disease progresses 2
- Symptomatic effusions (joint swelling) may occur, particularly during flares 1
Clinical Context
A confident clinical diagnosis can be made in adults aged over 40 years when these typical features are present, particularly when pain on usage is accompanied by only mild morning stiffness 1. The combination of age, characteristic symptom pattern, and physical findings allows for diagnosis without necessarily requiring imaging in straightforward cases, though radiographic evidence (joint space narrowing, osteophytes) confirms structural damage 1, 4.