What is Knee Osteoarthritis?
Knee osteoarthritis (OA) is a degenerative joint disease that occurs when the protective cartilage cushioning the ends of your bones wears down over time. As the cartilage deteriorates, bones may rub directly against each other, causing pain, stiffness, and reduced mobility.
Often called “wear-and-tear” arthritis, knee OA is the most common form of arthritis, affecting over 32 million Americans. While it can occur at any age, the risk significantly increases after age 50.
Understanding the Stages of Knee Osteoarthritis
Knee OA progresses through four distinct stages, each requiring different treatment approaches:
Stage 1: Minor
- Minimal cartilage damage
- Little to no pain during daily activities
- X-rays may show small bone spurs
- Treatment focus: Lifestyle modifications, exercise
Stage 2: Mild
- Noticeable cartilage wear
- Pain after prolonged activity
- Morning stiffness lasting less than 30 minutes
- Treatment focus: Physical therapy, over-the-counter pain relief
Stage 3: Moderate
- Significant cartilage erosion
- Frequent pain during walking, climbing, or kneeling
- Joint swelling after activity
- Noticeable stiffness after sitting
- Treatment focus: Prescription treatments, viscosupplementation (gel injections)
Stage 4: Severe
- Near-complete cartilage loss (bone-on-bone)
- Chronic pain affecting daily activities
- Significant joint stiffness and instability
- Treatment focus: Advanced injections, surgical evaluation
Symptoms to Watch For
Knee osteoarthritis develops gradually, and symptoms often worsen over time. Early recognition allows for earlier intervention and better outcomes.
Common Symptoms
- Pain that increases with activity and improves with rest
- Stiffness especially in the morning or after sitting
- Swelling around the joint
- Decreased range of motion affecting daily activities
- Grinding or popping sensations during movement
- Instability or feeling that the knee might “give out”
When to Seek Treatment
Consider seeing a specialist if you experience:
- Pain that doesn’t improve with rest or over-the-counter medications
- Stiffness lasting more than 30 minutes
- Difficulty performing daily activities
- Noticeable changes in walking pattern
- Sleep disruption due to knee pain
Risk Factors You Can and Can’t Control
Non-Modifiable Risk Factors
- Age: The primary risk factor; cartilage naturally degrades over time
- Gender: Women are more likely to develop knee OA, especially after menopause
- Genetics: Family history increases your risk
- Previous injuries: Joint trauma can accelerate cartilage breakdown
Modifiable Risk Factors
- Weight: Each pound of excess weight adds 3-4 pounds of pressure on your knees
- Occupation: Jobs requiring repetitive kneeling, squatting, or heavy lifting
- Activity level: Both inactivity and overuse can contribute to OA
- Muscle strength: Weak quadriceps increase stress on knee joints
Diagnosis
Proper diagnosis is essential for developing an effective treatment plan. A thorough evaluation typically includes:
Clinical Examination
- Review of symptoms and medical history
- Physical examination of knee function
- Assessment of range of motion and stability
- Observation of walking pattern
Imaging Studies
- X-rays reveal joint space narrowing and bone spurs
- MRI (when needed) shows cartilage damage and soft tissue conditions
- Fluoroscopic imaging ensures precise injection placement for treatments
Treatment Options
Modern knee osteoarthritis treatment follows a stepped approach, starting with conservative options and progressing as needed.
Conservative Treatments
- Physical therapy to strengthen supporting muscles
- Weight management to reduce joint stress
- Low-impact exercise like swimming and cycling
- Assistive devices such as braces or shoe inserts
- Over-the-counter medications for pain relief
Medical Treatments
- Viscosupplementation (gel injections): Hyaluronic acid injections to restore joint lubrication and cushioning
- Corticosteroid injections: Short-term anti-inflammatory relief
- Prescription medications: For pain and inflammation management
Surgical Options (When Conservative Treatment Fails)
- Arthroscopy: Minimally invasive cleaning of the joint
- Osteotomy: Bone realignment to shift weight away from damaged areas
- Partial knee replacement: Replacing only the damaged portion
- Total knee replacement: Complete joint replacement
Why Treatment Precision Matters
For injection-based treatments, accuracy directly impacts outcomes. Studies show that “blind” injections (without imaging guidance) miss the joint space up to 30% of the time.
Fluoroscopic-guided injections use real-time X-ray imaging to ensure:
- Precise needle placement within the joint space
- Optimal medication distribution
- Higher success rates and better outcomes
- Reduced need for repeat procedures
Living with Knee Osteoarthritis
While there’s no cure for knee OA, many patients successfully manage their symptoms and maintain active, fulfilling lives through:
- Consistent exercise tailored to your condition
- Weight management to reduce joint stress
- Appropriate treatment based on your specific stage
- Regular monitoring to adjust treatment as needed
Questions to Ask Your Healthcare Provider
- What stage is my knee osteoarthritis?
- What treatment options are appropriate for my condition?
- Do you use imaging guidance for injections?
- What outcomes can I realistically expect?
- How can I slow the progression of my OA?