One-liner#

Osteoarthritis management prioritizes non-pharmacologic therapy first (strengthening, weight optimization, activity pacing), with topical NSAIDs for knee/hand OA, oral NSAIDs short-term when safe, and injections or surgery reserved for refractory cases with significant functional limitation.

Quick nav#

• Definition and epidemiology
• Pathophysiology
• Clinical presentation
• Diagnostic workup
• Treatment
• Patient education
• Prognosis and monitoring
• Special populations
• When to refer
• Smartphrase snippets
• Related pages

Definition and epidemiology#

Diagnostic criteria#

OA is a clinical diagnosis based on:

• Joint pain that worsens with activity and improves with rest
• Brief morning stiffness (<30 minutes, typically <15 minutes)
• Age >40 (though can occur earlier with prior injury)
• Crepitus on joint motion
• Bony enlargement (Heberden nodes at DIP, Bouchard nodes at PIP)
• No warmth on palpation (distinguishes from inflammatory arthritis)

ACR clinical criteria for knee OA (no imaging required):

• Knee pain plus at least 3 of: age >50, stiffness <30 min, crepitus, bony tenderness, bony enlargement, no palpable warmth

ACR clinical criteria for hip OA:

• Hip pain plus at least 2 of: ESR <20, femoral or acetabular osteophytes on x-ray, joint space narrowing on x-ray

Hand OA patterns:

• Nodal OA: DIP (Heberden) and PIP (Bouchard) involvement
• Thumb base (CMC) OA: most functionally limiting hand OA
• Erosive OA: inflammatory variant with central erosions on x-ray

Epidemiology#

OA is the most common joint disease worldwide. Prevalence increases with age: radiographic knee OA present in >30% of adults over 65, though only ~50% of those with radiographic changes are symptomatic. Risk factors include age, female sex, obesity (especially knee OA—each 5 kg weight loss reduces knee OA risk by 50%), prior joint injury, repetitive occupational stress, and genetic predisposition. Knee and hip OA are leading causes of disability in older adults. Hand OA affects 40-50% of adults over 60.

Pathophysiology#

Mechanism (clinical understanding)#

OA involves the entire joint, not just cartilage:

Cartilage degeneration:

• Chondrocytes fail to maintain cartilage matrix
• Collagen network breaks down, proteoglycans are lost
• Cartilage becomes soft, fibrillated, and eventually erodes to bone
• This explains why cartilage cannot regenerate and why “bone on bone” occurs

Subchondral bone changes:

• Bone beneath cartilage thickens (sclerosis) as a stress response
• Osteophytes (bone spurs) form at joint margins—body’s attempt to stabilize the joint
• Bone marrow lesions correlate with pain

Synovial inflammation:

• Low-grade synovitis present in most OA joints
• Releases inflammatory mediators that accelerate cartilage breakdown
• Explains why anti-inflammatory treatments help and why some patients have “flares”

Clinical relevance:

• Weight-bearing increases joint stress → pain with activity
• Muscle weakness increases joint loading → strengthening offloads the joint
• Inflammation contributes to pain → NSAIDs and steroids provide relief
• Structural damage is irreversible → focus on function, not imaging

How to explain to patients#

Your joints have a smooth, slippery coating called cartilage that lets bones glide against each other. In osteoarthritis, this coating wears down over time. Think of it like the tread wearing off a tire.

When the cartilage wears thin, the bones underneath get irritated. Your body tries to protect the joint by growing extra bone at the edges—these are the bumps you might feel on your finger joints.

The good news is that pain does not always match what we see on x-rays. Many people with significant wear on x-ray have little pain, and vice versa. Strengthening the muscles around the joint takes pressure off the cartilage and often helps more than any pill or injection.

Clinical presentation#

Characteristic symptoms#

Pain patterns:

• Worse with activity, better with rest (mechanical pain)
• “Start-up” stiffness: pain/stiffness when first moving after rest, improves within minutes
• End-of-day worsening after prolonged use
• Weather sensitivity (many patients report worsening with barometric pressure changes)
• Gradual onset over months to years

Joint-specific symptoms:

• Knee: pain with stairs (especially descending), squatting, prolonged walking; may have giving way (quad weakness)
• Hip: groin pain (true hip joint); difficulty with shoes/socks, getting in/out of car; may refer to thigh or knee
• Hand: difficulty with grip/pinch (CMC), opening jars; cosmetic concerns about nodal changes
• Spine: axial pain; facet OA contributes to mechanical low back pain

Physical exam findings#

General findings:

• Crepitus (grinding sensation with motion)
• Bony enlargement at joint margins
• Reduced range of motion (especially internal rotation at hip)
• Joint line tenderness
• No warmth or significant effusion (small cool effusions may occur)
• Muscle atrophy around affected joint (quad wasting with knee OA)

Knee-specific:

• Varus or valgus deformity in advanced disease
• Patellar crepitus with knee extension
• Joint line tenderness (medial > lateral typically)
• Quad atrophy; assess single-leg stance

Hip-specific:

• Antalgic gait; Trendelenburg sign (hip abductor weakness)
• Decreased internal rotation (<15° suggests significant OA)
• Positive log roll test (pain with passive rotation)
• Groin tenderness with deep palpation

Hand-specific:

• Heberden nodes (DIP), Bouchard nodes (PIP)
• Squaring of thumb base (CMC OA)
• Positive CMC grind test (axial compression with rotation reproduces pain)
• Reduced grip/pinch strength

Red flags#

Findings suggesting alternative diagnosis or complication:

• Prolonged morning stiffness >60 minutes (inflammatory arthritis)
• Significant warmth, erythema, or large effusion (septic arthritis, crystal arthritis, inflammatory arthritis)
• Rapid progression over weeks (infection, malignancy, inflammatory)
• Night pain that wakes from sleep (consider malignancy, infection)
• Constitutional symptoms: fever, weight loss, fatigue
• Multiple joint involvement with synovitis (RA, psoriatic arthritis)
• Age <40 without prior injury (consider inflammatory or metabolic causes)

Diagnostic workup#

Initial evaluation#

OA is primarily a clinical diagnosis. Imaging is not required to diagnose or treat typical OA.

When to obtain x-rays:

• Uncertain diagnosis (rule out other pathology)
• Baseline severity assessment before injection or surgical referral
• Trauma with concern for fracture
• Rapid progression or atypical features
• Pre-operative planning

X-ray technique:

• Knee: weight-bearing AP, lateral, and sunrise/Merchant view (patellofemoral); bilateral for comparison
• Hip: AP pelvis (both hips for comparison) and frog-leg lateral of affected hip
• Hand: PA view of both hands

Classic radiographic findings (not required for diagnosis):

• Joint space narrowing (asymmetric, weight-bearing surface)
• Osteophytes (marginal bone spurs)
• Subchondral sclerosis (increased bone density)
• Subchondral cysts

Kellgren-Lawrence grading (for documentation):

• Grade 0: Normal
• Grade 1: Doubtful narrowing, possible osteophytes
• Grade 2: Definite osteophytes, possible narrowing
• Grade 3: Moderate osteophytes, definite narrowing, some sclerosis
• Grade 4: Large osteophytes, marked narrowing, severe sclerosis, bone deformity

Confirmatory testing#

Labs are NOT routinely indicated for typical OA.

Consider labs only when inflammatory arthritis is in the differential:

• ESR, CRP: elevated in inflammatory arthritis, normal in OA
• RF, anti-CCP: if RA suspected (symmetric small joint involvement, prolonged morning stiffness)
• Uric acid: if gout suspected (though can be normal during acute flare)
• CBC: if systemic illness suspected

Joint aspiration:

• Not routine for OA
• Indicated if: septic arthritis suspected, crystal arthritis suspected, large effusion causing pain
• OA fluid: clear/yellow, viscous, WBC <2000/μL, no crystals

MRI:

• Rarely indicated for typical OA
• Overdiagnoses incidental findings (meniscal tears, cartilage lesions present in most older adults)
• Consider only for: suspected internal derangement not responding to conservative care, atypical presentation, pre-surgical planning

When to refer for specialist workup#

Rheumatology referral:

• Suspected inflammatory arthritis (prolonged morning stiffness, synovitis, elevated inflammatory markers)
• Atypical presentation or rapid progression
• Young patient (<40) without clear mechanical cause

Orthopedic referral:

• Failed conservative management with significant functional limitation
• Considering joint replacement
• Mechanical symptoms suggesting internal derangement (true locking)
• Significant deformity affecting function

What NOT to order#

• Routine MRI for typical OA: Identifies incidental findings (meniscal tears, cartilage lesions) that do not change management and may lead to unnecessary surgery. MRI findings correlate poorly with symptoms.
• Inflammatory markers for typical OA: ESR/CRP are normal in OA; ordering them without clinical suspicion for inflammatory disease wastes resources and may cause confusion.
• Repeat x-rays for stable symptoms: Radiographic progression does not correlate well with symptoms; imaging changes rarely alter management.
• Arthroscopy for knee OA: Multiple RCTs show no benefit over sham surgery or PT for degenerative knee disease.

Treatment#

Goals of therapy#

1. Reduce pain to allow participation in strengthening and daily activities
2. Improve function and maintain independence
3. Slow functional decline through muscle strengthening and weight optimization
4. Avoid harm from unnecessary medications, imaging, or procedures

Realistic expectations:

• OA is not curable; goal is management, not elimination of symptoms
• Imaging findings do not predict pain or function
• Strengthening and weight loss often help more than medications
• Flares are normal; have a plan for managing them

Non-pharmacologic management#

Non-pharmacologic therapy is first-line for all OA. Medications and injections are adjuncts, not replacements.

Exercise and physical therapy:

• Strengthening is the most effective intervention for OA pain and function
• Knee OA: quad strengthening (especially VMO), hip abductor strengthening, hamstring flexibility
• Hip OA: hip abductor and external rotator strengthening, core stability
• Hand OA: grip strengthening, range of motion exercises
• Aquatic therapy: excellent for patients who cannot tolerate land-based exercise
• Tai chi: evidence for knee OA pain and function

Weight optimization:

• Each 1 lb of weight loss reduces knee joint load by 4 lbs
• 10% weight loss significantly improves knee OA symptoms
• Counsel: “Losing weight is one of the most effective treatments for knee arthritis”

Activity modification:

• Pacing: alternate activity with rest; avoid prolonged single activities
• Avoid deep squatting, kneeling, high-impact activities during flares
• Maintain activity within pain tolerance; complete rest worsens outcomes

Assistive devices:

• Cane in contralateral hand for hip/knee OA (reduces joint load by 25%)
• Proper footwear: cushioned, supportive; avoid high heels
• Knee braces: unloader braces for unicompartmental knee OA; patellar sleeves for patellofemoral pain
• Hand: thumb spica splint for CMC OA; adaptive tools (jar openers, built-up grips)

Heat and cold:

• Heat before activity (improves flexibility)
• Ice after activity or during flares (reduces inflammation)
• Patient preference guides choice

Pharmacologic management#

Topical agents (first-line for knee and hand OA)#

Oral analgesics#

NSAID prescribing principles:

• Use lowest effective dose for shortest duration
• Add PPI if: age >65, history of GI bleed/ulcer, concurrent anticoagulation/steroids/aspirin
• Avoid in CKD stage 4-5, decompensated HF, uncontrolled HTN
• Topical preferred over oral for knee/hand OA

Intra-articular injections#

Injection principles:

• Use for flares that limit rehabilitation or function
• Not a substitute for exercise and weight management
• Limit corticosteroid injections to 3-4 per joint per year
• Steroid injections may accelerate cartilage loss with repeated use—use judiciously

Patient counseling points#

For exercise/PT:

• “Strengthening the muscles around your joint is the most effective treatment we have. It takes pressure off the cartilage and reduces pain.”
• “Exercise may cause some discomfort initially, but it should not cause sharp pain or significant swelling. Some muscle soreness is normal.”
• “Consistency matters more than intensity. Doing a little every day is better than a lot once a week.”

For weight loss:

• “Every pound you lose takes 4 pounds of pressure off your knee. Losing 10-15 pounds can make a significant difference in your pain.”

For medications:

• “The topical gel works as well as pills for knee arthritis but is much safer. Apply it 4 times a day and rub it in well.”
• “Anti-inflammatory pills help with pain but can cause stomach and kidney problems, especially with long-term use. Use them for flares, not every day.”

For injections:

• “A steroid injection can help calm down a flare and let you participate in physical therapy. It’s not a cure—the effect wears off in weeks to months.”
• “We limit injections to 3-4 per year because too many may actually speed up cartilage wear.”

For expectations:

• “Arthritis is a chronic condition we manage, not cure. The goal is to keep you active and functional.”
• “X-ray findings don’t predict how much pain you’ll have. Many people with severe arthritis on x-ray have little pain, and vice versa.”

Monitoring and follow-up#

Initial phase:

• Follow-up in 4-6 weeks after starting PT/exercise program
• Assess adherence, pain response, functional improvement
• Adjust analgesics as needed

Stable phase:

• Follow-up every 3-6 months for chronic OA
• Monitor for disease progression, medication side effects
• Reinforce exercise and weight management

After injection:

• Follow-up in 4-6 weeks to assess response
• If good response, continue conservative management
• If poor response, reassess diagnosis and consider referral

Parameters to track:

• Pain level (0-10 scale)
• Functional status: walking distance, stairs, ADLs
• Medication use and side effects
• Weight (if weight loss is a goal)
• Range of motion (especially hip internal rotation)

Patient education#

What is this condition?#

Osteoarthritis is the most common type of arthritis. It happens when the smooth coating on the ends of your bones, called cartilage, wears down over time. Think of it like the tread wearing off a tire.

When cartilage wears thin, the bones can rub together and cause pain. Your body may grow extra bone at the edges of the joint, which can make the joint look larger or feel bumpy.

Osteoarthritis is not the same as rheumatoid arthritis. Rheumatoid arthritis is caused by your immune system attacking your joints. Osteoarthritis is wear-and-tear arthritis.

What you can do#

Exercise is the best treatment for arthritis. Strengthening the muscles around your joint takes pressure off the cartilage and reduces pain. Try to do your exercises every day, even when your joint hurts a little.

Losing weight helps a lot, especially for knee arthritis. Every pound you lose takes 4 pounds of pressure off your knee.

Use heat before activity to loosen up your joint. Use ice after activity or when your joint is swollen.

Pace yourself. Alternate activity with rest. Avoid doing too much on good days, which can cause a flare the next day.

Use a cane if walking is painful. Hold it in the hand opposite your painful hip or knee.

When to seek care#

Call your doctor if your joint becomes hot, red, and very swollen. This could be an infection or a different type of arthritis that needs different treatment.

Call if you have a sudden increase in pain that does not improve with rest and your usual treatments.

Call if you develop new numbness, weakness, or your joint gives way and causes you to fall.

Call if you have fever along with joint pain.

Questions to ask your doctor#

• What exercises are best for my arthritis?
• Should I see a physical therapist?
• Is it safe for me to take anti-inflammatory medicine?
• Would an injection help me?
• When should I consider joint replacement surgery?
• How much weight loss would help my symptoms?

Prognosis and monitoring#

Expected course#

Natural history:

• OA is a slowly progressive condition over years to decades
• Symptoms often fluctuate with flares and remissions
• Radiographic progression does not always correlate with symptoms
• Many patients remain stable or improve with conservative management

With treatment:

• Exercise and weight loss can significantly reduce pain and improve function
• Most patients can be managed in primary care without surgery
• Joint replacement provides excellent outcomes for end-stage disease

Factors associated with faster progression:

• Obesity
• Malalignment (varus/valgus)
• Prior joint injury
• Inflammatory component (erosive hand OA)
• Continued high-impact activities

Monitoring parameters#

Complications to watch for#

Disease progression:

• Increasing pain despite conservative management
• Decreasing range of motion
• Progressive deformity (varus/valgus at knee)
• Loss of function affecting independence

Medication complications:

• GI bleeding from NSAIDs (black stools, abdominal pain)
• Renal dysfunction from NSAIDs (check Cr if prolonged use)
• Steroid injection complications: infection (rare), post-injection flare, skin depigmentation

Secondary complications:

• Falls due to pain, weakness, or giving way
• Deconditioning from inactivity
• Depression related to chronic pain and disability
• Opioid dependence if inappropriately prescribed

Special populations#

Elderly/geriatric#

Treatment considerations:

• Non-pharmacologic therapy remains first-line
• Higher risk of NSAID complications (GI, renal, CV)—prefer topical NSAIDs
• Acetaminophen safer but less effective; max 3 g/day, consider 2 g/day in frail elderly
• Fall risk: assess gait, strength, balance; PT for fall prevention
• Polypharmacy: review all medications; avoid adding unnecessary drugs

Beers criteria considerations:

• Oral NSAIDs: avoid chronic use in age >75 or if CKD, HF, or GI risk
• Muscle relaxants: avoid (anticholinergic effects, sedation, fall risk)
• Opioids: avoid if possible; high fall risk, constipation, cognitive effects

Dose adjustments:

• Acetaminophen: max 2-3 g/day
• NSAIDs: use lowest dose, shortest duration; add PPI
• Duloxetine: start 20-30 mg; monitor for hyponatremia

Goals may differ:

• Prioritize function and independence over pain elimination
• Focus on fall prevention
• Consider goals of care discussions for end-stage disease

Chronic kidney disease#

Medication adjustments:

Special considerations:

• Topical NSAIDs preferred; systemic absorption is minimal but not zero
• Acetaminophen is safest oral analgesic in CKD
• Avoid NSAIDs if possible; if used, monitor Cr closely
• Corticosteroid injections safe in CKD
• PT and weight loss even more important when medications limited

Other populations#

Diabetes:

• Corticosteroid injections cause glucose spikes for 1-2 weeks; warn patients and adjust diabetes medications
• Check blood glucose more frequently after injection
• Weight loss particularly beneficial (improves both OA and diabetes)

Cardiovascular disease:

• All NSAIDs increase CV risk; avoid in recent MI, unstable angina, or decompensated HF
• Naproxen may have lowest CV risk among NSAIDs (but still has risk)
• Topical NSAIDs preferred
• Celecoxib: similar CV risk to non-selective NSAIDs despite COX-2 selectivity

Polypharmacy considerations:

• NSAIDs + anticoagulants: increased bleeding risk; avoid combination if possible
• NSAIDs + ACE-I/ARB + diuretics (“triple whammy”): high risk of acute kidney injury
• NSAIDs + aspirin: NSAIDs may reduce cardioprotective effect of aspirin
• NSAIDs + SSRIs: increased GI bleeding risk
• Duloxetine + tramadol: serotonin syndrome risk

Obesity:

• Weight loss is the most effective intervention for knee OA
• Consider GLP-1 agonists or bariatric surgery referral for severe obesity
• Aquatic therapy helpful when land-based exercise is difficult
• Bariatric surgery before joint replacement improves outcomes

When to refer#

Specialist referral criteria#

Orthopedic surgery referral:

• Failed conservative management (PT, weight loss, medications, injections) with persistent significant functional limitation
• Considering joint replacement: unable to walk desired distances, night pain, significant impact on quality of life
• Mechanical symptoms suggesting internal derangement (true locking, not just stiffness)
• Significant deformity affecting gait or function
• Younger patient considering joint-preserving procedures (osteotomy)

Rheumatology referral:

• Suspected inflammatory arthritis (prolonged morning stiffness >60 min, synovitis, elevated inflammatory markers)
• Atypical presentation or rapid progression
• Young patient (<40) without clear mechanical cause
• Erosive OA with significant inflammation

Physical therapy referral:

• All patients with OA should be offered PT or a structured exercise program
• Particularly important for: post-injection rehabilitation, pre-operative optimization, fall risk, difficulty with home exercise program

Pain management referral:

• Refractory pain despite optimized conservative management
• Contraindications to surgery
• Considering interventional procedures (nerve blocks, radiofrequency ablation)

Urgency levels#

Smartphrase snippets#

Knee OA, stable on conservative management: Knee OA with [mild/moderate/severe] symptoms, managed with PT, topical NSAID, and activity pacing. Weight and functional status stable. Continue current regimen; f/u 3-6 months.

Hip OA, initiating treatment: Hip OA with groin pain and decreased internal rotation. Plan: PT referral, topical NSAID, cane for ambulation, weight optimization discussion. F/u 6 weeks; will consider injection if not improving.

OA flare, injection performed: OA flare limiting function; performed intra-articular injection with triamcinolone 40 mg. Discussed post-injection care and return to PT in 2-3 days. F/u 4-6 weeks to assess response.

OA, referring to orthopedics: Advanced OA with significant functional limitation despite optimized conservative management. Referring to orthopedics for surgical evaluation. Continue current management pending evaluation.

Related pages#

• Knee Pain (complaint) — symptom-based approach to knee pain including OA as a common cause
• Hip Pain (complaint) — symptom-based approach to hip pain including OA and GTPS
• Hand Pain (complaint) — symptom-based approach to hand pain including CMC and nodal OA
• Back Pain (complaint) — facet OA contributes to mechanical low back pain
• Gout (problem) — crystal arthropathy in the differential for acute joint pain; can coexist with OA
• Osteoporosis (problem) — often comorbid; both increase with age; fall prevention relevant to both