II. Epidemiology
- Most common form of Arthritis
- Associated functional Impairment increases with age
-
Prevalence directly increases with age
- Age over 40 years: 70% of U.S. population
- Age over 65 years: 80% of U.S. population
- See Rheumatologic Conditions in the Elderly
III. Pathophysiology
- Primary lesion resides in the articular cartilage
- Abnormal cartilage repair and remodeling
- Chondrocytes produce proteolytic enzymes
- Proteolytic enzymes destroy cartilage
- End result
- Asymmetric joint cartilage loss
- Subchondral sclerosis (bone density increased)
- Subchondral cysts
- Marginal osteophytes
IV. Risk Factors
- Age over 50 years old
- Female gender
- Obesity
- Prior joint injury
- Job duties with frequent squatting or bending
- Osteoarthritis Family History
- Repetitive-impact sports (e.g. soccer, football)
V. Etiologies
- Primary
- Secondary
- Acute or Chronic Trauma
- History of knee meniscectomy
- Congenital abnormalities
- Rheumatic Conditions
- Gouty Arthritis
- Rheumatoid Arthritis
- Calcium pyrophosphate deposition disease (CPPD)
- Endocrine Conditions
VI. Symptoms
- Pain worse later in the day, and better with rest
- Pain on motion that worsens with increasing joint usage (gelling)
- If morning stiffness is present, is of short duration (<30 minutes)
- Contrast with Rheumatoid Arthritis which has morning stiffness >30 minutes
- Slowly progressive deformity and variably painful
- Initial high-use Joint Pain relieved with rest
- Next, pain is constant on affected joint usage
- Eventually pain occurs at rest and at night
- No systemic manifestations
- No Fatigue
- No generalized weakness
- Associated Muscle spasm, contractures and atrophy
- Symptoms uncommon before age 40 years old
- Asymmetric involvement
VII. Signs
- Joint Exam
- Joint Effusion
- Atrophy
- Joint instability
- Joint tenderness
- Crepitation
- Limited range of motion
- Joints spared (Contrast with Rheumatoid Arthritis)
- Wrist spared
- Metacarpal-phalangeal joints spared (except thumb)
- Elbow spared
- Ankle spared (variable involvement)
- Joints commonly involved
- See Shoulder Osteoarthritis
- See Acromioclavicular Osteoarthritis
- See Knee Osteoarthritis
- See Hip Osteoarthritis
- See Foot Osteoarthritis
- See Hand Osteoarthritis
- Distal interphalangeal joints (Heberden's Nodes)
- Proximal interphalangeal joints (Bouchard's Nodes)
- First carpometacarpal joint (thumb)
- Cervical and Lumbar Spine
- Mechanisms
- Apophyseal joint Arthritis and Osteophytes
- Disc degeneration
- Secondary affects
- Local Muscle spasm
- Nerve root impingement with radiculopathy
- Cervical stenosis
- Lumbar Stenosis (Pseudoclaudication)
- Mechanisms
VIII. Labs: General (if indicated)
- Routine labs are not indicated in typical Osteoarthritis
- Obtain for unclear diagnosis
- Abnormal results suggest alternative diagnosis
- Erythrocyte Sedimentation Rate normal
- C-Reactive Protein normal
- Rheumatoid Factor negative
- Uric Acid normal
IX. Labs: Synovial Fluid (if indicated)
-
Synovial Fluid appearance
- Clear fluid
- High viscosity and good mucin
-
Synovial Fluid Crystals
- Basic Calcium Phosphate (BCP) Crystals
- Apatite crystals
-
Synovial Fluid White Blood Cell Count
- Non-Inflammatory fluid: 200 - 2000 WBC/mm3
- WBC Count usually <500 cells (mostly mononuclear)
X. Differential Diagnosis: General
- Bursitis or Tendonitis
- Mechanical intra-articular disorder
- Rheumatoid Arthritis
- Psoriatic Arthritis
- Gouty Arthritis
- Pseudogout
- Lyme Disease
- Hemochromatosis
- Hyperparathyroidism
- Acromegaly
- Wilson Disease
- Musculoskeletal Autoimmune Conditions (e.g. Systemic Lupus Erythematosus, Ankylosing Spondylitis)
XI. Differential Diagnosis: By Region
- See Rheumatologic Conditions affecting the Foot
- See Rheumatologic Conditions affecting the Hand
- See Rheumatologic Conditions affecting the Hip
- See Rheumatologic Conditions affecting the Knee
- See Rheumatologic Conditions affecting the Low Back
- See Rheumatologic Conditions Affecting the Shoulder
- See Rheumatologic Conditions affecting the Wrist
- See Rheumatologic Conditions associated with Ocular Disease
- See Rheumatologic Conditions in the Elderly
- See Rheumatologic Conditions Presenting with Fever
- See Rheumatologic Conditions Presenting with Rash
- See HIV Related Rheumatologic Conditions
XII. Imaging
- Imaging is not required for Osteoarthritis diagnosis in patients with typical presentations
- XRay, MRI Imaging often does not correlate with Osteoarthritis severity and patient function
- Imaging indicated for pre-operative evaluation or if other diagnosis considered
- Joint Trauma
- Joint Pain at night
- Progressive Joint Pain
- Family History of other arthritic conditions
- Age under 18 years
- Findings
XIII. Management: Non-Pharmacologic Treatment
- See Knee Osteoarthritis for Muscle Strengthening
- Reduce Obesity
- Weight loss of 5% from baseline or 6 kg (13 pounds) decreases pain and Disability
- Physical Therapy
- Physiotherapy (Heat, Cold, Contrast Baths or Ultrasound)
- TENS not found to be effective
- Consider comorbidity
- See Depression in the Elderly
-
Exercise Program (do not exacerbate symptoms)
- Stretching
- Mild aerobic, active, Isometric Exercise (eliptical trainer, Bicycle)
- Swimming
- Highly effective Exercise for strength, flexibility and aerobic fitness
- Tai chi
- Joint protection
- Work and home modified in severe disease
- Surgery
- Hip replacement or knee replacement in refractory cases
XIV. Management: Pharmacologic Management
-
Acetaminophen (Tylenol) 1 gram orally twice daily (limit to 2-3 grams daily)
- Less effective than NSAIDs, but safer
-
NSAIDs
- Cautious use in age over 65 years, prior GI Bleed, Aspirin, Plavix, Warfarin or Corticosteroid
- Consider with Proton Pump Inhibitor if 1-2 GI risks
- Avoid NSAIDs completely if 3 or more GI risks
- Avoid Feldene - higher risk of GI toxicity
- Naproxen may have less Cardiovascular Risks
- Observe for CNS effects (esp. Indomethacin)
- Consider topical Diclofenac (see below)
- Switch classes when one NSAID is not effective
- Cautious use in age over 65 years, prior GI Bleed, Aspirin, Plavix, Warfarin or Corticosteroid
- COX2 Inhibitors
- Topical agents
- Topical Diclofenac
- May be as effective as oral NSAIDs if only a few joints involved
- Expensive and risk of skin reaction
- Topical Capsaicin cream
- Effective for refractory Joint Pain
- Poorly tolerated
- Avoid topical Salicylates such as Bengay (ineffective for Osteoarthritis)
- Topical Diclofenac
- Intraarticular agents
- Intra-articular Corticosteroid injection
- Avoid more than 3-4 times per year
- Sodium hyaluronate (Synvisc) in Knee Osteoarthritis
- Intra-articular Corticosteroid injection
- Other systemic Analgesics
- Tramadol (Ultram)
- Effective, but with risks (NNT 6, NNH 8)
- Cepeda (2007) J Rheumatol 34(3): 543-55 [PubMed]
- Duloxetine (Cymbalta)
- Effective, but with moderate Nausea risk (NNT 7, NNH 6)
- Duloxetine, Milnacipran, SSRIs and Tricyclic Antidepressants offer a small pain and function benefit (hip, knee OA)
- However, adverse effects (see above) limit their use
- Consider in Comorbid Mood Disorder (Major Depression, Anxiety Disorder)
- Leaney (2022) Cochrane Database Syst Rev (10): CD012157 [PubMed]
- Opioids
- Generally not recommended due to significant risks
- Tramadol (Ultram)
XV. Management: Alternative Medications
- Possibly effective agents (insufficient evidence to recommend)
- Dimethyl Sulfoxide (DMSO) 25% applied topically
- Small, 3 week studies showed reduced pain
- Devil's Claw 2.4 grams daily
- Ginger Extract 510 mg daily
- Methlsulfonylmethane (MSM) 500 mg three times daily
- S-Adenosylmethionine (SAMe) 200 mg three times daily
- Methyl donor in proteoglycan synthesis
- More effective than Placebo for pain, stiffness
- Very expensive and unstable shelf life (Butanedisulfonate salt is most stable)
- Glucosamine Sulfate
- Dosing 1500 mg once daily or 500 mg orally three times daily
- Effect may be delayed for 2 months
- Initial studies demonstrated benefit
- Later studies show no significant benefit
- Dimethyl Sulfoxide (DMSO) 25% applied topically
- Unknown benefit (anecdotal, inconclusive data or only small studies support)
- Avocado-soybean unsaponifiables 300 mg daily
- Boron supplementation
- Effects Calcium Metabolism in bones, joints
- Higher Arthritis rates with low boron intake
- Cetyl Myristoleate (anti-inflammatory effects)
- Acupuncture
- FLUIDjoint
- Agents to avoid
- Agents that are ineffective for Osteoarthritis (but may have other indications)
- Vitamin D Supplementation
- Antioxidant supplements
- Ineffective agents (avoid these based on high quality studies)
- Chondroitin sulfate 400 mg orally three times daily
- Tipi
- Reumalex
- Ionized wrist bracelets
- Osteoarthritis Shoes
- Preparations with serious adverse effects and either ineffective or unproven efficacy
- Limbrel (Flavocoxid)
- Risk of Acute Hepatitis and Hypersensitivity pneumonitis
- Limbrel (Flavocoxid)
- Agents that are ineffective for Osteoarthritis (but may have other indications)
- References
XVI. Prevention
- Maintain appropriate body weight
- Continued moderate joint activity is critical
- Normal joint use directs cartilage remodeling
- Decreased joint use risks abnormal cartilage repair
XVII. Resources: Patient Education
- Information from your Family Doctor: Staying Active
XVIII. References
- Klippel (1997) Primer Rheumatic Diseases, AF
- Brandt (1995) Ann Intern Med 122:874-5 [PubMed]
- Ebell (2018) Am Fam Physician 97(8): 523-6 [PubMed]
- Griffin (1995) Arch Fam Med 4:1049-55 [PubMed]
- Hinton (2002) Am Fam Physician 65(5):841-8 [PubMed]
- Hunter (2008) Rheum Dis Clin North Am 34(3): 689-712 [PubMed]
- Manek (2000) Am Fam Physician 61:1795-804 [PubMed]
- Sinusas (2012) Am Fam Physician 85(1): 49-56 [PubMed]
- Swagerty (2001) Am Fam Physician 64(2):279-86 [PubMed]