Osteoarthritis

Overview

   ·         Definition and Risk Factors

   ·         Idiopathic vs. Secondary OA

   ·         Clinical Features

   ·         Diagnosis

   ·         Radiologic Features

   ·         ACR OA dx for knees, hands, hips

   ·         Goals of Treatment

   ·         Non-pharmacologic treatment

   ·         Pharmacologic treatment

   ·         Surgical Considerations

Osteoarthritis

·         Articular cartilage failure induced by a complex interplay of genetic, metabolic, biochemical, and biomechanical factors

·         With secondary components of inflammation

·         Initiating mechanism is damage to normal articular cartilage by physical forces (macrotrauma or repeated microtrauma)

·         Not necessarily normal consequence of aging

Risk Factors

1.       Age

2.       Female versus male sex

3.       Obesity

4.       Lack of osteoporosis

5.       Occupation

6.       Sports activities

7.       Previous injury

8.       Muscle weakness

9.       Proprioceptive deficits

10.   Genetic elements

11.   Acromegaly

12.   Calcium crystal deposition disease

13.   Idiopathic Osteoarthritis

Localized or generalized forms

·         Localized OA most commonly affects the hands, feet, knee, hip, and spine

·         Other joints less commonly involved (shoulder, temporomandibular, sacroiliac, ankle, and wrist joints)

·         Generalized OA-three or more joint sites

Patterns of Presentation

·         Monoarticular in young adult

·         Pauciarticular, large-joint in middle age

·         Polyarticular generalized

·         Rapidly progressive

·         Secondary to trauma, congenital abnormality, or systemic disease

Secondary Osteoarthritis

·         Trauma

·         Congenital or developmental disorders

·         Calcium pyrophosphate dihydrate deposition disease (CPPD)

·         Other bone and joint disorder-Osteonecrosis, rheumatoid arthritis, gouty arthritis, septic arthritis, and Paget disease of bone

·         Other diseases -Diabetes mellitus, acromegaly, hypothyroidism, neuropathic (Charcot) arthropathy, and frostbite

Specific conditions may cause or enhance the risk of developing osteoarthritis.

likely to present in an atypical fashion, such as acutely or with unusual patterns of joint involvement

 

Clinical Features

Age of Onset > 40 years

Commonly Affected Joints

·         Cervical and lumbar spine

·         First carpometacarpal joint

·         Proximal interphalangeal joint

·         Distal interphalangeal joint

·         Hip

·         Knee

·         Subtalar joint

·         First metarsophalangeal joint

Uncommonly Affected Joints

·         Shoulder

·         Wrist

·         Elbow

·         Metacarpophalangeal joint

·         TMJ

·         SI

·         Ankle

Clinical Diagnosis

Symptoms

·         Pain

·         Stiffness

·         Gelling

Physical examination

·         Crepitus

·         Bony enlargement

·         Decreased range of motion

·         Malalignment

·         Tenderness to palpation

The more features, the more likely the diagnosis

Differential Diagnosis

·         Rheumatoid Arthritis

·         Gout

·         CPPD (Calcium pyrophosphate crystal deposition disease)

·         Septic Joint

·         Polymyalgia Rheumatica

Synovial fluid analysis

·         Severe, acute joint pain is an uncommon manifestation of OA

·         Clear fluidWBC <2000/mm3

·         Normal viscosity

Radiographic Features

·         Joint space narrowing

·         Subchondral sclerosis

·         Marginal osteophytes

·         Subchondral cyst

Joint Space Narrowing

OA typically asymmetrical

Subchondral Sclerosis

Increased bone density or thickening in the subchondral layer

Osteophytes

Bone spurs

Subchondral Cysts

Fluid-filled sacs in subchondral bone

OA of the Knee: Classic Criteria

1. Greater than 50 years of age

2. Morning stiffness for less than 30 minutes

3. Crepitus on active motion of the knee

4. Bony tenderness

5. Bony enlargement

6. No palpable warmth

3 of 6 criteria give sensitivity of 95% and specificity of 69%

The classic criteria method for OA of the knee is based upon the presence of knee pain plus at least three of the following six clinical characteristics

sensitivity and specificity for OA of 95 and 69 percent

The inclusion of laboratory criteria to these clinical characteristics alters the accuracy of diagnosis of knee OA. As an example, if an ESR less than 40 mm/h, a rheumatoid factor titer less than 1:40, and synovial fluid suggestive of OA (clear color, viscous fluid, white blood cell count less than 2000/mm3) are added to the six clinical characteristics, the diagnostic criteria of knee pain and at least five of the nine features (six physical plus three laboratory) now has a sensitivity and specificity for OA of 92 and 75 percent, respectively.

The addition of radiographic data further alters the diagnostic accuracy. The criteria of knee pain, radiographic evidence of osteophytes, and one of three additional findings — age greater than 50 years of age, morning stiffness of less than 30 minutes, or crepitus — has a sensitivity and specificity for OA of 91

OA of the Knee: Addition of X-rays

ACR Criteria of:

1. knee pain

2. radiographic evidence of osteophytes

3. one of three additional findings:

·         age greater than 50 years of age

·         morning stiffness of less than 30 minutes

·         crepitus

Sensitivity and specificity for OA of 91 and 86%

Hand Osteoarthritis

Diagnosis by hand pain

Plus at least three of the following four features:

1. Hard tissue enlargement of 2 or more of 10 selected joints.

The 10 selected joints are the second and third distal interphalangeal (DIP) joints, the second and third proximal interphalangeal (PIP) joints, and the first carpometacarpal (CMC) of both hands

2. Hard enlargement of two or more DIP joints

3. Fewer than three swollen metacarpophalangeal (MCP) joints

4. Deformity of at least 1 of the 10 selected joints

Sensitivity and Specificity for hand OA of 94 and 87%

Hip Osteoarthritis Diagnosis

Use history, physical, laboratory, and radiographic features (ACR)

Hip Pain, plus at least two of the following three features:

1. ESR of less than 20 mm/h

2. Radiographic osteophytes

3. Joint space narrowing on radiography

Sensitivity of 89 percent and a specificity of 91 percent

Distinction between Osteoarthritis and rheumatoid arthritis

Typical OA work-up

·         History

·         PE

·         Consider following (especially if OA of knees or hips)

Erythrocyte sedimentation rate (ESR)

Rheumatoid factor titers

Evaluation of synovial fluid

Radiographic study of affected joints

Overview

·         Definition and Risk Factors

·         Idiopathic vs. Secondary OA

·         Clinical Features

·         Diagnosis

·         Radiologic Features

·         ACR OA dx for knees, hands, hips

·         Goals of Treatment

·         Non-pharmacologic treatment

·         Pharmacologic treatment

·         Surgical Considerations

Goals of Treatment

·         Control pain and swelling

·         Minimize disability

·         Improve the quality of life

·         Prevent progression

·         Education

·         Chronic Condition and Management

Non-pharmacologic Treatment

Weight Loss

Ten-pound weight loss over 10 years decreased the odds for developing knee OA by 50%

Even a modest amount of weight loss may be beneficial

Rest

Short period of time, typically 12-24 hours

Prolonged rest can lead to muscle atrophy and decreased joint mobility

Physical Therapy

“Manual therapy" may be more beneficial than exercise programs that focus on muscle strengthening, endurance training, and improved coordination

May be more beneficial in those with mild OA

Ultrasound therapy may have some benefit based on 2009 Cochrane Review

Tens

·         SOR B

·         Safety/Tolerability: High

·         Efficacy: Medium 

·         20 points more effective on scale of 100 compared to placebo

·         Few long term studies

·         Price: Low to medium

Knee Braces/Shoe Inserts - SOR C

Cochrane reports a “sliver of benefit”

73% taping for 3 weeks reported improvement (elastic knee sleeve)

Price: Low $30

Acupuncture

Cochrane January 2010

Very small improvements in pain and physical function after 8 weeks and 26 weeks

A lot seems to be placebo effect due to incomplete blinding

Price: Medium to  high, 1000$  over 3-4 months

Reasonable to offer if patient resistant to conventional treatment and wants to try alternative therapies

Exercise – focus on low load exercise

Tai Chi

Yoga

Swimming

Biking

Walking

Most important aspect to counsel patients for prevention and treatment

Cochrane Review 2009 compares efficacy to NSAIDs in short-term benefits

Heat and Cold

Lack of convincing data despite being commonly used

Acetaminophen

·         Cochrane 2009 Review

·         NSAIDs are superior to acetaminophen for improving knee and hip pain in people with OA

·         Treatment effect was modest

·         Median trial duration was only six weeks

·         In OA subjects with moderate-to-severe levels of pain

·         NSAIDs > Acetaminophen > Placebo

·         NNT for Acetaminophen 4 to 16

·         1000mg three to four times daily

NSAIDs

·         Tend to avoid for long-term use

Rash and hypersensitivity reactions

Abdominal pain and gastrointestinal bleeding

Impairment of renal, hepatic, and bone marrow function, and platelet aggregation

Central nervous system dysfunction in the elderly

·         Low dose ibuprofen (less than 1600 mg/day) may have less serious GI toxicity

·         Nonacetylated salicylates (salsalate, choline magnesium trisalicylate), sulindac, and nabumetone appear to have less renal toxicity

·         Indomethacin should be avoided for long-term use in patients with hip OA

Associated with accelerated joint destruction

Topical NSAIDs

·         A 2004 meta-analysis included 13 trials involving almost 2000 patients

·         Randomly assigned to topical NSAID, oral NSAID, or placebo

·         Significant short term (one to two weeks) efficacy for pain relief and functional improvement when topical NSAIDs were compared to placebo

·         Effect was not apparent at three to four weeks

·         Topical NSAIDs were generally inferior to oral NSAIDs

·         However topical route was safer than oral use

·         Topical Diflofenac (1% gel or patch)

COX-2 Inhibitors

COX-2 inhibitors appear to be as effective NSAIDs

Associated with less GI toxicity

However increased risk of CV events 

Use of low dose ASA may negate the GI sparing effects of COX-2 inhibitors

Those who are receiving low dose aspirin and a COX-2 selective agent may benefit from antiulcer prophylaxis

Capsaicin

Capsaicin Ointment 0.025% (qid) & 0.075% (bid)

·         Principle ingredient of chili peppers (substance P)

·         Love It!

·         Tolerability: Medium

50% experience burning which wanes

50% decrease in pain, 25% with placebo

Price: 15$ per month

Apply 2-4 times per day

Glucosamine

·         Glucosamine Sulfate 1500mg po daily

·         Supplement, typically not covered

·         Cochrane 2009

Rotta preparation glucosamine was superior to placebo in the treatment of pain and functional impairment

Non-Rotta preparation failed to show benefit

·         Majority of trials that have evaluated the effectiveness of glucosamine sulfate demonstrated significant clinical benefits

·         Glucosamine hydrochloride trials are scarce and much less convincing

·         Bottom-Line, most likely beneficial if Rotta brand and Sulfate formulation, not HCL

Injections

Corticosteroid

Safety: High for short-term use, data on frequency and degree of use is limited.

Study of pt’s receiving 8 injections over 2 year period showed no ill effects in comparison with pt’s receiving placebo.

Tolerability: Medium to high

Efficacy: Low to medium.  Modest benefit. 16 point reduction in pain on 100-point scale for one month.

Price: Low, 100$-200$

SOR A

Hyaluronic Injections of Knees

Safety: High

Tolerability: Medium. Small number pts get flare up of symptoms.

Efficacy: Low. Recent Meta-analyses and reviews small clinical effect.  75% were satisfied with treatment. Lasts 3-4 months.

Price: High. 3 injections costs $700 to $1000 per injection. Claims of substantial savings d/t delayed joint replacement.

SOR A

Narcotics for Refractory Pain

Vicodin/Oxycodone

Safety: Medium

Tolerability:  Medium

Constipation, somnolence, mental status changes

Price: Low,<$20 per month with vicodin

Use of opiates indicated in those who are not candidates for surgery and who continue to have moderate to severe pain despite being on NSAIDs or selective cyclooxygenase (COX)-2 inhibitors

Arthroscopic Interventions

Controversial

Arthroscopic debridement with lavage

Sham-surgery versus arthroscopic lavage/debridement study

Remove loose pieces of bone and cartilage

Resurface (smooth out) bones

A direct, three-armed comparison of arthroscopically directed lavage, arthroscopically directed lavage and debridement, and sham surgery was performed in a study that randomized 180 patients with radiographic and symptomatic osteoarthritis of the knee to one of the three procedures [7]. Patients were followed for 24 months; the result of this blinded study was that there was no clinically important or statistically significant advantage in the reduction in knee pain or improvement in knee function in the groups that received an arthroscopic intervention (lavage alone or lavage and debridement) when compared to the sham group

Prosthetic Joints

·         Commonly of the hip or knee or shoulder

·         Several types: metal, plastic, ceramic

·         Last 10-15 years or more

·         About 10% need to be redone

·         Usually a treatment of “last resort”

Joint Replacement

·         Surgical candidate?

·         Often greater improvement in pain rather than function

·         Recovery can be strenuous and lengthy

·         Infection rate 1%

·         Low mortality 0.6% to 0.7%

·         Complications include thrombo-embolic events 5%

Education and Self-Help

·         Understand the disease

·         Reduce pain but remain active

·         Clear Functional goals

·         Cope physically, emotionally, and mentally

·         Have greater control over the disease

·         Build confidence