Osteoarthritis of Knee joint

Dilshan Munidasa

OverviewOverview Definition and Risk FactorsDefinition and Risk Factors Idiopathic vs. Secondary OAIdiopathic vs. Secondary OA Clinical FeaturesClinical Features DiagnosisDiagnosis Radiologic FeaturesRadiologic Features ACR OA dx for knees, hands, hipsACR OA dx for knees, hands, hips Goals of TreatmentGoals of Treatment Non-pharmacologic treatmentNon-pharmacologic treatment Pharmacologic treatmentPharmacologic treatment Surgical ConsiderationsSurgical Considerations

OsteoarthritisOsteoarthritis

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

With secondary components of With secondary components of inflammation inflammation

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

Not necessarily normal consequence of Not necessarily normal consequence of agingaging

Risk FactorsRisk Factors AgeAge Female versus male sexFemale versus male sex ObesityObesity Lack of osteoporosisLack of osteoporosis OccupationOccupation Sports activitiesSports activities Previous injuryPrevious injury Muscle weaknessMuscle weakness Proprioceptive deficitsProprioceptive deficits Genetic elementsGenetic elements AcromegalyAcromegaly Calcium crystal deposition diseaseCalcium crystal deposition disease

Idiopathic OsteoarthritisIdiopathic Osteoarthritis

Localized or generalized forms Localized or generalized forms Localized OA most commonly affects Localized OA most commonly affects

the hands, feet, knee, hip, and spinethe hands, feet, knee, hip, and spine Other joints less commonly involvedOther joints less commonly involved

– shoulder, temporomandibular, shoulder, temporomandibular, sacroiliac, ankle, and wrist jointssacroiliac, ankle, and wrist joints

Generalized OA Generalized OA – three or more joint sitesthree or more joint sites

Patterns of PresentationPatterns of Presentation

Monoarticular in young adultMonoarticular in young adult Pauciarticular, large-joint in middle Pauciarticular, large-joint in middle

ageage Polyarticular generalizedPolyarticular generalized Rapidly progressiveRapidly progressive Secondary to trauma, congenital Secondary to trauma, congenital

abnormality, or systemic diseaseabnormality, or systemic disease

Clinical DiagnosisClinical Diagnosis SymptomsSymptoms

– PainPain– StiffnessStiffness– Gelling Gelling

Physical examinationPhysical examination– CrepitusCrepitus– Bony enlargementBony enlargement– Decreased range of motionDecreased range of motion– MalalignmentMalalignment– Tenderness to palpationTenderness to palpation

The more features, the more likely the diagnosisThe more features, the more likely the diagnosis

Differential DiagnosisDifferential Diagnosis

Rheumatoid ArthritisRheumatoid Arthritis GoutGout CPPD (Calcium pyrophosphate CPPD (Calcium pyrophosphate

crystal deposition disease)crystal deposition disease) Septic JointSeptic Joint Polymyalgia Rheumatica Polymyalgia Rheumatica

Synovial fluid analysisSynovial fluid analysisSevere, acute joint pain is an Severe, acute joint pain is an

uncommon manifestation of OA uncommon manifestation of OA

Clear fluidWBC <2000/mm3Clear fluidWBC <2000/mm3

Normal viscosityNormal viscosity

Radiographic FeaturesRadiographic Features

Joint space narrowingJoint space narrowingSubchondral sclerosisSubchondral sclerosisMarginal osteophytesMarginal osteophytesSubchondral cystSubchondral cyst

Joint Space NarrowingJoint Space Narrowing

OA typically asymmetricalOA typically asymmetrical

Paget’s disease

Subchondral SclerosisSubchondral Sclerosis

Increased bone density or thickening Increased bone density or thickening in the subchondral layerin the subchondral layer

OA of the Knee: Classic CriteriaOA of the Knee: Classic Criteria

1. Greater than 50 years of age1. Greater than 50 years of age2. Morning stiffness for less than 30 minutes2. Morning stiffness for less than 30 minutes3. Crepitus on active motion of the knee3. Crepitus on active motion of the knee4. Bony tenderness4. Bony tenderness5. Bony enlargement5. Bony enlargement6. No palpable warmth6. No palpable warmth

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

OA of the Knee: Addition of X-raysOA of the Knee: Addition of X-rays

ACR Criteria of:ACR Criteria of:1. knee pain1. knee pain2. radiographic evidence of osteophytes2. radiographic evidence of osteophytes3. one of three additional findings:3. one of three additional findings:

age greater than 50 years of ageage greater than 50 years of agemorning stiffness of less than 30 minutesmorning stiffness of less than 30 minutescrepitus crepitus

– Sensitivity and specificity for OA of 91 Sensitivity and specificity for OA of 91 and 86%and 86%

Typical OA work-upTypical OA work-up

HistoryHistory PEPE Consider following (especially if OA of Consider following (especially if OA of

knees or hips)knees or hips)– Erythrocyte sedimentation rate (ESR)Erythrocyte sedimentation rate (ESR)– Rheumatoid factor titersRheumatoid factor titers– Evaluation of synovial fluidEvaluation of synovial fluid– Radiographic study of affected jointsRadiographic study of affected joints

OverviewOverview Definition and Risk FactorsDefinition and Risk Factors Idiopathic vs. Secondary OAIdiopathic vs. Secondary OA Clinical FeaturesClinical Features DiagnosisDiagnosis Radiologic FeaturesRadiologic Features ACR OA dx for knees, hands, hipsACR OA dx for knees, hands, hips Goals of TreatmentGoals of Treatment Non-pharmacologic treatmentNon-pharmacologic treatment Pharmacologic treatmentPharmacologic treatment Surgical ConsiderationsSurgical Considerations

Goals of TreatmentGoals of Treatment

Control pain and swellingControl pain and swelling Minimize disabilityMinimize disability Improve the quality of lifeImprove the quality of life Prevent progression Prevent progression EducationEducation Chronic Condition and ManagementChronic Condition and Management

Non-pharmacologic TreatmentNon-pharmacologic Treatment

Weight LossWeight Loss– Ten-pound weight loss over 10 years Ten-pound weight loss over 10 years

decreased the odds for developing knee OA by decreased the odds for developing knee OA by 50%50%

– Even a modest amount of weight loss may be Even a modest amount of weight loss may be beneficialbeneficial

RestRest– Short period of time, typically 12-24 hours Short period of time, typically 12-24 hours – Prolonged rest can lead to muscle atrophy and Prolonged rest can lead to muscle atrophy and

decreased joint mobilitydecreased joint mobility

Non-pharmacological TreatmentNon-pharmacological Treatment

Physical TherapyPhysical Therapy

– May be more beneficial in those with May be more beneficial in those with mild OAmild OA

– Ultrasound therapy may have some Ultrasound therapy may have some benefit based on 2009 Cochrane Reviewbenefit based on 2009 Cochrane Review

Knee Braces / TapingKnee Braces / Taping

– Cochrane reports a “sliver of benefit”Cochrane reports a “sliver of benefit”– 73% taping for 3 weeks reported improvement 73% taping for 3 weeks reported improvement

(elastic knee sleeve(elastic knee sleeve

TensTens

Safety/Tolerability: High Safety/Tolerability: High Efficacy: Medium Efficacy: Medium 20 points more effective on scale of 20 points more effective on scale of

100 compared to placebo100 compared to placebo Few long term studiesFew long term studies

Non-pharmacologic TreatmentNon-pharmacologic Treatment

AcupunctureAcupuncture– Very small improvements in pain and physical

function after 8 weeks and 26 weeks– A lot seems to be placebo effect due to incomplete A lot seems to be placebo effect due to incomplete

blindingblinding– Reasonable to offer if patient resistant to Reasonable to offer if patient resistant to

conventional treatment and wants to try alternative conventional treatment and wants to try alternative therapiestherapies

Non-pharmacological TreatmentNon-pharmacological Treatment Exercise – focus on low load exerciseExercise – focus on low load exercise

– Tai Chi Tai Chi – YogaYoga– SwimmingSwimming– BikingBiking– WalkingWalking– Most important aspect to counsel patients for prevention Most important aspect to counsel patients for prevention

and treatmentand treatment– Cochrane Review 2009 compares efficacy to NSAIDs in Cochrane Review 2009 compares efficacy to NSAIDs in

short-term benefitsshort-term benefits

Heat and ColdHeat and Cold– Lack of convincing data despite being commonly usedLack of convincing data despite being commonly used

AcetaminophenAcetaminophen

NSAIDs are superior to acetaminophenNSAIDs are superior to acetaminophen Treatment effect was modestTreatment effect was modest Median trial duration was only six weeksMedian trial duration was only six weeks In OA subjects with moderate-to-severe In OA subjects with moderate-to-severe

levels of painlevels of pain NSAIDs > Acetaminophen > PlaceboNSAIDs > Acetaminophen > Placebo 1000mg three to four times daily1000mg three to four times daily

NSAIDsNSAIDs Tend to avoid for long-term useTend to avoid for long-term use

– Rash and hypersensitivity reactionsRash and hypersensitivity reactions– Abdominal pain and gastrointestinal bleedingAbdominal pain and gastrointestinal bleeding– Impairment of renal, hepatic, and bone marrow function, Impairment of renal, hepatic, and bone marrow function,

and platelet aggregationand platelet aggregation– Central nervous system dysfunction in the elderlyCentral nervous system dysfunction in the elderly

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

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

Indomethacin should be avoided for long-term use Indomethacin should be avoided for long-term use in patients with hip OAin patients with hip OA– associated with accelerated joint destruction associated with accelerated joint destruction

Topical NSAIDsTopical NSAIDs

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

Effect was not apparent at three to four weeks Effect was not apparent at three to four weeks Topical NSAIDs were generally inferior to oral Topical NSAIDs were generally inferior to oral

NSAIDsNSAIDs However topical route was safer than oral useHowever topical route was safer than oral use Topical Diflofenac (1% gel or patch)Topical Diflofenac (1% gel or patch)

COX-2 InhibitorsCOX-2 Inhibitors

COX-2 inhibitors appear to be as effective COX-2 inhibitors appear to be as effective NSAIDsNSAIDs

Associated with less GI toxicityAssociated with less GI toxicity However increased risk of CV events However increased risk of CV events Use of low dose ASA may negate the GI Use of low dose ASA may negate the GI

sparing effects of COX-2 inhibitorssparing effects of COX-2 inhibitors Those who are receiving low dose Those who are receiving low dose

aspirin and a COX-2 selective agent may aspirin and a COX-2 selective agent may benefit from anti-ulcer prophylaxisbenefit from anti-ulcer prophylaxis

CapsaicinCapsaicin Capsaicin Ointment 0.025% (qid) & Capsaicin Ointment 0.025% (qid) &

0.075% (bid)0.075% (bid)– Principle ingredient of chili peppers Principle ingredient of chili peppers

(substance P)(substance P)– Love It!Love It!– Tolerability: Medium Tolerability: Medium

50% experience burning which wanes50% experience burning which wanes50% decrease in pain, 25% with placebo50% decrease in pain, 25% with placeboApply 2-4 times per dayApply 2-4 times per day

Glucosamine Glucosamine Glucosamine Sulfate 1500mg po dailyGlucosamine Sulfate 1500mg po daily Supplement, typically not coveredSupplement, typically not covered Cochrane 2009Cochrane 2009

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

– Non-Rotta preparation failed to show benefit Non-Rotta preparation failed to show benefit Majority of trials that have evaluated the Majority of trials that have evaluated the

effectiveness of glucosamine sulfate effectiveness of glucosamine sulfate demonstrated significant clinical benefits demonstrated significant clinical benefits

Glucosamine hydrochloride trials are Glucosamine hydrochloride trials are scarce and much less convincingscarce and much less convincing

InjectionsInjections

CorticosteroidCorticosteroid– Safety: High for short-term use, data on Safety: High for short-term use, data on

frequency and degree of use is limited. frequency and degree of use is limited. Study of pt’s receiving 8 injections over 2 year Study of pt’s receiving 8 injections over 2 year

period showed no ill effects in comparison with period showed no ill effects in comparison with pt’s receiving placebo.pt’s receiving placebo.

– Strict aseptic technique must be usedStrict aseptic technique must be used– Tolerability: Medium to highTolerability: Medium to high– Efficacy: Low to medium. Modest benefit. 16 Efficacy: Low to medium. Modest benefit. 16

point reduction in pain on 100-point scale for point reduction in pain on 100-point scale for one month.one month.

InjectionsInjections

Hyaluronic Injections of KneesHyaluronic Injections of Knees Efficacy: Low. Recent Meta-analyses and Efficacy: Low. Recent Meta-analyses and

reviews small clinical effect. 75% were reviews small clinical effect. 75% were satisfied with treatment. Lasts 3-4 months.satisfied with treatment. Lasts 3-4 months.

Price: High. 3 injections cost Rs.15000Price: High. 3 injections cost Rs.15000

Narcotics for Refractory PainNarcotics for Refractory Pain Safety: MediumSafety: Medium Tolerability: MediumTolerability: Medium

– Constipation, somnolence, mental status Constipation, somnolence, mental status changeschanges

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

Arthroscopic InterventionsArthroscopic Interventions

Arthroscopic InterventionsArthroscopic Interventions

Minimally invasive procedureMinimally invasive procedure Arthroscopic debridement with Arthroscopic debridement with

lavage – Short term benefitlavage – Short term benefit Remove loose pieces of bone and Remove loose pieces of bone and

cartilage cartilage Lateral release can be done to off Lateral release can be done to off

load patellaload patella

Autologus Chondrocyte Autologus Chondrocyte TransplantTransplant

Prosthetic JointsProsthetic Joints

Several types: Unicondylar / Total Several types: Unicondylar / Total kneeknee

Last 10-15 years or moreLast 10-15 years or more About 10% need to be redoneAbout 10% need to be redone Usually a treatment of “last resort”Usually a treatment of “last resort”

Joint ReplacementJoint Replacement

Surgical candidate?Surgical candidate? Often greater improvement in pain Often greater improvement in pain

rather than functionrather than function Recovery can be strenuous and Recovery can be strenuous and

lengthylengthy Infection rate 1%Infection rate 1% Low mortality 0.6% to 0.7%Low mortality 0.6% to 0.7% Complications include thrombo-Complications include thrombo-

embolic events 5%embolic events 5%

Education and Self-HelpEducation and Self-Help

Understand the diseaseUnderstand the disease Reduce pain but remain activeReduce pain but remain active Clear Functional goalsClear Functional goals Cope physically, emotionally, and Cope physically, emotionally, and

mentallymentally Have greater control over the Have greater control over the

diseasedisease Build confidenceBuild confidence