OsteoarthritisOsteoarthritis

DefinitionDefinition• Also known as Also known as

degenerative joint degenerative joint disease or “wear and disease or “wear and tear arthritis”.tear arthritis”.

• Progressive loss of Progressive loss of cartilage with cartilage with remodeling of remodeling of subchondral bone subchondral bone and progressive and progressive deformity of the joint deformity of the joint (s). (s).

• Cartilage destruction Cartilage destruction may be a result of a may be a result of a variety of etiologiesvariety of etiologies

Prevalence and epidemiologyPrevalence and epidemiology

• It’s the commonest form of arthritisIt’s the commonest form of arthritis

• About 60-90% of people over age 65About 60-90% of people over age 65

• Under 45 yrs it is equally common in Under 45 yrs it is equally common in men and womenmen and women

• Over 55 yrs its more common in Over 55 yrs its more common in womenwomen

• Nodal OA involving DIP and PIP joints Nodal OA involving DIP and PIP joints is more common in women and their is more common in women and their first degree female relativesfirst degree female relatives

• Premature OA associated with gene Premature OA associated with gene mutations that encode collagen types 2, 9, mutations that encode collagen types 2, 9, 1010

• OA of knee is more common in womenOA of knee is more common in women

• Commonest cause of long-term disabilityCommonest cause of long-term disability

• Large economic impact as a result of Large economic impact as a result of medical costsmedical costs

• It is not an inevitable part of aging, It is not an inevitable part of aging, some people are more susceptible some people are more susceptible than othersthan others

• A combination of different factors are A combination of different factors are involved. involved.

• Both mechanical and biologic Both mechanical and biologic destructive processes play a role in destructive processes play a role in OA.OA.

Risk factorsRisk factors

• Metabolic (hemachromatosis) Metabolic (hemachromatosis)

• Inflammatory (RA, infection)Inflammatory (RA, infection)

• ageage

• gendergender

• genetic factorsgenetic factors

• traumatrauma

• weightweight

ClassificationClassification• PrimaryPrimary• IdopathicIdopathic

• Localized or Localized or generalizedgeneralized

Local: knee, hip, Local: knee, hip, spine, handsspine, hands

Generalized:Generalized: large large joints and spinejoints and spine

Small peripheral Small peripheral joints and spinejoints and spine

Mixed and spineMixed and spine

• SecondarySecondary

• Post-traumataicPost-traumataic

• Congenital or Congenital or developmentaldevelopmental

• Localized or Localized or generalizedgeneralized

• Calcium deposition Calcium deposition diseasedisease

Inflammatory OAInflammatory OA• OA is generally a non-inflammtory arthritis.OA is generally a non-inflammtory arthritis.

• Increasing evidence for inflammatory type: Increasing evidence for inflammatory type: caused by cytokines, metalloproteinase caused by cytokines, metalloproteinase release. release.

• This erosive inflammatory type may have This erosive inflammatory type may have flares but later acts like typical OA.flares but later acts like typical OA.

• Primarily in womenPrimarily in women

• May be suspected from evidence of active May be suspected from evidence of active synovitis, chondrocalcinosis on x-rays, synovitis, chondrocalcinosis on x-rays, morning stiffness greater than 30 mins, morning stiffness greater than 30 mins, history of swelling and night pain.history of swelling and night pain.

Overview of the processOverview of the process

• Articular cartilage Articular cartilage gets disruptedgets disrupted

• Damage Damage progresses progresses deeper to deeper to subchondral bonesubchondral bone

• Fragments of Fragments of cartilage released cartilage released into jointinto joint

• Matrix degeneratesMatrix degenerates

• Eventually there is Eventually there is complete loss of complete loss of cartilagecartilage

• Bone is exposedBone is exposed

Normal knee anatomyNormal knee anatomy

• left: Normal x-rayleft: Normal x-ray• Right: worn away cartilage reflected by Right: worn away cartilage reflected by

decreased joint spacedecreased joint space

The process – The process – at a cellular levelat a cellular level

• Cartilage matrix has increased water content and Cartilage matrix has increased water content and decreased proteoglycandecreased proteoglycan

• With aging With aging cartilage dries up. cartilage dries up.

• Increased activity of proteinases compared to inhibitors Increased activity of proteinases compared to inhibitors of proteinases.of proteinases.

• The cartilage with less water is less resistant to wear The cartilage with less water is less resistant to wear and tear.and tear.

• Cycle of destruction starts Cycle of destruction starts

• Compensatory bone overgrowth occurs - subchondral Compensatory bone overgrowth occurs - subchondral bone increases in densitybone increases in density

Left: View of normal elbow cartilage through Left: View of normal elbow cartilage through an arthroscope - white, glistening, smooth an arthroscope - white, glistening, smooth

Right: severe elbow osteoarthritis - cartilage Right: severe elbow osteoarthritis - cartilage is lost and the bone underneath is exposed is lost and the bone underneath is exposed

The process cont’dThe process cont’d• Bony proliferations at joint margins Bony proliferations at joint margins

form, osteophytesform, osteophytes

• Thought to be new bone formation in Thought to be new bone formation in response to degenerating cartilageresponse to degenerating cartilage

• They cause joint motion restrictionThey cause joint motion restriction

What to look for in an x-rayWhat to look for in an x-ray

• Radiographic changes visible Radiographic changes visible relatively late in the diseaserelatively late in the disease

• Subchondral sclerosisSubchondral sclerosis

• Joint space narrowing esp where Joint space narrowing esp where there is stressthere is stress

• Subchondral cystsSubchondral cysts

• OsteophytesOsteophytes

• Bone mineralization should be Bone mineralization should be normalnormal

• Joint space Joint space narrowing where narrowing where there is more there is more stressstress

• Subchondral bone Subchondral bone has thickenedhas thickened

• bony overgrowthbony overgrowth

significant joint space narrowing as well as proliferative significant joint space narrowing as well as proliferative bone formation around the femoral neck (arrows) bone formation around the femoral neck (arrows)

Left: normal hipLeft: normal hipRight: There is some joint space medially but the superior portion is Right: There is some joint space medially but the superior portion is

completely destroyed. Supralateral aspects affected most because completely destroyed. Supralateral aspects affected most because the weight is transfered through the roof of the acetabulum. the weight is transfered through the roof of the acetabulum.

Note the sclerosis and oseophyte formation (arrow). Note the sclerosis and oseophyte formation (arrow).

painful bone on bone contact at the CMC joint and the large painful bone on bone contact at the CMC joint and the large bone spurs -- osteophytes. bone spurs -- osteophytes.

X-ray shows lateral osteophytes, varus deformity, narrow joint X-ray shows lateral osteophytes, varus deformity, narrow joint space in a 70 yr old female with OAspace in a 70 yr old female with OA

Clinical features and diagnosisClinical features and diagnosis• PainPainSourcesSources

– Joint effusion and stretching of the joint Joint effusion and stretching of the joint capsule capsule

– Torn menisci Torn menisci – Inflammation of periarticular bursaeInflammation of periarticular bursae– Periarticular muscle spasm Periarticular muscle spasm – Psychological factors Psychological factors

• Deep, aching localized to the jointDeep, aching localized to the joint• Slow in onsetSlow in onset• Worsened with activity in initial stagesWorsened with activity in initial stages• Occurs at rest with advanced diseaseOccurs at rest with advanced disease

• May be referred eg hip pain referred May be referred eg hip pain referred to the thigh, groin, knee. to the thigh, groin, knee.

• Pain may be aggravated with Pain may be aggravated with weather changesweather changes

ExamExam

• Joint line Joint line tendernesstenderness

• Bony enlargement Bony enlargement of jointof joint

• +/- effusion+/- effusion

• Crepitus Crepitus

• Decreased range of Decreased range of motionmotion

Joint examJoint exam

• Joint line pain can Joint line pain can indicate tear of the indicate tear of the lining of the lining of the capsule or the capsule or the meniscus.meniscus.

Joint examJoint exam

• In the evaluation of joint In the evaluation of joint line pain, perform a line pain, perform a varus or or valgus stress test. .

• Apply stress across the Apply stress across the joint, place fingers joint, place fingers directly over the joint directly over the joint line to assess for pain, a line to assess for pain, a clunk may indicate a clunk may indicate a meniscal tear, or , or crepitus may indicate crepitus may indicate cartilage damage.cartilage damage.

• Have the patient to lie supine on the Have the patient to lie supine on the exam table with leg muscles relaxed exam table with leg muscles relaxed

• Press the patella downward and Press the patella downward and quickly release it. quickly release it.

• the patella visibly rebounds.the patella visibly rebounds.

• This mean a large knee effusionThis mean a large knee effusion

• Called ballotable patellaCalled ballotable patella

• Have the patient lie supine Have the patient lie supine with leg muscles relaxedwith leg muscles relaxed

• Compress the Compress the suprapatellar pouch with suprapatellar pouch with your thumb, palm, and your thumb, palm, and index finger. index finger.

• "Milk" downward and "Milk" downward and laterally so that any excess laterally so that any excess fluid collects on the medial fluid collects on the medial side. side.

• Tap gently over the Tap gently over the collected fluid and observe collected fluid and observe the effect on the lateral the effect on the lateral side side

• A fullness on the lateral A fullness on the lateral side indicates the presence side indicates the presence small knee effusion small knee effusion

Involved jointsInvolved joints

• DIPDIP• 11stst carpometacarpal carpometacarpal• cervical/lumbar facet jointscervical/lumbar facet joints• 11stst metatarsophalangeal metatarsophalangeal • HipsHips• KneesKnees

• UncommonUncommon• Wrist, elbows, shoulders, Wrist, elbows, shoulders,

anklesankles

• 11stst metatarso-phalangeal most commonly metatarso-phalangeal most commonly affected in OA of the foot. affected in OA of the foot.

Typical findingsTypical findings

• Heberden’s nodesHeberden’s nodes

• Bouchard’s nodesBouchard’s nodes

Varus deformity of the kneeVarus deformity of the knee

TreatmentTreatment• Non-pharmacologicalNon-pharmacological• No proven medication-based disease No proven medication-based disease

modifying intervention exists. modifying intervention exists. • Analgesics (acetominophen/ paracetamol)Analgesics (acetominophen/ paracetamol)• NSAIDSNSAIDS Help pain symptoms but controversial for Help pain symptoms but controversial for

long term use in non-inflammatory OA long term use in non-inflammatory OA because of risks vs benefitsbecause of risks vs benefits

• NarcoticsNarcotics• Intra-articular steroidsIntra-articular steroids• Chondroprotective agentsChondroprotective agents• Anti-depressantsAnti-depressants

Non-pharmacological rxNon-pharmacological rx

• Reasonable evidence Reasonable evidence for efficacyfor efficacy

• Exercise – prevent Exercise – prevent disuse atrophy of disuse atrophy of musclesmuscles

• Physical therapy: Physical therapy: Hydrotherapy/heat/colHydrotherapy/heat/cold, paraffin baths d, paraffin baths

• Weight lossWeight loss

• Education Education

• Wedges shoe Wedges shoe insoles/bracesinsoles/braces

• Refer to physiatrist for Refer to physiatrist for management plan.management plan.

AnalgesicsAnalgesics• Paracetamol at doses of up to 4g per Paracetamol at doses of up to 4g per

dayday

Opioid analgesicsOpioid analgesics

• Generally should be avoided for long Generally should be avoided for long term useterm use

• For short term rx they may be For short term rx they may be effective.effective.

• In older pts use caution because of In older pts use caution because of side effects such as confusion, side effects such as confusion, constipation, sedation.constipation, sedation.

• Can use tramadol with pcm, in Can use tramadol with pcm, in addition to NSAID/COX-2 inhibitoraddition to NSAID/COX-2 inhibitor

• A controlled study showed codeine A controlled study showed codeine and pcm combination to be and pcm combination to be equivalent to tramadol and pcmequivalent to tramadol and pcm

• Consider opiates if pt is not a Consider opiates if pt is not a candidate for surgery, or is at high candidate for surgery, or is at high risk for side effects from NSAIDSrisk for side effects from NSAIDS

NSAIDSNSAIDS• Useful in non-inflammatory OA when Useful in non-inflammatory OA when

pain is moderate to severepain is moderate to severe

• Topical preparations availableTopical preparations available

• PGE2 may contribute to local PGE2 may contribute to local inflammation and so there is a role inflammation and so there is a role for NSAIDS in inflammatory OA for NSAIDS in inflammatory OA

Selective COX-2 inhibitorsSelective COX-2 inhibitors• They have 200-300 times selectivity They have 200-300 times selectivity

for COX-2 over COX-1.for COX-2 over COX-1.

• Less gastroduodenal toxicityLess gastroduodenal toxicity

• Avoid in pts with atherosclerotic CAD Avoid in pts with atherosclerotic CAD - use traditional NSAIDS with a - use traditional NSAIDS with a PPI/sucralfate/misoprostolPPI/sucralfate/misoprostol

Side effectsSide effects

• Rash/hypersensitivityRash/hypersensitivity

• GI bleedingGI bleeding

• CNS dysfunction in elderlyCNS dysfunction in elderly

• Impairment of renal/hepatic/platelet Impairment of renal/hepatic/platelet function. function.

How can NSAIDS lead to renal How can NSAIDS lead to renal dysfunction?dysfunction?

• By interfering with vasodilator renal By interfering with vasodilator renal PG and causing renal ischemia.PG and causing renal ischemia.

Intra-articular corticosteroidsIntra-articular corticosteroids• May be used if NSAIDS are May be used if NSAIDS are

contraindicated, persistent pain despite contraindicated, persistent pain despite use of other medications.use of other medications.

• (not > 2 injections per year per joint)(not > 2 injections per year per joint)• saline vs. steroid injection?saline vs. steroid injection?• A study comparing the two in knee OA A study comparing the two in knee OA

showed no effect on joint space narrowing showed no effect on joint space narrowing or significant difference in pain at the end or significant difference in pain at the end of the study, but over a 2 yr period saline of the study, but over a 2 yr period saline injections has less pain relief.injections has less pain relief.

Intra-articular hyaluronansIntra-articular hyaluronans

• Evidence shows they have a small Evidence shows they have a small advantage in terms of pain control, advantage in terms of pain control, compared to intra-articular placebos compared to intra-articular placebos or NSAIDS.or NSAIDS.

• No evidence for improvement in No evidence for improvement in functionfunction

• Two studies comparing intra-articular Two studies comparing intra-articular steroids to hyaluronans have come to steroids to hyaluronans have come to opposite conclusions-more trials are opposite conclusions-more trials are needed.needed.

Surgical: arthroscopySurgical: arthroscopy

• arthroscopy is not recommended for arthroscopy is not recommended for nonspecific "cleaning of the knee“.nonspecific "cleaning of the knee“.

• Used to fix specific structural Used to fix specific structural damage on imaging (repairing damage on imaging (repairing meniscal tears, removing fragments meniscal tears, removing fragments of torn menisci that are producing of torn menisci that are producing symptoms). symptoms).

Joint replacementJoint replacement• If all other rx If all other rx

ineffective, and ineffective, and pain is severepain is severe

• Loss of joint Loss of joint functionfunction

• Joints last 8-15 Joints last 8-15 years without years without complicationscomplications

The endThe end