骨關(guān)節(jié)炎 綜述

1、DefinitionOsteoarthritis is a disease of complex etiology that results in loss of normal function due to breakdown of articular cartilage. A consensus definition comes from a workshop held in 1995: Osteoarthritic diseases are a result of both mechanical and biologic events that destabilize the norma

2、l coupling of degradation and synthesis of articular cartilage chondrocytes and extracellular matrix, and subchondral bone. Although they may be initiated by multiple factors, including genetic, developmental, metabolic, and traumatic, osteoarthritic diseases involve all of the tissues of the diarth

3、rodial joint. Ultimately, osteoarthritis diseases are manifested by morphological, biochemical, molecular, and biochemical changes of both cells and matrix which lead to a softening, fibrillation, ulceration, loss of articular cartilage, sclerosis and eburnation of subchondral bone, osteophytes, and

4、 subchondral cysts. When clinically evident, osteoarthritis diseases are characterized by joint pain, tenderness, limitation of movement, crepitus, occasional effusion, and variable degrees of inflammation without systemic effects.1Thirty-seven million people in the United States suffer from some fo

5、rm of arthritis. In 1994 the Centers for Disease Control reported that by year 2020, when one out of every two Americans will be over the age of 50, there will be a larger increase in new cases of arthritis than of any other disease in the United States. Among the leading causes of disability, arthr

6、itis heads the list; osteoarthritis is the most prevalent form and has the greatest economic impact. Because osteoarthritis (30% of the population over the age of 65) is much more prevalent than rheumatoid arthritis, the economic impact of osteoarthritis may be 30 times greater than that of rheumato

7、id arthritis. Osteoarthritis will soon account for more than 30% of office visits. As physicians, our most important contribution will be to limit days lost from work as well as the social and psychological impact of this devastating disease.II. PathogenesisOsteoarthritis is primarily a disease of t

8、he articular cartilage. However, subchondral bone, synovium, ligament and supporting neuromuscular apparatus, if damaged will contribute to accelerated cartilage degradation. The components of articular cartilage include type II and other collagens, proteoglycans and chondrocytes. Nutrition of chond

9、rocytes is provided by diffusion from the blood supply of subchondral bone and synovial fluid.NORMALOSTEOARTHRITIScapsulesynoviurn 1bonealtered contour of bonesynovial hypertrophythickened capsule cyst formation and scl&rosis in subchondral bone shelving fibnllated cartilage ostophytic lippingcartil

10、age IFigure 1- Diagram of a joint, normal on the left and osteoarthritic on the rightTypes III, IV, IX, X and XI collagen make up 10-20% of the total cartilage collagen and maintain the stability of Type II collagen. For example, type IX and XI collagen regulate its fibril diameter. The proteoglycan

11、 aggrecan is highly hydrophilic, with low viscosity. Its ability to retain water under conditions of load and release it during unloading imparts to articular cartilage its elastic property, allowing the cartilage to function as a shock absorber in the diarthrodial joint. An abnormality in the struc

12、ture of these proteins leads to cartilage with poor function and thus to the development of osteoarthritis.Biochemistry of Articular CartilageGlycosamtnoglycan subunits + Procollagen*- Chondrocyte -*n Factory-IncreaMd DKwa&BdTGF-pMBi.IncroAMcl OfrdMiM-FGF TGF-3/BMPsIncrsiased DBcnaasetaTable 1- Cyto

13、kine regulation of cartilage systhesis and DegradationCartilage HomeostasisFigure 7- Cartilage HomeostasisEpidemiological data suggest a genetic component to idiopathic osteoarthritis.Heberdens nodes (see Figure 8) are autosomally dominantly inherited in women and are associated with primary general

14、ized osteoarthritis, a variant that involves multiple weight bearing joints in patients under the age of 50. In men Heberdens nodes are autosomally recessive. There may be an hormonal component to osteoarthritis, since estrogen replacement therapy confers a protective effect on its development in po

15、st-menopausal women.Trauma is a risk factor for secondary osteoarthritis, especially periarticular injuries of the menisci, cruciate, and collateral ligaments of the knee, as well as fractures that involve the joint. Occupational injuries are less well established as risk factors, but studies report

16、 an increased incidence of osteoarthritis among jackhammer operators (wrists, hands and elbows), coal miners (knee), floor layers, construction workers, forestry workers and farmers, cotton pickers (fingers), and farmers (hips).14,15,16 More recently, three more studies have related occupation to hi

17、p osteoarthritis.17,18,19 Though a recent report noted an increased incidence of radiological but asymptomatic osteoarthritis in ex-female athletes and in a subgroup of control women engaged in long-term weight-bearing exercise, recreational sports are not associated with osteoarthritis in any age g

18、roup.20 Varus-valgus laxity, possibly related to defects in proprioception, may increase the risk of preventable knee osteoarthritis in women.21powtive riskWeak positive riskLocalized-Joint rnttabiMy/hypemwl ity-Abnorwl fotnt hp (oxigenital Of acquired)Table 2- Risk Factors Associated with Osteoarth

19、ritisThe role of quadriceps strengthening exercises on already involved knees was further investigated by Sharma, L et al.22 Adults with primary knee osteoarthritis were studied prospectively for eighteen months. Baseline quadriceps strength was measured and greater strength was associated with grea

20、ter risk for progressive tibiofemoral joint space narrowing among adults with malaligned or very lax knees. Although these results do not imply that physical activity in adults with knee osteoarthritis is harmful it does call intoquestion whether maximum quadriceps exercise in patients with malalign

21、ed and/or lax knees is protective or actually harmful.Obesity is associated with preventable osteoarthritis of the knee in women.23Lack of vitamin D predisposes patients with established osteoarthritis of the knee to further progression, and low levels of 25-OH Vitamin D are associated with radiogra

22、phic progression of hip osteoarthritis.III. Clinical PresentationMost clinicians divide osteoarthritis into two basic forms. Primary or idiopathic osteoarthritis refers to the type that occurs without any underlying predisposing factor. Secondary osteoarthritis follows an identifiable predisposing f

23、actor, either local or systemic.Fewer patients have symptomatic disease than is seen on x-ray.More than 80% of persons over the age of 50 have some radiographic evidence of osteoarthritis. The joints most commonly involved are the distal and proximal interphalangeals of the hand, first carpometacarp

24、al of the wrist, hip, knee and cervical and lumbar spine, in an asymmetrical fashion.Osteoarthritis SecondaryOlher joint and/ or bone cMBBaass(e.g-4 RAh septic adhrdis, Pagels diseaseh avascular necrosij)CaEcium deposition diseases(e.g. CPPD. apatile, desiructive anhropalhy), Congenital/ development

25、al diseases-Localized(e.g.b congenital Np dispiacmerit. valgus/varus) Generalised bone dysp&tas, h&machromalass)Other diseases-Melabalic .g. ochronosis, acromegaly)-Neuropathic arthropathy-Miscellaneous (e.g., frostbite)Table 3 - Causes of Secondary OsteoarthritisPREVALENCE OF RADJOGRAPHIC OSTEOARTH

26、RITISIN THREE MAJQH JOINT SITES*JOINT SITESEXHIPKNEEDISTAL INTERPHALAMGEAL JOINT65MEN6%渤50%WOMEN4%40%BO%APPROXIMATE OVERALL PREVALENCE OF0 7%1.6%3.0%SYMPTDMAHC DA IN ADULTS IN USA APPROXIMATE % OF THOSE-WITH ADVANCED腿頰 3&40%1020%RADIOGRAPHIC CHANGES(M=F)(FM伊峋W(wǎng)ITH SYMPTOMS -UUjtUK 4 LXWUMX： au.l MTab

27、le 4 - Prevalence of Radiographic Osteoarthritis in 3 Major Joint SitesPain is the most prominent feature and the most common presenting complaint of osteoarthritis. Pain appears upon motion of the affected joint and resolves with rest. Since cartilage has no nerve supply, the pain comes from subcho

28、ndral bone, synovium, joint capsule, ligaments, and muscle. Passive and active motion of the joint elicits pain, and coarse crepitus on motion may be heard or palpated. Although the sources of pain are well known, the perception of pain depends on the relationship between structural change and perip

29、heral and central pain processing, with input from cultural, gender, and psychological factors.24 Since the major symptom of osteoarthritis is pain, consideration of all of these issues is important in the treatment plan.In osteoarthritis, stiffness in the morning typically lasts less than 20 minute

30、s. After being immobile, some patients report a transient stiffness, the so-called gelling phenomenon, which also lasts no longer than 20 minutes. In contrast, in rheumatoid arthritis, gelling lasts for several hours. Osteoarthritis is not associated with the presence of fever, weight loss, anorexia

31、, severe muscle atrophy, or symmetry of joint involvement.As the disease progresses decreased range of motion occurs because of joint surface incongruity and because of increased pain with motion. Other reasons for decreased range of motion are muscle spasm and contracture, capsular contracture, and

32、 mechanical problems related to osteophytes or loose bodies in the joint. Accumulation of synovial fluid may contribute to pain, decreased range of motion, and distention of the capsule.Advanced disease is associated with subluxation of the joint and gross deformity. In osteoarthritis, Heberdens nod

33、es (see Figure 8)Figure 8 - Heberdens Nodes in Osteoarthritisare bony enlargements of the distal interphalangeal joints with loss of joint space and osteophyte formation. Small gelatinous cysts (synovial herniations) may also be seen alongside the node. A similar bony enlargement of the proximal int

34、erphalangeal joints is called a Bouchards node.Heberdens and Bouchards nodes begin after age 45 and affect women more than men by 10:1. Heredity plays an important role in their development in women. Most are asymptomatic but some at onset are inflamed and painful. Involvement of the first carpometa

35、carpal joint (base of the thumb) limits a patients ability to open jars or use the wrist. Symptoms in this joint are the only evidence of wrist involvement in osteoarthritis and clearly differentiate it from rheumatoid arthritis, in which the entire wrist is swollen. Often the joint will sublux and

36、give the hand a squared off appearance.Osteoarthritis: Bouchards NodesFigure 9 - Bouchards Nodes in OsteoarthritisThe talonavicular and the first metatarsophalangeal joints are the most common joints involved in the feet. In the metatarsophalangeal joint, bunion formation causes pain and widening of

37、 the foot. In addition hallux rigidus (rigid great toe) can also occur, limiting motion and causing difficulty in walking. Very often the patient finds he must buy wider shoes to accommodate the deformity.Figure 10 - First Metacarpal Joint Involvement in OsteoarthritisA rocker bar placed under the f

38、irst metatarsophalangeal joint is often very effective in decreasing pain. Pain on inversion and eversion motions of the ankle is usually due to degenerative osteoarthritis of the subtalar or talonavicular joint and should be differentiated from the true ankle joint (tibiotalar, plantar and dorsifle

39、xion of the foot) arthritis, which is more likely to be due to traumatic secondary osteoarthritis.Hip osteoarthritis is more common in men, is usually unilateral, and causes a characteristic painful (antalgic) gait. Very often hip pain is referred to the knee. In hip disease, the following motions a

40、re impaired, in order of frequency: internal rotation in flexion, internal rotation in extension, flexion, external rotation in flexion, external rotation in extension, and extension.Knee osteoarthritis is common. Unlike rheumatoid arthritis, osteoarthritis is of usually limited to a single (patello

41、femoral, medial, or lateral) compartment of the knee and is not symmetrical. The effusions are less inflammatory in osteoarthritis than in rheumatoid arthritis. Loss of lateral compartment joint space causes genu valgus or knock knee. Loss of medial compartment space leads to genu varus or a bow leg

42、s. In patellofemoral involvement the patient complains of anterior pain usually going up (more than down) stairs.IV. Laboratory Findings and ImagingThe laboratory evaluation in osteoarthritis is important for the lack of positive findings associated with the disease. Routine tests such as blood coun

43、t, urinalysis, sedimentation rate (ESR), biochemistries, and specialized tests such as rheumatoid factor, antinuclear antibody, and thyroid function tests are normal but useful to exclude other disease. However, the elderly have a high incidence of rheumatoid factor, antinuclear antibody, and elevat

44、ed ESR without obvious illness. The history and clinical presentation are the most important elements of diagnosing a specific type of arthritis. The laboratory helps support, rule out, or subclassify a clinical diagnosis.Synovial fluid analysis should be done on joints with large effusions. In oste

45、oarthritis aspiration should demonstrate clear fluid with a cell count of less than 10,000 WBC/mm3 (higher than this suggests inflammatory arthritis or infection) with normal protein and glucose, good viscosity, and a negative polarized light microscopic examination for crystals. (When aspirating an

46、y joint, use aseptic technique, wear gloves, and send a specimen from every aspiration of joint fluid for culture and sensitivity regardless of the working diagnosis.)Measurement of degradation components of cartilage of cartilage and matrix in serum, urine or joint fluid has attracted much recent i

47、nterest, since finding evidence of early cartilage breakdown might lead to earlier diagnosis and intervention. One can measure constituents of the extracellular matrix, (proteoglycans aggrecan, collagen, and non-collagenous proteins), degradative proteolytic enzymes, cytokines, and nitric oxide. Mea

48、surement of these products in joint fluid offers an advantage in that the concentration will be higher and demonstration of their presence more specific than in serum. However, assessment of biologic markers is still experimental.25,26X-ray evaluation is the gold standard in the diagnosis of osteoar

49、thritis.X-rays of the knee and hip should always be obtained weight bearing. For the knee, it is helpful to obtain a lateral and Merchant view to evaluate the patellofemoral joint. In addition one should do a standing semi-flexed view of the knee to approximate the normal anatomic standing position

50、(Buckland-Wright) (see figure 12).Figure 11- Postero-Anterior view of knee in full extension: Note joint spaceFigure 12 - Buckland-Wright view of the same knee: Note true joint spaceJoint space narrowing is a non-specific finding that results from degeneration and disappearance of the articular cart

51、ilage for any cause. Increased bone density due to subchondral bony sclerosis and marginal osteophyte formation is more specific for osteoarthritis. Osteophytes are a late sign. Bone cysts are seen as periarticular translucent areas. Bone scans may be useful to rule out fracture due to metabolic, tr

52、aumatic, or metastatic causes; mild increased activity at the involved joints is commonly seen in osteoarthritis. Bone scan coupled with radio-labeled bone-seeking diphosphonates may predict subsequent radiographic progression. Nuclear magnetic resonance imaging (MRI) is extremely helpful in the spi

53、ne and has almost replaced computerized tomography (CT) scanning and myelography in defining disc disease, tumors, and spinal stenosis.X-ray changes in osteoarthritis occur slowly and the possible value of MRI in the future would be in allowing investigators to demonstrate a change in the progressio

54、n of the disease with medication in a shorter period of time. Methodologies are now being developed and validated to look at surrogate markers such as Global Cartilage Volume loss. Correlations with x-ray joint space narrowing in patients with osteoarthritis are being defined and related to fast and

55、 slow progressors. In preliminary data by Jean-Pierre Pelletier, it appears as if medial meniscal extrusion (but a not a simple tear of the medial meniscus) is associated with significant cartilage volume loss at 2 years.MRI otherwise offers little benefit in the evaluation of primary osteoarthritis

56、 but may also be helpful in identifying avascular necrosis, pigmented villonodular synovitis, and internal derangement of the knee. In sports injuries MRI changes correlate with changes seen at arthroscopy.Differential DiagnosisThe key to differentiating among the various rheumatic diseases is first

57、 to divide the diseases into inflammatory and non-inflammatory categories. Patients in the former category have swelling and systemic symptoms, such as morning stiffness and fatigue, and may have extraarticular features such as olecranon nodules. Next, determine whether the illness is symmetric or a

58、symmetric, and whether its onset is gradual or acute. Lastly, define its course as progressive or episodic, with flares and remissions. Osteoarthritis is asymmetric, unassociated with extraarticular or systemic features, and has a gradual onset. Careful correlation of the clinical, laboratory and x-

59、ray findings is important.Rheumatoid ArthritisRheumatoid arthritis is the illness that many clinicians confuse with osteoarthritis.Rheumatoid factor is not diagnostic of rheumatoid arthritis. In contrast to the inflammatory conditions (polymyalgia rheumatica, rheumatoid arthritis, psoriatic arthriti

60、s, etc.), anemia is not a feature of osteoarthritis. In rheumatoid arthritis a symmetrical pattern of joint involvement is almost always seen, while osteoarthritis is usually a disease of asymmetry affecting the large joints and spine. Osteoarthritis affects the first carpometacarpal joint but rarel