Presentation on theme: "MUSCULOSKELETAL BLOCK Pathology Disease of Joints"— Presentation transcript:
1 MUSCULOSKELETAL BLOCK Pathology Disease of Joints 2013Dr. Maha Arafah
2 Objectives Rheumatoid arthritis 1. Pathogenesis2. Morphology3. Major joints affected4. Clinical courseGout and gouty arthritis2. Morphology of acute and chronic articular lesions3. Clinical courseOsteoarthritis (degenerative joint disease)1. The primary articular defect in osteoarthritis.2. Pathogenesis3. Morphology4. Major joints affected5. Clinical course
3 JOINTS TYPES Synovial joints: also called diarthroses Nonsynovial joints: also called solid joint or synarthrosis
4 Inflammatory disease of joints (arthritis and synovitis) has four main causesDegeneration, e.g. osteoarthritis.Autoimmity, e.g. rheumatoid arthritis, SLE, autoimmunity, rheumatic feverCrystal deposition, e.g. gout and other crystalline arthropathies.Infection, e.g. septic arthritis, tuberculous arthritis.
6 X-Ray AbnormalitiesArticular cartilage, synovium, intra-articular ligaments, and synovial fluid are normally radiolucent(1) an increase in the joint space (fluid, blood, or proliferation of the synovium)(2) decreased joint space (degeneration of the articular cartilage)(3) abnormalities in articular cartilage (opacification, and subchondral bone, such as erosion and cyst formation)(4) the presence of abnormal loose bodies in the joint space.Magnetic resonance imaging (MRI) permits visualization of all structures and is an excellent method of evaluation of joints
9 Osteoarthritis Definition and Incidence Osteoarthritis is a nonneoplastic disorder of progressive erosion of articular cartilage.Common and important degenerative disease, with both destructive and reparative componentsUsually age 50+ years (present in 80% at age 65 years)
10 Osteoarthritis Aetiology The main factors in the development of osteoarthritis are:agingabnormal load on jointscrystal depositioninflammation of joints
11 Osteoarthritis Pathogenesis In general, osteoarthritis affects joints that are constantly exposed to wear and tear.It is an important component of occupational joint diseasee.g. osteoarthritis ofthe fingers in typiststhe knee in professional footballers
13 appears insidiously with age and without apparent initiating cause Osteoarthritis TypesPrimary osteoarthritis:appears insidiously with age and without apparent initiating cause usually affecting only a few jointsSecondary osteoarthritis
14 Osteoarthritis TypesPrimary osteoarthritis:Secondary osteoarthritis:some predisposing condition, such as previous traumatic injury, developmental deformity, or underlying systemic disease such as diabetes, ochronosis, hemochromatosis, or marked obesitySecondary osteoarthritis affect youngoften involves one or several predisposed jointsless than 5% of cases
15 Osteoarthritis Common sites usually one joint or same joint bilaterallyGender has some influence:Women : knees and handsMen : hips
16 Osteoarthritis The pathological changes involve: cartilage bone synoviumjoint capsulewith secondary effects onmuscle ( atrophy)
17 Osteoarthritis Pathogenesis The early change: destruction of articular cartilage, which splits (fibrillation), becomes eroded, and leads to narrowing of the joint space on X rayThere is inflammation and thickening of the joint capsule and synovium
18 constant friction of bone surfaces, leading to a highly polished bony articular surface (eburnation) Small cysts develop in the boneosteophytes
19 Osteoarthritis. : Histologic demonstration of the characteristic fibrillation of the articular cartilage.
22 Pathological changes in osteoarthritis normal synovial jointearly change in osteoarthritis'Heberden's nodes (osteophytes on the interphalangeal joints of the fingers)Eburnation & osteophytes formation
23 Osteoarthritis Clinical features An insidious disease predominantly affecting patients beginning in their 50s and 60s.Characteristic symptoms include deep, aching pain exacerbated by use, morning stiffness and limited range of movementswelling of affected jointsOsteophyte impingement on spinal foramina can cause nerve root compression with radicular pain, muscle spasms, muscle atrophy, and neurologic deficits.Heberden nodes in fingers of women only (osteophytes at DIP joints)Loose bodies: may form if portion of articular cartilage breaks off
25 Course & PrognosisOsteoarthrosis is a slowly progressive, chronic joint disabilityEventually, elderly sufferers may become confined to wheelchairsRecent advancements in the technique of joint replacement with prostheses have improved the outlook of these patients
26 Osteoarthritis Summary Incidence: common after 50 yearPrimary and secondary types: underlying conditionsPathogenesis: erosion of articular cartilageClinical features: pain and limitation of function
28 Rheumatoid arthritisDefinition aetiology pathological features clinical features radiological features
29 Rheumatoid arthritis Definition Chronic systemic inflammatory disorder affecting synovial lining of joints, bursae and tendon sheaths; also skin, blood vessels, heart, lungs, musclesProduces nonsuppurative proliferative synovitis, may progress to destruction of articular cartilage and joint ankylosis1% of adults, 75% are women, peaks at ages years; also menopausal women
31 Rheumatoid arthritis Aetiology The joint inflammation in RA is immunologically mediatedGenetic and environmental variables
32 Rheumatoid arthritis Aetiology triggered by exposure of immunogenetically susceptible host to arthitogenic microbial antigenautoimmune reaction then occurs with T helper activation and release of inflammatory mediators, TNF and cytokines, that destroys jointscirculating immune complexes deposit in cartilage, activate complement, cause cartilage damageParvovirus B19 may be important in pathogenesis.
33 HLA-DR4, DR1 (65%)are derived from proteins in which arginine residues are converted to citrulline residues posttranslationally Antibodies against cyclic citrullinated peptides (CCP protein antibodies) is the most specific for a diagnosis of rheumatoid arthritis
34 Rheumatoid arthritis Laboratory Findings: 80% have IgM autoantibodies to Fc portion of IgG (rheumatoid factor), which is not sensitive or specific;synovial fluid has increased neutrophils (particularly in acute stage) & proteinAnti-CCP (cyclic citrullinated peptides)protein antibodies most specific for a diagnosis of rheumatoid arthritisOther antibodies include antikeratin antibody (specific, not sensitive), antiperinuclear factor, anti-rheumatoid arthritis associated nuclear antigen (RANA)Genetics: HLA-DR4, DR1 (65%)
35 Rheumatoid arthritis Pathologic Features synovial cell hyperplasia and proliferationdense perivascular inflammatory cell infiltrates (frequently forming lymphoid follicles) in the synovium composed of CD4+ T cells, plasma cells, and macrophagesincreased vascularity due to angiogenesisneutrophils and aggregates of organizing fibrin on the synovial surfaceincreased osteoclast activity in the underlying bone bone erosion.
36 Rheumatoid arthritis Pathologic Features Pannusformed by proliferating synovial-lining cells admixed with inflammatory cells, granulation tissue, and fibrous connective tissueEventually the pannus fills the joint space, and subsequent fibrosis and calcification may cause permanent ankylosis.
38 increased vascularity dense perivascular inflammatory cell infiltratesincreased vascularityneutrophils and aggregates of organizing fibrin on the synovial surfacesynovial cell hyperplasia and proliferationPannus formationincreased osteoclast activity in the underlying bone bone erosionswan neck finger
43 Rheumatoid arthritis X-ray: joint effusions, juxta- articular osteopenia, erosionsnarrowing of joint space; destruction of tendons, ligaments and joint capsules produce radial deviation of wrist, ulnar deviation of digits, swan neck finger abnormalities
44 Rheumatoid arthritis Clinical course: variable; malaise, fatigue, musculoskeletal pain and joint involvementjoints are warm, swollen, painful, stiff in morning10% have acute onset of severe symptoms, but usually joint involvement occurs over months to years50% have spinal involvementrheumatoid nodules, rheumatoid factor, typical radiographic changes
46 Rheumatoid arthritis Prognosis Reduces life expectancy by 3-7 yearsDeath due to amyloidosis, vasculitis, GI bleeds from NSAIDs, infections from steroids.
47 Rheumatoid arthritis Summary RA is a chronic inflammatory disease that affects mainly the joints, especially small joints, but can affect multiple tissues.The disease is caused by an autoimmune response against an unknown self antigen(s)This leads to T-cell reactions in the joint with production of cytokines that activate phagocytes that damage tissues and stimulate proliferation of synovial cells (synovitis).The cytokine TNF plays a central role, and antagonists against TNF are of great benefit.
48 Comparison of the morphologic features of RA and osteoarthritis
49 Comparison of Osteoarthrosis & Rheumatoid Arthritis
50 Gout Gout is an inflammatory disease. The first metatarsophalangeal joint is the site most commonly affected.It is swollen, red, and, no doubt, very painful.Sodium urate crystals have precipitated into the joint, producing an acute inflammatory response.
52 Hands, chronic gout - Clinical presentation This is an example of chronic gout with gouty tophi. Note that there are numerous asymmetrical, periarticular swellings.These represent inflammatory reaction to sodium urate crystals.Tophi appear only after repeated attacks of gout in patients whose hyperuricemia has not been treated.
53 Tophus, gout - Low powerHistologically, tophi consist of crystals that are surrounded by macrophages, lymphocytes, and often foreign body giant cells. In routinely processed sections, the crystals are removed during processing.Long, slender, needle-shaped monosodium urate crystals
54 Gout Besides joints, what other organ is affected in gout? approximately 20% of patients die of renal failure.Renal lesions are many:precipitation of urates in the medulla forms tophi;uric acid stones may formacute renal failure due to precipitation of urates in the collecting tubes
57 ScenarioA 40-year-old white woman presented to her physician with vague complaints of fatigue, anorexia, and generalized weakness for the previous six months. She complained that it was difficult to ambulate upon rising from bed, but after about 30 minutes she felt better and was able to move about the house. She also complained that stiffness and pain in her wrists and fingers made it difficult to do routine chores in the kitchen, because her manual dexterity was compromised. She was especially concerned about the recent swelling in the joints of her fingers.
60 Physical examinationher knees were swollen and tender, and motion in both her knees and hips waslimited. Her knees and both wrist joints were warm but not erythemic. The proximal interphalangeal joints of both hands were warm and enlarged by nonbony fusiform swelling. She had two small, nonpainful, subcutaneous (soft tissue) nodules along the proximal ulna of her left arm.
61 Radiographs of affected joints indicated soft tissue swelling, joint effusion, and juxtaarticular osteopenia.Synovial fluid was aspirated and had the following characteristics:Viscosity - low Color - translucent, yellow White blood cells cells per cu mm with 50% neutrophils No crystals Bacterial culture – negativeAs well, the patient had the following clinical pathologic features:HLA-DR4 - positive Rheumatoid factor - positive at a titer of 1:500 Erythrocyte sedimentation rate – increased
62 Acute rheumatoid arthritis This is a classic presentation of acute rheumatoid arthritis. It is polyarthritic, affects the proximal interphalangeal joints, and has produced a fusiform swelling of the soft tissue. The lesion is usually symmetrical.
63 How does the distribution of affected joints in the hand differ from that seen in degenerative joint disease? The lesions of degenerative joint disease in the hand are found in the distal interphalangeal joints, are bony, and are not symmetrical.
64 In this case, there is marked destruction of the epiphyseal bone In this case, there is marked destruction of the epiphyseal bone. The joint spaces are narrowed, because of the destruction of the articular cartilage. In severe cases, the joints become fused by bony ankylosis.
65 What is the significance of the radiologic findings in rheumatoid arthritis (RA)? In RA, there is diffuse narrowing of the joint space. The cartilage is destroyed by the release of IL-1 and TNF, which depresses the synthesis of proteoglycans, and by proteases released from neutrophils. As well, proliferation of the synovial membrane leads to pannus formation, which isolates the cartilage from the synovial fluid, its source of nutrients. The severe, extensive damage of RA often leads to ankylosis.
66 What is the significance of the radiologic findings in rheumatoid arthritis (RA)? In chronic RA, the periarticular bone is osteoporotic, a change secondary to disuse of the affected limbs, to the stimulation of osteoclasts by corticosteroid therapy, or to the release of RANK-L by activated lymphocytes in the synovium.
67 List two important histologic changes found in the synovial membrane in joints affected by rheumatoid arthritis. The synovium is proliferative and is infiltrated by numerous lymphocytes and plasma cells.
68 Which class of lymphocytes predominates in the inflammatory infiltrate Which class of lymphocytes predominates in the inflammatory infiltrate? An autoimmune reaction in which T cells play the pivotal role accounts for the inflammation and joint destruction. CD4+ cells accumulate in affected joints, where they stimulate monocyte- macrophages to release cytokines and recruit B cells, which produce antibody - most importantly, the autoantibody rheumatoid factor (IgM against the Fc portion of IgG). During active inflammation, the synovial tissue generates a plethora of cytokines/growth factors. It is now generally accepted that IL-1 and TNF are key mediators in the cytokine cascade.
69 What is the significance of the clinical signs of anorexia, fatigue, and generalized weakness in the first patient? It is important to realize that RA is a chronic, relapsing, inflammatory disease that includes the joints. While the principal target is the synovial lining of joints, the disease also affects many organ systems - skin, heart, lungs, blood vessels, and muscle. The release of inflammatory cytokines, such as IL-1 and TNF, from the joints into the circulation can lead to the generalized systemic signs and symptoms. As well, 80% of individuals with RA have autoantibodies (usually IgM) to the Fc portion of IgG. These circulating complexes contribute to the extra-articular signs of RA.
70 What is the significance of finding inflammatory cells in the joint fluid? Quantitation of white blood cells is an important part of synovial fluid analysis, especially because it is the major basis for classification of an effusion as septic, inflammatory, or noninflammatory.
71 Hands, chronic rheumatoid arthritis - Clinical presentation The destructive nature of chronic, severe rheumatoid arthritis:Subluxation and fusion of jointsUlnar deviation of the digitsNote that the lesion is polyarticular and symmetrical.The most common deformity of the thumb is flexion with hyperextension at the interphalangeal joint.
72 Rheumatoid nodule - Low power Rheumatoid nodules consist of a central zone of fibrinoid necrosis surrounded by a prominent rim of epithelioid histiocytes and numerous lymphocytes and plasma cells.Rheumatoid nodules occur in approximately 20% to 25% of patients with definitive or classic rheumatoid arthritis. Nodules generally are associated with severe articular and systemic disease and with high titers of rheumatoid factor.
73 Rheumatoid nodules occur in approximately 20% to 25% of patients with definitive or classic rheumatoid arthritis. Nodules generally are associated with severe articular and systemic disease and with high titers of rheumatoid factor.
74 Where do rheumatoid nodules typically develop Where do rheumatoid nodules typically develop? The nodules typically appear on the extensor surface of the forearm below the elbow, or at sites of local pressure, such as the Achilles tendon. Less commonly, they form in the lungs, spleen, myocardium, and heart valves. The subcutaneous nodules are firm, nontender, and round to oval.
75 degenerative joint disease is the formation of osteophytes at the margin of affected joints. What is the common name of osteophytes that develop at the distal interphalangeal joints of women? These osteophytes are called Heberden nodes.