Pathology of Joints PDF

Pathology of Joints Dr. Kareem M Ahmed Leader of MSK Module  A typical joint Key features: Cartilage Synovium Synovial fluid Bursa Ligaments Labrum / meniscus Tendon/muscles Bone  1. Cartilage - structure -normally hyaline cartilage in joints -type 2 collagen and chondroi...

Pathology of Joints Dr. Kareem M Ahmed Leader of MSK Module  A typical joint Key features: Cartilage Synovium Synovial fluid Bursa Ligaments Labrum / meniscus Tendon/muscles Bone  1. Cartilage - structure -normally hyaline cartilage in joints -type 2 collagen and chondroitin polysaccharide -firm gel-like structure -cartilage has no blood supply -poor ability to repair -degeneration leads to osteoarthritis  causes of osteoarthritis # primary -Genetic # secondary – common sequelae of many joint pathologies -trauma -infection -dysplasia -inflammation  Osteoarthritis: general features # clinical -post exercise stiffness -joint pain andtenderness -crepitus -bony swelling -angulation deformities -functional impairment # non-inflammatory synovial fluid  Radiographic features of OA # osteophytes # joint spacenarrowing # subchondral -Cysts and sclerosis # malalignment  Histological features of OA # osteophytes # joint spacenarrowing # subchondral -Cysts and sclerosis # absence of inflammatory tissue  OA -management # OAis usually slow and irreversible # Treatments include: -analgesics -NSAIDs -activity modification -mobility aids -?glucosamine sulphate Arthroplasty Sir John Charnley Low frictional-torque arthoplasty  Anatomy of hip replacement # stem –metal # head –metal / ceramic # cup – polyethylene / ceramic # cement - PMMA DIY hip replacement  2. synovium # innermost portion of the joint capsule # highly vascular # loose, lack of connectivetissue # produces synovial fluid # nourishes the avascular cartilage  Rheumatoid arthritis # abnormal activation of immune system # multi-system disorder # small joints synovitis (hands and feet) # also hip, shoulder, knee and spine # assoc. with vasculitis, iritis, and cardio-resp disease Tenosynovitis Tendon rupture # erosive arthritis # joint destruction # atlanto-axial subluxation  Rheumatoid arthritis treatment # analgesics # anti-inflammatories # surgery -tendon transfers -arthroplasty # disease modifying drugs -methotrexate -biological therapies (anti-TNF)  3. synovial fluid # fluid poduced by synovium # ultra-filtrate of plasma with hyaluronicacid # viscous, lubricating fluid # nourishment for cartilage # effusion = excessive fluid # easily seen in subcut joints  septic arthritis # medical emergency # risk of postiinfective arthritis # high index of suspicion # differential: -inflammatory arthritis -gout # investigations -WBC, CRP -fluid aspiration and analysis  septic arthritis management # urgent gram stain -usually Gram positive cocci (staphlococcus) # IV antibiotics # arthroscopic washout  gout # abrupt onset of severe joint inflammation, often with onset in thenight # 75% of initial attacks in first MTPjoint # usually monarticular, may be polyarticular # attack subsides in 3-10 days # urate crystals present in synovial fluid # hyperuricemia may or may not bepresent  gout # bi-refingent crystals # tophi deposits # hot painful joint # treatment -exclude infection -NSAIDs -colchicine -allopurinol Hard to differentiate between gout, sepsisand inflammatory arthritis  4. bursa # lubricating cushion around a joint # enables skin/tendons to movefreely # potential space # may become inflammed or infected # repetitive use  bursitis # housemaid’s knee (pre-patellar bursitis) - normally electricians! # student’s elbow (olecranon bursitis)  bursitis management # activity modification -rest / knee pads # NSAIDs / analgesics # antibiotics if infected# surgical debridement  5. Ligaments # tough collagen tissue # connects bones to bones # dynamic stability to all joints # prevent dislocation / subluxation # more mobile joints more dependenton ligaments for support (egshoulder) # weight-bearing joints under higher stressand more likely to fail ACLrupture ACLreconstruction  6. Meniscus / Labrum # thickened fibrocartilage # provide extra stability (shoulder labrum) # help distribute load (knee menisci) Shoulder dislocation Bankart lesion and repair  7. muscles and tendons # provide forces to enable joint movement # coordinated movements enable locomotion # work with agonists and against antagonists # muscle imbalance leads to -stiffness -contractures -subluxation  Cerebral palsy # non progressive neuromeuscular disorder # onset before 2 years old # aetiology: perinatal infection, anoxia, prematurity, headinjury # joint contractures -cartilage deformity -joint dysplasia # spine, hip, knee, foot, hand effected  Cerebral palsy classification # spastic (70%) -upper motor neuron involvement -increased tone and reflexes -only type readily amenable to surgery # dyskinetic (20%) -basal ganglia involvement -slow writhing, involuntary movements -worse when emotionally tense #ataxic (10%) -cerebellum involvement -weakness and incoordination  hip joint in cerebralpalsy # excessive contracture -quadriceps -adductors # progressive subluxation # posterior dislocation # developmental dysplasia -valgus neck -shallow acetabulum  CPhip treatment # bracing / serial casting # physiotherapy to maintain ROM # botulinum A toxin injection # release of adductor tendons # femoral / acetabulum osteotomy  CPhip treatment # Surgical aims of osteotomy: -correct alignment of femur -covered by horizontal acetabulum 8. Bones  Summary Anatomical part Pathology encountered.Cartilage 1Osteoarthritis.Synovium 2Rheumatoid arthritis.Synovial fluid 3 Gout / sepsis.Bursa 4 bursitis.Ligaments 5 ACLrupture.Labrum / meniscus 6 Bankart lesion.Tendon/muscles 7 Cerebral palsy.Bone 8 Fractures