Musculoskeletal Infections and Inflammatory Disorders Quiz

Musculoskeletal Infections and Inflammatory Disorders

• Musculoskeletal system is prone to various inflammatory disorders and infections
• Common inflammatory disorders include gout and rheumatoid arthritis
• Rheumatology deals with inflammation of muscles, bones, and joints
• Myositis is inflammation of the muscles, while osteomyelitis is inflammation of the bone usually due to infection

Osteomyelitis

• Bone is normally resistant to infection, but bacterial infections can occur due to breaks in the bone or spread from the bloodstream
• Risk factors for bone infections include immunosuppression, comorbid diseases like diabetes mellitus, nutritional deficiencies, and presence of prosthetic material
• Synovial fluid found in synovial joints, amount may increase in disease states
• Joint effusion refers to edema of the joint
• Limited blood supply makes it difficult to deliver medications, so intra-articular injection is preferred
• Osteomyelitis is an infection of the bone, usually caused by Staphylococcus aureus
• Sickle cell anemia patients are at risk for Salmonella osteomyelitis

Types of Osteomyelitis

• Hematogenous: rapid onset of symptoms, more common in children
• Contiguous: caused by trauma, surgery, or decubitus ulcers, more common in those with diabetes or peripheral vascular disease
• Chronic: defined by >6-8 weeks duration or lack of response to treatment, leads to necrotic bone and increased gangrene risk

Diagnosing Osteomyelitis

• Lab tests: CBC, ESR, C-RP
• Blood cultures are positive in only 50% of cases
• Culture and aspiration may fail to identify the pathogen
• Imaging: X-ray, CT scan, MRI
• Diagnosis can be challenging, requiring a combination of clinical presentation and diagnostic tests

Treating Osteomyelitis

• Antibiotic therapy: IV for 2-6 weeks, then oral
• Debridement of necrotic tissue
• Surgical drainage of abscesses
• Regular reevaluation of the patient for 2 years
• Removal of infected prosthesis may be necessary in some cases

Lyme Disease

• Bacterial disease caused by Borrelia burgdorferi, transmitted by ticks
• Incubation period of 7-14 days, fewer than 50% recall tick bite
• Erythema migrans ("bull's-eye rash") may develop
• Bacteria can disseminate throughout the body, infecting skin, heart, joints, eyes, nervous system
• Patients may present with arthralgia, myalgias, fatigue, and headache

Stages of Lyme Disease

• Early localized stage (3-30 days): fever, myalgias, erythema migrans
• Early disseminated stage (3-12 weeks): vague symptoms, lymphocytic meningitis, cranial neuritis, carditis, ocular involvement
• Late disseminated stage (months to years): severe joint pain, central nervous system involvement, polyradiculopathy

Diagnosing and Treating Lyme Disease

• Diagnosis based on symptoms, tick exposure, and lab tests (ELISA and Western blot)
• Single prophylactic dose of doxycycline for those with tick bite in endemic areas
• 10-21 day course of doxycycline for treatment
• Post-Lyme syndrome may occur, possibly due to prolonged immune response

Gout

• Hyperuricemia triggers inflammation, affecting specific joints like the first metatarsal
• Podagra: acute inflammation of the metatarsophalangeal joint of the great toe
• Primary and secondary forms of gout exist
• Uric acid crystals may be deposited in subcutaneous tissue ("tophi")
• Patients present with redness, warmth, swelling of the affected joint, often at night or early morning

Risk Factors for Gout

• Diet high in meat (purines)
• High alcohol consumption
• Obesity and yo-yo dieting
• Family history
• Chemotherapy, medications

Diagnosing and Treating Gout

• Chronic gout may involve multiple joints, can be confused with OA and RA
• Hyperuricemia may not be present, so should not be sole diagnostic criteria
• Aspiration of joint showing urate crystals is the gold standard for diagnosis
• Management involves treating acute attacks and preventing future attacks
• NSAIDs, colchicine, allopurinol are common treatments