Post on 10-Oct-2020
Musculoskeletal disordersGbadero D. A.
Origin and function
• The musculoskeletal system develop from the embryonic mesoderm
• The muscles and the bones are intricately linked together
• They function together, facilitated by the nerves, to enable motions in different parts of the body
Components
• Muscles
• Bones
• Joints, ligaments and collagen
Major disorders of the MS system
• Infections
• Traumas
• Genetic disorders
• Congenital disorders
• Collagen vascular diseases
• Neoplastic disorders
Major features of MS diseases
• Pain
• Swelling
• Limitation of motions
• Fever
Pain
• Occurs early
• Often associates with swelling and limited motion
• Progressively worsens
• Commonly associated with infections and traumas
• Associates with SCD VOC
• Injections
Swelling
• Common when the cause of MS disorder is infection of tumours
• Rapid in infection and some cancers
• Occurs also with traumas
Fever
• Can associate with all MS disorders but is particularly more common with acute infection
• Acute fever and swelling with pain often connotes infection in the MS in the absence of trauma
Motion limitation
• Very common in acute infections of bones and joints
• Associates with injuries of the MS
• Often helps to locate the site of pathology
Infections
• Osteomyelitis
• Pyomyositis
• Arthritis
Trauma
• Very common due to falls and RTA
• Results mostly from falls during play
• Commonly involves the head and bones of the extremities
• Fractures and sprains are common
Neoplasm
• Osteosarcoma
• Chondrosarcoma
• Ewing’s sarcoma
Acute osteomyelitis
• Acute febrile illness of long bones often caused by bacteria
• Found globally but more in low income settings where bacterial infections are commoner
• Genetic disposition e.g. SCD patients
• May progress to chronicity if poorly managed
Aetiology
• Staph aureus
• H. influenzae
• S. pnuemo
• S. pyogenes
Pathogenesis
• Preceding traumas?
• Genetic disposition
• Spread from septicaemic infections
• Spread from adjourning joint infections
Clinical features
• Acute onset of fever
• Associated with progressive swelling of parts of the limb
• Pain
• Limitation of or inability to use the limb involved
• Long bone more frequently involved but can affect virtually all bones
• In chronic cases; discharging sinuses, abnormal gait, elongation/shortening of involved limb
Diagnosis
• Fever, swelling and limitation of motion
• Local heat and tenderness over involved bone
• Differential diagnosis include fracture, septic arthritis
Investigations
• FBC
• ESR
• Genotype
• Blood culture
• X-Ray
Treatment
• Antibiotics
• Rest
• Analgesics
• Surgery, cortical window (Incision and Drainage)
Complications
• Septicaemia
• Spread to adjourning joints
• Chronicity
• Limitation of movements
• Abnormal gait
Prognosis
• Often progress to chronicity if poorly treated
• Limb deformity
Prevention
• General improvement in improved hygiene and sanitation
• Immunization
• Improved healthcare services
• Good nutrition
Septic arthritis
• Largely resembles osteomyelitis in its clinical features
• Similar organisms
• Similar treatment
Clinical features
• Pain
• Swelling of the involved joint
• Limitation of movements
• Fever
Differential diagnosis
• Osteomyelitis
• Trauma and bone fracture
• Sickle Cell Disease bone pain crisis
• Injection myositis
Treatment
• Antibiotics
• Surgical drainage
• Antipyretic analgesia
Collagen vascular diseases
• Rheumatic arthritis
• Juvenile rheumatic arthritis: Poly and pauci-articular disease NSAIDS
• Rheumatic fever: Acute fever, myocarditis and congenital heart failure, arthritis and chorea
• SLE: fever, arthritis, myalgia, butterfly rash, leucopenia, anti-nuclear antibodies.
Congenital disorders of the MS
• Tallipes equinoarus
• Genu varus/valgus
• Coxa vara - Blount’s disease
• Hip problems – congenital dislocation
• Rickets
• Osgood-Schlatter’s disease
Neuromuscular disorders
• Motor unit components
• Motor neuron or ventral horn cell
• The ventral horn cells’ axons constitute the peripheral nerve together with the sensory dorsal horn cells
• The motor fiber innervated by a single motor neuron
Muscular disorders
• Muscular dystrophies
• Muscular disuse atrophy
• Muscular infections
Muscular dystrophy
• Duchenne and Becker muscular dystrophies
• Common neuromuscular disorders
• X-linked recessive inheritance
• Affects 1:3600 live male infants of all races
• Gower’s sign
• Trendelenburg’s gait
• Becker’s similar but more protractive with longer life span
• No medical cure; supportive treatment only
Myotubular myopathy
• X-linked recessive inheritance
• Highly lethal
• Increased creatinine kinase
• No drug therapy
• Gene therapy promising
Myasthenia gravis
• Rare disease caused by immune-mediated neuromuscular blockade
• Postsynaptic muscle membrane or post-synaptic endplate is less responsive to acetylcholine than normal
• Mostly non-hereditary
• Prognosis rather unpredictable
Clinical features
• Progressive muscular weakness
• Facial weakness and dysphagia
• Diplopia
• Ptosis
Diagnosis
• Clinical test is done with administration of short acting cholinesterase inhibitor Edrophonium chloride – Within a few seconds of IV administration ptosis and ophthalmoplegia improve and weakness of other muscles decrease significantly.
• Characteristic EMG findings
• Serum Anti-Ach antibodies may be present
• Creatinine kinase always normal
Treatment
• Im Neostigmine 0.04mg/kg 4hrly
• Steroid treatment with Prednisolone as adjunct
• Thymectomy may produce a cure
Myotubular disease
• X-linked congenital disease of muscles
• Affects boys only
• No known drug therapy
• Promising gene therapy
• Poor log term prognosis
VOC of SCD patients
• Acute painful episodes mainly of long bones and back bones but may affect the smaller bones of the hand and feet and the sternum and ribs as well
• VOC can also affect the GIT and the skull causing headache
• Affects HbSS patients mostly
• Can also affect HbSC patients
Pathogenesis
• Sickling of red cells cause slugging and occlusion of microvasculature
• Occlusion leads to ischaemia
• Ischaemia causes pain
• Ischaemia increases propensity for infections
Clinical features
• Pain
• Insomnia
• Loss of appetite
• Dehydration from reduced fluid intake and vomiting
• Swelling/tenderness
• Limitation of movements
• Features of SCD
Differential diagnosis
• Acute osteomyelitis
• Septic arthritis
• Pyomyositis
• Acute pneumonia
• Acute abdomen
• Muscle spraying or Fracture of bones with history of trauma
Investigations
• FBC and PCV
• MP smear
• B/C
• E/U
• Sickling test
• RBC morphology
• Genotype
• X-ray
Treatment
• Adequate hydration
• Analgesia
• Muscle relaxation
• Anti-malarial therapy
• Antibiotic prophylaxis
• Faradin
Prevention
• Cleanliness
• Improved sanitation and hygiene
• Prevent dehydration with liberal fluids
• Avoid mosquitoes
• Avoid undue stress
• Good nutrition
• Prompt treatment of illnesses
• Counselling for self acceptance