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