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Musculoskeletal system

Pediatric musculoskeletal conditions

Radial head subluxation (Nursemaid elbow)

Developmental dysplasia of the hip

Legg-Calve-Perthes disease

Slipped capital femoral epiphysis

Transient synovitis

Osgood-Schlatter disease (traction apophysitis)

Musculoskeletal injuries and trauma

Rotator cuff tear

Dislocated shoulder

Radial head subluxation (Nursemaid elbow)

Winged scapula

Thoracic outlet syndrome

Carpal tunnel syndrome

Ulnar claw

Erb-Duchenne palsy

Klumpke paralysis

Iliotibial band syndrome

Unhappy triad

Anterior cruciate ligament injury

Patellar tendon rupture

Meniscus tear

Patellofemoral pain syndrome

Sprained ankle

Achilles tendon rupture



Degenerative disc disease

Spinal disc herniation


Compartment syndrome


Bone disorders

Osteogenesis imperfecta


Pectus excavatum


Genu valgum

Genu varum

Pigeon toe

Flat feet

Club foot

Cleidocranial dysplasia



Bone tumors




Osteomalacia and rickets


Paget disease of bone


Lordosis, kyphosis, and scoliosis

Joint disorders



Spinal stenosis

Rheumatoid arthritis

Juvenile idiopathic arthritis


Calcium pyrophosphate deposition disease (pseudogout)

Psoriatic arthritis

Ankylosing spondylitis

Reactive arthritis


Septic arthritis


Baker cyst

Muscular disorders

Muscular dystrophy



Inclusion body myopathy

Polymyalgia rheumatica



Neuromuscular junction disorders

Myasthenia gravis

Lambert-Eaton myasthenic syndrome

Other autoimmune disorders

Sjogren syndrome

Systemic lupus erythematosus

Mixed connective tissue disease

Antiphospholipid syndrome

Raynaud phenomenon


Limited systemic sclerosis (CREST syndrome)

Musculoskeletal system pathology review

Back pain: Pathology review

Rheumatoid arthritis and osteoarthritis: Pathology review

Seronegative and septic arthritis: Pathology review

Gout and pseudogout: Pathology review

Systemic lupus erythematosus (SLE): Pathology review

Scleroderma: Pathology review

Sjogren syndrome: Pathology review

Bone disorders: Pathology review

Bone tumors: Pathology review

Myalgias and myositis: Pathology review

Neuromuscular junction disorders: Pathology review

Muscular dystrophies and mitochondrial myopathies: Pathology review




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High Yield Notes

4 pages



of complete

External References

First Aid








Candida spp.

osteomyelitis p. 177

Mycobacterium avium-intracellulare p. , 138

vertebral osteomyelitis p. 177

Mycobacterium tuberculosis p. , 138

osteomyelitis p. 177

Neisseria gonorrhoeae p. , 140

osteomyelitis p. 177

Osteomyelitis p. 177

diagnostic findings p. 722

Pseudomonas aeruginosa p. , 141

sickle cell anemia p. 417

Staphylococcus aureus p. , 133

Pasteurella multocida

osteomyelitis p. 177

Pseudomonas spp.

osteomyelitis p. 177

Salmonella spp.

osteomyelitis p. 177

Staphylococcus aureus p. , 133

osteomyelitis and p. 177

Staphylococcus epidermidis p. , 133

osteomyelitis p. 177


Content Reviewers

Rishi Desai, MD, MPH


Marisa Pedron

Evan Debevec-McKenney

Osteomyelitis can be broken down. Osteo- refers to bones, –myel stands for myelo and relates to the bone marrow, and lastly, –itis refers to inflammation.

So, osteomyelitis is an inflammation of the bone or bone marrow, and it typically results from an infection.

Normally, if we look at a cross-section of a bone, we can see that it has a hard-external layer known as the cortical bone and a softer internal layer of spongy bone that looks like honeycombs.

There’s also another layer called the periosteum that covers the cortical bone - like the lamination of a basketball card - and it's where the muscles, tendons, and ligaments are attached.

If we zoom into a cross-section of cortical bone, we can see that it has many pipe-like structures called osteons running through the length of the bone.

Each pipe has an empty center called a Haversian canal which contains the nerves and blood vessels that supply the osteon.

At the outer-border of the osteon is a ring of cells called osteoblasts which synthesize bone.

Along with these cells are osteoclasts that break down bone.

In bones, like the long femur bones, the tips of the bone are called the epiphysis, while the shaft is called the diaphysis of the bone.

Between the epiphysis and diaphysis, we have the metaphysis. It contains the growth plate, the part of the bone that grows during childhood.

In osteomyelitis, microorganisms, such as bacteria, reach the bone to cause an infection in a few different ways.

Bacteria particularly affect certain high-risk individuals like those with a weak immune system, and those with poor blood circulation due to uncontrolled diabetes.

In fact, a major way that bacteria reach the bone is through the bloodstream, and it's called hematogenous spread. For example, this might happen in a person who uses contaminated needles to inject drugs or in individuals undergoing hemodialysis that may be contaminated by a bacteria or even through the dental extraction of an infected tooth.


Osteomyelitis is an infection and inflammation of the bone or bone marrow. It is often caused by bacteria like Staphylococcus aureus, which enters the bone through an injury, surgery, or a blood infection. Common symptoms of osteomyelitis include pain, swelling, swelling, and warmth around the affected bone. People can also have fever and chills, and weakness. The treatment typically involves weeks of antibiotics directed at the organism causing the infection.


  1. "Robbins Basic Pathology" Elsevier (2017)
  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "Pathophysiology of Disease: An Introduction to Clinical Medicine 7/E (ENHANCED EBOOK)" McGraw Hill Professional (2014)
  4. "CURRENT Medical Diagnosis and Treatment 2020" McGraw Hill Professional (2019)
  5. "Osteomyelitis" Infectious Disease Clinics of North America (2017)
  6. "Etiology of Osteomyelitis Complicating Sickle Cell Disease" Pediatrics (1998)
  7. "T1-weighted MRI Imaging Features of Pathologically Proven Non-pedal Osteomyelitis" Academic Radiology (2013)

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