MUSCULOSKELETAL PATHOLOGY - 3 Flashcards
Covers Traumatic & mechanical injuries, Infectious Bone Pathology
List 2 tumors that may develop in the sinus tracts of long standing chronic osteomyelitis
squamous cell carcinoma in the draining sinus tracts
sarcoma in the infected bone.
What’s your diagnosis?
History of prolonged steroid therapy
pain that was initially associated only with activity but has now become constant

Subchondral bone infarct due to avascular bone necrosis
Overuse injury
presents in young, female athletes as anterior knee pain.
Exacerbated by prolonged sitting or weight-bearing on a flexed knee
Patellofemoral Syndrome
the hole formed in the bone during the formation of a draining sinus
Cloaca
What’s your diagnosis?
localized pain over bone (spine)
compression fracture/neurologic deficit
low-grade fevers, chills, weight loss
Bone biopsy shows granulomas with caseous necrosis
Tuberculous spondylitis (Pott disease)
One important complication of TB osteomyelitis presenting as :
Fever, back/flank pain, inguinal mass, difficulty walking
Pain referred to hip or knee
Pain exacerbated with hip extension
Psoas abscess
List few causes for avascular bone necrosis
Alcohol abuse
Corticosteroid therapy
Trauma
Sickle cell crisis
Bisphophonate therapy
Organisms causing osteomyelitis in individuals with genitourinary tract infections or who are intravenous drug abusers.
Escherichia coli , Pseudomonas, and Klebsiella
Morphologic finding in bone infarct
empty lacunae surrounded by necrotic adipocytes

most commonly seen in adolescent obese males
African-American males aged 10-16 years
Antalgic gait
Pain in the groin/ thigh
see attached radiograph

Slipped capital femoral epiphysis
What is the morphologic finding associated with the condition described below?
formation of reactive bone in muscle after trauma, burns, or surgery

bone spicule formation
(The condition described in Myositis ossificans)
lesion in which periosteal new bone formation forms a sheath around the necrotic sequestrum
Involucrum
Identify the condition and state what’s the most likely cause.
4-8 year old child
Insidious onset of hip pain
May cause child to limp
loss of internal rotation and abduction of hip joint

The condition is Legg Calve Perthes disease
The most likely cause is idiopathic avascular necrosis of the proximal femoral epiphysis
Most common organism implicated in osteomyelitis
Staphylococcus aureus
11-15 year old child
physically active
pain on anterior aspect of knee exacerbated by squatting
tenderness over tibial tubercle
Osgood-Schlatter disease (traction apophysitis)
Identify the structure indicated in the attached image

Sequestrum
List the 5 Ps of compartment syndrome
Pain, Pallor, Paresthesias, Pulselessness, Paralysis
The first event in fracture healing

Hematoma
List 4 complications of a fracture
- Compartment syndrome - Ps: Pain, Pallor, Paresthesias, Pulselessness, Paralysis.
- Myositis ossificans (mesenchymal metaplasia- bone in muscle)*
- Fat embolism (long bone)
- Infection
Pediatric fracture wherein the convex surface is fractured while the concave surface of the bent bone remains intact.

Greenstick fracture

fragment of necrotic bone that is embedded in the pus in a focus of osteomyelitis
Sequestrum
Organism specifically associated with osteomyelitis in sickle cell disease
Salmonella
Classic clinical presentation of osteomyelitis
malaise, fever, chills, leukocytosis, and marked-to-intense throbbing pain over the affected region
Identify the structure indicated in the image

Involucrum
Radiograph finding in osteomyelitis
lytic focus of bone destruction surrounded by a zone of sclerosis
Organisms causing osteomyelitis in neonates
Haemophilus influenzae and group B streptococci
Pediatric fracture wherein the Convex side(tension side) remains intact
Torus (Buckle) Fracture