stress fracture (fatigue fracture)

Classification

• fatigue fracture
• stress insufficiency facture*

* MKSAP19 confuses stress insufficiency fractures with minimal trauma fractures or osteoporotic fractures referring to them as stress fractures

Etiology

• fracture of a bone that occurs as the result of repetitive stress, generally transverse in configuration.

Pathology

• most commonly occurs in metatarsals, tarsals & calcaneus
• stress insufficiency fractures* typically occur in the spine, sacrum, pelvis, or knee (MKSAP19)

* these are osteoporotic fractures but MKSAP19 calls them stress fractures

Clinical manifestations

• pain with percussion
• pain hopping on one leg

Radiology

• plain radiography (X-ray) 1st line but may fail to show fracture line
• bone densitometry (female distance runner with low BMI & amenorrhea)

Differential diagnosis

• minimal trauma fracture (osteoporotic fracture, insufficiency fracture)

Management

• depends on risk of non-union, determined largely by location of fracture
  • stress fractures at high risk of non-union include fractures of:
    • base of 2nd metatarsal
    • 5th metatarsal diaphysis
    • medial malleolus
• reduce activity to achieve pain-free function
  • gradual return to pain-free activity

More general terms

• bone fracture

More specific terms

• calcaneus stress fracture
• metararsal stress fracture (march fracture)
• subtrochanteric stress fracture
• tibial stress fracture

Additional terms

• minimal trauma (pathologic, osteoporotic, fragility, insufficiency) fracture