Pelvis / Coccyx
Pelvic Stress Fracture
골반 피로골절
Repetitive-load microfracture of pelvis (most often inferior pubic ramus)
- How common
- 1–5% of distance runners/recruits
- Typical age
- Young female runners, military recruits
What is it?
Repetitive impact exceeds bone remodeling capacity; microdamage accumulates. Nutritional/hormonal factors (female athlete triad) worsen risk.
Commonly affected: Inferior pubic ramus (most common), sacrum, femoral neck base
How it develops
- Repetitive LoadCumulative impact from running/marching
- Remodeling ImbalanceResorption exceeds formation
- Microfracture AccumulationLinear microfractures in pubic ramus/sacrum
- Completed Stress FxContiguous fracture line, pain with load
Symptoms
- Gradual groin painDull pain worsening with activity
- Weight-bearing painWorse with walking/running/single-leg stance
- Gait alterationAntalgic limp
- Focal tendernessFocal tenderness over ramus or sacrum
- Night painRest pain as severity progresses
How it is examined
- Focal bone tendernessPoint tenderness over fracture site
- Single-leg hop testPain on single-leg hop
- Flamingo testSingle-leg stance provokes pain
- Weight-bearing assessmentAntalgic gait / avoidance of weight-bearing
Imaging
Early X-ray often normal; callus visible after 2–4 weeks.
- Normal early (false negative)
- Late callus formation
- Sclerotic line
- Periosteal reaction
STIR MRI is gold standard — detects marrow edema and fracture line early.
- Extensive marrow edema (STIR)
- Hypointense fracture line (T1)
- Surrounding soft-tissue edema
- Replaces bone scan
Non-surgical care
- Protected weight-bearingLimit to pain-free level, crutches if needed
- Graded rehabSwim/bike → gradual running progression
- Nutrition/hormone evalAssess energy, vitamin D, calcium, menstrual cycle
- Female athlete triad careIntegrated management of energy, menses, BMD
Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.
When surgery is considered
Displaced fracture, high-risk sites (femoral neck), conservative failure
Procedures that may be discussed
- Open reduction internal fixation (ORIF)
- Sacral screw fixation
Outlook
Most heal in 6–12 weeks; training/nutrition management prevents recurrence.