Femoral Neck Stress Fracture M84.359A



Femoral Neck Stress Fracture ICD-10

Femoral Neck Stress Fracture ICD-9

  • 733.95 (stress fracture of Bone)

Femoral Neck Stress Fracture Etiology / Epidemiology / Natural History

  • Associated with the Female Athlete Triad.
  • Most commonly seen in military recruits and long distance running
  • Femoral sees 8.5 times body weight with running. Repetitive loading without osteoblastic repair leads to microfractures/stress  fracture.
  • 0.04% of military recruits, higher in women.

Femoral Neck Stress Fracture Anatomy

  • May have increased incidence and patients with femoracetabular impingement. 

Femoral Neck Stress Fracture Clinical Evaluation

  • hip pain, groin pain, generally in long distance runner. 
  • Activity related groin pain.
  • Advanced stages may be unable to bear weight due to hip, groin pain. 
  • Groin pain with hip ROM.  May have groin tenderness. 

Femoral Neck Stress Fracture Xray / Diagnositc Tests

  • AP pelvis, hip series may demonstrate endosteal callous formation, a sclerotic line traversing the trabeculae, or a radiolucent fracture line.
  • "Gray cortex sign” = subtle decrease in definition of the affected femoral neck cortex.  
  • 90% of the initial radiographs and 50% of the repeat radiographs at 4 to 6 weeks may be normal. 
  • Bone scan or MRI: the diagnosis of femoral neck stress fracture must be ruled out with bone scan or MRI in any patient suspected of having a femoral neck stress fracture before return to any sporting activity to decrease the risk of a displaced fracture.  MRI is prefered. 
  • MRI stress reaction = periosteal or bone marrow edema present on Short Tau Inversion Recovery (STIR) or fat-suppressed T2 sequences (Figure 2).
  • MRI stress fracture = a line of decreased signal intensity perpendicular to the cortex on T1 coronal sequences with corresponding high signal intensity on T2 and STIR sequences.
  • MRI with hip joint effusion is linked to failure of conserative care and need for operative fixation.  

Femoral Neck Stress Fracture Classification / Treatment

  • Compression-side fracture line <50% or tension side stress reaction: crutches and non-weight bearing for 6 weeks.  At 6 weeks increased WB 25% per week until painless full weight bearing is achieved.  When painfree may begin gradual return to activity over 4 month period.  If continued pain at 6 weeks consider repeat MRI. 
  • Compression-side fracture line >50% or with hip joint effusion: high risk of progression, consider operative fixation with inverted triangle three cannulated screws.
  • Tension-side fracture-on the superior side of the femoral neck.  High risk of displacement even if non-weight bearing=ORIF.  If fx displaces prognosis for return to sport is poor even after fixation
  • Metabolic workup with CBC, chemistry panel, vitamin D levels. 

Femoral Neck Stress Fracture Associated Injuries / Differential Diagnosis

  • Acetabular Labral Tear 719.95
  • Adult Hip Dysplasia
  • Femoroacetabular Impingement M25.859 719.95
  • hernia
  • Hip osteoarthritis
  • Hip Arthritis M16.10 715.15
  • Hip Joint Loose Body
  • Iliopsoas Tendinitis M76.10 726.5
  • intra-articular loose body
  • Osteitis Pubis
  • Pelvic Stress Fracture
  • Piriformis Syndrome G57.00 355.0
  • Pubalgia
  • sacroiliac arthritis
  • Snapping Hip Syndrome
  • Spinal Pathology
  • Greater Trochanteric Bursitis M70.60 726.5
  • Femoral Neck Stress Fracture / reaction
  • Transient Osteoporosis of the Hip


Femoral Neck Stress Fracture Complications

  • Displaced femorl neck fracture
  • AVN

Femoral Neck Stress Fracture Follow-up Care

  • Progressive weight bearing post-operatively as tolerated for 12 weeks. 
  • May begin return to run program  at 12 weeks provided they are pain free. 

Femoral Neck Stress Fracture Review References

  • Bernstein EM, J Am Acad Orthop Surg 2022;30:302-311
  • Boden BP, JAAOS 8:344;2000
  • Mora SaA OKU-Sports Medicine 3, 139-153
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