Subchondral insufficiency fractures of the femoral head: associated imaging findings and predictors of clinical progression.
OBJECTIVE
To characterize the morphology and imaging findings of femoral head subchondral insufficiency fractures (SIF), and to investigate clinical outcomes in relation to imaging findings.


METHODS
Fifty-one patients with hip/pelvis magnetic resonance (MR) images and typical SIF characteristics were identified and reviewed by two radiologists. Thirty-five patients had follow-up documentation allowing assessment of clinical outcome. Subgroup comparisons were performed using regression models adjusted for age and body mass index.


RESULTS
SIF were frequently associated with cartilage loss (35/47, 74.5 %), effusion (33/42, 78.6 %), synovitis (29/44, 66 %), and bone marrow oedema pattern (BMEP) (average cross-sectional area 885.7 ± 730.2 mm(2)). Total hip arthroplasty (THA) was required in 16/35 patients, at an average of 6 months post-MRI. Compared to the THA cohort, the non-THA group had significantly (p < 0.05) smaller overlying cartilage defect size (10 mm vs. 29 mm), smaller band length ratio and fracture diameters, and greater incidence of parallel fracture morphology (p < 0.05). Male gender and increased age were significantly associated with progression, p < 0.05.


CONCLUSIONS
SIF were associated with synovitis, cartilage loss, effusion, and BMEP. Male gender and increased age had a significant association with progression to THA, as did band length ratio, fracture diameter, cartilage defect size, and fracture deformity/morphology.


CONCLUSIONS
• Femoral head subchondral insufficiency fractures (SIF) frequently require total hip arthroplasty (THA). • SIF frequently coexist with synovitis, cartilage loss, and bone marrow oedema pattern. • SIF cartilage defect size, band length ratio, and fracture diameter/morphology can predict progression risk.
Department of Radiology and Biomedical Imaging, University of California, San Francisco, 185 Berry Street, Suite 350, San Francisco, CA, 94107, USA. lhackney@montefiore.org.
Lauren A
LA
Hackney
Department of Radiology and Biomedical Imaging, University of California, San Francisco, 185 Berry Street, Suite 350, San Francisco, CA, 94107, USA.|Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Min Hee
MH
Lee
Department of Radiology and Biomedical Imaging, University of California, San Francisco, 185 Berry Street, Suite 350, San Francisco, CA, 94107, USA.
Gabby B
GB
Joseph
Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA.
Thomas P
TP
Vail
Department of Radiology and Biomedical Imaging, University of California, San Francisco, 185 Berry Street, Suite 350, San Francisco, CA, 94107, USA.
Thomas M
TM
Link
D000368:Aged; D018450:Disease Progression; D005260:Female; D005264:Femoral Fractures / Q000175:diagnosis*; D005270:Femur Head / Q000000981:diagnostic imaging / Q000293:injuries*; D015775:Fractures, Stress / Q000175:diagnosis*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies
Femoral head; Insufficiency fracture; Magnetic resonance imaging; Subchondral fracture; Total hip arthroplasty