Subchondral insufficiency fractures of the femoral head: associated imaging findings and predictors of clinical progression

Abstract

Objectives 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 crosssectional 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.

Subchondral Insufficiency Fracture of the Femoral Head in a Pregnant Woman with Pre-existing Anorexia Nervosa

“…Thin bone trabeculae indicated the presence of osteoporosis, which is a major risk factor for SIF (Yamamoto and Bullough 1999;Ikemura et al 2013) It is also possible that the present patient might have developed SIF of the right femoral head considering the radiological findings, although there was no histopathological examination. The resolution of symptoms with conservative treatment was consistent with the previously reported cases of SIF (Bangil et al 1996;Rafii et al 1997;Yoon et al 2014;Hackney et al 2016;Sonoda et al 2016). Furthermore, increased uptake in the bilateral femoral heads on bone scintigraphy was also compatible with SIF (Rafii et al 1997;Yamamoto and Bullough 1999;Iwasaki et al 2011), without a "cold in hot" appearance, which is compatible with ON (Sugano et al 1999).…”

“…The prognosis of SIF may depend on the initial treatment, as well as the degree of osteopenia (Yamamoto et al 2008). Restricted weight-bearing can be successful in SIF, and about a half (Yoon et al 2014;Hackney et al 2016) or twothirds (Sonoda et al 2016) of SIF cases might improve without surgical treatment. Precise diagnosis might contribute to a better outcome by avoiding early arthroplasty in young women.…”

“…Subchondral insufficiency fracture (SIF) of the femoral head is a relatively new entity that may cause femoral head collapse with no evidence of osteonecrosis (ON) caused by normal or physiological stress to the femoral head (Bangil et al 1996;Rafii et al 1997;Yamamoto and Bullough 1999). Previously thought to be a disease predominantly affecting elderly osteoporotic patients, SIF has been reported in adults of varying ages and activity levels (Yamamoto et al 2008;Iwasaki et al 2011;Yoon et al 2014;Hackney et al 2016). To the best of our knowledge, however, SIF of the femoral head has never been reported to occur in pregnant women.…”

Clinical outcomes in relation to locations of bone marrow edema lesions in patients with a subchondral insufficiency fracture of the hip: a review of fifteen cases

“…A recent study showed that cartilage defect size is associated with a clinical subchondral insufficiency fracture of the femoral head progression. 11 Further investigations with histopathological assessments at both the femoral head and acetabulum are necessary to clarify the impact of comorbid BME lesions on the prognosis of subchondral insufficiency fracture of the hip.…”

MR Imaging of the Hip: An Update on Bone Marrow Edema

“…BME, which invariably accompanies this lesion, was reported to be an insignificant predictor of clinical progression. 62 Small cartilaginous defect size, smaller fracture diameter, and parallel morphology with regard to the joint surface were suggested as good prognostic factors. 62 Surrounding muscle edema, synovitis, and hip joint effusion represent additional common features.…”