Published online Aug 28, 2016. doi: 10.4329/wjr.v8.i8.750
Peer-review started: January 27, 2016
First decision: March 23, 2016
Revised: April 10, 2016
Accepted: May 31, 2016
Article in press: June 2, 2016
Published online: August 28, 2016
Processing time: 212 Days and 12.5 Hours
To assess the potential value of femoral head (FH) volume measurements to predict joint collapse, as compared to articular surface involvement, in post-treatment osteonecrosis (ON) in pediatric patients affected by lymphoproliferative diseases.
Considering 114 young patients with lymphoproliferative diseases undergone a lower-limbs magnetic resonance imaging (MRI) examination between November 2006 and August 2012 for a suspected post-treatment ON, we finally considered a total of 13 cases (7 males, mean age 15.2 ± 4.8 years), which developed a FH ON lesions (n = 23). The MRI protocol included coronal short tau inversion recovery and T1-weighted sequences, from the hips to the ankles. During the follow-up (elapsed time: 9.2 ± 2 mo), 13/23 FH articular surface (FHS) developed articular deformity. The first MRI studies with diagnosis of ON were retrospectively analyzed, measuring FH volume (FHV), FHS, ON volume (ONV) and the articular surface involved by ON (ONS). The relative involvement of FHS, in terms of volume [relative volume (RV): ONV/FHV] and articular surface [relative surface (RS): ONS/FHS], was then calculated.
By using receiver operating characteristic curve analysis (threshold of 23% of volume involvement), RV predicted articular deformity in 13/13 FHS [sensitivity 100%, specificity 90%, accuracy 95%, positive predictive value (PPV) 93%, negative predictive value (NPV) 100%]. Considering a threshold of 50% of articular involvement, RS predicted articular deformity in 10/13 femoral heads (sensitivity 77%, specificity 100%, accuracy 87%, PPV 100%, NPV 77%).
RV might be a more reliable parameter than RS in predicting FH deformity and could represent a potential complementary diagnostic tool in the follow-up of femoral heads ON lesions.
Core tip: Osteonecrosis can affect different bone segments but the most common sites are the weight-bearing joints of the lower limbs (hips and knees), with potential evolution to disability. To date magnetic resonance imaging represents the standard imaging method in the assessment of bone necrotic lesions [osteonecrosis (ON)], replacing other techniques in diagnostic work-up of initial ON, allowing also the detection of early bone marrow changes. Our preliminary data show that the volume of the necrotic portion of the femoral head might be a parameter highly predictive of future collapse of femoral head affected by osteonecrosis also in young patients treated for haematological malignancies.