David Paul Johnson BS, Presenter: Nothing to Disclose

Marta Hernanz-Schulman MD, Abstract Co-Author: Stockholder, Biogen Idec Inc Stockholder, Bristol-Myers Squibb Company Stockholder, Healthways, Inc Stockholder, Pfizer Inc Stockholder, RTI Biologics, Inc Stockholder, sanofi-aventis Group

Steven A Lovejoy MD, Abstract Co-Author: Nothing to Disclose

Chang Yu PhD, Abstract Co-Author: Nothing to Disclose

J. Herman Kan MD, Abstract Co-Author: Nothing to Disclose

Contrast-enhanced musculoskeletal MRI is valuable in the work-up of musculoskeletal infections to delineate surgically significant abscesses. Our purpose is to evaluate the incidence and clinical impact of ECPA in pediatric osteomyelitis/septic arthritis.

This is an IRB approved, retrospective review of 19 children aged <5 with final diagnosis of osteomyelitis/septic arthritis seen from 2/2003 to 12/2008, who underwent MRI with IV gadolinium and subsequent surgical exploration for suspected infection yielding 28 epiphyses or apophyses in the study group. The control group consisted of 28 age-matched children with normal exams without evidence of infection who underwent gadolinium-enhanced MR for other reasons in the same period; 44 epiphyses or apophyses were imaged in 28 controls. Images were reviewed for frequency of focal and global ECPA, and correlated with epiphyseal cartilage abscesses or cartilage destruction. Findings were compared with surgical reports.

Study and control ECPA were respectively present in 19/28 (67.9%- 8 global, 11 focal) and 13/44 (29.6%- 0 global, 13 focal), P=0.014. Analysis of pattern of perfusion defects between study and control patients showed significant difference for global (P=0.00026) but no difference for focal perfusion defects (P=0.3927) when present. For the 8 study epiphyses with global perfusion defects, surgically confirmed epiphyseal abscess was present in 1 (12.5%) and epiphyseal cartilage destruction without abscess was present in 1 (12.5%); 6 epiphyses were normal. For the 11 study epiphyses with focal perfusion defects, epiphyseal abscesses were present in 2 (18.1%); 9 epiphyses were normal. For the control group, no abnormalities were found on follow-up of 13 patients with focal perfusion defects.

ECPA are seen normally, but are statistically more common in children with osteomyelitis/septic arthritis. Focal perfusion abnormalities were seen in both study and control populations. However, global perfusion abnormalities were only seen in children with infection.

ECPA are frequent in infection and portend pathology in a minority of patients. For most, these abnormalities may be related to increased intra-articular pressure and transient epiphyseal ischemia.

Johnson, D, Hernanz-Schulman, M, Lovejoy, S, Yu, C, Kan, J, Significance of Epiphyseal Cartilage Perfusion Abnormalities (ECPA) in Pediatric Osteomyelitis/Septic Arthritis Identified by MRI with Surgical Correlation.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8011717.html