we present the case of a 13-year - old girl with left knee pain , an mri diagnosed focal periphyseal oedema ( fope ) lesion and no other identified injury or morphological abnormality . according to our literature search , this is the only case report that provides follow - up images for a case of isolated symptomatic fope . fope is a term used to describe the mri finding of bone marrow oedema situated around a physis at the time of its fusion , and affects lower limb bones of the adolescent skeleton in either sex . this is a rare finding of uncertain aetiology and significance that has shown itself to be a self - limiting condition [ 1 , 2 ] . fope lesions have so far only been described in patients with pain in the knee . most often they are active adolescents , and it may occur with or without a definitive history of trauma and associated injury [ 1 , 2 ] . proposed theories for the aetiology and significance of fope lesions were made when it was initially named in 2011 . however , the volume of evidence currently in existence and the lack of basic science mean that at present these are untested . a literature search using pubmed and medline produced just two papers [ 1 , 2 ] presenting a total of 15 cases , of which only five had isolated findings of fope . the remaining cases all had evidence of concomitant injury , morphological abnormality or musculoskeletal disease complicating the clinical picture . none of the five cases of isolated fope underwent mri imaging follow - up and so it is difficult to see if their symptoms correlated with changes to the fope lesion . the images presented here are those of a fit and active 13-year - old girl with no significant medical history . she complained of intermittent pain , swelling and locking in the left knee of nine months duration . her symptoms arose following a twisting injury sustained when she fell from a horse and settled into their intermittent pattern after an initial period of pain , swelling and reduced mobility that lasted for one week . clinical findings at the time of injury were unremarkable and x - ray imaging ( fig . ap and lateral radiographs of the knee from the time of initial injury . on examination at nine months she had medial tenderness and a positive mcmurray 's test , raising the suspicion of meniscal injury , for which the initial mri investigation was performed . this scan showed a focal region of oedema centred in the medial aspect of the distal femoral physis with no other internal derangement , and she was managed with observation . the follow - up mri images show the progression of the fope lesion over a four month period . there is a clear reduction in the intensity of the signal produced by the fope lesion in all three planes of the imaging ( fig . figure 2:mri images of the knee at 9 ( left ) and 13 months ( right ) after initial injury . mri images of the knee at 9 ( left ) and 13 months ( right ) after initial injury . her symptoms gradually improved without treatment , and with the significant improvement seen on her mri scan she was eventually discharged from our care fourteen months after her initial injury . whilst coining the term fope , zbojniewicz and laor   also attempted to theorize its underlying aetiology . they suggest the possibility of micro - fractures from athletic activity or trauma before going on to conclude that it may be an incidental finding relating to endochondral ossification , which may or may not be painful . their final conclusion was based on the preponderance for fope lesions to occur in adolescents during physeal fusion coupled with the presence of additional pathology in the majority of cases . however , the apparent correlation with athletic activity or trauma , and the absence of reported asymptomatic cases does not support this conclusion . the case described here shows a progression of the fope lesion towards resolution that is well correlated with the clinical development experienced by our patient . the story clearly relates to trauma in an active adolescent , and is very similar to that described previously . this suggests that in this case fope was the cause of pain and that our findings support the theory that trauma may play a role its aetiology . this case is in keeping with the previously described cohort of affected patients and supports the current data suggesting that fope is a self - limiting condition that does not require any invasive investigation or management . it provides added insight into the progression of fope that has previously not been reported and suggests that trauma is implicit in the development of fope lesions .
focal periphyseal oedema ( fope ) is a rare mri finding associated with pain in adolescent patients with very few reported cases . 
 we present a case of fope in a 13-year - old girl and the only follow - up imaging available for an isolated presentation of this condition.this article describes a clinical course that correlates well with the imaging obtained . 
 this article describes a clinical course that correlates well with the imaging obtained .