title: Abnormal findings in hallucal sesamoids on MR imaging-Associated with different pathologies of the forefoot? An observational study.
abstract: BACKGROUND
  To evaluate the prevalence and localization of abnormalities in the hallucal sesamoids detectable by magnetic resonance (MR) imaging in patients with forefoot pain and to determine which pathologies of tarsus, metatarsus and phalanges are associated with these abnormalities.
  
  
  METHODS
  The forefoot MRI examinations of 50 consecutive patients (32 females, 18 males; mean age 51 years, age range 20-86 years) were retrospectively analyzed by two musculoskeletal radiologists. A minimum of coronal and sagittal T1-weighted images and STIR images or T2-weighted images with fat saturation were performed on a 1.5-T scanner. Abnormal findings in the sesamoids were correlated with pathology in the I.MTP (metatarsal-phalangeal) joint, pathology in other parts of the forefoot and clinical information.
  
  
  RESULTS
  Signal abnormalities of the sesamoids were found in 7 patients out of 50 (14%). Two patients presented a bone marrow edema (BME) in both sesamoids, in 1 patient only the lateral one was affected; all three associated with pathology and pain in the I.MTP joint. In four patients only the medial sesamoid was affected, not associated with pathology in the I.MTP joint but with pathology in other parts of the forefoot.
  
  
  CONCLUSIONS
  The prevalence of signal abnormalities in hallucal sesamoids was 14%. BME of the lateral sesamoid or of both were predominantly associated with pathology in the I.MTP joint. In contrast, signal abnormalities of the medial sesamoid, without affection of the lateral one, were associated with pathology in other parts of the forefoot suggesting an overuse injury as a result of compensating posture.
authors.affiliation: Department of Radiology, Medical University of Vienna, Waehringer Gürtel 18-20, 1090 Vienna, Austria. vanessa.kulemann@meduniwien.ac.at
authors.forename: Vanessa
authors.initials: V
authors.lastname: Kulemann
authors.forename: Marius
authors.initials: M
authors.lastname: Mayerhoefer
authors.forename: Hans-Jörg
authors.initials: HJ
authors.lastname: Trnka
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Kristen
authors.forename: Erich
authors.initials: E
authors.lastname: Steiner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000842:Ankle / Q000473:pathology; D005260:Female; D006214:Hallux / Q000002:abnormalities / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008684:Metatarsus / Q000473:pathology; D008875:Middle Aged; D019370:Observation; D011859:Radiography; D012189:Retrospective Studies; D012716:Sesamoid Bones / Q000002:abnormalities / Q000000981:diagnostic imaging* / Q000473:pathology; D050277:Toe Phalanges / Q000473:pathology; D055815:Young Adult