title: MRI characteristics of healed and unhealed peripheral vertical meniscal tears.
abstract: OBJECTIVE
  The objective of our study was to retrospectively compare the MRI characteristics of surgically confirmed healed and unhealed peripheral vertical meniscal tears.
  
  
  METHODS
  The study group consisted of 64 patients with 86 peripheral vertical meniscal tears diagnosed on MRI who subsequently underwent knee surgery. The MRI examinations were retrospectively reviewed to assess the following tear characteristics: tear location relative to the meniscocapsular junction, tear width, tear length, tear extension through one or both surfaces, sequences on which tear was visualized, signal intensity of tear on T2-weighted imaging, and presence of low-signal-intensity strands bridging the tear on T2-weighted imaging. Multivariate logistic regression models were used to determine whether MRI characteristics could be used to distinguish between healed and unhealed tears at surgery.
  
  
  RESULTS
  Tear location was the most significant characteristic (p<0.001) for distinguishing between healed and unhealed tears: 17 of 18 (94.4%) tears located at the meniscocapsular junction of the medial meniscus were healed and 15 of 68 (22.1%) tears not located at the meniscocapsular junction were healed. For tears not located at the meniscocapsular junction, MRI characteristics significantly associated with healed tears included a tear width of less than 2 mm (p=0.01), tear visualized only on intermediate-weighted imaging (p=0.01), tear showing intermediate or bright signal intensity on T2-weighted imaging (p=0.06), and low-signal-intensity strands bridging the tear on T2-weighted imaging (p<0.001).
  
  
  CONCLUSIONS
  Most peripheral vertical tears at the meniscocapsular junction of the medial meniscus spontaneously heal. The MRI characteristics of tears not located at the meniscocapsular junction can help distinguish between healed and unhealed tears.
authors.affiliation: 1 Department of Radiology, University of Wisconsin, 600 Highland Ave, Clinical Science Center E3/311, Madison, WI 53792-3252.
authors.forename: Richard
authors.initials: R
authors.lastname: Kijowski
authors.forename: Humberto G
authors.initials: HG
authors.lastname: Rosas
authors.forename: Kenneth S
authors.initials: KS
authors.lastname: Lee
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Lee
authors.forename: Arnold
authors.initials: A
authors.lastname: Cheung
authors.forename: Alejandro
authors.initials: A
authors.lastname: Munoz del Rio
authors.forename: Ben K
authors.initials: BK
authors.lastname: Graf
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008592:Menisci, Tibial / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012421:Rupture / Q000473:pathology / Q000601:surgery; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000379:methods; D000070600:Tibial Meniscus Injuries; D014945:Wound Healing; D055815:Young Adult