MRI can accurately detect meniscal ramp lesions of the knee.
OBJECTIVE
Posterior horn meniscal tears are commonly found in conjunction with anterior cruciate ligament (ACL) injury. Some believe tears in the posterior meniscocapsular zone, coined ramp lesions, are important to knee stability. The purpose of this study was to determine whether pre-operative MRI evaluation was able to accurately and reproducibly identify ramp lesions.


METHODS
Three blinded reviewers assessed MRIs twice for the presence of ramp lesions in patients undergoing ACL reconstruction. Sensitivity, specificity, negative predictive value, and positive predictive value for MRI were calculated based on arthroscopic diagnosis of a ramp lesion. Intra-class correlation coefficient was calculated to assess intra- and interobserver reliability of the MRI assessment between the three examiners. Significance was set at p < 0.05.


RESULTS
Ninety patients met inclusion criteria (45 males, 45 females, mean age 28.0 years). Thirteen of these patients had arthroscopy-confirmed ramp lesions, while the other 77 had other meniscal pathology. Sensitivity of detecting a ramp lesion on MRI ranged from 53.9 to 84.6%, while specificity was 92.3-98.7%. Negative predictive value was 91.1-97.4%, while positive predictive value was 50.0-90.0%. Inter-rater reliability between three reviewers was moderate at 0.56. The observers had excellent intra-rater reliability ranging from 0.75 to 0.81.


CONCLUSIONS
This study demonstrates high sensitivity and excellent specificity in detecting meniscal ramp lesions on MRI. Ramp lesions are likely more common and may have greater clinical implications than previously appreciated; the outcomes of untreated lesions must be investigated. Pre-operative identification of ramp lesions may aid clinicians in surgical planning and patient education to improve outcomes by addressing pathology which may have otherwise been missed.


METHODS
III.
UPMC Center for Sports Medicine, 3200 S Water St, Pittsburgh, PA, 15203, USA.
Justin W
JW
Arner
UPMC Center for Sports Medicine, 3200 S Water St, Pittsburgh, PA, 15203, USA.
Elmar
E
Herbst
UPMC Center for Sports Medicine, 3200 S Water St, Pittsburgh, PA, 15203, USA.
Jeremy M
JM
Burnham
UPMC Center for Sports Medicine, 3200 S Water St, Pittsburgh, PA, 15203, USA.
Ashish
A
Soni
UPMC Center for Sports Medicine, 3200 S Water St, Pittsburgh, PA, 15203, USA.
Jan-Hendrik
JH
Naendrup
UPMC Center for Sports Medicine, 3200 S Water St, Pittsburgh, PA, 15203, USA.
Adam
A
Popchak
UPMC Center for Sports Medicine, 3200 S Water St, Pittsburgh, PA, 15203, USA.
Freddie H
FH
Fu
UPMC Center for Sports Medicine, 3200 S Water St, Pittsburgh, PA, 15203, USA. musahlv@upmc.edu.
Volker
V
Musahl
D000293:Adolescent; D000328:Adult; D000070598:Anterior Cruciate Ligament Injuries / Q000000981:diagnostic imaging* / Q000601:surgery; D059549:Anterior Cruciate Ligament Reconstruction; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000000981:diagnostic imaging* / Q000601:surgery; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000070600:Tibial Meniscus Injuries / Q000000981:diagnostic imaging* / Q000601:surgery; D055815:Young Adult
ACL reconstruction; MRI; Meniscocapsular separation; Posteromedial meniscus; Posteromedial portal; Ramp; Rotatory instability