title: Accuracy of high-resolution ultrasound in the detection of meniscal tears and determination of the visible area of menisci.
abstract: BACKGROUND
  Imaging is of great importance in diagnosing meniscal tears. The aim of this study was to assess the accuracy of high-resolution ultrasound in the diagnosis of meniscal tears, with arthroscopic examination as the standard reference, after resolution was confirmed with a target-mounted reference phantom. An additional goal was to elucidate the area of the meniscus that could be visualized with the same ultrasound machine after placement of markers into the menisci of cadaveric knees.
  
  
  METHODS
  Seventy patients were included for the assessment of the accuracy of a high-resolution ultrasound machine with a 14.0 to 6.0-MHz linear transducer. The preoperative ultrasound diagnosis, in terms of the presence and type of tear, was compared with that in the surgical reports. In the cadaveric studies, nine needles were placed in the peripheral zone of the menisci at regular intervals and the number of needles that could be observed with the system was recorded.
  
  
  RESULTS
  The overall sensitivity, specificity, positive predictive value, and negative predictive value of ultrasound examination for meniscal tears were 88%, 85%, 85%, and 88%, respectively. These statistical parameters did not differ significantly between the medial and lateral menisci. The sensitivity for diagnosing horizontal, vertical, radial, flap, bucket-handle, and complex tears and for detecting discoid lateral menisci was 83%, 64%, 0%, 64%, 54%, 90%, and 80%, respectively. Ten percent of the lateral menisci could not be evaluated because of poor images. The cadaveric studies revealed that the ultrasound visualized the entire meniscus except for the anterior horn.
  
  
  CONCLUSIONS
  The findings of this study suggest that ultrasound examination may be suitable for screening for meniscal tears. The fact that almost 10% of the lateral menisci could not be evaluated because of poor images appears to be a weakness of ultrasound.
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. E-mail address for T. Sasho: sasho@faculty.chiba-u.jp.
authors.forename: Yorikazu
authors.initials: Y
authors.lastname: Akatsu
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. E-mail address for T. Sasho: sasho@faculty.chiba-u.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamaguchi
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. E-mail address for T. Sasho: sasho@faculty.chiba-u.jp.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Mukoyama
authors.affiliation: Seikei-kai Chiba Medical Center, 1-11-12 Minamityou, Chuo-ku, Chiba City, Chiba, 260-0842, Japan.
authors.forename: Tsuguo
authors.initials: T
authors.lastname: Morikawa
authors.affiliation: Center for Frontier Medical Engineering, Chiba University Graduate School, 1-33 Yayoi-cho, Inage-ku, Chiba City, 263-8522, Chiba, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yamaguchi
authors.affiliation: Kitachiba Spine & Sports Clinic, 3-1-43, Inagekaigan, Mihama-ku, Chiba City, Chiba, 261-0005, Japan.
authors.forename: Kan
authors.initials: K
authors.lastname: Tsuchiya
authors.affiliation: Seikei-kai Chiba Medical Center, 1-11-12 Minamityou, Chuo-ku, Chiba City, Chiba, 260-0842, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Iwasaki
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. E-mail address for T. Sasho: sasho@faculty.chiba-u.jp.
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Akagi
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. E-mail address for T. Sasho: sasho@faculty.chiba-u.jp.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Muramatsu
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. E-mail address for T. Sasho: sasho@faculty.chiba-u.jp.
authors.forename: Joe
authors.initials: J
authors.lastname: Katsuragi
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. E-mail address for T. Sasho: sasho@faculty.chiba-u.jp.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Fukawa
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. E-mail address for T. Sasho: sasho@faculty.chiba-u.jp.
authors.forename: Jun
authors.initials: J
authors.lastname: Endo
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. E-mail address for T. Sasho: sasho@faculty.chiba-u.jp.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Department of Orthopedic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. E-mail address for T. Sasho: sasho@faculty.chiba-u.jp.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Sasho
mesh_terms: D000328:Adult; D001182:Arthroscopy; D002102:Cadaver; D005260:Female; D006801:Humans; D008297:Male; D008592:Menisci, Tibial / Q000000981:diagnostic imaging*; D009339:Needles; D011859:Radiography; D012421:Rupture / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D014463:Ultrasonography