title: Incidence of bilateral discoid lateral meniscus in an Asian population: an arthroscopic assessment of contralateral knees.
abstract: OBJECTIVE
  To investigate the incidence of bilateral discoid lateral meniscus (DLM) and to evaluate the arthroscopic features of lateral meniscus in asymptomatic contralateral knees in an Asian population who presented with symptomatic DLMs.
  
  
  METHODS
  This study prospectively enrolled 52 consecutive patients who underwent arthroscopic procedures for symptomatic DLMs (31 complete and 21 incomplete) and who consented to the examination of the contralateral knee at the time of arthroscopy. Types of DLMs and of meniscus tears were assessed by use of arthroscopic findings. Preoperative and postoperative functional outcomes were evaluated with Lysholm and Tegner activity scores.
  
  
  RESULTS
  Arthroscopic examinations showed 21 complete DLMs, 19 incomplete DLMs, 11 normal lateral menisci, and 1 ring-shaped lateral meniscus in contralateral knees. The incidence of bilateral DLM in our study population was 79% (41 of 52 contralateral knees). Furthermore, 65% of patients (34 pairs of knees) had the same DLM types. In addition, 3 pairs of knees with complete DLMs had menisci of different thicknesses. DLM tears were observed in 2 contralateral knees (1 radial and 1 longitudinal) and were treated by partial central meniscectomy.
  
  
  CONCLUSIONS
  This study provides evidence of the high prevalence of bilateral DLM in an Asian population.
authors.affiliation: Department of Orthopaedic Surgery, Inje University, Ilsanpaik Hospital, Ilsan, South Korea.
authors.forename: Ji-Hoon
authors.initials: JH
authors.lastname: Bae
authors.forename: Hong-Chul
authors.initials: HC
authors.lastname: Lim
authors.forename: Dae-Hee
authors.initials: DH
authors.lastname: Hwang
authors.forename: Jae-Kwang
authors.initials: JK
authors.lastname: Song
authors.forename: Jun-Sung
authors.initials: JS
authors.lastname: Byun
authors.forename: Kyung-Wook
authors.initials: KW
authors.lastname: Nha
mesh_terms: D000328:Adult; D001182:Arthroscopy; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007718:Knee Injuries / Q000175:diagnosis / Q000209:etiology / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000002:abnormalities* / Q000601:surgery; D009139:Musculoskeletal Abnormalities / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology* / Q000601:surgery; D015995:Prevalence; D011446:Prospective Studies; D020127:Recovery of Function; D056910:Republic of Korea / Q000453:epidemiology; D000070600:Tibial Meniscus Injuries; D016896:Treatment Outcome