Incidence of bilateral discoid lateral meniscus in an Asian population: an arthroscopic assessment of contralateral knees

Arthroscopy. 2012 Jul;28(7):936-41. doi: 10.1016/j.arthro.2011.12.003. Epub 2012 Feb 24.


Purpose: 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.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Arthroscopy*
  • Cohort Studies
  • Female
  • Follow-Up Studies
  • Humans
  • Incidence
  • Knee Injuries / diagnosis
  • Knee Injuries / etiology
  • Knee Injuries / surgery
  • Magnetic Resonance Imaging
  • Male
  • Menisci, Tibial / abnormalities*
  • Menisci, Tibial / surgery
  • Musculoskeletal Abnormalities / complications
  • Musculoskeletal Abnormalities / diagnosis
  • Musculoskeletal Abnormalities / epidemiology*
  • Musculoskeletal Abnormalities / surgery
  • Prevalence
  • Prospective Studies
  • Recovery of Function
  • Republic of Korea / epidemiology
  • Tibial Meniscus Injuries
  • Treatment Outcome