2015 ISAKOS Biennial Congress ePoster #1623

Anatomical Observation of Cadaveric Knees With Discoid Lateral Meniscus. Correlation Between Meniscal Tear and Osteoarthritic Change

Yuki Kato, MD, PhD, Tokyo JAPAN
Midori Oshida, MD, Tokyo JAPAN
Shin Aizawa, MD, Tokyo JAPAN
Takashi Horaguchi, MD, PhD, Tokyo JAPAN
Akiyoshi Saito, MD, Tokyo JAPAN
Yasuaki Tokuhashi, MD, PhD, Tokyo JAPAN

Nihon University, Tokyo, JAPAN

FDA Status Not Applicable

Summary: Anatomical Observation of Cadaveric Knees with Discoid Lateral Meniscus.-Correlation between meniscal tear and osteoarthritic change-.




The discoid lateral meniscus was first recognized by Young in 1889. Asian population seems to have a significantly higher incidence (Kato Y et al, 2004). Clinically knee disorder associated with discoid lateral meniscus is common. However, long-term follow-up data of knee joint with discoid lateral meniscus is unclear.


The purpose of this study is to reveal relationship of discoid lateral meniscus to osteoarthritic change of the knee joint.


Macroscopically 976 cadaveric knees were observed. According to Ikeuchi’s classification, lateral menisci were classified into normal lateral meniscus (NLM), incomplete discoid lateral meniscus (ICDLM), complete discoid lateral meniscus (CDLM) and others. The presence and extent of torn lateral menisci were assessed. The types of osteoarthritic change (OA) on femoral-tibial joint were classified into medial (Med) OA, lateral (Lat) OA, and all OA (Med + Lat OA).


Lateral menisci from 976 knees were classified as follows: NLM (n=634, 65%); ICDLM (n=280, 29%); CDLM (n=49, 5%); others (n=13, 1%). The frequency of tears in each lateral meniscal shape (NLM, ICDLM, and CDLM) was as follows: 67 (10.6%) of 634 NLM; 86 (30.7%) of 280 ICDLM; and 21 (28.6%) of 49 CDLM. Types of CDLM tears were as follows: 16 middle segment radial tears, 3 posterior segment longitudinal tears, and 2 complex tears. In OA types of all NLM knees (n=634), there were 118 Med OA (18.6%), 15 Lat OA (2.4%), and 37 all OA (5.8%). In OA types of all ICDLM knees (n=280), there were 69 Med OA (24.6%), 17 Lat OA (6.1%), and 45 all OA (16.1%). In OA types of all CDLM knees (n=49), there were 13 Med OA (26.5%), 4 Lat OA (8.2%), and 3 all OA (6.1%). In intact CDLM knees (n=28), there were 20 intact knees (71.4%) and 8 Med OA knees (28.6%). In torn CDLM knees (n=21), there were 9 intact knees (45.0%), 5 Med OA knees (25.0%), 4 Lat OA knees (20.0%), and 3 all OA knees (15.0%).


There was no significant difference in OA types between three LM shapes. The most frequent OA type was medial OA, regardless of three LM shapes. CDLM tear can provide cause of lateral OA.