Objective　　　 To investigate the correlation between the time course after lateral meniscus tear and articular cartilage lesions.　　　 Methods　　　 Totally 376 consecutive patients with arthroscopy diagnosed lateral meniscus tear admitted in our center from January 2010 to December 2011 were retrospectively reviewed. They were divided into 3 groups according to Keene’s time regulation

acute phase (≤2 months)

subacute phase (2 to 12 months)

and chronic phase (＞12 months). The time since tear of lateral meniscus and the severity of the articular cartilage lesions were documented in a systematic fashion. Correlation between t

he time course after lateral meniscus tear and articular cartilage lesions were analyzed.　　　 Results　　　 Of these 376 patients

129 (34.31%) were documented with articular cartilage lesions

and their average time course was significantly longer than those without cartilage lesions (P0.05). And there were 7 (5.43%) of them having articular cartilage lesions at grade Ⅰ

42 (32.56%) at grade Ⅱ

59 (45.74%) at grade Ⅲ and 21 (16.28%) at grade Ⅳ. The incidence of articular cartilage lesions was increased with the time course after lateral meniscus tear

with 23.64% for acute phase

30.59% for subacute phase and 42.38% for chronic phase. The prevalence of cartilage lesions was significantly higher in those at chronic phase than those at acute phase and subacute phase (

P

0.05). The patients at acute phase and subacute phase mainly showed articular cartilage lesions at grade Ⅰ to Ⅲ

and those at chronic phase were common having the lesion at grade Ⅱ to Ⅲ

and only some had lesion at grade Ⅳ.　　　 Conclusion　　　 The prevalence of articular cartilage lesions arises with the increased time course after lateral meniscus tear. Patients should accept treatment in time.