Clinical Characteristics of Meniscal Cyst of the Knee:Analysis on 104 Cases / 中国微创外科杂志

ABSTRACT

Objective To study the clinical features of meniscal cyst of the knee. Methods From January 2001 to December 2007,totally 5986 cases of meniscus operation were performed in our hospital,104 of them were diagnosed as having meniscal cyst in the knee. The clinical data of these patients,including gender and age distributions,causes and mechanism of injury,clinical presentations,characteristics of the cyst,and the type of the injury,were investigated. Results Incidence rate of meniscal cyst was 1.7% (104/5986) and the ratio between medial and lateral meniscal cysts was 1∶12 (8∶96). The mean age of the 104 patients was (30.7?12.2) years (range,13 to 65 years),and the radio of male to female was 1.2 to 1. Of the patients,60 cases (57.7%) had history of trauma,32 or them were hurt in sports,including football (11 cases),basketball (8 cases) and others. The most common primary symptom was pain (102 cases,98.1%),followed by swelling (50 cases,48.1%). Tenderness over the joint line (85 cases,81.7%) and palpable mass (79 cases,76.0%) with or without signs of meniscal tear were common presentations. The anterior and middle portions of the medial meniscus (5/8,62.5%),and posterior extension of the lateral meniscus (88/96,91.7%) were the most commonly involved sites (?2=15.167,P=0.000). The most frequently observed meniscal tear was a horizontal cleavage,alone (25/104,24.0%) or associated with another types of lesions (52/104,50.0%). In 5.8% (6/104) of the cases,the discoid meniscus was involved. Conclusions Meniscus cysts are unusual. The ratio between medial and lateral meniscal cysts favors the lateral meniscus. Meniscal tear and myxoid degeneration are the common causes of the cyst. The most frequently observed meniscal tear is a horizontal cleavage,and the anterior and middle portions of the medial meniscus and posterior extensions of the lateral meniscus are the most commonly involved sites.