Meniscectomy as a risk factor for knee osteoarthritis: a systematic review.

INTRODUCTION: This review defines the recognized risk factors responsible for the development of knee osteoarthritis after surgical management of meniscal tears. SOURCES OF DATA: We performed a literature search using Medline, Ovid, Cochrane and Google Scholar using the keywords: 'Meniscal tears', 'meniscectomy', 'osteoarthritis', 'complications' and 'risk factors'. Thirty-two published studies were identified. AREAS OF AGREEMENT: In the long term, osteoarthritis develops in the knee of patients undergoing surgery for meniscal tears. The Coleman methodology score showed great heterogeneity in terms of patient characteristics and outcome assessment. Amount of meniscus removed, duration of pre-operative symptoms and lateral meniscectomy show strong statistical association to onset of knee osteoarthritis. AREAS OF CONTROVERSY: We did not find univocal findings defining the risk factors responsible for the development of post-operative knee osteoarthritis. GROWING POINTS: There is a need for standardized clinical and imaging validated scale to improve definition of post-operative knee osteoarthritis to allow easier and more reliable comparison of outcomes in different studies. AREAS TIMELY FOR DEVELOPING RESEARCH: Appropriately powered randomized controlled trials reporting clinical and imaging-related outcomes in patients undergoing arthroscopic minimally invasive procedures and meniscal suturing should be performed. Comparing imaging findings of patients undergoing arthroscopic partial and open meniscectomy, a lower incidence of knee osteoarthritic evolution was detected after arthroscopy. The amount of removed meniscus is the most important predictor factor for the development of osteoarthritis. Minimally invasive procedures seem to reduce the incidence of long-term osteoarthritic changes of the knee compared with more invasive open and or arthroscopic procedures.