Risk factors for radiographic progression of osteoarthritis after partial meniscectomy of discoid lateral meniscus tear

Introduction: Partial meniscectomy has been preferred in the treatment of discoid lateral meniscus (DLM) with tear, rather than total or subtotal meniscectomy, which could lead to late radiographic degenerative changes. Hypothesis: One or more risk factors contribute to radiographic progression of osteoarthritis after partial meniscectomy of DLM tear. Material and methods: Inclusion criteria were consecutive patients who underwent arthroscopic surgeries for DLM tear from January 2005 to December 2010 by one surgeon. Exclusion criteria were preoperative osteoarthritis with KL grade 3 or more, osteochondritis dissecans, minimal width of meniscal remnant less than 6 mm after meniscectomy, meniscal repair of an unstable discoid meniscus, age over 60 years, loss to follow-up for a minimum of 5 years and simultaneous surgery on articular cartilage or anterior cruciate ligament. According to the KL grade at the last follow-up, all enrolled knees were sorted into no progression to knee osteoarthritis (KL grade 1 or 2 - NOA) and progression to osteoarthritis (KL grade 3 or 4 - POA) groups. Multivariate logistic regression was used to analyze the risk factors of high-grade osteoarthritis. Results: In comparison with NOA group (n = 135) and POA group (n= 67), prolonged symptom duration, increased relative percentage of DLM thickness (RPDT) and the presence of horizontal tear were significant risk factors. The presence of horizontal tear (P= 0.048, adjusted OR= 19.364) was the strongest predictor, compared with prolonged symptom duration (P = 0.030, adjusted OR= 1.150) and increased RPDT (P= 0.003, adjusted OR= 1.377). Discussion: Horizontal tear, prolonged symptom duration, and increased RPDT are significant risk factors for radiographic progression to high-grade osteoarthritis after partial meniscectomy of DLM tear with a minimum follow-up of 5 years. Level of evidence: III, case-control study. (C) 2017 Elsevier Masson SAS. All rights reserved.