E. Carlos Rodriquez-Merchan - Department of Orthopaedic Surgery, La Paz University Hospital-IdiPaz, Madrid, Spain
Jose Garcia-Ramos - Department of Orthopaedic Surgery, La Paz University Hospital-IdiPaz, Madrid, Spain
Norma Padilla-Eguiluz - Department of Orthopaedic Surgery, La Paz University Hospital-IdiPaz, Madrid, Spain
Enrique Gomez-Barrena - Department of Orthopaedic Surgery, La Paz University Hospital-IdiPaz, Madrid, Spain.

  Background: The role of arthroscopic partial meniscectomy (APM) for painful degenerative meniscal tears (PDMT) is currently controversial. To define the rate of early (1 to 5 years) conversion to total knee replacement (TKR) and their predictors after APM for PDMT in patients with knee osteoarthritis and more than 50 years of age. Methods: Retrospective cohort study of patients more than 50 years of age with the diagnosis of PDMT, treated by means of APM. Patients were classified in two groups: Patients that required an early (between 1 and 5 years after APM) TKR (TKR group) after its failure and patients that did not require a TKR (non-TKR group). Patient demographics, general characteristics, Kellgren & Lawrence (KL) classification, Outerbridge classification, and other characteristics were analyzed. Postoperative variables were also analyzed: pain, use of walking aids and use of intra-articular injections (hyaluronic acid or corticosteroids) at 3, 6, and 12 months of follow-up. Results: A total of 356 patients (356 APMs) were included. Forty-nine patients (13.7%) required an early (1.8 years on average) TKR and 307 did not. The main predictor of early TKR was the grade of the KL classification. After APM, the presence of pain and the need of walking aids also were predictors of an early TKR. Conclusion: In patients older than 50 years with PDMT, APM should be cautiously indicated in case of KL grade of 1 or more. Postoperative pain and prolonged need of walking aids were also predictors of an early (mean 1.8 years) TKR. Level of evidence: IV

Arthroscopic partial meniscectomy, Degenerative meniscal tear, Failure, knee, Total knee replacement