title: Arthroscopic Partial Meniscectomy or Conservative Treatment for Nonobstructive Meniscal Tears: A Systematic Review and Meta-analysis of Randomized Controlled Trials.
abstract: To conduct a meta-analysis of randomized controlled trials comparing the outcome of arthroscopic partial meniscectomy (APM) with conservative treatment in adults with nonobstructive meniscal tears and to recommend a treatment of choice.
  
  
  
  We systematically searched the databases of MEDLINE, Excerpta Medica Database, Cochrane, the National Health Service Centre for Reviews and Dissemination, and Physiotherapy Evidence Database from inception to May 2, 2016. Two authors independently searched the literature and selected eligible studies. The meta-analyses used a random-effects model. The primary outcome was physical function, measured by knee-specific patient-reported outcomes. Secondary outcomes included knee pain, activity level, the progression of osteoarthritis, adverse events, general health, and quality of life.
  
  
  
  We included 6 randomized controlled trials, with a total of 773 patients, of whom 378 were randomized to APM and 395 were randomized to the control treatment. After pooling the data of 5 studies, we found small significant differences in favor of the APM group for physical function at 2 to 3 months (mean difference [MD] = 3.31; 95% confidence interval [CI] = 0.69-5.93; P = .01; I(2) = 0% [Lysholm knee score]), and at 6 months (MD = 3.56; 95% CI = 0.24-6.88; P = .04; I(2) = 0% (Knee injury and Osteoarthritis Outcome Score [KOOS] and Western Ontario and McMaster Universities Osteoarthritis Index); standardized MD = 0.17; 95% CI = 0.01-0.32; P = .03; I(2) = 0% [Lysholm knee score, KOOS, and Western Ontario and McMaster Universities Osteoarthritis Index]). We also found small significant differences for pain at 6 months (MD = 3.56; 95% CI = 0.18-6.95; P = .04; I(2) = 0% [KOOS] and MD = 0.56; 95% CI = 0.28-0.83; P ≤ .0001; I(2) = 0% [visual analog scale and numeric rating scale]). We found no significant differences after 12 and 24 months.
  
  
  
  We found small, although statistically significant, favorable results of APM up to 6 months for physical function and pain. However, we found no differences at longer follow-up.
  
  
  
  Level I, systematic review and meta-analysis of Level I studies.
authors.affiliation: Department of Orthopaedic Surgery, Joint Research, Onze Lieve Vrouwe Gasthuis Amsterdam, Amsterdam, The Netherlands. Electronic address: vandegraaf@gmail.com.
authors.forename: Victor A
authors.initials: VA
authors.lastname: van de Graaf
authors.affiliation: Department of Orthopaedic Surgery, St. Antonius Ziekenhuis Nieuwegein, Nieuwegein, The Netherlands.
authors.forename: Nienke
authors.initials: N
authors.lastname: Wolterbeek
authors.affiliation: Department of Orthopaedic Surgery, Joint Research, Onze Lieve Vrouwe Gasthuis Amsterdam, Amsterdam, The Netherlands.
authors.forename: Eduard L A R
authors.initials: EL
authors.lastname: Mutsaerts
authors.affiliation: Department of Orthopaedic Surgery, Joint Research, Onze Lieve Vrouwe Gasthuis Amsterdam, Amsterdam, The Netherlands.
authors.forename: Vanessa A B
authors.initials: VA
authors.lastname: Scholtes
authors.affiliation: Department of Orthopaedic Surgery, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Daniel B F
authors.initials: DB
authors.lastname: Saris
authors.affiliation: Department of Orthopaedic Surgery, Clinical Orthopaedic Research Center Midden-Nederland, Diakonessenhuis Utrecht, Utrecht, The Netherlands.
authors.forename: Arthur
authors.initials: A
authors.lastname: de Gast
authors.affiliation: Department of Orthopaedic Surgery, Joint Research, Onze Lieve Vrouwe Gasthuis Amsterdam, Amsterdam, The Netherlands.
authors.forename: Rudolf W
authors.initials: RW
authors.lastname: Poolman
mesh_terms: D000072700:Conservative Treatment; D018450:Disease Progression; D006801:Humans; D007718:Knee Injuries / Q000601:surgery*; D008592:Menisci, Tibial / Q000601:surgery*; D020370:Osteoarthritis, Knee / Q000453:epidemiology*; D010147:Pain Measurement; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D000070600:Tibial Meniscus Injuries / Q000601:surgery*