title: Large meniscus extrusion ratio is a poor prognostic factor of conservative treatment for medial meniscus posterior root tear.
abstract: OBJECTIVE
  The purpose of this study was to find a prognostic factor of medial meniscus posterior root tear (MMPRT) for surgical decision making.
  
  
  METHODS
  Eighty-eight patients who were diagnosed as acute or subacute MMPRT without severe degeneration of the meniscus were treated conservatively for 3 months. Fifty-seven patients with MMPRT showed good response to conservative treatment (group 1), while the remaining 31 patients who failed to conservative treatment (group 2) received arthroscopic meniscus repair. Their demographic characteristics and radiographic features including hip-knee-ankle angle, joint line convergence angle, Kellgren-Lawrence grade in plain radiographs, meniscus extrusion (ME) ratio (ME-medial femoral condyle ratio, ME-medial tibial plateau ratio, ME-meniscus width ratio), the location of bony edema, and cartilage lesions in MRI were compared. Receiver operating characteristic (ROC) curve analysis was also performed to determine the cut-off values of risk factors.
  
  
  RESULTS
  The degree of ME-medial femoral condyle and medial tibia plateau ratio of group 2 was significantly higher than group 1 (0.08 and 0.07 vs. 0.1 and 0.09, respectively, both p < 0.001). No significant (n.s.) difference in other variables was found between the two groups. On ROC curve analysis, ME-medial femoral condyle ratio was confirmed as the most reliable prognostic factor of conservative treatment for MMPRT (area under ROC = 0.8).
  
  
  CONCLUSIONS
  The large meniscus extrusion ratio was the most reliable poor prognostic factor of conservative treatment for MMPRT. Therefore, for MMPRT patients with large meniscus extrusion, early surgical repair could be considered as the primary treatment option.
  
  
  METHODS
  III.
authors.affiliation: Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.
authors.forename: Yoon-Ho
authors.initials: YH
authors.lastname: Kwak
authors.affiliation: Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.
authors.forename: Sahnghoon
authors.initials: S
authors.lastname: Lee
authors.affiliation: Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.
authors.forename: Myung Chul
authors.initials: MC
authors.lastname: Lee
authors.affiliation: Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea. oshawks7@snu.ac.kr.
authors.forename: Hyuk-Soo
authors.identifier: http://orcid.org/0000-0003-1229-8863
authors.initials: HS
authors.lastname: Han
mesh_terms: D000328:Adult; D000368:Aged; D001182:Arthroscopy; D000066491:Clinical Decision-Making / Q000379:methods; D000072700:Conservative Treatment; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D000070600:Tibial Meniscus Injuries / Q000175:diagnosis / Q000473:pathology / Q000601:surgery / Q000628:therapy*
keywords: Conservative treatment; Meniscus; Prognostic factor; Root tear