title: MRI evaluation of isolated arthroscopic partial meniscectomy patients at a minimum five-year follow-up.
abstract: BACKGROUND
  The risk of radiographic knee degeneration after partial or total meniscectomy is well documented, but no prior study has employed cartilage-sensitive MRI technology to assess degenerative changes after meniscectomy.
  
  
  OBJECTIVE
  Arthroscopic partial meniscectomy results in early articular cartilage wear and subchondral bony degeneration, even in the absence of clinical symptoms, and these findings can be evaluated with cartilage-sensitive MRI.
  
  
  METHODS
  Retrospective cohort.
  
  
  METHODS
  Twenty-nine patients (ages: 15-40) who had undergone isolated arthroscopic partial medial or lateral meniscectomy with at least 5-year follow-up were evaluated. All patients had arthroscopically normal articular cartilage at the time of initial meniscectomy. Seventeen patients (18 knees) underwent partial medial meniscectomy (MM) and 12 patients underwent partial lateral meniscectomy (LM) with mean follow-up of 8.4 and 7.1 years, respectively. Follow-up evaluation included physical examination, outcome questionnaires, and cartilage-sensitive MRI examination with modified Outerbridge grading of articular surfaces.
  
  
  RESULTS
  Outerbridge grades II-IV were noted in 64% of medial compartment joint surfaces in group MM knees versus 33% of lateral compartment joint surfaces in group LM knees. Abnormal cartilage surfaces (grades II-IV), subchondral sclerosis, and condylar squaring were all significantly more frequent after medial meniscectomy (p < 0.05). Groups MM and LM had no significant differences among outcome scores, which remained excellent in both groups. A significant negative correlation was found between the severity of cartilage wear and functional scoring in the MM group, suggesting that functional disability lags behind early MRI evidence of degeneration.
  
  
  CONCLUSIONS
  Despite optimal preoperative prognostic factors and excellent functional outcomes, MRI evidence of early articular cartilage degeneration was present in both partial medial and lateral meniscectomy patients at a minimum 5-year follow-up. Results support the use of cartilage-sensitive MRI as a noninvasive screening technique to evaluate cartilage changes after arthroscopic partial meniscectomy and may help to counsel the high-risk patient in regard to postoperative activity.
authors.affiliation: Sports Medicine and Shoulder Service, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, USA. williamsr@hss.edu
authors.forename: Riley J
authors.initials: RJ
authors.lastname: Williams
authors.forename: Kristin K
authors.initials: KK
authors.lastname: Warner
authors.forename: Frank A
authors.initials: FA
authors.lastname: Petrigliano
authors.forename: Hollis G
authors.initials: HG
authors.lastname: Potter
authors.forename: Joshua
authors.initials: J
authors.lastname: Hatch
authors.forename: Frank A
authors.initials: FA
authors.lastname: Cordasco