title: Quantitative MRI T2 relaxation time evaluation of knee cartilage: comparison of meniscus-intact and -injured knees after anterior cruciate ligament reconstruction.
abstract: BACKGROUND
  Associated meniscal injury is well recognized at anterior cruciate ligament (ACL) reconstruction, and it is a known risk factor for osteoarthritis.
  
  
  OBJECTIVE
  To evaluate and characterize the postoperative appearance of articular cartilage after different meniscal treatment in ACL-reconstructed knees using T2 relaxation time evaluation on MRI.
  
  
  METHODS
  Cohort study; Level of evidence, 3.
  
  
  METHODS
  A total of 62 consecutive patients who under ACL reconstruction were recruited in this study, including 23 patients undergoing partial meniscectomy (MS group), 21 patients undergoing meniscal repair (MR group), and 18 patients with intact menisci (MI group) at time of surgery. Clinical evaluation, including subjective functional scores and physical examination, was performed on the same day as the MRI examination and at follow-up times ranging from 2 to 4.2 years. The MRI multiecho sagittal images were segmented to determine the T2 relaxation time value of each meniscus and articular cartilage plate. Differences in each measurement were compared among groups.
  
  
  RESULTS
  No patient had joint-line tenderness or reported pain or clicking on McMurray test or instability. There were also no statistically significant differences in functional scores or medial or lateral meniscus T2 values among the 3 groups (P > .05 for both). There was a significantly higher articular cartilage T2 value in the medial femorotibial articular cartilage for the MS group (P < .01) and the MR group (P < .05) compared with that of the MI group, while there was no significant difference in articular cartilage T2 value between the MS and MR groups (P > .05) in each articular cartilage plate. The medial tibial articular cartilage T2 value had a significant positive correlation with medial meniscus T2 value (r = 0.287; P = .024) CONCLUSION: This study demonstrates that knees with meniscectomy or meniscal repair had articular cartilage degeneration at 2 to 4 years postoperatively, with higher articular cartilage T2 relaxation time values compared with the knees with an intact meniscus.
authors.affiliation: Department of Sports Medicine, Huashan Hospital, Shanghai, People's Republic of China.
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Radiology, Huashan Hospital, Shanghai, People's Republic of China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Radiology, Huashan Hospital, Shanghai, People's Republic of China.
authors.forename: Hongyue
authors.initials: H
authors.lastname: Tao
authors.affiliation: Department of Sports Medicine, Huashan Hospital, Shanghai, People's Republic of China cshiyi@163.com.
authors.forename: Shiyi
authors.initials: S
authors.lastname: Chen
mesh_terms: D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction; D002358:Cartilage, Articular / Q000473:pathology; D015331:Cohort Studies; D005500:Follow-Up Studies; D006801:Humans; D007718:Knee Injuries / Q000473:pathology / Q000601:surgery*; D007719:Knee Joint / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008592:Menisci, Tibial / Q000473:pathology; D011184:Postoperative Period; D012307:Risk Factors; D013977:Tibia / Q000473:pathology; D013997:Time Factors; D055815:Young Adult
keywords: MRI; anterior cruciate ligament; cartilage; meniscal repair; meniscectomy