title: Autologous chondrocyte implantation in cartilage lesions of the knee: long-term evaluation with magnetic resonance imaging and delayed gadolinium-enhanced magnetic resonance imaging technique.
abstract: BACKGROUND
  Various treatment options are available for articular cartilage lesions, but controversy exists regarding the quality of the repair tissue and the durability of the results posttreatment. Noninvasive techniques are needed for the assessment of the repair tissue.
  
  
  OBJECTIVE
  Magnetic resonance imaging (MRI) with delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) can give valuable information regarding the quality and quantity of the repaired cartilage lesion.
  
  
  METHODS
  Cohort study; Level of evidence, 3.
  
  
  METHODS
  Thirty-six knees in 31 patients were assessed 9 to 18 years after treatment with autologous chondrocyte implantation (ACI). All patients had isolated lesions. The knees were clinically evaluated with the Knee injury and Osteoarthritis Outcome Score and the dGEMRIC technique. The T1 value was measured for 2 regions of interest (ROIs), 1 in the repair tissue area (ROI 1) and 1 in the surrounding cartilage (ROI 2), giving information of the content of proteoglycans.
  
  
  RESULTS
  The average T1 value in ROI 1 was 467.5 milliseconds and in ROI 2, 495.3 milliseconds, which yielded no significant difference, thus suggesting comparable levels of proteoglycans in the repair tissue and surrounding cartilage. Intralesional osteophytes were in 64% of the lesions, mainly in younger patients with osteochondritis dissecans lesions or a history of subchondral bone surgeries. Medium or large bone marrow edema was found in 14% of the knees and subchondral cysts, in 39%. There was no correlation between the KOOS and any MRI findings.
  
  
  CONCLUSIONS
  Magnetic resonance imaging with dGEMRIC gives valuable information for the macroscopic appearance and micro-molecular quality of the repair tissue after ACI. Nine to 18 years posttreatment, the quality of the repair tissue is similar to the surrounding normal cartilage, although intralesional osteophytes, subchondral cysts, and bone marrow edema were common. The defect area is restored in most patients. However, there was no correlation between the dGEMRIC values and the KOOS outcomes.
authors.affiliation: Molecular Cell Biology and Regenerative Medicine, Sahlgrenska Academy, University of Gothenburg, Sweden. haris.vasiliadis@clinchem.gu.se
authors.forename: Haris S
authors.initials: HS
authors.lastname: Vasiliadis
authors.forename: Barbro
authors.initials: B
authors.lastname: Danielson
authors.forename: Maria
authors.initials: M
authors.lastname: Ljungberg
authors.forename: Brian
authors.initials: B
authors.lastname: McKeon
authors.forename: Anders
authors.initials: A
authors.lastname: Lindahl
authors.forename: Lars
authors.initials: L
authors.lastname: Peterson
mesh_terms: D000328:Adult; D002358:Cartilage, Articular / Q000293:injuries / Q000601:surgery*; D019902:Chondrocytes / Q000637:transplantation*; D015331:Cohort Studies; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007718:Knee Injuries / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D019637:Orthopedic Procedures; D019651:Plastic Surgery Procedures; D012189:Retrospective Studies; D014182:Transplantation, Autologous; D055815:Young Adult
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA