title: Longitudinal assessment of femoral knee cartilage quality using contrast enhanced MRI (dGEMRIC) in patients with anterior cruciate ligament injury--comparison with asymptomatic volunteers.
abstract: OBJECTIVE
  In this observational longitudinal study we estimate knee joint cartilage glycosaminoglycan (GAG) content, in patients with an acute anterior cruciate ligament (ACL) injury, with or without a concomitant meniscus injury.
  
  
  METHODS
  29 knees (19 men/10 women) were prospectively examined by repeat delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC), approximately 3 weeks and 2.3±1.3 (range 4.5) years after the injury. We estimated the GAG content (T1Gd) in the central weight-bearing parts of the medial and lateral femoral cartilage and compared results with a reference cohort (n=24) with normal knees and no history of injury examined by dGEMRIC at one occasion previously.
  
  
  RESULTS
  The healthy reference group had longer T1Gd values compared with the ACL-injured patients at follow-up both medially: 428±38 vs 363±61ms (P<0.0001) and laterally: 445±41 vs 396±48ms (P=0.0002). At follow-up T1Gd was lower in meniscectomized patients compared to those without a meniscectomy, both medially (-84ms, P=0.002) and laterally (-38ms, P=0.05). In the injured group, the medial femoral cartilage showed similar T1Gd at the two dGEMRIC investigations: 357±50 vs 363±61ms (P=0.57), whereas the lateral femoral cartilage T1Gd increased: 374±48 vs 396±48ms (P=0.04).
  
  
  CONCLUSIONS
  The general decrease in cartilage T1Gd in ACL-injured patients compared with references provide evidence for structural matrix GAG changes that seem more pronounced if a concomitant meniscal injury is present. The fact that post-traumatic OA commonly develops in ACL-injured patients, in particularly those with meniscectomy, suggests that shorter T1Gd may be an early biomarker for OA.
authors.affiliation: Department of Orthopedics, Clinical Sciences, Malmö, Lund University, Sweden. paul.neuman@skane.se
authors.forename: P
authors.initials: P
authors.lastname: Neuman
authors.forename: J
authors.initials: J
authors.lastname: Tjörnstrand
authors.forename: J
authors.initials: J
authors.lastname: Svensson
authors.forename: C
authors.initials: C
authors.lastname: Ragnarsson
authors.forename: H
authors.initials: H
authors.lastname: Roos
authors.forename: M
authors.initials: M
authors.lastname: Englund
authors.forename: C J
authors.initials: CJ
authors.lastname: Tiderius
authors.forename: L E
authors.initials: LE
authors.lastname: Dahlberg
mesh_terms: D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000473:pathology*; D000070598:Anterior Cruciate Ligament Injuries; D002358:Cartilage, Articular / Q000473:pathology*; D016022:Case-Control Studies; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D019786:Gadolinium DTPA; D006025:Glycosaminoglycans / Q000378:metabolism; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis*; D007719:Knee Joint / Q000473:pathology*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D055815:Young Adult
chemical_list: D003287:Contrast Media; D006025:Glycosaminoglycans; D019786:Gadolinium DTPA