title: Morphological and compositional monitoring of a new cell-free cartilage repair hydrogel technology - GelrinC by MR using semi-quantitative MOCART scoring and quantitative T2 index and new zonal T2 index calculation.
abstract: OBJECTIVE
  To evaluate cartilage repair tissue (RT) using MOCART scoring for morphological and T2 mapping for biochemical assessment following implantation of GelrinC, a biosynthetic, biodegradable hydrogel implant.
  
  
  METHODS
  MR imaging (1.5/3T) was performed on 21 patients at six sites. Standard protocols were used for MOCART evaluation at 1 week (baseline) 1, 3, 6, 12, 18 and 24 months. Multi-echo SE was used for T2 mapping. Global (T2 in RT divided by T2 in normal cartilage) and zonal T2 index (deep T2 divided by superficial T2) of RT were calculated.
  
  
  RESULTS
  Average MOCART score was 71.8 (95% CI 62.2 to 81.3) at six, 75.2 (95% CI 62.8 to 87.5) at twelve, 71.8 (95% CI 55.4 to 88.2) at eighteen and 84.4 (95% CI 77.7 to 91.0) at twenty-four months. The global T2 index ranged between 0.8 and 1.2 (normal healthy cartilage) in 1/11 (9%) patients at baseline, 8/12 (67%) at 12 months, 11/13 (85%) at 18 months and 13/16 (81%) at 24 months. The zonal T2 index for RT was <20% difference to the zonal T2 index for normal cartilage in: 6/12 patients (50%) at 12 months, 7/13 (53.8%) at 18 months and 10/16 (63.5%) at 24 months. The standard deviation for T2 showed a significant decrease over the study.
  
  
  CONCLUSIONS
  The increase of MOCART scores over follow-up indicates improving cartilage repair tissue. Global and zonal T2 repair values at 24 months reached normal cartilage in 81% and 63.5% of the patients respectively, reflecting collagen organization similar to hyaline cartilage.
authors.affiliation: High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria; CD Laboratory for Clinical Molecular MR Imaging, Austria. Electronic address: siegfried.trattnig@meduniwien.ac.at.
authors.forename: S
authors.initials: S
authors.lastname: Trattnig
authors.affiliation: Regentis Biomaterials Ltd., 12 Ha'ilan Street, Northern Industrial Zone, P.O.B. 260, Or Akiva, 3060000, Israel. Electronic address: Kitty@regentis.co.il.
authors.forename: K
authors.initials: K
authors.lastname: Ohel
authors.affiliation: High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria. Electronic address: vladimir.mlynarik@meduniwien.ac.at.
authors.forename: V
authors.initials: V
authors.lastname: Mlynarik
authors.affiliation: High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria. Electronic address: vladimir.juras@meduniwien.ac.at.
authors.forename: V
authors.initials: V
authors.lastname: Juras
authors.affiliation: High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria. Electronic address: stefan.zbyn@meduniwien.ac.at.
authors.forename: S
authors.initials: S
authors.lastname: Zbyn
authors.affiliation: Regentis Biomaterials Ltd., 12 Ha'ilan Street, Northern Industrial Zone, P.O.B. 260, Or Akiva, 3060000, Israel. Electronic address: Amit@regentis.co.il.
authors.forename: A
authors.initials: A
authors.lastname: Korner
mesh_terms: D000293:Adolescent; D000328:Adult; D054544:Arthroplasty, Subchondral / Q000379:methods*; D002358:Cartilage, Articular / Q000293:injuries / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D005260:Female; D005340:Fibrinogen; D006025:Glycosaminoglycans / Q000378:metabolism; D048091:Guided Tissue Regeneration / Q000379:methods*; D006801:Humans; D051457:Hyaline Cartilage / Q000473:pathology; D007718:Knee Injuries / Q000601:surgery; D007719:Knee Joint / Q000473:pathology* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols; D054457:Tissue Scaffolds; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D006025:Glycosaminoglycans; C437167:poly(ethylene glycol)diacrylate; D011092:Polyethylene Glycols; D005340:Fibrinogen
keywords: Articular cartilage; Cartilage repair tissue; GelrinC; Global and zonal T2 index; MR imaging; T2 mapping