title: Clinical results and MRI evolution of a nano-composite multilayered biomaterial for osteochondral regeneration at 5 years.
abstract: BACKGROUND
  Several cartilage lesions involve the subchondral bone, and there is a need for biphasic scaffolds to treat the entire osteochondral unit to reproduce the different biological and functional requirements and guide the growth of the 2 tissues.
  
  
  OBJECTIVE
  To evaluate the results of a cell-free collagen-hydroxyapatite osteochondral scaffold at midterm, and to use magnetic resonance imaging (MRI) analysis to document the imaging evolution of the tissue regeneration process through 5 years of follow-up.
  
  
  METHODS
  Case series; Level of evidence, 4.
  
  
  METHODS
  Twenty-seven patients (9 women, 18 men; mean age, 34.9 ± 10.2 years) treated for knee chondral or osteochondral lesions (size, 1.5-6 cm(2)) were followed for 2 and 5 years and were clinically evaluated using the International Knee Documentation Committee (IKDC) and Tegner scores. An MRI evaluation was performed at both follow-ups in 23 lesions, and the magnetic resonance observation of cartilage repair tissue (MOCART) score and specific subchondral bone parameters (bone regeneration, bone signal quality, osteophytes or upcoming bone front, sclerotic areas, and edema) were analyzed.
  
  
  RESULTS
  A statistically significant improvement in all clinical scores was observed from the initial evaluation to the 2- and 5-year follow-ups, and the results were stable over time. The mean IKDC subjective score improved from 40.0 ± 15.0 to 76.5 ± 14.5 (2-year follow-up) and 77.1 ± 18.0 (5-year follow-up) and the mean Tegner score from 1.6 ± 1.1 to 4.0 ± 1.8 (2-year follow-up) and 4.1 ± 1.9 (5-year follow-up). The MRI evaluation showed a significant improvement in both the MOCART score and subchondral bone status from 2 to 5 years. At 5 years, complete filling of the cartilage was shown in 78.3% of the lesions, complete integration of the graft was detected in 69.6% of cases, the repair tissue surface was intact in 60.9%, and the structure of the repair tissue was homogeneous in 60.9% of the cases. No correlation was found between MRI findings and clinical outcome.
  
  
  CONCLUSIONS
  This osteochondral scaffold was used for the treatment of chondral and osteochondral knee defects with a single-step procedure. The study results highlighted the safety and potential of this procedure, which offered a good clinical outcome with stable results at midterm follow-up. Although the MRI findings improved over time, some abnormalities persisted, but no correlation was found between the imaging and clinical results.
authors.affiliation: Elizaveta Kon, Biomechanics Laboratory, Rizzoli Orthopaedic Institute, Via Di Barbiano, 1/10 - 40136 Bologna, Italy. e.kon@biomec.ior.it.
authors.forename: Elizaveta
authors.initials: E
authors.lastname: Kon
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Filardo
authors.forename: Alessandro
authors.initials: A
authors.lastname: Di Martino
authors.forename: Maurizio
authors.initials: M
authors.lastname: Busacca
authors.forename: Antonio
authors.initials: A
authors.lastname: Moio
authors.forename: Francesco
authors.initials: F
authors.lastname: Perdisa
authors.forename: Maurilio
authors.initials: M
authors.lastname: Marcacci
mesh_terms: D000328:Adult; D001672:Biocompatible Materials / Q000494:pharmacology; D001861:Bone Regeneration / Q000502:physiology*; D002358:Cartilage, Articular / Q000601:surgery*; D003094:Collagen / Q000494:pharmacology*; D017886:Durapatite / Q000494:pharmacology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D053761:Nanocomposites; D011446:Prospective Studies; D054457:Tissue Scaffolds; D016896:Treatment Outcome; D014945:Wound Healing / Q000502:physiology
chemical_list: D001672:Biocompatible Materials; D003094:Collagen; D017886:Durapatite
keywords: articular cartilage; articular cartilage resurfacing; knee; magnetic resonance imaging; osteochondral scaffold