title: Use of cell-free collagen type I matrix implants for the treatment of small cartilage defects in the knee: clinical and magnetic resonance imaging evaluation.
abstract: OBJECTIVE
  Articular cartilage defects of the knee are a common condition for which several repair techniques have been described. The aim of the present study was to assess medium-term results of a one-step procedure using a cell-free collagen type I matrix.
  
  
  METHODS
  Fifteen patients with articular cartilage defects of the knee were treated with an 11-mm-diameter cell-free collagen type 1 matrix implant. The matrices were implanted in a press-fit manner into the defect after careful debridement down to the subchondral bone but without penetration of this margin. Follow-up examinations were carried out at 6 weeks, 6 months, and at 12, 24, 36, and 48 months after implantation. Clinical assessment included the visual analogue scale (VAS), the Tegner activity scale, and the International Knee Documentation Committee (IKDC) score. Radiological assessment for graft attachment and tissue regeneration was performed using the magnetic observation of cartilage repair tissue (MOCART) score.
  
  
  RESULTS
  A total of 15 patients (males: n = 6 and females: n = 9) with a mean age of 26.4 years (range 19-40) were treated. The mean VAS improved significantly when compared to the preoperative values (P < 0.05). Six weeks after implantation, IKDC values were slightly lower than the preoperative values (n.s.), but increased significantly at final follow-up (P < 0.05). At 24 months, there were no significant differences in the median Tegner score between the post-operative values and the preoperative values (n.s.). However, after 36 months, a significant improvement was noted that lasted at least up to 48 months (P < 0.05). The MOCART score improved consistently up to 4 years after implantation, with significant improvements already observed after 12 months (P < 0.05). No correlation between the clinical scores and the MOCART score could be perceived.
  
  
  CONCLUSIONS
  The present study showed that the use of cell-free collagen type I matrix implants led to a significant and durable improvement in all the clinical and imaging scores investigated 4 years after implantation.
  
  
  METHODS
  IV.
authors.affiliation: Department of Orthopaedics and Rheumatology, University Hospital Marburg, Baldingerstrasse, 35043, Marburg, Germany.
authors.forename: Karl F
authors.initials: KF
authors.lastname: Schüttler
authors.forename: Hanno
authors.initials: H
authors.lastname: Schenker
authors.forename: Christina
authors.initials: C
authors.lastname: Theisen
authors.forename: Markus D
authors.initials: MD
authors.lastname: Schofer
authors.forename: Alan
authors.initials: A
authors.lastname: Getgood
authors.forename: Philip P
authors.initials: PP
authors.lastname: Roessler
authors.forename: Johannes
authors.initials: J
authors.lastname: Struewer
authors.forename: Marga B
authors.initials: MB
authors.lastname: Rominger
authors.forename: Turgay
authors.initials: T
authors.lastname: Efe
mesh_terms: D000328:Adult; D002357:Cartilage Diseases / Q000601:surgery*; D002358:Cartilage, Articular / Q000601:surgery; D024042:Collagen Type I / Q000008:administration & dosage*; D005109:Extracellular Matrix; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies; D019736:Prostheses and Implants; D016896:Treatment Outcome; D014945:Wound Healing; D055815:Young Adult
chemical_list: D024042:Collagen Type I