title: Resorbable collagen scaffolds for the treatment of meniscus defects: a systematic review.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the clinical and structural outcomes after resorbable collagen meniscus scaffold implantation through a systematic review of the published literature.
  
  
  METHODS
  A systematic search of both the PubMed and Embase databases was undertaken to identify all studies that reported clinical and/or structural outcomes after resorbable collagen meniscus scaffold implantation for the treatment of defects involving either the medial or lateral meniscus. Extracted data included study characteristics; surgical methods and rehabilitation protocols; objective outcomes; and preoperative and postoperative subjective outcome scores including Lysholm, Tegner, International Knee Documentation Committee, and visual analog scale scores.
  
  
  RESULTS
  Thirteen studies were included in this review. There were 10 Level IV studies, 2 Level II studies, and 1 Level I study with follow-up intervals ranging from 3 months to 12.5 years. With a few exceptions, the study designs used in each study generally followed those which had been previously performed. Substantial differences in rehabilitation protocols and concomitant procedures were noted that may have had an effect on overall clinical outcomes. Objective findings were mostly consistent and typically showed minimal degenerative changes on postoperative radiographs, decreased signal intensity of the scaffold over time on magnetic resonance imaging, the presence of meniscus-like tissue at second-look arthroscopy, and good integration of new tissue as evidenced by histologic analysis of biopsy specimens. Most studies reported satisfactory clinical outcomes, and most patients showed substantial improvements in comparison with mean preoperative baseline values.
  
  
  CONCLUSIONS
  On the basis of this systematic review, implantation of resorbable collagen scaffolds for the treatment of meniscus defects provides satisfactory clinical and structural outcomes in most cases. There is evidence that collagen meniscus scaffold implantation provides superior clinical outcomes when compared with partial meniscectomy alone.
  
  
  METHODS
  Level IV, systematic review of Level I, II, and IV studies.
authors.affiliation: Center for Outcomes-based Orthopaedic Research, Steadman Philippon Research Institute, Vail, Colorado, U.S.A.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Warth
authors.affiliation: Center for Translational and Regenerative Medicine Research, Steadman Philippon Research Institute, Vail, Colorado, U.S.A.. Electronic address: cartilagedoc@hotmail.com.
authors.forename: William G
authors.initials: WG
authors.lastname: Rodkey
mesh_terms: D020341:Absorbable Implants; D024042:Collagen Type I / Q000502:physiology*; D006801:Humans; D065466:Lysholm Knee Score; D008592:Menisci, Tibial / Q000166:cytology / Q000601:surgery*; D063868:Patient Outcome Assessment; D012038:Regeneration / Q000502:physiology*; D054457:Tissue Scaffolds; D064232:Visual Analog Scale
chemical_list: D024042:Collagen Type I