title: Outcome after partial medial meniscus substitution with the collagen meniscal implant at a minimum of 10 years' follow-up.
abstract: OBJECTIVE
  The aim of the study was to evaluate the clinical outcome of a collagen meniscus graft implanted in an injured medial meniscus after a minimum of 10 years' follow-up.
  
  
  METHODS
  Twenty-five patients underwent arthroscopic implantation of the collagen meniscus device. They had either persistent compartmental joint line pain due to a previous medial meniscus resection (5 cases) or a large irreparable meniscus tear at arthroscopy (20 cases). Implant failure was defined as infection due to the implant or mechanical failure of the device. Twenty-two patients returned for clinical, functional, and radiographic evaluation. Magnetic resonance imaging was also performed and was analyzed with the criteria of Genovese et al. (where type 3 indicates normal and type 1 indicates completely abnormal). All the aforementioned evaluations were carried out at a minimum of 10 years (range, 10.1 to 12.5 years) after the procedure.
  
  
  RESULTS
  The mean Lysholm score improved from 59.9 preoperatively to 89.6 at 1 year (P < .001), and it was 87.5 at final follow-up (P < .001). The results were good or excellent in 83% of the population. No differences were observed when we compared the Lysholm score at 1 year of follow-up with the score at final follow-up (P > .05). The mean pain score on a visual analog scale improved by 3.5 points at final follow-up. Patient satisfaction with the procedure was 3.4 of 4 points. Radiographic evaluation showed either minimal or no narrowing of the joint line. Magnetic resonance imaging showed type 2 in 64% of cases and type 3 in 21%. All cases showed less volume than expected (size type 2 in 89%). The failure rate in the patient population was 8% (2 of 25). There were no complications related to the device.
  
  
  CONCLUSIONS
  Although there were several different types of patients and acute and chronic tears were treated in a limited number of patients, meniscal substitution with the collagen meniscal implant provides significant pain relief and functional improvement after a minimum of 10 years' follow-up. The implant generally diminished in size, but the procedure proved to be safe and had a low rate of implant failure on a long-term basis. No development or progression of degenerative knee joint disease was observed in most cases.
  
  
  METHODS
  Level IV, therapeutic case series.
authors.affiliation: Department of Orthopaedic Surgery, Hospital de Sant Pau, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Monllau
authors.forename: Pablo Eduardo
authors.initials: PE
authors.lastname: Gelber
authors.forename: Ferrán
authors.initials: F
authors.lastname: Abat
authors.forename: Xavier
authors.initials: X
authors.lastname: Pelfort
authors.forename: Rosa
authors.initials: R
authors.lastname: Abad
authors.forename: Pedro
authors.initials: P
authors.lastname: Hinarejos
authors.forename: Marc
authors.initials: M
authors.lastname: Tey
mesh_terms: D000328:Adult; D018771:Arthralgia / Q000209:etiology / Q000601:surgery; D001175:Arthrography; D001182:Arthroscopy / Q000009:adverse effects; D003094:Collagen; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology; D022125:Lacerations / Q000209:etiology / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000601:surgery*; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000009:adverse effects; D010147:Pain Measurement; D011182:Postoperative Care; D011446:Prospective Studies; D019736:Prostheses and Implants; D000070600:Tibial Meniscus Injuries; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D003094:Collagen