title: Patient-related risk factors for the extrusion of lateral meniscal allograft transplants.
abstract: OBJECTIVE
  The objective of this study was to identify the patient-related risk factors for lateral meniscal extrusion after lateral meniscal allograft transplantation (MAT) regarding demographic characteristics, alignment, and pre-existing arthrosis.
  
  
  METHODS
  Seventy-one patients who underwent arthroscopic lateral MAT with bone bridge fixation between 2008 and 2011 were assessed. Lateral meniscal subluxation was measured on mid-coronal sections of magnetic resonance images 1 year postoperatively. Subluxation of more than 3 mm was considered to be extrusion. Age, gender, body mass index, time from previous meniscectomy, mechanical axis deviation, Kellgren-Lawrence grade on preoperative radiographs, and intraoperative International Cartilage Repair Society grade were assessed as possible patient-related factors.
  
  
  RESULTS
  The mean lateral subluxation in the coronal plane was 2.6 ± 1.6 mm. Among our patients, 23 transplants (32.4%) showed extrusion. The intraoperative cartilage status of the femoral condyle and tibial plateau showed significant differences between the nonextruded (≤3 mm) and extruded (>3 mm) groups (P = .010 and P = .001, respectively). There were no differences in other factors between these 2 groups. Binary logistic regression analysis showed that tibial-side cartilage wear of International Cartilage Repair Society grade 3 or more was a significant risk factor for meniscal extrusion.
  
  
  CONCLUSIONS
  Lateral meniscal extrusion 1 year after lateral MAT is affected by the degree of intraoperative cartilage wear, most notably on the tibial side. Patient demographic characteristics, alignment, and radiographic arthritic changes did not differ between nonextruded and extruded MAT cases.
  
  
  METHODS
  Level IV, therapeutic case series.
authors.affiliation: Department of Orthopedic Surgery, Incheon St. Mary's Hospital, College of Medicine, Incheon Catholic University, Incheon, Republic of Korea.
authors.forename: Bum-Sik
authors.initials: BS
authors.lastname: Lee
authors.affiliation: Department of Orthopedic Surgery, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea.
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Kosin University Gospel Hospital, Busan, Republic of Korea.
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Biomedical Engineering, College of Medicine, Chungbuk National University, Chungcheongbuk-do, Republic of Korea.
authors.forename: Kyung-Ah
authors.initials: KA
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea. Electronic address: sibin@amc.seoul.kr.
authors.forename: Seong-Il
authors.initials: SI
authors.lastname: Bin
mesh_terms: D000293:Adolescent; D000328:Adult; D064591:Allografts; D005260:Female; D006085:Graft Survival; D006801:Humans; D007718:Knee Injuries / Q000601:surgery*; D007719:Knee Joint / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000473:pathology / Q000601:surgery / Q000637:transplantation*; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D014184:Transplantation, Homologous / Q000009:adverse effects*; D055815:Young Adult