title: Osteochondral allograft transplantation of the knee in the pediatric and adolescent population.
abstract: BACKGROUND
  Multiple studies in adults have shown that osteochondral allograft transplantation is an effective treatment option for large chondral and osteochondral defects of the knee. Limited outcome data are available on osteochondral allografts in the pediatric and adolescent patient populations.
  
  
  OBJECTIVE
  To describe a 28-year experience with osteochondral allograft transplantation in patients younger than 18 years with a focus on subjective outcome measures, return to activities, and allograft survivorship.
  
  
  METHODS
  Case series; Level of evidence, 4.
  
  
  METHODS
  A total of 39 patients (43 knees) underwent fresh osteochondral allograft transplantation for treatment of chondral and osteochondral lesions. Twenty-six male and 17 female knees with a mean age of 16.4 years (range, 11.0-17.9 years) at index surgery were followed-up at a mean of 8.4 years (range, 1.7-27.1 years). Thirty-four knees (79%) had at least 1 previous surgery. The most common underlying causes of the lesions were osteochondritis dissecans (61%), avascular necrosis (16%), and traumatic chondral injury (14%). Mean allograft size was 8.4 cm(2). The most common allograft location was the medial femoral condyle (41.9%), followed by the lateral femoral condyle (35%). Each patient was evaluated with the International Knee Documentation Committee pain, function, and total scores; a modified Merle d'Aubigné-Postel (18-point) scale; and Knee Society function score. Failure was defined as revision osteochondral allograft or conversion to arthroplasty.
  
  
  RESULTS
  Five knees experienced clinical failure at a median of 2.7 years (range, 1.0-14.7 years). Four failures were salvaged successfully with another osteochondral allograft transplant. One patient underwent prosthetic arthroplasty 8.6 years after revision allograft. Graft survivorship was 90% at 10 years. Of the knees whose grafts were in situ at latest follow-up, 88% were rated good/excellent (18-point scale). The mean International Knee Documentation Committee scores improved from 42 preoperatively to 75 postoperatively, and the Knee Society function score improved from 69 to 89 (both P < .05). Eighty-nine percent of patients reported "extremely satisfied" or "satisfied."
  
  
  CONCLUSIONS
  With 88% good/excellent results and 80% salvage rate of clinical failures with an additional allograft, osteochondral allograft transplantation is a useful treatment option in pediatric and adolescent patients.
authors.affiliation: William D. Bugbee, Scripps Clinic, 10666 North Torrey Pines Road, MS 116, La Jolla, CA 92037, USA. Bugbee.William@scrippshealth.org.
authors.forename: Ryan T
authors.initials: RT
authors.lastname: Murphy
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Pennock
authors.forename: William D
authors.initials: WD
authors.lastname: Bugbee
mesh_terms: D000293:Adolescent; D064591:Allografts; D016025:Bone Transplantation; D002356:Cartilage / Q000637:transplantation*; D002358:Cartilage, Articular / Q000293:injuries / Q000601:surgery*; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006085:Graft Survival; D006801:Humans; D007719:Knee Joint / Q000473:pathology / Q000601:surgery*; D008297:Male; D010008:Osteochondritis Dissecans / Q000601:surgery; D010020:Osteonecrosis / Q000601:surgery; D017060:Patient Satisfaction; D011446:Prospective Studies; D012086:Reoperation; D016879:Salvage Therapy
keywords: adolescent; cartilage; fresh osteochondral allograft transplantation; knee; osteochondral defect; pediatric