title: Outcomes of Total Knee Arthroplasty After Osteochondral Allograft Transplantation.
abstract: BACKGROUND
  Fresh osteochondral allograft (OCA) transplantation is an effective treatment for osteochondral defects. Some patients require further surgical intervention, such as total knee arthroplasty (TKA). The effects of prior OCA transplantation on TKA outcomes are unknown.
  
  
  OBJECTIVE
  This study evaluated TKA failure rates after long-term follow-up and identified factors that may have contributed to an inferior outcome. Its aims were to (1) assess if having a prior OCA transplantation would increase the surgical complications of the subsequent TKA, (2) measure the infection and failure rates following TKA, (3) ascertain subjective outcomes scores from patients with intact TKA at latest follow-up, and (4) identify potential factors that contributed to inferior outcomes.
  
  
  METHODS
  Case series; Level of evidence, 4.
  
  
  METHODS
  A total of 35 patients who underwent TKA after OCA were identified. Pain, symptoms, function, and quality of life were evaluated using the Knee Society Function score and Knee injury and Osteoarthritis Outcome Score (KOOS). Associations between outcomes scores versus total number of surgeries before TKA were assessed using Spearman correlation. Patient characteristics (age, sex, total OCA area, presentation of osteoarthritis, and number of surgeries before TKA) were calculated between failures and nonfailures.
  
  
  RESULTS
  For patients with TKA surviving at latest follow-up (n = 24), mean follow-up time was 9.2 ± 4.3 years after TKA and 16.1 ± 5.2 years after OCA. While TKA after OCA did not present a technical challenge in the operating room, there was a high failure rate (31.4%). Activities of daily living, as measured on KOOS, were negatively correlated with total number of surgeries before TKA (ρ(2) = -0.5, P = .041). Patient age and number of surgeries before TKA influenced the failure rate, while sex and OCA area did not appear to be factors associated with inferior outcomes.
  
  
  CONCLUSIONS
  Patients with multiple knee operations before TKA were more likely to experience functional limitations or TKA failure. The patients who experienced TKA failure were part of a challenging subset of young patients treated with numerous orthopaedic procedures, and while these patients had inferior results with TKA after OCA, the OCA transplantation extended the time before a TKA was required without adding surgical complications.
authors.affiliation: San Marcos Outpatient Medical Center, Kaiser Permanente Orthopedics, San Marcos, California, USA.
authors.forename: Amy K
authors.initials: AK
authors.lastname: Steinhoff
authors.affiliation: Division of Orthopaedic Surgery, Scripps Clinic, La Jolla, California, USA.
authors.forename: William D
authors.initials: WD
authors.lastname: Bugbee
keywords: osteochondral allograft; outcomes; revision rates; total knee arthroplasty