title: A dual-center review of compressive osseointegration for fixation of massive endoprosthetics: 2- to 9-year followup.
abstract: BACKGROUND
  Aseptic failure of massive endoprostheses used in the reconstruction of major skeletal defects remains a major clinical problem. Fixation using compressive osseointegration was developed as an alternative to cemented and traditional press-fit fixation in an effort to decrease aseptic failure rates.
  
  
  OBJECTIVE
  The purpose of this study was to answer the following questions: (1) What is the survivorship of this technique at minimum 2-year followup? (2) Were patient demographic variables (age, sex) or anatomic location associated with implant failure? (3) Were there any prosthesis-related variables (eg, spindle size) associated with failure? (4) Was there a discernible learning curve associated with the use of the new device as defined by a difference in failure rate early in the series versus later on?
  
  
  METHODS
  The first 50 cases using compressive osseointegration fixation from two tertiary referral centers were retrospectively studied. Rates of component removal for any reason and for aseptic failure were calculated. Demographic, surgical, and oncologic factors were analyzed using regression analysis to assess for association with implant failure. Minimum followup was 2 years with a mean of 66 months. Median age at the time of surgery was 14.5 years.
  
  
  RESULTS
  A total of 15 (30%) implants were removed for any reason. Of these revisions, seven (14%) were the result of aseptic failure. Five of the seven aseptic failures occurred at less than 1 year (average, 8.3 months), and none occurred beyond 17 months. With the limited numbers available, no demographic, surgical, or prosthesis-related factors correlated with failure.
  
  
  CONCLUSIONS
  Most aseptic failures of compressive osseointegration occurred early. Longer followup is needed to determine if this technique is superior to other forms of fixation.
authors.affiliation: Division of Orthopaedic Surgery, Department of Surgery, City of Hope National Medical Center, 1500 E Duarte Road, Duarte, CA, 91010, USA, gcalvert@coh.org.
authors.forename: George T
authors.initials: GT
authors.lastname: Calvert
authors.forename: Judd E
authors.initials: JE
authors.lastname: Cummings
authors.forename: Austin J
authors.initials: AJ
authors.lastname: Bowles
authors.forename: Kevin B
authors.initials: KB
authors.lastname: Jones
authors.forename: L Daniel
authors.initials: LD
authors.lastname: Wurtz
authors.forename: R Lor
authors.initials: RL
authors.lastname: Randall
mesh_terms: D000293:Adolescent; D001859:Bone Neoplasms / Q000601:surgery*; D002983:Clinical Competence; D005260:Female; D006801:Humans; D007196:Indiana; D053208:Kaplan-Meier Estimate; D059032:Learning Curve; D023821:Limb Salvage; D008297:Male; D019637:Orthopedic Procedures / Q000009:adverse effects / Q000295:instrumentation*; D016348:Osseointegration; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D011475:Prosthesis Failure; D019919:Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D019651:Plastic Surgery Procedures / Q000009:adverse effects / Q000295:instrumentation*; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D062606:Tertiary Care Centers; D013997:Time Factors; D016896:Treatment Outcome; D014589:Utah; D055815:Young Adult