title: BMP Use and the Risk of Revision Surgery After Long Posterolateral Fusions in the Elderly.
abstract: METHODS
  Retrospective database review.
  
  
  OBJECTIVE
  The objective of the study was to assess whether bone morphogenetic protein (BMP) decreases the risk of revision surgery in elderly patients treated with 3-7 level or 8 or greater level fusions.
  
  
  BACKGROUND
  Revision spine surgery in the elderly is a complex undertaking, highlighting the importance of discovering methods to decrease the risk of repeat procedures. The role of BMP in modulating risk of future revision surgery is not well studied in the elderly.
  
  
  METHODS
  The PearlDiver database (2005-2012) was queried for elderly adult spinal deformity patients treated with a primary thoracolumbar posterolateral fusion of 3 or more levels. To compare how BMP modifies revision surgery rates in 3-7 level versus 8 level or greater fusions, 4 mutually exclusive cohorts were created and matched to one another: 1043 patients treated with 8 or greater level fusions with BMP; 1111 patients with 8 or greater level fusions without BMP; 2813 patients with 3-7 level fusions with BMP; and 4770 patients with 3-7 level fusions without BMP. Revision and complication rates were compared. Complications included seroma formation, heterotopic ossification, and postoperative neuritis within 90 days.
  
  
  RESULTS
  Patients treated with BMP during an 8 or greater level fusion were significantly less likely to require a revision surgery than matched controls (relative risk, 0.75, P=0.015). BMP use was not associated with a decreased risk of revision surgery in 3-7 level fusions (relative risk, 0.89, P=0.20). Patients treated with BMP during 3-7 level fusions were significantly less likely to develop any of the assessed complications (P=0.02). There were no other significant differences in pairwise comparisons of subcohorts of each of the fusion lengths.
  
  
  CONCLUSIONS
  BMP use decreases revision rates in elderly adult spinal deformity patients treated with 8 or greater level fusions, but not in those treated with 3-7 level fusions.
  
  
  METHODS
  Level III.
authors.affiliation: *Department of Orthopaedic Surgery, Johns Hopkins Hospital, Baltimore, MD †Department of Orthopaedic Surgery, University of Virginia, Charlottesville, VA ‡Orthopaedic Medicine & Surgery, Washington, DC.
authors.forename: Varun
authors.initials: V
authors.lastname: Puvanesarajah
authors.forename: Amit
authors.initials: A
authors.lastname: Jain
authors.forename: Jourdan M
authors.initials: JM
authors.lastname: Cancienne
authors.forename: Benjamin E
authors.initials: BE
authors.lastname: Stein
authors.forename: Wendy M
authors.initials: WM
authors.lastname: Novicoff
authors.forename: Adam L
authors.initials: AL
authors.lastname: Shimer
authors.forename: Francis
authors.initials: F
authors.lastname: Shen
authors.forename: Hamid
authors.initials: H
authors.lastname: Hassanzadeh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D015331:Cohort Studies; D003710:Demography; D005260:Female; D006801:Humans; D007902:Length of Stay / Q000191:economics; D008297:Male; D011183:Postoperative Complications / Q000209:etiology; D012086:Reoperation / Q000009:adverse effects / Q000191:economics; D012307:Risk Factors; D013123:Spinal Fusion / Q000009:adverse effects / Q000191:economics; D016019:Survival Analysis
chemical_list: D019485:Bone Morphogenetic Proteins