title: Acute versus chronic vertebral compression fractures treated with kyphoplasty: early results.
abstract: BACKGROUND
  Kyphoplasty, a minimally invasive technique for fracture reduction and stabilization, has been shown to reduce pain and restore vertebral body height in patients with vertebral compression fractures (VCFs). Analyses comparing treatment outcomes of acute versus chronic VCFs have not yet been reported.
  
  
  OBJECTIVE
  To assess whether kyphoplasty results in better clinical outcome and fracture reduction in patients with either acute or chronic VCFs.
  
  
  METHODS
  A prospective, consecutive cohort study of patients who underwent kyphoplasty between March 2000 and December 2001 to treat osteoporotic VCFs that were either less than 10 weeks old (acute) or more than 4 months old (chronic). Fifteen subacute fractures (treated 10 to 16 weeks after fracture) were excluded from analyses.
  
  
  METHODS
  Eighty-six VCFs in 47 patients (35 female and 12 male) were treated during 55 kyphoplasty procedures. Mean patient age was 74 years (range, 47 to 91).
  
  
  METHODS
  Clinical outcomes were determined by comparison of preoperative and postoperative data from patient-reported indexes (pain assessment, pain medication usage and Oswestry Disability Index for Back Pain). Radiographs were assessed as to percent vertebral collapse, vertebral height restoration and local kyphosis correction.
  
  
  RESULTS
  By 2 weeks after surgery, 90% of acute and 87% of chronic fractures were associated with pain relief. Narcotic usage decreased and Oswestry scores improved in almost all patients. Mean vertebral body height significantly improved after kyphoplasty (acute: 58% to 86% of estimated normal vertebral height, p< .001; chronic: 56% to 79% of estimated normal vertebral height, p< .001). Restoration to 89% or greater estimated normal vertebral height was achieved in 60% of acute fractures and 26% of chronic fractures. In addition, more acute fractures were reducible (greater than 80% restoration of height lost) compared with chronic fractures (p= .01). After kyphoplasty, less than 10% correction of height lost occurred in 8% of acute fractures and 20% of chronic fractures. Local kyphosis significantly improved after kyphoplasty (mean local Cobb angle: acute, 15 to 8 degrees, p< .001; chronic, 15 to 10 degrees, p< .001).
  
  
  CONCLUSIONS
  Fracture reduction was best achieved in acute fractures. Symptomatic chronic fractures may also remain candidates for kyphoplasty because pain relief and improvement in patient function are reliable and some kyphosis correction can still be achieved in many of these patients.
authors.affiliation: Sonoran Spine Center, 2610 North 3rd Street, Suite B, Phoenix, AZ 85004, USA. DGC@sonoranspine.com
authors.forename: Dennis
authors.initials: D
authors.lastname: Crandall
authors.forename: Douglas
authors.initials: D
authors.lastname: Slaughter
authors.forename: P J
authors.initials: PJ
authors.lastname: Hankins
authors.forename: Claire
authors.initials: C
authors.lastname: Moore
authors.forename: Jonathan
authors.initials: J
authors.lastname: Jerman
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000379:methods*; D005598:Fractures, Spontaneous / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D010024:Osteoporosis / Q000150:complications* / Q000175:diagnosis; D010147:Pain Measurement; D011446:Prospective Studies; D011859:Radiography; D012720:Severity of Illness Index; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000209:etiology / Q000601:surgery*; D016896:Treatment Outcome