title: Lumbar adjacent segment degeneration and disease after arthrodesis and total disc arthroplasty.
abstract: METHODS
  Systematic review of published incidence of radiographic adjacent segment degeneration (ASDeg) and symptomatic adjacent segment disease (ASDis) after arthrodesis or total disc replacement.
  
  
  OBJECTIVE
  Assess impact of surgery method and other factors on the incidence of ASDeg and ASDis.
  
  
  BACKGROUND
  Twenty-seven articles, none of which were class I or II, met the inclusion criteria. Twenty involved arthrodesis (1732 patients) and 7 involved arthroplasty (758 patients). Nineteen detailed ASDeg and 16 detailed ASDis.
  
  
  METHODS
  Data were established for number of patients, gender, average patient age, incidence of ASDeg and ASDis, average time to follow-up, and level and type of surgery. Multivariate logistic regression was used to identify which parameters had a significant effect on the incidence of ASDeg and ASDis.
  
  
  RESULTS
  Three hundred fourteen of 926 patients in the arthrodesis group (34%) and 31 out of 313 patients in the total disc replacement group (9%) developed ASDeg. (P < 0.0001) Multivariate logistic regression indicated that higher odds of ASDeg were associated with: older patients (P < 0.001); arthodesis (P = 0.0008); and longer follow-up (P = 0.0025). For ASDis, 173/1216 (14%) arthrodesis patients developed ASDis compared to 7/595 (1%) of arthroplasty patients (P < 0.0001). Using multivariate logistic regression, higher odds of ASDis were seen in studies with fusion (P < 0.0001), higher percentages of male patients (P = 0.0019), and shorter follow-up (P < 0.05).
  
  
  CONCLUSIONS
  Analysis of the literature suggests a correlation between fusion and the development of ASDeg compared to arthroplasty, but this association is dampened by the influence of patient age. There is a stronger correlation between fusion and ASDis compared to arthroplasty. The data supports only a class C recommendation (lowest tier) for the use of arthroplasty to reduce ASDis and disc degeneration compared to arthrodesis.
authors.affiliation: Department of Orthopaedics and Neurological Surgery, Thomas Jefferson University, Philadelphia, PA, USA. James.harrop@jefferson.edu
authors.forename: James S
authors.initials: JS
authors.lastname: Harrop
authors.forename: Jim A
authors.initials: JA
authors.lastname: Youssef
authors.forename: Mitch
authors.initials: M
authors.lastname: Maltenfort
authors.forename: Peggy
authors.initials: P
authors.lastname: Vorwald
authors.forename: Pascal
authors.initials: P
authors.lastname: Jabbour
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Bono
authors.forename: Neil
authors.initials: N
authors.lastname: Goldfarb
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Vaccaro
authors.forename: Alan S
authors.initials: AS
authors.lastname: Hilibrand
mesh_terms: D019643:Arthroplasty, Replacement / Q000379:methods*; D016009:Chi-Square Distribution; D017586:Diskectomy / Q000379:methods*; D006801:Humans; D015994:Incidence; D007403:Intervertebral Disc; D016015:Logistic Models; D008159:Lumbar Vertebrae / Q000473:pathology* / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology*; D019919:Prosthesis Implantation; D013123:Spinal Fusion / Q000379:methods*