Lumbar adjacent segment degeneration and disease after arthrodesis and total disc arthroplasty

Study Design. 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. Summary of Background Data. 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). Conclusion. 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.