How many physical therapy sessions are required to reach a good outcome in symptomatic lumbar spondylolisthesis? A retrospective study

Background: There is a lack of conclusive information about the optimal dosage of physical therapy treatments in Spondylolisthesis (SPL) patients. Purpose: The present study attempted to evaluate the comparative effectiveness of two different doses in reaching similar clinical outcomes. Methods: A retrospective cohort study of 64 consecutive patients admitted for physical therapy with symptomatic lumbar grade I SPL (42 ± 15years, 57% female) was conducted. At the end of the treatment, all participants were retrospectively assigned to one of two groups, receiving either 5e8 or 9e12 sessions (experimental or control group, respectively) of physical therapy treatments. The Prone Bridge Test (PBT) and the Supine Bridge Test (SBT) were used to measure muscular endurance. Results: The area under the ROC curve for the PBT was 0.64 (95% CI 0.45e0.83) and for the SBT was 0.57 (95% CI 0.33e0.80). The optimal cutoff points were 25.5s for the PBT and 55.0s for the SBT. Logistic regression revealed that PBT (OR ¼ 1.062) was associated with SPL. The final regression model explained 77.4% (R2 ¼ 0.341; p ¼ 0.024) of the variability. Conclusions: In this sample, the number of sessions required to achieve satisfactory outcomes ranged from 5 to 12. The clinical results of the subjects in the 5e8 sessions group were similar to the 9e12 sessions group. Individual's coping mechanisms could be considered in future studies to understand which patients will require more therapeutic sessions.