Evaluating the Association Between Physical Therapy Variables and Outcomes After Lumbar Fusion.

Study design: Retrospective cohort study.

Objective: The purpose of this study was to investigate how inpatient physical therapy variables impact (1) inpatient complications, (2) 90-day readmissions, (3) 1-year reoperation rates, and (4) length of stay after posterior lumbar decompression and fusion.

Summary of background data: Previous studies have emphasized the role of early ambulation in postoperative spine patients as an effective method for improving pain and decreasing length of stay, but few studies have evaluated the efficacy of inpatient physical therapy.

Methods: Patients 18 years of age or older who underwent primary 1-level or 2-level posterior lumbar decompression and fusion from 2019 to 2020 were retrospectively identified. Physical therapy data, including time to first inpatient PT session, gait trial distance achieved, post-treatment pain rating, and Activity Measure for Post-Acute Care (Activity Measure for Post-Acute Care [AM-PAC]) scores were collected using manual chart review. Surgical outcome variables included length of stay, inpatient complications, 90-day readmissions, and reoperations within 1 year of primary surgery.

Results: Overall, 425 patients were identified. There was no difference in hours to PT or total gait trial distance achieved between patients who experienced a complication and those that did not. Patients in the noncomplication group had higher AM-PAC scores than patients in the complication group. There was no difference with regards to time to PT, AM-PAC score, or gait trial distance achieved between readmitted patients and nonreadmitted patients or revision patients and nonrevision patients. Stepwise logistic regression showed that having a physical therapy session within 6 hours of surgery was predictive of a decreased length of stay both in all patients.

Conclusions: While inpatient physical therapy within 6 hours of surgery does not appear to impact readmissions, complications, or reoperations, surgeons should encourage early ambulation postoperatively to decrease extended hospital stays. Future investigation should seek to identify factors that delay inpatient PT in the 6 hours after surgery.