Patient-specific Risk Factors Increase Episode of Care Costs After Lumbar Decompression.

STUDY DESIGN: Retrospective cohort analysis. OBJECTIVE: To determine, which patient-specific risk factors increase total episode of care (EOC) costs in a population of Centers for Medicare and Medicaid Services beneficiaries undergoing lumbar decompression. SUMMARY OF BACKGROUND DATA: Lumbar decompression is an effective option for the treatment of central canal stenosis or radiculopathy in patients unresponsive to nonoperative management. Given that elderly Americans are more likely to have one or more chronic medical conditions, there is a need to determine, which, if any, patient-specific risk factors increase health care costs after lumbar decompression. METHODS: Care episodes limited to lumbar decompression surgeries were retrospectively reviewed on a Centers for Medicare and Medicaid Service reimbursement database at our academic institution between 2014 and 2019. The 90-day total EOC reimbursement payments were collected. Patient electronic medical records were then matched to the selected care episodes for the collection of patient demographics, medical comorbidities, surgical characteristics, and clinical outcomes. A stepwise multivariate linear regression model was developed to predict patient-specific risk factors that increased total EOC costs after lumbar decompression. Significance was set at P <0.05. RESULTS: A total of 226 patients were included for analysis. Risk factors associated with increased total EOC cost included increased age (per year) (ß = $324.70, P < 0.001), comorbid depression (ß = $4368.30, P = 0.037), revision procedures (ß = $6538.43, P =0.012), increased hospital length of stay (per day) (ß = $2995.43, P < 0.001), discharge to an inpatient rehabilitation facility (ß = $14,417.42, P = 0.001), incidence of a complication (ß = $8178.07, P < 0.001), and readmission (ß = $18,734.24, P < 0.001) within 90 days. CONCLUSIONS: Increased age, comorbid depression, revision decompression procedures, increased hospital length of stay, discharge to an inpatient rehabilitation facility, and incidence of a complication and readmission within 90 days were all associated with increased total episodes of care costs.

A Short-Term Assessment of Lumbar Sagittal Alignment Parameters in Patients Undergoing Anterior Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To determine if intraoperative on-table lumbar lordosis (LL) and segmental lordosis (SL) coincide with perioperative change in lordosis. SUMMARY OF BACKGROUND DATA: Improvements in sagittal alignment are believed to correlate with improvements in clinical outcomes. Thus, it is important to establish whether intraoperative radiographs predict postoperative improvements in LL or SL. MATERIALS AND METHODS: Electronic medical records were reviewed for patients ≥18 years old who underwent single-level and two-level anterior lumbar interbody fusion with posterior instrumentation between 2016 and 2020. LL, SL, and the lordosis distribution index were compared between preoperative, intraoperative, and postoperative radiographs using paired t tests. A linear regression determined the effect of subsidence on SL and LL. RESULTS: A total of 118 patients met inclusion criteria. Of those, 75 patients had one-level fusions and 43 had a two-level fusion. LL significantly increased following on-table positioning [delta (Δ): 5.7°, P <0.001]. However, LL significantly decreased between the intraoperative to postoperative radiographs at two to six weeks (Δ: -3.4°, P =0.001), while no change was identified between the intraoperative and more than three-month postoperative radiographs (Δ: -1.6°, P =0.143). SL was found to significantly increase from the preoperative to intraoperative radiographs (Δ: 10.9°, P <0.001), but it subsequently decreased at the two to six weeks follow up (Δ: -2.7, P <0.001) and at the final follow up (Δ: -4.1, P <0.001). On linear regression, cage subsidence/allograft resorption was predictive of the Δ SL (ß=0.55; 95% confidence interval: 0.16-0.94; P =0.006), but not LL (ß=0.10; 95% confidence interval: -0.44 to 0.65; P =0.708). CONCLUSION: Early postoperative radiographs may not accurately reflect the improvement in LL seen on intraoperative radiographic imaging, but they are predictive of long-term lumbar sagittal alignment. Each millimeter of cage subsidence or allograft resorption reduces SL by 0.55°, but subsidence does not significantly affect LL. LEVELS OF EVIDENCE: 4.