34. Postoperative changes in pelvic indices after MIS-TLIF for lumbar spondylolisthesis: retrospective analysis

Abstract

BACKGROUND CONTEXT

Lumbar spondylolisthesis often results in pelvic imbalance, contributing to chronic pain and disability. Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) has emerged as an effective surgical option, offering stabilization and correction of spinal alignment with reduced tissue disruption.

PURPOSE

This retrospective study evaluates postoperative improvements in pelvic indices, including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and lumbar lordosis (LL), in patients with lumbar spondylolisthesis treated with MIS-TLIF.

STUDY DESIGN/SETTING

The study design is retrospective. It involves reviewing and analyzing the medical records and radiographic data of patients who underwent MIS-TLIF for lumbar spondylolisthesis between 2018 and 2024. The study examines preoperative and postoperative changes in pelvic indices and their correlation with clinical outcomes.

PATIENT SAMPLE

A total of 354 patients were included in this retrospective study.

OUTCOME MEASURES

Pelvic Indices: PI, PT, SS, LL. Preoperative and postoperative changes in these parameters were assessed through radiographic imaging. Clinical Outcomes: pain levels, assessed using a visual analog scale (VAS) preoperatively and postoperatively. Functional improvements, measured using the Oswestry Disability Index (ODI) or a similar functional assessment tool. Sagittal Alignment: improvement in overall spinal sagittal balance, evaluated through radiographic measurements and clinical examination. Correlation between radiographic and clinical outcomes: The relationship between improvements in pelvic indices and clinical improvements in pain and function was analyzed. Complications: any intraoperative or postoperative complications, such as infection or hardware failure, were documented.

METHODS

This is a retrospective study involving patients who underwent MIS-TLIF for lumbar spondylolisthesis between 2018 and 2024. The following steps were involved: Patient Selection: inclusion criteria: patients diagnosed with lumbar spondylolisthesis who underwent MIS-TLIF surgery. Exclusion criteria: patients with incomplete clinical or radiographic data or those who had additional spine surgeries outside the MIS-TLIF approach. Radiographic Analysis: Preoperative and postoperative radiographs (x-rays or CT scans) were reviewed to measure key pelvic parameters, including: PI, PT, SS, LL. Changes in these pelvic indices were analyzed to evaluate improvements in sagittal alignment. Clinical Outcome Assessment: Pain Assessment: pain levels were measured using the VAS preoperatively and at follow-up intervals. Functional Outcome: Functional improvements were assessed using the ODI or other relevant clinical scoring tools. Follow-up: Patients were followed up at regular intervals (eg, 1, 3, and 6 months; 1, 2, and 4 years) to assess clinical and radiographic outcomes. Statistical Analysis: Descriptive statistics were used to summarize patient demographics, radiographic data, and clinical outcomes. Paired t-tests or other appropriate statistical tests were used to compare preoperative and postoperative pelvic indices and clinical scores. The correlation between radiographic improvements and clinical outcomes (pain relief and functional improvement) was evaluated. Complications: Any surgical complications, including hardware failure, infection, or neurological injury, were documented and analyzed.

RESULTS

Significant postoperative improvements were observed in PT and SS, contributing to better overall sagittal balance. PI improved significantly in patients with high grade spondylolisthesis. Patients reported reduced pain and improved functional outcomes postoperatively.

CONCLUSIONS

MIS-TLIF effectively restores pelvic parameters and improves sagittal alignment in lumbar spondylolisthesis patients. The correction of pelvic indices correlates with enhanced clinical outcomes, supporting MIS-TLIF as a reliable surgical approach for managing this condition.

FDA Device/Drug Status

This abstract does not discuss or include any applicable devices or drugs.