Prone-transpsoas as single-position, circumferential access to the lumbar spine: A brief survey of index cases

Analyzing the L4-5 Segmental Alignment Change of Two Minimally Invasive Prone-Based Interbody Fusions

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVE

Restoration of lumbar lordosis (LL) is a principal objective during spinal fusion procedures, traditionally focusing on achieving an LL within 10° of the pelvic incidence (PI). Recent studies have demonstrated a relatively constant L4-S1 alignment of 35-40° at L4-S1 and at least 15° at L4-5, regardless of PI. Based on these results, this study was created to examine the success rate of achieving a minimum of 15° at L4-5 through two differing prone-based techniques: Prone Lateral (pLLIF) and Trans Foraminal Interbody Fusion (TLIF).

METHODS

One hundred patients with a primary single-level L4-5 interbody fusion (50 pLLIF and 50 TLIF) were retrospectively analyzed. Pre and post-operative radiographs were measured to examine the segmental change at each level in the lumbar spine and calculate the success rate for achieving a minimum L4-5 segmental lordosis of 15° at the final follow-up.

RESULTS

The overall success rate of achieving an L4-5 segmental alignment >15° at the final follow-up was 70%. Prone LLIF was significantly more likely than TLIF to achieve this goal, achieving L4-5 > 15° 84% of the time vs TLIFs 56% (P = 0.002). Prone LLIF demonstrated an average L4-5 increase of 5.6 ± 5.9° which was larger than the mean increase for TLIF 0.4 ± 3.8° (P < 0.001). In both techniques, there was an inverse correlation between pre-operative L4-5 angle and L4-5 angle change.

CONCLUSION

Prone lateral lumbar interbody fusion demonstrates a high success rate for achieving a post-operative L4-5 angle >15° and achieves this at a higher rate than TLIF.

Comparison of standard and modified prone positioning for lateral lumbar spine fusion: a feasibility study to reduce lumbar plexus injury

Single-prone-lateral (PL) positioning is a new technique that allows for simultaneous anterior and posterior lumbar spine surgery. However, there is a concern regarding the risk of lumbar plexus injury in PL positioning. This study compared the risk of lumbar plexus damage and the overall safety profile of a modified PL (mPL) position to the standard PL (sPL) position for lateral lumbar spine fusion surgery. A crossover soft cadaveric study was conducted with two raters examining the comparative outcomes of position A: sPL and position B: mPL. The mPL position differs from the sPL position in that the ipsilateral arm is placed at the side of the body rather than above the head. To assess positive results (no lumbar plexus injury) between positions A and B, a mixed effects logistic regression model was utilized. The odds ratio of a good result between positions B and A was also determined. The odds ratio of the favorable outcome between position B and A was 1.77, indicating significantly higher odds of a favorable outcome in the modified position B than in the control or position A. The mPL positioning outperformed the sPL positioning in terms of safety and efficacy for lateral lumbar spine fusion. The mPL positioning may reduce the risk of lumbar plexus injury by allowing for a more direct approach to the lumbar spine and by avoiding excessive stretching of the lumbar plexus.

Prone Transpsoas Lateral Lumbar Interbody Fusion for Degenerative Lumbar Spine Disease: Case Series With an Operative Video Using Fluoroscopy-Based Instrument Tracking Guidance

BACKGROUND

Lateral lumbar interbody fusion has inherent limitations, such as the necessity to reposition the patient. To overcome this limitation, the prone transpsoas (PTP) approach for lateral lumbar interbody fusion has been developed.

OBJECTIVE

To report clinical and radiographic outcome measures of a series of patients who underwent PTP at our hospital.

METHODS

A retrospective chart review was conducted to identify patients who underwent PTP for degenerative lumbar spine disease between September 2019 and August 2021. A thorough analysis of clinical and radiographic outcome measures for these patients was conducted.

RESULTS

Our search resulted in the identification of 15 consecutive patients. Four patients were operated using the assistance of fluoroscopy-based instrument tracking. Overall, the mean follow-up duration was 11.9 ± 7.9 months. Radiographically, the PTP approach resulted in significant postoperative improvement of lumbar lordosis ( P = .03) and pelvic incidence minus lumbar lordosis ( P &lt; .005). No significant difference was found postoperatively in other regional sagittal alignment parameters, including pelvic tilt, sacral slope, or pelvic incidence. Clinically, the patients' Oswestry Disability Indices ( P = .002) and Short Form Survey-12 Physical Scores improved significantly ( P = .01). The estimated mean blood loss for patients who underwent the PTP procedure was 137.7 ± 96.4 mL, the mean operative time was 212.5 ± 77.1 minutes, and the mean hospital stay was 2.7 ± 1.4 days. One patient each had superficial wound infection, transient paralytic ileus, transient pulmonary embolism, transient urinary retention, or required revision lumbar surgery.

CONCLUSION

This study demonstrates that the PTP approach is associated with significant improvement in radiographic and clinical outcomes.

Comparison of prone transpsoas lateral lumbar interbody fusion and transforaminal lumbar interbody fusion for degenerative lumbar spine disease: A retrospective radiographic propensity score-matched analysis

INTRODUCTION

This is the first study to compare the prone transpsoas (PTP) approach for lateral lumbar interbody fusion (LLIF) and transforaminal lumbar interbody fusion (TLIF) through an analysis of radiographic and clinical outcomes.

MATERIALS AND METHODS

A retrospective chart review of data for patients who underwent the PTP approach or TLIF for degenerative lumbar spine disease was conducted. Propensity score matching was completed through the utilization of a linear regression model with the classification of surgery (PTP vs. TLIF) being used as the indicator (dependent variable) and the radiographic outcomes as covariates (independent variables). Both cohorts (PTP and TLIF) were propensity score matched according to preoperative radiographic parameters using a 1-to-1 ratio to the nearest neighbor. Eleven patients in the TLIF group were matched to an equal number of patients in the PTP group who had similar propensity scores to perform a thorough analysis of clinical and radiographic outcomes.

RESULTS

The PTP approach significantly improved the lumbar lordosis angle, pelvic tilt, and the pelvic incidence minus lumbar lordosis value when compared to TLIF (p < 0.05). Clinically, the PTP group improved significantly in terms of the Oswestry Disability Index (p < 0.05). That approach also significantly minimized blood loss and hospital stay (p < 0.05). Furthermore, significantly more cages were placed anteriorly in the PTP group than in the TLIF group (p < 0.05). However, the PTP group had a significantly longer duration of radiation exposure (p < 0.05).

CONCLUSION

The PTP approach resulted in greater improvement in postoperative radiographic measurements as well as patient-reported outcomes.