Expandable cages that expand both height and lordosis provide improved immediate effect on sagittal alignment and short-term clinical outcomes following minimally invasive transforaminal lumbar interbody fusion (MIS TLIF)

Background

Failure to restore lordotic alignment is not an uncommon problem following minimally invasive transforaminal lumbar interbody fusion (MIS TLIF), even with expandable cages that increase disc height. This study aims to investigate the effect of the expandable cage that is specifically designed to expand both height and lordosis. We evaluated the outcomes of MIS TLIF in restoring immediate postoperative sagittal alignment by comparing two different types of expandable cages. One cage is designed to solely increase disc height (Group H), while the other can expand both height and lordosis (Group HL).

Methods

Patients undergoing MIS TLIF using expandable cages were retrospectively reviewed, including 40 cases in Group H and 109 cases in Group HL. Visual analog scores of back and leg pain, and Oswestry disability index were collected. Disc height, disc angle, and sagittal alignment were measured. Complications were recorded, including early subsidence which was evaluated with computed tomography.

Results

Clinical and radiographic outcomes significantly improved in both groups postoperatively. Group HL showed superior improvement in segmental lordosis (4.4°±3.5° vs. 2.1°±4.8°, P=0.01) and disc angle (6.3°±3.8 vs. 2.2°±4.3°, P<0.001) compared to Group H. Overall incidence of early subsidence was 23.3%, predominantly observed during initial cases as part of the learning curve, but decreased to 18% after completion of the first 20 cases.

Conclusions

Expandable cages with a design specifically aimed at increasing lordotic angle can provide favorable outcomes and effectively improve immediate sagittal alignment following MIS TLIF, compared to conventional cages that only increase in height. However, regardless of the type of expandable cage used, it is crucial to avoid applying excessive force to achieve greater disc height or lordosis, as this may contribute to subsidence and a possible reduction in lordotic alignment restoration. Long-term results are needed to evaluate the clinical outcome, fusion rate, and maintenance of the sagittal alignment.

Ten-step minimally invasive slalom unilateral laminotomy for bilateral decompression (sULBD) with navigation

BACKGROUND

Unilateral laminotomy for bilateral decompression (ULBD) is a MIS surgical technique that offers safe and effective decompression of lumbar spinal stenosis (LSS) with a long-term resolution of symptoms. Advantages over conventional open laminectomy include reduced expected blood loss, muscle damage, mechanical instability, and less postoperative pain. The slalom technique combined with navigation is used in multi-segmental LSS to improve the workflow and effectiveness of the procedure.

METHODS

We outline ten technical steps to achieve a slalom unilateral laminotomy for bilateral decompression (sULBD) with navigation. In a retrospective case series, we included patients with multi-segmental LSS operated in our institution using the sULBD between 2020 and 2022. The primary outcome was a reduction in pain measured by Visual Analogue Scale (VAS) for back pain and leg pain and Oswestry Disability Index (ODI).

RESULTS

In our case series (N = 7), all patients reported resolution of initial symptoms on an average follow-up of 20.71 ± 9 months. The average operative time and length of hospital stay were 196.14 min and 1.67 days, respectively. On average, VAS (back pain) was 4.71 pre-operatively and 1.50 on long-term follow-up of an average of 19.05 months. VAS (leg pain) decreased from 4.33 to 1.21. ODI was reported as 33% pre-operatively and 12% on long-term follow-up.

CONCLUSION

The sULBD with navigation is a safe and effective MIS surgical procedure and achieves the resolution of symptoms in patients presenting with multi-segmental LSS. Herein, we demonstrate the ten key steps required to perform the sULBD technique. Compared to the standard sULBD technique, the incorporation of navigation provides anatomic localization without exposure to radiation to staff for a higher safety profile along with a fast and efficient workflow.

Ten-Step 3-Dimensional-Navigated Single-Stage Lateral Surgery With Microtubular Decompression: A Case Series

BACKGROUND

Single-stage lateral lumbar interbody fusion is a safe and effective procedure that relies on indirect decompression and fusion to treat various lumbar pathologies. This technique, however, has an overall 9% rate of indirect decompression failure, which may require additional surgery to achieve adequate direct decompression. To address this concern, we modified this technique by adding a minimally invasive, direct tubular decompression in lateral position when indicated. No study has described the technical nuances of incorporating a microtubular decompression into the single-stage lateral lumbar interbody fusion workflow (SSLLIF+).

OBJECTIVE

To report on the procedural steps and clinical outcomes of the SSLLIF+.

METHODS

In this retrospective case series of prospectively collected data, we present the detailed surgical approach of the SSLLIF+ with a single-center case series over a 5-year period. Surgical and clinical outcomes are presented.

RESULTS

A total of 7 patients underwent a SSLLIF+ with a total of 18 levels fused and 7 levels decompressed. The SSLLIF+ was successfully performed in all cases without the occurrence of intraoperative complications in this case series. There was 1 revision after 20 months of follow-up because of adjacent segment disease. There was no need for further direct decompression in a delayed fashion.

CONCLUSION

SSLLIF with direct microtubular decompression in lateral position is a safe and effective procedure in patients where indirect decompression alone may not achieve the surgical goal. Adherence to minimally invasive spine surgery principles and thoughtful patient selection facilitate the successful management of these patients while demonstrating short hospital stay and low-risk of perioperative complications.