Comparison of Spinal Alignment between XLIF, TLIF, PLIF, and PLF in the Treatment of Single Level Spondylolisthesis: A Retrospective Study

Background: Most lumbar spinal fusion procedures are performed to increase fusion potential, correct a deformity, and decompress spinal nerve roots. Nowadays, there are several spinal fusion techniques such as extreme lateral lumbar interbody fusion (XLIF), transforaminal lumbar interbody fusion (TLIF), posterior lumbar interbody fusion (PLIF), and posterolateral fusion (PLF). However, there are no studies directly comparing their capacity to alter lumbar lordosis, segmental lordosis, intervertebral disc height, foraminal height, and the grade of slip for treating single level spondylolisthesis in Thailand. Objective: To compare which lumbar interbody technique amongst XLIF, TLIF, PLIF, and PLF, is the most effective in restoring spinal alignment in cases such as lumbar lordosis, increased segmental lordosis, increased intervertebral disc height, increased foraminal height, and a reduced slip grade in spondylolisthesis patients. Materials and Methods: The medical records and radiographs of single level spondylolisthesis patients treated in Siriraj hospital between 2002 and 2017 were retrospectively reviewed. Clinical data and radiographic parameters such as lumbar lordosis, segmental lordosis, intervertebral disc height, foraminal height, and grade of slip, including preoperative and postoperative data were collected and analyzed. An inter-observer/ intra-observer reliability test for all parameters was also performed. Results: Two hundred forty patients including 192 females and 48 males with a mean age of 60.1 years were included in the present study. There was no statistically significant difference in demographic data except in younger patients in the PLF group and those with shorter length of stays in the XLIF group. The present study results indicated that there was a statistically significant increase in lumbar lordosis, increased foraminal height, and decreased slip grade in the XLIF group when compared to other three groups as TLIF, PLIF, and PLF. Conclusion: All spinal fusion techniques could improve lumbar spinal alignment, however, XLIF is superior to other procedures, especially in lumbar lordosis, foraminal height restoration, and slip grade. Keywords: Lumbar spondylolisthesis; Extreme lateral lumbar interbody fusion; Transforaminal lumbar interbody fusion; Posterior lumbar interbody fusion; Posterolateral fusion; Lumbar lordosis

Effect of pedicle-screw rod fixation on oblique lumbar interbody fusion in patients with osteoporosis: a retrospective cohort study

Study design A retrospective cohort study. Objective To investigate the radiological and clinical outcomes of patients with or without pedicle-screw rod fixation (PSRF) in OLIF surgery. Methods Between June 2017 and December 2019, 66 consecutive patients who underwent OLIF surgery at two centers were divided into stand-alone and combined groups according to whether or not PSRF was used. Imaging and clinical data were collected preoperatively, postoperatively, 3 and 6 months postoperatively, and at the last follow-up. Related coefficient and multiple linear regression analysis was used to detect the influencing factors of cage subsidence (CS). Results There was a lower baseline BMD in the combined group (p = 0.005). The combined group showed superior VAS score at 3 months postoperatively, although there was no difference in long-term VAS and ODI scores between the two groups. The foraminal height (FH) of the two groups was comparable at preoperatively, postoperatively, and 3 months postoperatively, but the combined group showed better maintenance of FH at 6 months postoperatively (p = 0.049) and last follow-up (p = 0.019). The total CS (tCS) of the combined group was lower than that of the stand-alone group during the whole follow-up period (all p ≤ 0.001). Multiple linear regression suggested that lower BMD was the risk factor for main CS, and PSRF could significantly reduce the BMD threshold for severe CS (−4.77 vs −1.38). Conclusions OLIF combined with PSRF can effectively avoid foraminal height loss and prevent severe CS, which may be more suitable for patients with osteoporosis or osteopenia and improve clinical outcomes.

A Technical Nuance to Avoid Lumbar Five Radiculopathy with Anterior Lumbar Fusion and Posterior Instrumentation

The anterior lumbar interbody fusion (ALIF) is a well-established procedure used to treat a multitude of spinal pathologies. When performed at the L5-S1 level, the ALIF is often supplemented with posterior pedicle screw and rod fixation. Because the interbody device can restore disk and foraminal height, one benefit of the ALIF procedure is indirect neural decompression in the spinal canal and neural foramina. If the contour of the posterior rod is not matched to the exact position of the tulip heads on the pedicle screws, spondylolisthesis can be introduced, leading to foraminal stenosis and nerve compression. This concern is particularly germane when the posterior instrumentation is placed percutaneously without any direct foraminal decompression. In this report, we describe a patient who had an L4-S1 ALIF, resulting in new L5-S1 retrolisthesis and worsening L5 radiculopathy. Technical nuances and avoidance strategies are discussed.

Osteoporosis Delimit the Indication for Additional Fixation in Oblique Lumbar Interbody Fusion

Study design: A retrospective cohort study.Objective: To detect the boundary of indications of fixation in OLIF surgery.Methods: Review patients undergoing stand-alone or combined OLIF. Measure the disc height increment (ΔDH), foraminal height (FH), cage subsidence (CS). VAS and the ODI was used to evaluate low back pain and functionality. Multiple linear regression were used to determine the risk factors of CS.Results: A totle of 66 consecutive patients included. The BMD in combined group was significantly lower than that of stand-alone group(p=0.005). The combined group showed better FH maintenance at 6 months (p= 0.049) and last follow-up (p= 0.019). In combined group, tCS was significantly lower at all post-operation point (p≤0.001). BMD was a mild negative correlated factor for CS in combined group (r= -0.602, p= 0.001)and a strongly negative correlated factor in stand-alone group (r= -0.797, p< 0.001). Greater mCS significantly associated with worse VAS (r=0.685, p<0.001) and ODI (r=0.616, p<0.001) in stand-alone group, and this effect was significantly weakened in the combined group as VAS (r=0.427, p=0.033) and ODI (r=0.594, p=0.002). Patients with stand-alone OLIF were at risk of severe CS when BMD <-1.38, while those with combined OLIF had an equal risk when BMD < -4.77.Conclusions: The long-term fusion rates and functionality improvements of OLIF with or without fixation are comparable. Patients with BMD < -1.38 may not suitable for stand-alone procedure due to higher risk of severe CS and worse clinical outcomes. Additional fixation can extends the applicable boundary to a BMD = -4.77.

Does the Position of Cage Affect the Clinical Outcome of Lateral Interbody Fusion in Lumbar Spinal Stenosis?

Study Design: A retrospective study. Objective: This study aims to identify the ideal cage position in lateral lumbar interbody fusion (LLIF) and to investigate if the posterior instrumentation would affect the indirect decompression. Methods: Patients underwent 2-stage surgeries: stage I was LLIF and stage II was percutaneous pedicle screws fixation after 1 week. Anterior disc height (ADH), posterior disc height (PDH), left and right foraminal height (FH), and segmental angle (SA) were measured on lateral computed tomography reconstructions. The cross-sectional area of the thecal sac (CSA) was determined by the outlined area of the thecal sac on a T2-weighted axial magnetic resonance imaging. The patients were subgroups according to the cage position: the anterior (cage located at the anterior 1/3 of disc space) and posterior groups (cage located at the posterior 2/3 of disc space). P values <.05 were considered significant. Results: This study included 46 patients and 71 surgical levels. After stage I LLIF, significant increase in ADH, PDH, bilateral FH was found in both 2 subgroups, as well as the CSA (all Ps < .01). SA increased 2.84° ± 3.2° in the anterior group after stage I LLIF and increased 0.81° ± 3.1° in the posterior group ( P = .013). After stage II surgery, SA was similar between the anterior and posterior groups ( P = .20). Conclusion: The anteriorly placed cage may provide better improvement of anterior disc height and segmental angle after stand-alone LLIF surgery. After the second stage posterior instrumentation, the cage position would not affect the segmental angle or foraminal height.

Minimally invasive surgery for low-grade spondylolisthesis: percutaneous endoscopic or oblique lumbar interbody fusion

Aim: To compare the clinical and radiographic outcomes of percutaneous endoscopic-assisted lumbar interbody fusion (PELIF) versus oblique lumbar interbody fusion (OLIF) for the treatment of symptomatic low-grade lumbar spondylolisthesis. Material & methods: The clinical and radiographic records of 48 patients underwent single-level minimally invasive lumbar fusion with a PELIF (n = 16) or OLIF (n = 32) were reviewed. Results: The clinical and radiographic outcomes were similar in both groups. PELIF procedure exhibited superior capability of the enlargement of foraminal width, but inferior capability of the restoration of foraminal height than OLIF procedure. Conclusion: PELIF minimizes the iatrogenic damages and perioperative risks to a great extent, and seems to be a promising option for the treatment of symptomatic low-grade lumbar spondylolisthesis.