Acute Contralateral Radiculopathy after Unilateral Transforaminal Lumbar Interbody Fusion

Effects of "fixation-fusion" sequence of lumbar surgery on surgical outcomes for patients with lumbar spinal stenosis: study protocol for a multicenter randomized controlled trial

BACKGROUND

New-onset neurological symptoms such as numbness and pain in lower extremities might appear immediately after conventional lumbar interbody fusion (LIF) surgery performed in patients with lumbar spinal stenosis.

METHODS AND ANALYSIS

This is a multicenter, randomized, open-label, parallel-group, active-controlled trial investigating the clinical outcomes of modified LIF sequence versus conventional LIF sequence in treating patients with lumbar spinal stenosis. A total of 254 eligible patients will be enrolled and randomized in a 1:1 ratio to either modified LIF sequence or conventional LIF sequence group. The primary outcome measure is the perioperative incidence of new-onset lower extremity neurological symptoms, including new adverse events of pain, numbness, and foot drop of any severity. Important secondary endpoints include visual analogue scale (VAS) pain score and lumbar Japanese Orthopaedic Association (JOA) recovery rate. Other safety endpoints will also be evaluated. The safety set used for safety data analysis by the actual surgical treatment received and the full analysis set for baseline and efficacy data analyses according to the intent-to-treat principle will be established as the two analysis populations in the study.

CONCLUSION

This study is designed to investigate the clinical outcomes of modified LIF sequences in patients with lumbar spinal stenosis. It aims to provide clinical evidence that the modified "fixation-fusion" sequence of LIF surgery is effective in treating lumbar spinal stenosis.

TRIAL REGISTRATION

http://www.chictr.org.cn/index.aspx ID: ChiCTR2100048507.

Analysis of risk factors for contralateral symptomatic foraminal stenosis after unilateral transforaminal lumbar interbody fusion

PURPOSE

To analyze the risk factors of contralateral symptomatic foraminal stenosis (FS) after unilateral transforaminal lumbar interbody fusion (TLIF) and to guide and standardize the operation process of unilateral TLIF to reduce the occurrence of contralateral symptomatic FS.

METHODS

A retrospective study was undertaken on 487 patients with lumbar degeneration who underwent unilateral TLIF in the Department of Spinal Surgery of Ningbo Sixth Hospital between January 2017 and January 2021, comprising 269 males and 218 females, with a mean age of 57.1 years (range, 48-77 years). Cases of intraoperative improper operations, such as screw deviation, postoperative hematoma, and contralateral disc herniation, were excluded, and cases of nerve root symptoms caused by contralateral FS were analyzed. Post-surgery, 23 patients with nerve root symptoms caused by contralateral FS were categorized as group A, and 60 patients without nerve root symptoms were randomly selected as group B during the same period. The general data (gender, age, body mass index (BMI), bone mineral density (BMD), and diagnosis) and imaging parameters before and after operation (including contralateral foramen area (CFA), lumbar lordosis angle (LL), segmental lordosis angle (SL), disc height (DH), foramen height (FH), foramen width (FW), fusion cage position, and the difference between postoperative and preoperative) were compared between the two groups. Univariate analysis was performed, and multivariate analysis was undertaken through logistics analysis to determine the independent risk factors. Additionally, the clinical outcomes of the two groups were compared immediately before surgery and one year after surgery, using the visual analogue scale (VAS) score and the Japanese Orthopaedic Association (JOA) score for evaluation.

RESULTS

The patients in this study were followed up for a period of 19-25 (22.8atien months. Among them, 23 cases (4.72% incidence) were diagnosed with contralaterally symptomatic FS after the surgery. Univariate analysis indicated significant differences between the two groups in CFA, SL, FW, and cage coronal position. Logistic regression analysis identified preoperative contralateral foramen area (OR = 1.176, 95% CI (1.012, 1.367)), small segmental lordosis angle (OR = 2.225, 95% CI (1.124, 4.406)), small intervertebral foramen width (OR = 2.706, 95% CI (1.028, 7.118)), and cage coronal position not crossing the midline (OR = 1.567, 95% CI (1.142, 2.149)) as independent risk factors for contralateral symptomatic FS after unilateral TLIF. However, there was no statistically significant difference in the pain VAS score between the two groups one year after the operation. In contrast, there was a significant difference in the JOA score between the two groups.

CONCLUSION

The identified risk factors for contralateral symptomatic FS after TLIF include preoperative contralateral intervertebral foramen stenosis, a small segmental lordosis angle, a small intervertebral foramen width, and the coronal position of the cage not crossing the midline. For patients with these risk factors, it is recommended to carefully lock the screw rod during the recovery of lumbar lordosis and ensure that the coronal position of the fusion cage is implanted beyond the midline. If necessary, preventive decompression should also be considered. However, this study did not quantify the imaging data for each risk factor, and further research is needed to improve our understanding of the topic.

Iatrogenic contralateral foraminal stenosis following lumbar spine fusion surgery: illustrative cases

BACKGROUND

Lumbar spine fusion is the mainstay treatment for degenerative spine disease. Multiple potential complications of spinal fusion have been found. Acute contralateral radiculopathy postoperatively has been reported in previous literature, with unclear underlying pathology. Few articles reported the incidence of contralateral iatrogenic foraminal stenosis after lumbar fusion surgery. The aim of current article is to explore the possible causes and prevention of this complication.

OBSERVATIONS

The authors present 4 cases in which patients developed acute postoperative contralateral radiculopathy requiring revision surgery. In addition, we present a fourth case in which preventive measures have been applied. The aim of this article was to explore the possible causes and prevention to this complication.

LESSONS

Iatrogenic foraminal stenosis of the lumbar spine is a common complication; preoperative evaluation and middle intervertebral cage positioning are needed to prevent this complication.

Contralateral radiculopathy after unilateral transforaminal lumbar interbody fusion: causes and prevention

Background

Unilateral transforminal lumbar interbody fusion (TLIF) with a single cage can provide circumferential fusion and biomechanical stability. However, the causes and prevention of contralateral radiculopathy following unilateral TLIF remain unclear.

Methods

In total, 190 patients who underwent unilateral TLIF from January 2017 to January 2019 were retrospectively reviewed. Radiological parameters including lumbar lordosis, segmental angle, anterior disc height, posterior disc height (PDH), foraminal height (FH), foraminal width, and foraminal area (FA) were measured preoperatively and postoperatively. Preoperative and postoperative visual analog scale scores were also recorded.

Results

The incidence of contralateral radiculopathy after unilateral TLIF was 5.3% (10/190). The most common cause was contralateral foraminal stenosis. Unilateral TLIF could increase the lumbar lordosis, segmental angle, and anterior disc height but decrease the PDH, FA, and FH in patients with symptomatic contralateral radiculopathy. The intervertebral cage should be placed to cover the epiphyseal ring and cortical compact bone of the midline, and the disc height can be increased to enlarge the contralateral foramen.

Conclusion

The most common cause of contralateral radiculopathy is contralateral foraminal stenosis. Careful preoperative planning is necessary to achieve satisfactory outcomes. Improper unilateral TLIF will decrease the PDH, FA, and FH, resulting in contralateral radiculopathy.

Comparison of Different Approaches in Lumbosacral Spinal Fusion Surgery: A Systematic Review and Meta-Analysis

We aimed to systematically review the literature to analyze the differences in posterior lumbar interbody fusion (PLIF), anterior lumbar interbody fusion (ALIF), and transforaminal lumbar interbody fusion (TLIF), focusing on the complications, risk factors, and fusion rate of each approach. Spinal fusion surgery is a well-established surgical procedure for a variety of indications, and different approaches developed. The various approaches and their advantages, as well as approach-related pathology and complications, are well investigated in spinal surgery. Focusing only on lumbosacral fusion, the comparative studies of different approaches remain fewer in numbers. We systematically reviewed the literature on the complications associated with lumbosacral interbody fusion. Only the PLIF, ALIF, or TLIF approaches and studies published within the last decade (2007–2017) were included. The exclusion criteria in this study were oblique lumbar interbody fusion, extreme lateral interbody fusion, more than one procedure per patient, and reported patient numbers less than 10. The outcome variables were indications, fusion rates, operation time, perioperative complications, and clinical outcome by means of Visual Analog Scale, Oswestry Disability Index, and Japanese Orthopaedic Association score. Five prospective, 17 retrospective, and two comparative studies that investigated the lumbosacral region were included. Mean fusion rates were 91,4%. ALIF showed a higher operation time, while PLIF resulted in greater blood loss. In all approaches, significant improvements in the clinical outcome were achieved, with ALIF showing slightly better results. Regarding complications, the ALIF technique showed the highest complication rates. Lumbosacral fusion surgery is a treatment to provide good results either through an approach for various indications as causes of lower back pain. For each surgical approach, advantages can be depicted. However, perioperative complications and risk factors are numerous and vary with ALIF, PLIF, and TLIF procedures, as well as with fusion rates.

Clinical and Short-Term Radiographic Outcomes of Minimally Invasive Transforaminal Lumbar Interbody Fusion With Expandable Lordotic Devices

BACKGROUND

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is a well-accepted procedure for the treatment of degenerative lumbar disease. However, its ability to restore lumbar lordosis has been limited. Development of expandable lordotic interbody devices has challenged this limitation, furthering the scope of minimally invasive surgery.

OBJECTIVE

To evaluate the radiographic and clinical effects of expandable lordotic interbody devices placed through an MIS-TLIF approach.

METHODS

We conducted a retrospective review of 32 1-level and 18 2-level MIS-TLIFs performed using lordotic expandable interbody devices. Lumbar radiographic measurements, Oswestry Disability Index scores (ODI), and Visual Analogue Scale scores (VAS) were obtained at preoperative, 6 wk follow up, and last follow up time points. Last follow up occurred at a mean of 11.5 ± 7.6 mo (mean ± SD).

RESULTS

At 6-wk follow-up, segmental lordosis, disc height, and foraminal height increased by an average of 3.4°, 6.4 mm, and 4.4 mm, respectively. Only the 2-level group showed a significant increase in lumbar lordosis of 5.8°. No significant changes occurred in sacral slope, pelvic tilt, or pelvic incidence. Average ODI and VAS decreased by -12.0 and -4.5, respectively. Postoperative lumbar lordosis inversely correlated with preoperative lordosis in patients with an initial Pelvic Incidence to Lumbar Lordosis mismatch (PI-LL) of >10°, (r = -0.5, P = .009).

CONCLUSION

When applied across 2-levels, MIS-TLIF using expandable lordotic interbody devices produced a significant increase in lumbar lordosis. Preoperative lumbar lordosis was found to be a predictor of postoperative lumbar lordotic change in patients with sagittal imbalance.

A Transforaminal Endoscopic Surgical Technique for Treating Lumbar Disc Herniation in the Setting of Spina Bifida

Recent literature suggests that adult patients with spina bifida receive surgery for degenerative disc disease at higher rates than the general population. However, sometimes the complex anatomic features of co-occurring spina bifida and lumbar disc herniation can significantly challenge standard surgical techniques. Here, the technical steps are presented for treating a foraminal lumbar 4-5-disc herniation in the setting of a patient with multifaceted degenerative and spina bifida occulta anatomy. Utilized is a minimally invasive approach that does not require general anesthesia or fusion and allows the patient to leave the same day. To the best of our knowledge, this is the first-reported case of endoscopic surgical decompression of a lumbar disc in a patient with spina bifida.

CHANGES IN THE LUMBAR VERTEBRAL SEGMENT RELATED TO THE CAGE POSITION IN TLIF TECHNIQUE

Objective:

To evaluate the morphological changes on the intervertebral foramen and segmental lordosis related to the transforaminal lumbar interbody fusion (TLIF) positioning.

Methods:

PEEK cages were placed in the disc space (L1-S1) of a polyurethane anatomical model. Cages of different heights (8 mm, 10 mm, 12 mm and 14 mm) were positioned in the posterior, medial or anterior part of the vertebral body surface, and the intervertebral foramen and segmental lordosis heights were measured after their insertion.

Results:

The vertebral foramen height decreased in all positions and heights of the cages in relation to the control. The cage posterior positioning induced a smaller reduction in the vertebral foramen height. Vertebral lordosis tended to increase in relation to the control, and the greatest increase occurred with the cage posterior positioning.

Conclusion:

Cage positioning induces changes in the intervertebral foramen height and in the vertebral segment lordosis. Cage posterior positioning induces a smaller reduction of the intervertebral foramen height and increases the vertebral segment lordosis. Level of evidence III, Therapeutic study.

A modified procedure of single-level transforaminal lumbar interbody fusion reduces immediate post-operative symptoms: a prospective case-controlled study based on two hundred and four cases

STUDY DESIGN

This is a prospective case-controlled study.

PURPOSE

The purpose of this study is to investigate the effect of a modified transforaminal lumbar interbody fusion (TLIF) on the immediate post-operative symptoms in patients with lumbar disc herniation (LDH) accompanied with stenosis.

METHODS

A total of 204 LDH patients with single-level TLIF were enrolled. According to the sequence of the placement of rods and cage, patients were divided into group R (rod-prior-to-cage) and group C (cage-prior-to-rod). Neurological function was evaluated by the Japanese Orthopedic Association (JOA) score. Radiological assessment includes height of intervertebral space (HIS), foraminal height (FH), foraminal area (FA), and segmental lordosis (SL). Change of original symptoms (pain/numb) and new-onset symptoms (pain/numb) after surgery were also recorded.

RESULTS

Patients in group R had less change of HIS at L3/4, L4/5, and L5/S1 levels compared with pre-operation (all p > 0.05), whereas group C had larger change (all p < 0.05). No statistical difference was found in FH between the two groups before and after surgery at L3/4, L4/5, and L5/S1, respectively (all p > 0.05). In terms of FA, patients in group R had better improvement after surgery than those in group C at L3/4 and L4/5 (both p < 0.05). Patients in both groups acquired good improvement of neurological function. However, there were fewer patients in group R who experienced post-operative leg pain or numb compared with those in group C (p < 0.05).

CONCLUSION

The modified open TLIF can significantly reduce the incidence of immediate post-operative symptoms for patients with single-level lumbar disc herniation via installation of rods prior to insertion of cage and the "neural standard" should serve as the goal of decompression for spine surgeons to restore disc/foraminal height and to minimize nerve distraction.

Risk Factors for Symptomatic Contralateral Foraminal Stenosis After Unilateral Transforaminal Lumbar Interbody Fusion

OBJECTIVE

The most common cause of contralateral symptoms after unilateral transforaminal lumbar interbody fusion (TLIF) is contralateral foraminal stenosis (FS). This retrospective cohort study aimed to investigate the cause of and risk factors for contralateral FS after unilateral TLIF with a single cage.

METHODS

Patients with degenerative lumbar spinal disorders who underwent unilateral TLIF at L4-5 were divided into 2 groups: those without contralateral radicular symptoms after surgery (group A; n = 340) and those with contralateral radicular symptoms after surgery (group B; n = 16). We investigated the influence of various radiological and cage-related factors on postoperative contralateral FS with radicular symptoms. The cage location indicates whether the cage's anterior tip crosses the disc midline-exceeding 50%-and in such a case, how far.

RESULTS

Group B showed significantly increased postoperative coronal angle and sagittal angle and decreased contralateral foraminal height and foraminal area. Statistically significant (P < 0.01) factors according to the multivariate logistic regression analysis were the preoperative sagittal range of motion (odds ratio [OR]: 1.562, P = 0.004) and cage location (OR: 2.047, P = 0.015). The cutoff values for the sagittal range of motion and the cage location were 9.0° and 50.5%, respectively. The preoperative and postoperative 6-month visual analog scale scores and Oswestry disability index values were not significantly different between the groups.

CONCLUSIONS

The 2 most meaningful risk factors were the preoperative sagittal range of motion and cage location. Inserting the cage beyond the disc midline, especially in patients with a high preoperative sagittal range of motion (≥9.0°), would help reduce postoperative complications.

Morphological changes of contralateral intervertebral foramen induced by cage insertion orientation after unilateral transforaminal lumbar interbody fusion

Background

This study was performed to investigate the morphological changes of contralateral intervertebral foramen (IVF) based on computed tomography images of patients with lumbar spinal stenosis after unilateral transforaminal lumbar interbody fusion (TLIF) and to compare the influence of different orientation of cage insertion on these changes.

Methods

This is a retrospective cohort study. Sixty-nine patients with lumbar spinal stenosis who had undergone single-level unilateral TLIF were retrospectively analyzed. The patients were divided into two groups according to the cage insertion orientation: the oblique group (o-group, 39 cases) and the transverse group (t-group, 30 cases). The morphological parameters of contralateral IVF were measured before and 6 months after the operation. Changes in these parameters were compared and analyzed between the two groups. The 6-month clinical outcomes of the two groups were also collected and analyzed.

Results

There was a significant difference in the rate of increase in the segmental angle (p < 0.01) between the two groups, the mean value of segmental angle increased by an average of 29.08% ± 14.93% in the o-group and 48.63% ± 12.01% in the t-group. Overall, the posterior disc height had a significant positive correlation with the foraminal height and area. In the o-group, however, an increase in the segmental angle resulted in a decrease in the foraminal area. No significant difference in clinical outcomes was found between the two groups.

Conclusions

Compared with oblique cage insertion, transverse cage insertion could achieve greater restoration of segmental lumbar lordosis without decreasing contralateral foraminal dimensions.

Biomechanical evaluation of different surgical procedures in single-level transforaminal lumbar interbody fusion in vitro

BACKGROUNDS

A variety of improved surgical methods were adopted in the transforaminal lumbar interbody fusion. A mechanical stability provides an ideal environment for the formation of a fusion mass and is the basis of their good outcomes. The object of this study is to evaluate the initial similarities and differences of four commonly-used posterior surgical procedures biomechanically.

METHODS

Biomechanical testing was performed at L3-4 motion segment in 6 fresh-frozen human cadaveric lumbar spines (L2-L5), including the following sequentially tested configurations: 1) intact motion segment; 2) bilateral pedicle screw fixation; 3) unilateral pedicle screw fixation; 4) unilateral pedicle screw plus contralateral translaminar facet joint screw fixation according to the Magerl technique; and 5) bilateral pedicle screw fixation with bilateral facetectomies. The range of motion, neutral zone and stiffness of each method and intact segment were collected and compared.

FINDINGS

All of four methods reduce the range of motion significantly in flexion and extension and lateral bending but not in axial torsion compared with the native segment. There is no significant difference among four procedures about the range of motion in all loading modes. All of methods increase the stiffness of segmental motion compared with intact segment in all loading modes, but only bilateral pedicle screw fixation showed significant increases in stiffness in flexion and extension(p=0.02) and lateral bending(p=0.023). The stiffness offered by instrumented constructs in different methods showed no significant difference in all loading modes.

INTERPRETATION

The stiffness offered by four different posterior fixations in single segmental transforaminal lumbar interbody fusion is not significantly different.

Comparison of Clinical and Radiological Outcomes of Lumbar Interbody Fusion Using a Combination of Hydroxyapatite and Demineralized Bone Matrix and Autografts for Lumbar Degenerative Spondylolisthesis

Study Design

Prospective, cohort, non-inferiority study.

Purpose

This study evaluated the clinical and radiological outcomes of interbody fusion using a combination of demineralized bone matrix (DBM) and hydroxyapatite (HA).

Overview of Literature

The use of autografts remains a gold standard in lumbar interbody fusion, but the limited availability and donor site morbidity encourages the use of bone substitutes. In addition to autografts, a combination of HA and DBM is being increasingly use for lumbar interbody fusion. However, there are no data on the clinical and radiological outcomes of this procedure.

Methods

We examined 35 patients with lumbar degenerative spondylolisthesis who underwent transforaminal interbody fusion. Autografts were used in 18 patients, and 17 patients received a combination of HA and DBM. Clinical outcomes were evaluated using the visual analog scale (VAS) for back and leg pain, Oswestry disability index (ODI), and Japanese Orthopaedic Association (JOA) scores at 3, 6, and 12 months postoperatively. Fusion was evaluated using computed tomography images obtained at 12 months postoperatively.

Results

The mean ODI, JOA, and back and leg pain VAS scores increased significantly in both groups. However, the VAS, JOA, and ODI scores did not differ significantly between the two groups (p=0.599, p=0.543, and p=0.780, respectively). The fusion rates at 1 year postoperatively were 77.8% and 76.5% in the autograft and HA+DBM groups, respectively (p=0.99).

Conclusions

The clinical and radiological outcomes of using a combination of HA and DBM in lumbar interbody fusion were not inferior to those of using autografts. A combination of HA and DBM can be considered as an alternative in patients with lumbar degenerative spondylolisthesis requiring surgery.