Transforaminal Lumbar Interbody Fusion Cage Research Articles

Novel Use of Bilateral Prone Transpsoas Approach for the Treatment of Transforaminal Interbody Fusion Pseudarthrosis and Interbody Cage Subsidence.

Pseudarthrosis is a complication after transforaminal lumbar interbody fusion (TLIF) that leads to recurrent symptoms and potential revision surgery. Subsidence of the interbody adds to the complexity of surgical revision. In addition, we report a novel technique for the treatment of TLIF pseudarthrosis with subsidence and propose an approach algorithm for TLIF cage removal. Cases of reoperation for TLIF pseudarthrosis were reviewed. We report a novel technique using a bilateral prone transpsoas (PTP) approach to remove a subsided TLIF cage and place a new lateral cage. An approach algorithm was developed based on the experience of TLIF cage removal. The patient was placed in the prone position with somatosensory evoked potential and electromyography monitoring. A PTP retractor was placed using standard techniques on the ipsilateral side of the previous TLIF. After the discectomy, the subsided TLIF cage was visualized but unable to be removed. The initial dilator was closed, and a second PTP retractor was placed on the contralateral side. After annulotomy and discectomy to circumferentially isolate the subsided cage, a box cutter was used to push and mobilize the TLIF cage from this contralateral side, which could then be pulled out from the ipsilateral side. A standard lateral interbody cage was then placed. Retractor time was less than 10 minutes on each side. The patient's symptoms resolved postoperatively. We review illustrative cases of various approaches for TLIF cage removal spanning the lumbosacral spine and recommend an operative approach based on the lumbar level, degree of subsidence, and mobility of the interbody. Bilateral PTP retractors for TLIF cage removal may be effectively used in cases of pseudarthrosis with severe cage subsidence. Careful consideration of various factors, including patient surgical history, body habitus, and intraoperative findings, is essential in determining the appropriate treatment for these complex cases.

Radiographic and Patient-Reported Outcomes: Anteriorly Placed Transforaminal Lumbar Interbody Fusion Cage vs. Anterior Lumbar Interbody Fusion with Posterior Instrumentation.

Retrospective Cohort Study. To compare outcomes in anteriorly placed transforaminal lumbar interbody fusions (TLIFs) and anterior lumbar interbody fusions (ALIFs). TLIF and ALIF are surgical techniques that have become more prevalent in recent years. Although studies have compared the two, none have considered TLIFs with anteriorly placed cages, which may serve as a better comparison to ALIFs. Patients undergoing TLIF or ALIF with posterior instrumentation from 2010-2020 at a tertiary care institution were retrospectively identified. TLIF cage position was assessed and those with anterior placement were included. Electronic medical records were reviewed to identify patient characteristics and patient-reported outcomes. Radiographic outcomes included posterior disc height (DH), lumbar lordosis (LL), sacral slope (SS), pelvic incidence (PI) and pelvic tilt (PT). Statistical analysis was performed to compare the two groups. Of the 351 patients, 108 had ALIF with posterior instrumentation and 207 had a TLIF. Preoperatively, TLIF patients had less LL (53.7° vs. 60.6°, P<0.001), SS (38.3° vs. 43.7°, P<0.001), and PI (60.1° vs. 66.1°, P<0.001), all of which remained significant at one-year and long-term follow-up (P<0.001). The TLIF group had less ∆DH (1.51° vs. 5.43°, P<0.001), ∆LL (1.8° vs. 2.97°, P=0.038), and ∆SL (0.18° vs. 4.40°, P<0.001) at one year postoperatively. At two to three years, ∆DH (P<0.001) and ∆SL (P=0.001) remained significant, but ∆LL (P=0.695) did not. Patients in the TLIF group had higher VAS-Back scores one year postoperatively (3.68 vs. 2.16, P=0.008) and experienced less improvement in ODI (-17.1 vs. -28.6, P=0.012) and VAS-Back (-2.67 vs. -4.50, P=0.008) compared to ALIF patients. Our findings suggest that ALIF with posterior instrumentation performed superiorly in radiographic outcomes and PROMs compared to anteriorly placed TLIFs. Anteriorly placed TLIF cages may not achieve the same results as those of ALIF cages.

Anterior Cage Migration during Transforaminal Lumbar Interbody Fusion: A Case Report and Review of the Literature

Transforaminal lumbar interbody fusion (TLIF) is a popular procedure for patients with lumbar instability with unilateral foraminal stenosis. Many complications can occur during the procedure. However, cage migration during the procedure is rarely reported. Anterior cage migrations can lead to catastrophic consequences due to the possibility of major vessel injuries. Here, we present a 76-year-old male patient whose cage extruded anteriorly during L5-S1 TLIF. Fortunately, he did not experience any life-threatening complications, and the migrated cage was visible just below the iliac vessels’ bifurcation site on computed tomography angiography. As an alternative, an emergency anterior lumbar interbody fusion was successfully performed, and the TLIF cage was removed during this procedure.

494 Comparison of Disc Height Restoration and Subsidence Rates Between Static Versus Expandable Titanium Cages for Lateral Lumbar Interbody Fusion

INTRODUCTION: It has been shown that expandable cages for transforaminal lumbar interbody fusion (TLIF) are associated with increased rates of subsidence. However, as lateral lumbar interbody fusion (LLIF) cages offer substantially larger footprints, this may offset the risks. METHODS: A retrospective review was performed of a consecutive adult patients undergoing LLIF with either static or expandable cages from 2013-2021. Demographics and surgical details were collected. Posterior disc height (PDH), subsidence, and fusions status were compared between patients with static and expandable cages. Follow-up were reported at minimum 6-months and 1-year. RESULTS: A total of 120 patients had 173 cages implanted: 96 patients with 143 static cages vs. 24 patients with 30 expandable cages. Mean age was 63.4 and 62.4% were male. There were no significant differences in age, gender, BMI, smoking, or osteoporosis. Overall, PDH was significantly increased following LLIF (4.1 v 7.4 mm, p &lt; 0.001). Static and expandable cage types had similar magnitude (3.7 v 3.3 mm, p = 0.311) and percentage (89.0% v 121.5%, p = 0.127) change in PDH, respectively. Overall incidence of cage subsidence at 6-months and 1-year was 6.9% and 10.4% respectively. There was no significant difference in subsidence rates between cage types at 6 months (7.0% v 6.7%, p = 0.949) and 1-year (11.2 v 6.7%, p = 0.461). Radiographic evidence of fusion was present in 92.7% of cases at 1-year, and both cage types achieved similar fusion rates as well (92.2% v 95.6%, p = 0.555). CONCLUSIONS: LLIF static and expandable cages offer similar PDH restoration depending on surgical goals. Expandable cages seem to be less prone to subsidence than smaller TLIF cage counterparts and offer similar fusion rates to static cages. Larger cohort studies are warranted to further validate these findings which are ongoing.

The Use of Dual Direction Expandable Titanium Cage With Biportal Endoscopic Transforaminal Lumbar Interbody Fusion: A Technical Consideration With Preliminary Results.

Expandable cage technology has emerged for lumbar interbody fusion to restore intervertebral disc space height and alignment through a narrow surgical corridor. The purpose of this study is to present the technique of biportal endoscopic transforaminal lumbar interbody fusion (TLIF) using dual direction expandable cage and provide early clinical results. We performed the biportal endoscopic TLIF using a dual direction expandable titanium cage for height restoration and a larger footprint in 10 patients. Clinical parameters including Oswestry Disability Index (ODI), visual analogue scale (VAS), and complications were retrospectively analyzed. Also, we investigated radiologic parameters using preoperative and postoperative x-ray images. We successfully inserted dual direction expandable cages during biportal endoscopic TLIF. There was no significant subsidence or collapse of the expandable cages during the 6-month follow-up period. Lumbar lordosis and disc height were significantly increased after surgery. ODI and VAS scores were significantly improved at 6 months after surgery. In this report, we describe the first use of a dual direction expandable interbody TLIF cage that expands in both width and height in biportal endoscopic TLIF surgery. Early clinical and radiographic outcomes of this TLIF technique may be favorable in early 6-month follow-up.

Surgical treatment of degenerative lumbar spondylolisthesis: Effect of TLIF and slip reduction on sagittal alignment

IntroductionThe surgical treatment of lumbar degenerative spondylolisthesis (LDS) remains controversial. The aim of this study was to determine the effect of adding transforaminal lumbar interbody fusion (TLIF) to posterolateral fusion (PLF) on the local lordosis, sagittal alignment and potential complications. The second aim was to evaluate the effect of slip reduction on the same parameters. HypothesisThe initial hypothesis was that TLIF provides better correction of the local lordosis and that reducing the slip improves the global sagittal balance. MethodsIn this retrospective, single-center study, patients who had been operated on for LSD at one or two levels by laminectomy and PLF, with or without a TLIF cage, were included. Data collected consisted of age, sex, number of levels fused and whether or not a TLIF cage was used. Fusion was defined as the absence of indirect nonunion signs on radiographs at 2 years postoperative. The occurrence and time frame of any complications and the need for reoperation were documented. Lateral radiographs of the entire spine were analyzed preoperatively, in the early postoperative period (3 to 6 months) and at a minimum follow-up of 2 years. The following parameters were measured: pelvic parameters, C7 sagittal tilt (C7ST), spinosacral angle (SSA), maximum lumbar lordosis (LL), lordosis at slipped level (LS), slip percentage. The analysis compared patients treated by PLF and TLIF and determined the impact of slip reduction. ResultsOne hundred and three patients were included in the study (71% women). The mean follow-up was 38 months. The mean age was 69 years. Seventy-seven patients (75%) underwent PLF. Comparing the preoperative and early postoperative data identified 5.4% better spondylolisthesis reduction in the TLIF group than the PLF group (−8.9±9.5% vs −3.5±7.6%; p=0.04) that was not maintained at the final follow-up. The fusion rate was comparable between groups: 94% in APL and 89% in TLIF (p=0.7). The overall complication rate was 46% in the TLIF group versus 33% in the PLF group (p=0.35). A comparison based on whether or not the slip was reduced found significant improvement in the reduction group of the SSA by more than 6° (6.8°±6° vs 0.5°±7.4°; p=0.04). The fusion rate was 91% in the reduced group and 95% in the non-reduced group (p=0.81); the complication rate was 44% versus 28% in the non-reduced group (p=0.10). ConclusionThis study shows that slip reduction helps to improve the sagittal alignment by increasing the SSA when treating LDS. Posterolateral fusion and TLIF produce comparable radiographic outcomes at 2 years postoperative in the segmental lordosis, slip reduction, global sagittal alignment and fusion rate. Level of evidenceIV.

Assessment of the Strain Field Induced Under Load in Transforaminal Lumbar Interbody Fusion Cage Printed in Additive Manufacturing

Assessment of the Strain Field Induced Under Load in Transforaminal Lumbar Interbody Fusion Cage Printed in Additive Manufacturing

Multicenter assessment of outcomes and complications associated with transforaminal versus anterior lumbar interbody fusion for fractional curve correction.

Few studies have compared fractional curve correction after long fusion between transforaminal lumbar interbody fusion (TLIF) and anterior lumbar interbody fusion (ALIF) for adult symptomatic thoracolumbar/lumbar scoliosis (ASLS). The objective of this study was to compare fractional correction, health-related quality of life (HRQL), and complications associated with L4-S1 TLIF versus those of ALIF as an operative treatment of ASLS. The authors retrospectively analyzed a prospective multicenter adult spinal deformity database. Inclusion required a fractional curve ≥ 10°, a thoracolumbar/lumbar curve ≥ 30°, index TLIF or ALIF performed at L4-5 and/or L5-S1, and a minimum 2-year follow-up. TLIF and ALIF patients were propensity matched according to the number and type of interbody fusion at L4-S1. Of 135 potentially eligible consecutive patients, 106 (78.5%) achieved the minimum 2-year follow-up (mean ± SD age 60.6 ± 9.3 years, 85% women, 44.3% underwent TLIF, and 55.7% underwent ALIF). Index operations had mean ± SD 12.2 ± 3.6 posterior levels, 86.6% of patients underwent iliac fixation, 67.0% underwent TLIF/ALIF at L4-5, and 84.0% underwent TLIF/ALIF at L5-S1. Compared with TLIF patients, ALIF patients had greater cage height (10.9 ± 2.1 mm for TLIF patients vs 14.5 ± 3.0 mm for ALIF patients, p = 0.001) and lordosis (6.3° ± 1.6° for TLIF patients vs 17.0° ± 9.9° for ALIF patients, p = 0.001) and longer operative duration (6.7 ± 1.5 hours for TLIF patients vs 8.9 ± 2.5 hours for ALIF patients, p < 0.001). In all patients, final alignment improved significantly in terms of the fractional curve (20.2° ± 7.0° to 6.9° ± 5.2°), maximum coronal Cobb angle (55.0° ± 14.8° to 23.9° ± 14.3°), C7 sagittal vertical axis (5.1 ± 6.2 cm to 2.3 ± 5.4 cm), pelvic tilt (24.6° ± 8.1° to 22.7° ± 9.5°), and lumbar lordosis (32.3° ± 18.8° to 51.4° ± 14.1°) (all p < 0.05). Matched analysis demonstrated comparable fractional correction (-13.6° ± 6.7° for TLIF patients vs -13.6° ± 8.1° for ALIF patients, p = 0.982). In all patients, final HRQL improved significantly in terms of Oswestry Disability Index (ODI) score (42.4 ± 16.3 to 24.2 ± 19.9), physical component summary (PCS) score of the 36-item Short-Form Health Survey (32.6 ± 9.3 to 41.3 ± 11.7), and Scoliosis Research Society-22r score (2.9 ± 0.6 to 3.7 ± 0.7) (all p < 0.05). Matched analysis demonstrated worse ODI (30.9 ± 21.1 for TLIF patients vs 17.9 ± 17.1 for ALIF patients, p = 0.017) and PCS (38.3 ± 12.0 for TLIF patients vs 45.3 ± 10.1 for ALIF patients, p = 0.020) scores for TLIF patients at the last follow-up (despite no differences in these parameters at baseline). The rates of total complications were similar (76.6% for TLIF patients vs 71.2% for ALIF patients, p = 0.530), but significantly more TLIF patients had rod fracture (28.6% of TLIF patients vs 7.1% of ALIF patients, p = 0.036). Multiple regression analysis demonstrated that a 1-mm increase in L4-5 TLIF cage height led to a 2.2° reduction in L4 coronal tilt (p = 0.011), and a 1° increase in L5-S1 ALIF cage lordosis led to a 0.4° increase in L5-S1 segmental lordosis (p = 0.045). Operative treatment of ASLS with L4-S1 TLIF versus ALIF demonstrated comparable mean fractional curve correction (66.7% vs 64.8%), despite use of significantly larger, more lordotic ALIF cages. TLIF cage height had a significant impact on leveling L4 coronal tilt, whereas ALIF cage lordosis had a significant impact on restoration of lumbosacral lordosis. The advantages of TLIF may include reduced operative duration and hospitalization; however, associated HRQL was inferior and more rod fractures were detected in the TLIF patients included in this study.

Transforaminal Lumbar Interbody Fusion With Double Cages: 2-Dimensional Operative Video.

We provide a step-by-step technique guide for performing a transforaminal lumbar interbody fusion (TLIF) with double cages. An illustrative case was presented with detailed narration and discussion of technical nuances. Double TLIF cages create an anterior lumbar interbody fusion-sized footprint that increases the surface area for arthrodesis and force distribution while avoiding the added morbidity of an anterior approach. An appropriate TLIF technique creates lordosis through an all-posterior approach, and using a large TLIF window avoids the need for retraction of the nerve roots or thecal sac. The patient gave informed consent for the procedure and video recording. There is no identifying information in this video. Institutional review board approval was deemed unnecessary.

Expandable versus Static Transforaminal Lumbar Interbody Fusion Cages: 1-year Radiographic Parameters and Patient-Reported Outcomes

Expandable transforaminal lumbar interbody fusion (TLIF) cages capable of multidirectional in situ expansion have gained popularity as they increase axial surface area for fusion and may enhance lordotic correction through a traditional minimally invasive surgery (MIS) surgical corridor. We evaluated and compared the radiographic and clinical outcomes between a novel expandable versus static minimally invasive surgery TLIF cage for the treatment of degenerative disk disease. A single-center retrospective review of 120 consecutive adult patients undergoing 1- or 2-level MIS TLIF with an expandable (n= 60) or static cage was performed between 2015 and 2019. Preoperative and 1-year postoperative radiographic and clinical outcomes were assessed by upright flexion/extension radiographs and serial confidential surveys. One-hundred twenty patients (mean age 63.5 years, 60.0% female) undergoing 1- and 2-level MIS TLIF met inclusion criteria. A statistically significant reduction of spondylolisthesis, restoration of foraminal height as well as anterior and posterior disk height was achieved in both cohorts, however was greater in the expandable cage cohort (ECC) (all P < 0.05). Comparable rates of fusion, 93% and 91%, were observed in the ECC and static cage cohort. A significant reduction in Numeric Pain Rating Scale back and Oswestry Disability Index scores were observed in both cohorts but were more pronounced in the ECC (5.9 ± 2.4 to 2.2 ± 1.9 and 37.3 ± 16.2 to 17.1 ± 15.2) versus static cage cohort (6.2 ± 2.8 to 3.2 ± 2.5 and 41.8 ± 16.1 to 24.3 ± 17.5) (P < 0.05). One instance of cage migration requiring reoperation occurred in the ECC. Taken together, these radiographic and clinical findings suggest an expandable cage placed through an MIS corridor represents a safe, equitable, and efficacious alternative to a static TLIF in adults with degenerative lumbar pathology.

Preoperative Radiographic Prediction Tool for Early Postoperative Segmental and Lumbar Lordosis Alignment After Transforaminal Lumbar Interbody Fusion.

ObjectiveTransforaminal lumbar interbody fusion (TLIF) is a common approach and results in varying degrees of lordosis correction. The purpose of this study is to determine preoperative radiographic spinopelvic parameters that predict change in postoperative segmental and lumbar lordosis after TLIF.Materials & MethodsThis study is a single surgeon retrospective review of one-level and two-level TLIFs from L3-S1. All patients underwent bilateral facetectomies, 10 mm TLIF cage (non-lordotic) insertions, and bilateral pedicle screw-rod construct placements. Pre- and post-operative X-rays were assessed for preoperative segmental lordosis (SL), lumbar lordosis (LL), and pelvic incidence (PI). Univariate and multi-predictor linear regression analyses were performed to determine the relationships between preoperative radiographic findings and change in early postoperative segmental and lumbar lordosis.ResultsNinety-seven patients contributing 128 intervertebral segments were examined. The mean change in SL after TLIF was 7.3 (range: 0.10-28.9°, SD 6.39°). The mean change in LL after TLIF was 5.5˚ (range: -14.8-39.2°, standard deviation (SD) 7.16°). Greater preoperative LL predicted less postoperative LL correction, while greater preoperative PI predicted more postoperative SL and LL correction. Greater anterior disk height was noted to be associated with a decreased change in SL (∆SL). An annular tear on preoperative magnetic resonance imaging (MRI) predicted a 2.7° decrease in ∆SL. A Schmorl's node on preoperative MRI predicted a 4.0° decrease in change in LL (∆LL).ConclusionsA greater preoperative lordosis and a lower spinopelvic mismatch lessen the potential for an increase in the postoperative SL and LL after a TLIF, which is likely due to a ‘ceiling’ effect of an otherwise optimized spinal alignment. A greater anterior disk height and the presence of an annular tear are associated with decreased ∆SL.

Minimally Invasive Transforaminal Lumbar Interbody Fusion Using Expandable Cages: Increased Risk of Late Postoperative Subsidence Without a Real Improvement of Perioperative Outcomes: A Clinical Monocentric Study

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is one of several approaches to lumbar interbody fusion that has proven to be a safe and effective treatment for symptomatic lumbar degenerative disease The clinical outcomes of MIS-TLIF are generally favorable, but there is still controversy regarding its ability to restore sagittal alignment. For this reason, expandable transforaminal lumbar interbody fusion cages have been developed and designed to improve ability to restore disc height and segmental lordosis. The use of expandable cages in transforaminal lumbar interbody fusion has increased drastically; however, it is not clear how effective cage expansion is in regard to disc space lordosis, distraction, and long-term outcome. We reviewed a cohort of patients with symptomatic lumbar degenerative disc pathology who underwent MIS-TLIF at our institution. We compared clinical and radiographic outcomes of expandable versus nonexpandable cage use in MIS-TLIF focusing on mean changes in segmental lordosis, disc height, and postoperative complications. The results were compared with other studies reported in the international literature. Mean change in segmental lordosis was not significantly different between the 2 groups. A significantly higher rate of postoperative subsidence was demonstrated in the expandable cage group. This study established that expandable cage use in single-level transforaminal lumbar interbody fusion did not reduce the rate of postoperative complications, but rather significantly increased a patient's risk of postoperative subsidence. Expandable cages do not presently demonstrate improved clinical outcomes or improved sagittal alignment compared with static cages.

Comparing hyperlordotic and standard lordotic cages for achieving segmental lumbar lordosis during transforaminal lumbar interbody fusion in adult spinal deformity surgery.

Few studies directly compare the effect of interbody cages with different degrees of lordosis in producing segmental lumbar lordosis (SLL) in the transforaminal lumbar interbody fusion (TLIF) procedure. Thus, we aimed to investigate changes in SLL in hyperlordotic cages compared to standard lordotic cages in open TLIF procedures. Thirty-eight consecutive patients who received open TLIF procedures performed by a single surgeon between 2017 and 2018 were reviewed. Twenty patients had "hyperlordotic cages" (20° lordosis), while 18 patients had "standard lordotic cages" (6° lordosis). Twenty-three patients had one-level TLIF procedures and 15 had two-level TLIF. Standard radiographic measurements, including SLL were assessed preoperatively, postoperatively, and at 1-year follow-up. SLL was measured from the superior endplate of the cephalad vertebra to the inferior endplate of the caudal vertebra. Changes in SLL were compared using Student's and paired t-tests. In one- and two-level open TLIF, both hyperlordotic and standard lordotic cages produced significant improvement in SLL. Among those receiving a one-level TLIF, SLL increased 7.8° (P=0.024) in those with standard lordotic cages; it increased 8.2° (P=0.020) in those with hyperlordotic cages. Among those receiving a two-level TLIF, SLL increased 13.9° (P=0.032) in those with standard lordotic cages; it increased 8.8° (P=0.023) in those with hyperlordotic cages. However, the improvement in SLL was not significantly different between the two cage types in either one or two-level TLIF procedures (P=0.917, P=0.389). At 1-year follow-up, there was no significant change in SLL, among standard lordotic and hyperlordotic cages (P=0.501, P=0.781). Although it is theorized that hyperlordotic cages would increase SLL during open TLIF procedures more than standard lordotic cages, our data failed to demonstrate that. As our study examined cases performed by a single surgeon immediately before and after adoption of these lordotic cages, it is likely that surgical technique is of equal or greater importance in improving SLL than the amount of lordosis designed into interbody cages.

139. Segmental lordosis restoration using ALIF vs TLIF in adults with flatback deformity

139. Segmental lordosis restoration using ALIF vs TLIF in adults with flatback deformity

Delayed asymptomatic retroperitoneal dislodgement into the pouch of Douglas of a TLIF cage: A case report and review of the literature

Background: Intraoperative anteropulsion of a transforaminal lumbar interbody fusion (TLIF) cage is infrequent but may have disastrous complications. Here, we present an 80-year-old female whose L5-S1 TLIF cage extruded anteriorly and later migrated into the pouch of Douglas (i.e. an anterior peritoneal reflection between the uterus and the rectum) posing potential significant risks/complications, particularly of a major vessel injury. Notably, this 80-year-old patient with degenerative lumbosacral scoliosis should have only undergone a lumbar decompression alone.Case Description: An 80-year-old female underwent a two-level L4-L5 and L5-S1 TLIF to address lumbosacral canal stenosis with degenerative scoliosis. During the L5-S1 TLIF, intraoperative fluoroscopy showed the anterior displacement of the cage ventral to the sacrum. As she remained hemodynamically stable, the cage was left in place. The postoperative CT scan confirmed that the cage was located in the retroperitoneum but did not jeopardize the major vascular structures. Three months later, however, the cage migrated inferiorly into the pouch of Douglas. Although asymptomatic, general surgery and gynecology advised laparoscopic removal of the cage to avoid the potential for a major vessel/bowel perforation. However, the patient refused further surgery, and 3 years later remained asymptomatic.Conclusion: Anterior cage migration following TLIF has been rarely reported. In this case, an L5-S1 TLIF cage extruded anteriorly in an 80-year-old severely osteoporotic female and migrated 3 months later into the pouch of Douglas, posing the risk of a major vessel/bowel injury. Although surgical removal was recommended, the patient refused further surgery but remained asymptomatic 3 years later. Notably, the authors, in retrospect, recognized that choosing to perform a 2-level TLIF in an 80-year-old female reflected poor judgment.

Expandable Cage Technology-Transforaminal, Anterior, and Lateral Lumbar Interbody Fusion.

This review of the literature will focus on the indications, surgical techniques, and outcomes for expandable transforaminal lumbar interbody fusion (TLIF), anterior lumbar interbody fusion (ALIF), and lateral lumbar interbody fusion (LLIF) operations. The expandable TLIF cage has become a workhorse for common degenerative pathology, whereas expandable ALIF cages carry the promise of greater lordotic correction while evading the diseased posterior elements. Expandable LLIF cages call upon minimally invasive techniques for a retroperitoneal, transpsoas approach to the disc space, obviating the need for an access surgeon and decreasing risk of injury to the critical neurovascular structures. Nuances between expandable and static cages for all 3 TLIF, ALIF, and LLIF operations are discussed in this review.

The Results of Using a Transforaminal Lumbar Interbody Fusion Cage at the Upper Lumbar Level.

AimThe aim of this study is to apply surgical treatments to upper lumbar disc hernias in order to provide lumbar stability and lumbar lordosis using a transforaminal lumbar interbody fusion (TLIF) cage and to preserve the success rate of surgical results by protecting neural structures without excessive subject tension.Material and methodsBetween 2012 and 2017, 32 patients who had undergone an operation for upper lumbar disc herniation and who had received a transforaminal lumbar interbody fusion cage using a posterior technique were evaluated retrospectively.ResultsThe radiological and clinical findings, surgical methods, and results of the patients were evaluated. In our study, 25 (78.1%) of the patients with upper lumbar disc hernias who were evaluated retrospectively were female and seven (21.9%) were male. Their average age was 55.43 years. The average follow-up was 21.75 months. The most common complaints were lower back pain, leg pain, and claudication. In the findings from neurological examinations, a positive result on the femoral stretching test occurred in 30 (93.7%) patients. In the degenerative spinal structure of patients at the L1-2 and L2-3 levels, a transforaminal lumbar interbody fusion was performed via a wide laminectomy with posterior stabilization due to a wide-bottomed disc hernia and stenosis. Only one of the patients with a neurological deficit still had a motor deficit after surgery.ConclusionWhile planning a surgery for upper lumbar disc hernias, the anatomical features of this region and the patients' radiological and neurological findings should be carefully evaluated. If TLIF is performed during upper lumbar region surgery, it may be preferable to perform it using a posterior technique.

Long-term radiographic outcomes of expandable versus static cages in transforaminal lumbar interbody fusion.

Potential advantages of using expandable versus static cages during transforaminal lumbar interbody fusion (TLIF) are not fully established. The authors aimed to compare the long-term radiographic outcomes of expandable versus static TLIF cages. A retrospective review of 1- and 2-level TLIFs over a 10-year period with expandable and static cages was performed at the University of California, San Francisco. Patients with posterior column osteotomy (PCO) were subdivided. Fusion assessment, cage subsidence, anterior and posterior disc height, foraminal dimensions, pelvic incidence (PI), segmental lordosis (SL), lumbar lordosis (LL), pelvic incidence-lumbar lordosis mismatch (PI-LL), pelvic tilt (PT), sacral slope (SS), and sagittal vertical axis (SVA) were assessed. A consecutive series of 178 patients (with a total of 210 levels) who underwent TLIF using either static (148 levels) or expandable cages (62 levels) was reviewed. The mean patient age was 60.3 ± 11.5 years and 62.8 ± 14.1 years for the static and expandable cage groups, respectively. The mean follow-up was 42.9 ± 29.4 months for the static cage group and 27.6 ± 14.1 months for the expandable cage group. Within the 1-level TLIF group, the SL and PI-LL improved with statistical significance regardless of whether PCO was performed; however, the static group with PCOs also had statistically significant improvement in LL and SVA. The expandable cage with PCO subgroup had significant improvement in SL only. All of the foraminal parameters improved with statistical significance, regardless of the type of cages used; however, the expandable cage group had greater improvement in disc height restoration. The incidence of cage subsidence was higher in the expandable group (19.7% vs 5.4%, p = 0.0017). Within the expandable group, the unilateral facetectomy-only subgroup had a 5.6 times higher subsidence rate than the PCO subgroup (26.8% vs 4.8%, p = 0.04). Four expandable cages collapsed over time. Expandable TLIF cages may initially restore disc height better than static cages, but they also have higher rates of subsidence. Unilateral facetectomy alone may result in more subsidence with expandable cages than using bilateral PCO, potentially because of insufficient facet release. Although expandable cages may have more power to induce lordosis and restore disc height than static cages, subsidence and endplate violation may negate any significant gains compared to static cages.

Modified far lateral endoscopic transforaminal lumbar interbody fusion using a biportal endoscopic approach: technical report and preliminary results.

Endoscopic transforaminal lumbar interbody fusion (TLIF) has the disadvantage of the small cage size and by consequence risk for cage subsidence. We succeeded to insert a large oblique lumbar interbody fusion (OLIF) cage during biportal endoscopic TLIF. Unilateral total facetectomy was performed to expose the exiting and traversing nerve roots. The distance between the exiting and traversing nerve roots was measured before OLIF cage insertion. We inserted an OLIF cage instead of a TLIF cage. We successfully performed modified far lateral biportal endoscopic TLIF using large OLIF cages. Modified far lateral biportal endoscopic TLIF is usually suitable for the L4-5 and L5-S1 levels.

Transforaminal Endoscopic Surgical Treatment for Posterior Migration of Polyetheretherketone Transforaminal Lumbar Interbody Fusion Cage: Case Series

This study aims to report the clinical outcome of treating lumbar radiculopathy in the setting of retropulsed polyetheretherketone (PEEK) transforaminal lumbar interbody fusion (TLIF) cages with transforaminal endoscopic spine surgery. A retrospective study of 8 patients with lumbar radiculopathy in the setting of a retropulsed PEEK TLIF cage were included from January 2014 to January 2019. The inclusion criteria were 1) lumbar radiculopathy in the setting of a retropulsed PEEK TLIF cage causing nerve compression and 2) follow-up at least 1 year. Patients were asked to complete the following questionnaires for outcome evaluation: visual analog scales (VAS) for leg pain and the Oswestry Disability Index (ODI). Eight patients underwent transforaminal endoscopic surgery for treatment of radiculopathy in the setting of a retropulsed PEEK TLIF cage in the 5-year period evaluated. One year after surgery, the VAS and ODI scores showed a significant decrease: average preoperative VAS and ODI scores were 6.9 ± 1.2 and 50.5 ± 10.9, and 1-year postoperative VAS and ODI scores were 2.3 ± 1.3 and 17.3 ± 5.1. Transforaminal endoscopic spine surgery for the treatment of a retropulsed PEEK TLIF cage is a safe and effective approach with low morbidity and acceptable complication rates for patients with radiculopathy secondary to a retropulsed PEEK TLIF cage. Compared with a more invasive approach to removing or drilling the PEEK TLIF cage, endoscopic spine surgery could achieve a similar improvement in the patient-reported outcomes with possibly fewer complications.