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Objective: To investigate the biomechanical effects of interbody cage height on adjacent segments in patients with lumbar degeneration undergoing transforaminal lumbar interbody fusion (TLIF) surgery, so as to provide references for selection of interbody cage. Methods: The finite element model of normal lower lumbar spine (L3–S1) was built and validated, then constructed three different degenerative segments in L3–L4, and the cages with different height (8, 10, 12, 14 mm) were implanted into L4–L5 disc. All the twelve models were loaded with pure moment of 7.5 N m to produce flexion, extension, lateral bending and axial rotation motions on lumbar spine, and the effects of cage height on range of motion (RoM) and intervertebral pressure in lumbar spine were investigated. Results: The RoM of adjacent segments and the maximum stress of intervertebral discs increased with the increase in cage height, but this trend was not obvious in mild and moderate degeneration groups. After implantation of four different height cages (8, 10, 12, 14 mm), the RoM of L3/L4 segment reached the maximum during extension. The RoM of mild degeneration group was 2.07°, 2.45°, 2.48°, 2.54°, that of moderate degeneration group was 1.79°, 1.97°, 2.05°, 2.05°, and that of severe degeneration group was 1.43°, 1.66°, 1.74°, 1.74°. The stress of L3–L4 intervertebral disc reached the maximum during flexion. The maximum stress of L3–L4 intervertebral disc was 20.16 MPa, 20.28 MPa, 20.31 MPa and 20.33 MPa in the mild group, 20.58 MPa, 20.66 MPa, 20.71 MPa and 20.75 MPa in the moderate group, and 21.27 MPa, 21.40 MPa, 21.50 MPa and 21.60 MPa in the severe group. Conclusion: For patients with mild-to-moderate lumbar degenerative disease who need to undergo TLIF surgery, it is recommended that the height of fusion cage should not exceed the original intervertebral space height by 2 mm, while for patients with severe degeneration, a fusion cage close to the original intervertebral height should be selected as far as possible, and the intervertebral space should not be overstretched. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective cohort study.Objective: The purpose of this study was to compare segmental and regional radiographic parameters between anterior interbody fusion (ALIF) and posterior interbody fusion (TLIF) for treatment of L5-S1 isthmic spondylolisthesis, and to assess for changes in these parameters over time. Secondarily, we sought to compare clinical outcomes via patient-reported outcome measures (PROMs) between techniques and within groups over time.Summary Of Background Data: Isthmic spondylolistheses are frequently treated with interbody fusion via ALIF or TLIF approaches. Robust comparisons of radiographic and clinical outcomes are lacking.Methods: We reviewed pre- and postoperative radiographs as well as Patient-Reported Outcomes Measurement Information System (PROMIS) elements for patients who received L5-S1 interbody fusions for isthmic spondylolisthesis in the Mass General Brigham (MGB) health system (2016-2020). Intraclass correlation testing was used for reliability assessments; Mann-Whitney U tests and Sign tests were employed for intercohort and intracohort comparative analyses, respectively.Results: ALIFs generated greater segmental and L4-S1 lordosis than TLIF, both at first postoperative visit (mean 26 days [SE = 4]; 11.3° vs. 1.3°, P  < 0.001; 6.2° vs. 0.3°, P  = 0.005) and at final follow-up (mean 410days [SE = 45]; 9.6° vs. 0.2°, P < 0.001; 7.9° vs. 2.1°, P = 0.005). ALIF also demonstrated greater increase in disc height than TLIF at first (9.6 vs. 5.5 mm, P < 0.001) and final follow-up (8.7 vs. 3.6 mm, P < 0.001). Disc height was maintained in the ALIF group but decreased over time in the TLIF cohort (ALIF 9.6 vs. 8.7 mm, P = 0.1; TLIF 5.5 vs. 3.6 mm, P < 0.001). Both groups demonstrated improvements in Pain Intensity and Pain Interference scores; ALIF patients also improved in Physical Function and Global Health - Physical domains.Conclusion: ALIF generates greater segmental lordosis, regional lordosis, and restoration of disc height compared to TLIF for treatment of isthmic spondylolisthesis. Additionally, ALIF patients demonstrate significant improvements across more PROMs domains relative to TLIF patients.Level of Evidence: 3. [ABSTRACT FROM AUTHOR]

Background Context: Oblique lumbar interbody fusion (OLIF) has been proven to be effective in treating lumbar degenerative disorders (LDDs) via indirect decompression. However, its superiority over transforaminal lumbar interbody fusion (TLIF) remains questionable, especially in terms of medium-term follow-up.Purpose: To compare the medium-term clinical and radiological outcomes of TLIF and OLIF in treating patients with LDDs.Study Design: Retrospective comparative study.Patient Sample: Fifty-two patients treated by TLIF and forty-six patients treated by OLIF.Outcome Measures: Clinical records including the visual analog scale (VAS) score of the lower back and leg and the Oswestry Disability Index (ODI). Radiological records including disk height (DH), lumbar lordosis (LL), segmental lordosis (SL), the cross-sectional area (CSA) of the spinal canal, and fusion rate. Surgical-related information and complications were also recorded.Methods: A retrospective review was performed on patients who were surgically managed for LDDs at L4-5 between 2015 and 2017 and completed at least 4 years of follow-up. A total of 98 patients were analyzed, with 46 patients treated by OLIF combined with anterolateral single screw-rod fixation (OLIF-AF group), and 52 patients treated by TLIF (TLIF group). Parameters including postoperative outcomes and perioperative complications were compared with evaluate the efficacy of the two approaches.Results: There was significantly less bleeding, surgical duration, and hospitalization in the OLIF-AF group than in the TLIF group. Significant improvements in the clinical score were achieved in both groups. However, the VAS score of the lower back was significantly higher in the TLIF group than in the OLIF-AF group throughout the whole follow-up period. Significantly higher expansion of the CSA was found in the TLIF group than in the OLIF-AF group. However, the improvements in DH, LL, and SL were significantly lower in the TLIF group. The fusion rate was significantly higher in the OLIF-AF group than in the TLIF group within 6 months postoperatively, and there was no significant difference between the two groups at the final record. No significant difference was found in the rate of overall complications between the two groups (25.0% vs. 23.9%, p=.545). The intraoperative complication rate in the TLIF group (13.5%) was slightly higher than that in the OLIF-AF group (6.5%) (p=.257). There was no significant difference in the incidence of adjacent segment disorder (ASD) between the two groups (7.7% vs. 10.9%, p=.422). Cage subsidence was slightly lower in the TLIF group (5.8%) than in the OLIF-AF group (13.0%) (p=.298).Conclusions: Both the TLIF and OLIF-AF approaches demonstrated good medium-term outcomes in treating LDDs. Compared with TLIF, OLIF-AF showed advantages in postoperative recovery, improvement of intervertebral space and lumbar sagittal balance, and early intervertebral fusion but was associated with inferior spinal canal decompression efficacy. The two approaches shared comparable overall complication rates. However, OLIF-AF tended to have fewer intraoperative complications, and a higher incidence of subsidence. [ABSTRACT FROM AUTHOR]

Lumbar listhesis, is defined as a disorder that causes a vertebral body to slip over the one below it. Several surgical decompression and augmented fusion techniques are available for treatment. Transforaminal lumbar interbody fusion (TLIF) is a commonly used surgical technique for degenerative lumbar spondylolisthesis in cases in which conservative care fails to achieve satisfactory spinal fusion. Although TLIF is widely accepted because it is easy to perform and is very safe, cage migration is an important complication, and posterior migration is a serious one. Cage migration can be classified as posterior, anterior, or sagittal forms according to migration direction. An increasing number of the surgeons have encountered cage migration; however, consensus on its cause is lacking. In this report, a case of intradural cage migration with left leg pain is presented, and this complication is discussed in light of related studies. [ABSTRACT FROM AUTHOR]

Study Design: Prospective study.Objective: The aim of this study was to prospectively assess the clinical outcomes of modified minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for the treatment of singlesegment lumbar spondylolisthesis.Summary Of Background Data: MIS-TLIF is a safe and effective procedure in the treatment of lumbar degenerative disease. To avoid durotomy and nerve root injury, we modified the surgical order of MIS-TLIF such that the interbody fusion procedure was performed before the decompression procedure.Methods: One hundred thirty-nine patients with single-segment lumbar spondylolisthesis were separated into two groups. Sixty-seven patients underwent modified MIS-TLIF (group A). In group B, 72 patients underwent routine MIS-TLIF. The Japanese Orthopedic Association (JOA) score and the visual analogue scale (VAS) scores for lower back pain (LBP) and leg pain were assessed during the postoperative follow-up, and the lumbar interbody fusion rate was evaluated by CT scanning.Results: The mean operative time, incision length, average blood loss, and incision pain level were not significantly different (P  > 0.05) between the two groups. No nerve root or dural injuries were observed in group A. In group B, there were two cases of dural injury and three cases of nerve root injury. One patient experienced temporary numbness and weakness on dorsiflexion of the foot, which recovered in 3 months. No differences were identified between the two groups when postoperative JOA scores, back pain, leg pain VAS scores, or the lumbar interbody fusion rate.Conclusion: Both methods are effective in the treatment of lumbar degenerative disease. Modified MIS-TLIF is a safe and effective procedure that can significantly reduce the occurrence of injury to the dura and nerve root during decompression and the interbody fusion procedure.Level of Evidence: 3. [ABSTRACT FROM AUTHOR]

Innovations in spinal endoscopy technology and technique have broadened their applications during the past 10 years. Smaller outer-diameter working-channel endoscopes have permitted safe usage in the cervical spine for full endoscopic decompressions. Endoscopic fusions have now been widely reported, leveraging compatible instrumentation for disc preparation and expandable interbody grafts. This ultra–minimally invasive technique has also enabled the performance of fusion procedures in awake patients under monitored anesthesia care, affording speedier recovery and treatment options for those unable to undergo general anesthesia. Revision surgery after open or minimally invasive posterior discectomy or instrumentation can now be performed with endoscopic techniques, which often leverage the transforaminal approach to avoid scar tissue and adhesions. These procedures, among other endoscopic surgeries, are now being increasingly performed in ambulatory surgery centers, as safe outcomes, economic benefits to the healthcare system, and patients' desire to recover at home are becoming more apparent. Finally, the standardization of endoscopic terminology, which has long been a confounder to proper communication and education in this field, has recently been addressed by leading experts in a consensus document, which will serve as the foundation for future collaborative advancements. [ABSTRACT FROM AUTHOR]

To compare the short-term efficacy of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and transforaminal lumbar interbody fusion (TLIF) in the treatment of single segment lumbar degenerative diseases. Clinical data of 72 patients with single segment lumbar degenerative disease admitted to our hospital from April 2018 to December 2020 were retrospectively selected. According to surgical methods, they were divided into group A (n=36, TLIF treatment) and group B (n=36, MIS-TLIF treatment). The operation indexes (operation time, intraoperative blood loss, incision length) of the two groups were compared. The degree of pain and lumbar function in the two groups before operation, 1 month after operation and 6 month after operation were compared. The intervertebral fusion rate of the two groups was compared. Compared with group A, group B had longer operation time, shorter incision length, and less intraoperative blood loss (P<0.05). Compared with group A, visual analogue scale (VAS) scores in the group B at 1 month after operation and 6 months after operation were lower (P<0.05). Compared with group A, the Japanese Orthopaedic Association (JOA) scores in the group B at 1 month after operation and 6 months after operation were higher (P<0. 05). The interbody fusion rate in group B was 97.22% (35/36) higher than 88.89% (32/36) in group A, and the difference was not statistically significant (P>0.05). Compared with TLIF treatment, mis-tlif treatment of patients with single segment lumbar degenerative diseases has a longer operation time, but it is more obvious for the relief of pain and the improvement of lumbar function. [ABSTRACT FROM AUTHOR]

Background Context: Patients undergoing minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) frequently present with lower extremity neurologic symptoms with or without associated lower back pain. While symptomatic improvement of leg and back pain has been reported, the resolution of back pain when it is a predominant presenting symptom remains underreported following MI-TLIF.Purpose: The purpose of this study was to compare clinical outcomes at 1 year of patients undergoing MI-TLIF with lower extremity neurologic symptoms with and without a significant component of back pain.Study Design: A retrospective review of prospectively collected data from a single surgeon surgical database from 2017 to 2019 was performed.Patient Sample: Fifty one patients undergoing MI-TLIF.Outcome Measures: Self-reported measures included the Oswestry Disability Index (ODI), Visual analog scale back pain (VAS-back), and VAS leg pain (VAS-leg).Methods: Patients were divided into two groups: Leg Pain Predominant (patients reported greater than 50% leg pain upon presentation) and Back Pain Predominant (patients reported 50% or greater back pain). Multivariate analysis was performed to determine differences between groups based upon any significantly baseline characteristics.Results: Preoperative demographic and radiographic outcomes were similar between the two groups. Both groups demonstrated significant improvement in ODI, VAS-Back and VAS-leg at 1-year postoperatively. On multivariate analysis, there were differences in ODI at 1-year, 1-year back pain, and 1-year leg pain between groups with those who initially presented with leg pain having a lower ODI, VAS Back, and VAS leg. Patients who presented with predominantly leg pain were more likely to meet minimal clinically important difference (MCID) criteria for ODI and VAS-back compared to those with predominantly back pain.Conclusion: Following MI-TLIF, patients with lower extremity neurologic symptoms with and without a significant component of back pain have improvements in back pain, leg pain, and ODI regardless of their primary presenting pain complaint; however, patients who presented with predominantly leg pain were more likely to meet MCID criteria for improvement in their back pain and ODI score. [ABSTRACT FROM AUTHOR]

Objective: This study assessed the outcomes of transforaminal lumbar interbody fusion (TLIF) in patients with degenerative spine conditions above the age of 65 years and investigate the effects of fusion levels on the sagittal balance parameters. Materials and Methods: This retrospective study reviewed patients with degenerative spine diseases who underwent lumbar fusion with the TLIF procedure older than 65 years. Patients with three or less segments involved in the fusion were assigned to the short-level fusion group, and the patients with more than three segments involved in the fusion were assigned to the long-level fusion group. The anteroposterior and lateral spine radiographs of the patients were used to measure pelvic incidence (PI), pelvic tilt (PT), sacral slop (SS), lumbar lordosis (LL), distal lumbar lordosis, thoracolumbar kyphosis, thoracic kyphosis (TK), T1 spinopelvic inclination (T1SPI), T9 spinopelvic inclination (T9SPI) and T1 pelvic angle (TPA). Results: The study included 45 patients, 28 females and 17 males, who met the inclusion criteria. The long- and short-level fusion groups comprised 25 and 20 patients, with the mean ages of 68.87 and 67.72 years and mean follow-up periods of 26.96±15.53 and 27.61±11.83 months, respectively. TK and T9SPI values showed no difference between the groups before and after surgery, but a statistically significant increase in the values was observed postoperatively in the patients who underwent long-level fusion. The preoperative SVA values were significantly higher in the long-level fusion group than in the short-level fusion group. No difference in the postoperative SVA values was found between the groups. The PT, PI, SS, TPA, T1SPI was not statistically differ between the groups before and after surgery. Conclusion: TLIF contributes to the improvement of the sagittal balance parameters in both short- and long-level fusions in patients above the age of 65 years with degenerative spine conditions. [ABSTRACT FROM AUTHOR]

This section of the symposium draws the reader’s attention to various types of spondylolisthesis that are commonly encountered in daily routine practice on the basis of the Spinal Deformity Study Group (SDSG) classification. Each clinical scenario underlines the workup required for such cases along with various technical tips.

BackgroundA series of full-endoscopic lumbar interbody fusions have been reported, but special fusion cages or operating instruments are often needed, and there are many complications in the operation and the learning curve is long. We have used a single portal endoscopic system for lumbar interbody fusion in a novel posterolateral transarticular approach, which will take advantage of the incision for pedicle screw insertion and avoid nerve root damage by using a transparent plastic working tube. The purpose of this study was to present the surgical technique of full endoscopic posterolateral transarticular lumbar interbody fusion (FE-PTLIF) and to analyze the preliminary clinical results.MethodsA total of 39 patients (17 men and 22 women; mean age [x̅ ± s] 55.2 ± 12.2 years) have been enrolled in this retrospective study between March 2019 and January 2021 in the Second Affiliated Hospital of Chongqing Medical University. All patients were treated with full endoscopic lumbar interbody fusion via posterolateral transarticular approach with a transparent plastic working tube. Demographic characteristics, diagnosis, operative time, and estimated blood loss were evaluated. Intraoperative photo and perioperative imaging were recorded. The preoperative and postoperative clinical data were collected for statistical analysis.ResultsThe preliminary clinical follow-up data achieved good results. No patients had serious postoperative complications and none of these patients required revision surgery during the perioperative or follow-up period. We compared the visual analogue scale and Oswestry disability index scores before and after surgery. The differences were statistically significant (P

Steerable "banana" cages have been posited to increase segmental lordosis in short-segment transforaminal lumbar interbody fusions (TLIF). The same is not necessarily true for straight "bullet" cages. Although increased lordosis is generally thought to be advantageous, a potential complication is decreased foraminal height. Here we evaluate for any association between cage type and change in foraminal height and clinical outcomes following short-segment TLIFs. We retrospectively reviewed consecutive 1- and 2-level TLIFs with bilateral facetectomies with minimum 1-year clinical and radiographic follow-up. Two cohorts were based on cage morphology: steerable "banana" cage or straight "bullet" cage. Patient reported outcome measures (PROMs), radiographic measurements, and revision rates were compared. A total of 46 patients with 53 straight and 95 patients with 131 steerable cage levels were included. Steerable cages showed increased segmental lordosis (9.1° vs. 13.5°, P < 0.001) and decreased foraminal height (20.3 vs. 18.5 mm, P < 0.001) after surgery. Straight cages demonstrated similar segmental lordosis (8.7° vs 8.1°, P = 0.30) and foraminal height (19.4 vs 20.0 mm, P < 0.065). Both cohorts showed improved PROMs at last follow-up (P ≤ 0.005). Subanalysis comparing patients who had increased or decreased foraminal height revealed similarly improved PROMs between cohorts. Revision rates at 1 year were similar between cohorts (4.3% for straight and 3.2% for steerable group, P = 0.72). Although the increased segmental lordosis afforded by placement of steerable cages may decrease foraminal height after short segment TLIF, clinical outcomes are not negatively affected by this association. [ABSTRACT FROM AUTHOR]

Summary of background: Pseudoaneurysms of the lumbar arteries following transforaminal lumbar interbody fusion (TLIF) are rare postoperative complications that usually occur around the transverse process. However, there are few detailed descriptions of the transverse branch and other branches of the dorsal branches at the L1–L4 disks. Study design: Ten adult embalmed cadavers were anatomically studied. Objectives: The purposes of the study were to describe the vascular distribution of the dorsal branches, especially the transverse branches, at the L1–L4 levels and provide information useful for TLIF. Methods: Ten embalmed cadavers studied after their arterial systems were injected with red latex. The quantity, origin, pathway, distribution range and diameter of the branches were recorded and photographed. Results: The transverse branch appeared in all 80 intervertebral foramina. The transverse branch was divided into 2 types: In type 1, the arteries divided into superior branches and inferior branches; the arteries in type 2 divided into 3 branches (superior, intermedius and inferior branches). Conclusions: The transverse branches of the dorsal arteries are common structures from L1 to L4, and 2 types of transverse branches were found. A thorough understanding of the dorsal branches, especially the transverse branches of the lumbar artery, may be very important for reducing both intraoperative bleeding during the surgery and the occurrence of pseudoaneurysms after transforaminal lumbar interbody fusion. [ABSTRACT FROM AUTHOR]

To determine preoperative 12-Item Short Form Health Survey (SF-12) Mental Component Summary (MCS) influence on minimally important clinical difference (MCID) and patient-reported outcome measures in patients with isthmic spondylolisthesis receiving minimally invasive transforaminal lumbar interbody fusion. Patients with isthmic spondylolisthesis undergoing primary, single-level minimally invasive transforaminal lumbar interbody fusion at L5-S1 were retrospectively identified and divided into preoperative SF-12 MCS <50 and SF-12 MCS ≥50 groups. Visual analog scale (VAS) back/leg, Oswestry Disability Index (ODI), SF-12 Physical Composite Score (PCS), and Patient-Reported Outcome Measurement Information System physical function (PROMIS-PF) were assessed. Improvements from preoperative score were analyzed via paired samples t test. Patient-reported outcome measures and MCID attainment between groups were evaluated using linear regression and χ2, respectively. SF-12 MCS <50 and SF-12 MCS ≥50 groups included 35 and 26 patients, respectively. SF-12 MCS < 50 group had inferior scores for all VAS back time points except 6 weeks, all VAS leg time points except 6 weeks/1 year, all ODI time points, SF-12 PCS at 6 months/2 years, and PROMIS-PF at preoperative/6 months (all P ≤ 0.049). SF-12 MCS <50 group improved for VAS back/leg to 1 year, ODI and SF-12 PCS from 12 weeks to 1 year, and PROMIS-PF at 1 year only (all P ≤ 0.047). SF-12 MCS ≥50 group improved for VAS back from 12 weeks to 1 year, SF-12 PCS 6 months to 2 years, and VAS leg, ODI, and PROMIS-PF 12 weeks to 2 years (all P ≤ 0.018). MCID attainment differed for ODI at 6 weeks and PROMIS-PF at 12 weeks only (both P ≤ 0.035). Patients with SF-12 MCS <50 demonstrated fewer long-term improvements from preoperative to 2 years and inferior patient-reported outcome measures at most time points for pain and disability following minimally invasive transforaminal lumbar interbody fusion. MCID attainment largely did not differ by preoperative mental functioning. [ABSTRACT FROM AUTHOR]

We sought to assess differences in patient-reported outcome measures (PROMs) between patients who do and do not follow up for 2 years after lumbar fusion. Primary, elective, single-level anterior lumbar interbody fusion, lateral lumbar interbody fusion, or transforaminal lumbar interbody fusion procedures were identified. Patients were grouped by 2-year PROM follow-up completion. Mean and delta PROM scores for visual analog scale (VAS) back and leg, Oswestry Disability Index (ODI), short-form (SF)-12 Physical Composite Score (PCS), and Mental Composite Score (MCS) were computed for both groups preoperatively and postoperatively. Minimum clinically important difference (MCID) achievement was determined for PROM scores using established threshold values. Linear and logistic regression assessed mean and ΔPROM scores as predictors of 2-year follow-up completion and compared MCID achievement between groups, respectively. We included 316 lumbar fusion patients. PROM scores were more favorable for complete follow-up patients for 6-month VAS back (P = 0.003), 6-month and 1-year ODI (P ≤ 0.027, both), and 6-week and 6-month SF-12 PCS (P ≤ 0.015, both). Six-month VAS back (P = 0.007); 6-month and 1-year ODI (P ≤ 0.028, both); 6-week, 6-month, and 1-year SF-12 PCS (P ≤ 0.041, all); and 6-week SF-12 MCS (P ≤ 0.028, both) significantly predicted 2-year follow-up. ΔPROMs significantly differed between groups at 1 year for ΔVAS leg (P = 0.029), ΔODI (P = 0.013), and ΔSF-12 MCS (P = 0.004). One-year ΔVAS leg (P = 0.035), ΔODI (P = 0.011), and ΔSF-12 MCS (P = 0.003) significantly predicted follow-up. MCID achievement for ΔPROMs significantly differed between groups for 6-week VAS leg (P = 0.035), overall ODI (P = 0.034), and SF-12 PCS from 12 weeks through 1 year (P ≤ 0.011, all) and overall (P < 0.001). Patients with full follow-up demonstrated significantly more favorable outcome scores and improvement in pain, disability, and physical function at several postoperative time points. [ABSTRACT FROM AUTHOR]

To compare the outcomes of minimally invasive lateral lumbar interbody fusion (LLIF) with minimally invasive transforaminal lumbar interbody fusion (TLIF) and conventional open posterior lumbar interbody fusion (PLIF) for treating single-level spondylolisthesis at L4-L5. The patients underwent minimally invasive LLIF (n = 18), minimally invasive TLIF (n = 17), and conventional open PLIF (n = 20) for spondylolisthesis at L4-L5. Reduction of slippage, improvement in segmental lordosis, and restoration of foraminal height were measured. Perioperative parameters such as blood loss and operation time and clinical outcomes such as visual analog scale score and Oswestry Disability Index were compared. Compared with the open PLIF group, the minimally invasive LLIF group showed greater restoration of mean foraminal height, significantly smaller mean intraoperative estimated blood loss, and less mean hemoglobin reduction on the third day postoperatively. Compared with the minimally invasive TLIF group, the minimally invasive LLIF group showed greater restoration of mean segmental lordosis. The minimally invasive LLIF group showed a significantly shorter mean time to start walking after surgery compared with the conventional open PLIF and minimally invasive TLIF groups. However, compared with the minimally invasive TLIF group, the minimally invasive LLIF group showed a significantly longer mean operating time. Clinical outcomes were not statistically different among the 3 groups. In the treatment of spondylolisthesis of L4-L5, minimally invasive LLIF provided an effective surgical alternative to minimally invasive TLIF or conventional open PLIF, with the advantages of less blood loss, the faster start of postoperative walking, and comparable improvement in radiologic parameters. [ABSTRACT FROM AUTHOR]

Study Design: This was a dual-center study over an eight-year period on patients undergoing single level fusion surgery with either posterior- (PLIF) or transforaminal lumbar interbody fusion (TLIF). We analyzed prospectively collected pre- and postoperative data from the national Danish surgical spine database (DaneSpine).Objective: The aim of this study was to compare clinical and patient-reported outcome (PRO) 2 years after TLIF or PLIF in patients with symptomatic lumbar mechanical disc degeneration.Summary Of Background Data: PLIF and TLIF are well-described techniques for treating lumbar mechanical disc degeneration but whether the theoretical differences between the two techniques translate to different clinical outcomes is unknown.Methods: The primary outcome was Oswestry Disability Index (ODI) score at 2-year follow-up. Secondary outcome measures were scores on the European Quality of Life-5 Dimensions (EQ-5D) and visual analog scale (VAS) and the rate of intraoperative complications. To minimize baseline differences between the groups, propensity-score matching was employed in a 1:1 fashion, balancing the groups on preoperative factors including age, sex, back and leg pain, ODI, EQ-5D, and previous spine surgery.Result: The matched cohort included 211 patients in each cohort. There was no significant difference between the groups in the mean score on the ODI at two years (PLIF: 33 ± 20 vs. TLIF: 35 ± 20, P = 0.328). We found no statistically significant differences in EQ-5D score (0.54 ± 0.35 vs. 0.51 ± 0.34, P = 0.327), VAS score for back pain (47 ± 32 vs. 48 ± 29, P = 0.570) or leg pain (42 ± 33 vs. 41 ± 32, P = 0.936) between the PLIF and TLIF groups, respectively, at 2-year follow-up. Dural tears occurred in 9.5% in the PLIF group and 1.9% in the TLIF group (P = 0.002) corresponding to a relative risk of 5.0 (95% CI 1.7-14.4).Conclusion: We found no significant difference in PRO at 2-year follow-up between PLIF and TLIF for the treatment of lumbar disc degeneration. PLIF is associated with a five times higher risk of dural tears.Level of Evidence: 3. [ABSTRACT FROM AUTHOR]

Purpose of the study. To retrospectively analyze the results of surgical treatment of patients with spinal instability in the lumbosacral spine, operated on the basis of the Department of Spinal Neurosurgery, Pathology of the Peripheral Nervous System of JSC “National Centre for Neurosurgery” for the period from 2010 to 2021. Materials and methods. A retrospective analysis of the anamnesis and observation data of 3051 patients with spinal instability in the lumbosacral spine, operated on by the proposed method of surgical treatment, was carried out. In the period from 2010 to 2021, on the basis of the Department of Spinal Neurosurgery of JSC “NCN”, 3051 patients with various degenerative-dystrophic diseases of the lumbar spine were operated on, of which 1678 patients were operated on using the PLIF method (721 men and 957 women, mean age 53.4 ± 4, 1 year) and 1373 patients - TLIF using minimally invasive technologies (MIS) followed by percutaneous transpedicular fixation. Of these, 536 men and 837 women, the average age was 49.7 ± 3.8 years. Results and discussions. After surgery, all patients showed a significant decrease in the intensity of the pain syndrome. When comparing the parameters, patients operated on according to the TLIF method noted better results than PLIF: from 6.7±1.9 to 1.4±1.1 (p<0.001) at discharge, up to 1.1±0.8 at discharge. long-term period after surgery (p<0.001) and from 6.8±1.7 to 2.1±1.4 (p<0.001) at discharge, to 1.3±1.0 in the long-term period after surgery (p< 0.001) respectively. The study of the quality of life of patients in terms of the ODI index also revealed a positive trend in both groups, but with better results in the TLIF group: in the postoperative period from 55.2±6.9% to 19.6±4.1% at discharge and 15. 7±1.3% in the long-term postoperative period (p<0.001) than PLIF: from 54.7±6.8% to 26.7±4.4% at discharge and 17.6±1.4% in the long-term postoperative period (p<0.001). Conclusion. Thus, according to the literature sources and our own observations, we can conclude that the results of surgical treatment according to the TLIF method using MIS show better results compared to PLIF. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective study.Objective: The aim of this study was to investigate whether there is an association between revision surgery rates for adjacent segment degeneration (ASD) and Roussouly type after L4-5 transforaminal lumbar interbody fusion (TLIF) for spondylolisthesis.Summary Of Background Data: Revision surgery for ASD is known to occur after spinal fusion; however, it is unclear whether rates of ASD are associated with certain Roussouly types.Methods: Patients who underwent L4-5 TLIF for spondylolisthesis at the University of California San Francisco from January 2006 to December 2016 with minimum 2-year follow-up were retrospectively analyzed by Roussouly type. Revision surgery for ASD was noted and correlated by Roussouly type. Spinopelvic parameters were also measured for correlation. A value of P < 0.05 was significant.Results: There were 174 patients who met inclusion criteria, (59 males and 115 females). The average age was 62.3 (25-80) years. A total of 132 patients had grade I spondylolisthesis, and 42 had grade II. Mean follow-up was 45.2 months (24-497). A total of 22 patients (12.6%) underwent revision surgery for ASD after L4-5 TLIF. When classified by Roussouly type, revision surgery rates for ASD were: 1, 14.3%; 2, 22.6%; 3, 4.9%; and 4, 15.6% (P = 0.013). Type 3 spines with normal PI-LL (8.85° ± 6.83°) had the lowest revision surgery rate (4.9%), and type 2 spines with PI-LL mismatch (11.06° ± 8.81°) had the highest revision surgery rate (22.6%), a four-fold difference (P = 0.013). The PI-LL mismatch did not change significantly in each type postoperatively (P > 0.05).Conclusion: We found that there may be a correlation between Roussouly type and revision surgery for ASD after L4-5 TLIF for spondylolisthesis, with type 2 spines having the highest rate. Spinopelvic parameters may also correlate with revision surgery for ASD after L4-5 TLIF.Level of Evidence: 4. [ABSTRACT FROM AUTHOR]

Background Context: Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is a common operative approach to address degenerative lumbar stenosis and spondylolisthesis which has failed nonoperative care. Compared to open TLIF, MI-TLIF relies to a greater extent on indirect decompression resulting in a heightened awareness of spondylolisthesis reduction among MI surgeons. To what extent intraoperative reduction is achieved as well as the rate and clinical impact of loss or reduction and slip recurrence remain unknown.Purpose: To determine the rate and clinical impact of slip recurrence after MI-TLIF with expandable cage technology STUDY DESIGN/SETTING: Retrospective Cohort Study PATIENT SAMPLE: Patients undergoing MI-TLIF for degenerative spondylolisthesis using an articulating, expandable cage OUTCOME MEASURES: Patient-reported outcome measures (PROMs), including the Oswestry Disability Index (ODI), visual analog scale (VAS) for back/leg pain, Short Form-12 (SF-12), and PROMIS Physical Function (PF) METHODS: Patients undergoing MI-TLIF for degenerative spondylolisthesis using articulating, expandable cages from 2017 to 2019 were retrospectively studied. Lateral radiographs were reviewed and evaluated for the presence or absence of spondylolisthesis preoperatively, intraoperatively, and at follow-up times including 2 weeks, 6 weeks, 12 weeks, 6 months, and 1 year postoperatively. Spondylolisthesis was measured from the posterior inferior corner of the cephalad vertebra to the posterior superior corner of the caudal vertebra, with any measurement >1 mm classified as spondylolisthesis, and Meyerding grade was noted. Intraoperative reduction was measured, and loss of reduction was defined as >1 mm increase in spondylolisthesis comparing follow-up imaging to intraoperative films. PROMs were recorded at the preoperative and follow-up time points. Fusion was assessed at 1 year postoperatively via CT.Results: A total of 63 patients and 70 levels were included, with mean age 59.8 years (SD,13.8). 19 levels (27.1%) had complete reduction intraoperatively, 40 (57.1%) had partial reduction, and 11 (15.7%) had no reduction. Of the 30 levels with loss of reduction (50.8%), 20 (66.7%) occurred by 2 weeks postoperatively and 28 (93.3%) occurred by 12 weeks postoperatively. At 6 months, there were significant differences between those who had loss of reduction and those who did not in VAS back pain (3.0 vs. 0.9, p = .017) and SF-12 PCS (41.5 vs. 50.0, p = .035), but no differences were found between the groups for any instruments at any other time points. The overall fusion rate was 82.1% (32/39) at 1 year postoperatively. There was no significant difference in fusion rate between the loss of reduction (16/20) and no loss of reduction (20/23) groups. Patients with loss of reduction had no difference in reoperation rate (1/28) compared to those without loss of reduction (2/24).Conclusions: While a majority of patients demonstrated reduction intraoperatively, 51% had loss of reduction, most commonly in the acute postoperative period. There were few differences in PROMs between patients who had loss of reduction and those who did not, suggesting that radiographic loss of reduction after MI-TLIF in the setting of degenerative spondylolisthesis may not be clinically meaningful. [ABSTRACT FROM AUTHOR]

Relevance. The development of minimally invasive surgery has led to the development of new methods for surgical treatment of the spine. Conventional surgical technique, such as vertebrotomy is accompanied by a several number of disadvantages (high blood loss, prolonged hospital stay, long intraoperative time, postoperative neurological deficit). An alternative to improve sagittal balance in the spine is to use custom-made hyperlordotic cages, which can also be used for indirect decompression of neural structures. The objective is to compare the degree of segmental and total lumbar lordosis using hyperlordotic cages through ALIF and TLIF with posterior instrumentation.Materials and Methods. A single-center retrospective cohort study using 96 patients treated from 2018 to 2019 about degenerative spinal deformities. Comparison of two groups: group 1 (A) consisted of 30 patients who were held anterior spinal fusion with individual lordotic cages from minimally invasive anterior approach (MISS ALIF) without posterior fixation. Group 2 (B) consisted of 33 patients whom were performed spinal fusion from the posterior approach (TLIF) with Smith-Peterson Osteotomy (SPO) and transpedicular fixation. Measuring segmental and lumbar lordosis, teleradiographs were used in a standing position. For an accurate assessment, the non-commercial available Surgimap software, © Nemaris, was used.Results. Segmental lordosis were superior to preoperative ones. In the intergroup comparison, the ALIF group showed an excellent increase in the enlarged lordosis segment (L3-L4 in 8 degrees; p = 0.0005, L4-L5 in 7 degrees; p = 0.0002, L5-S1 in 7 degrees; p = 0.0001). When conducting an intergroup comparison of total lumbar lordosis in the preoperative period, there was a statistically significant difference between them (p = 0.0043). At the same time, a greater degree of correction of lordosis is shown in ALIF compared to TLIF group (29,1 in comparison with 22,5; p = 0.00005).Conclusion. The results of this study confirm that the using of custom-made lordotic cages can significantly increase segmental and total lumbar lordosis for patients with degenerative scoliosis in adults.

Background Context: Expandable transforaminal lumbar interbody fusion (TLIF) cages have become popular in recent years due to anticipated advantages of increased disc height, improved segmental lordosis, and ease of implantation. Such benefits have not been conclusively demonstrated in the literature., Purpose: To determine whether expandable cages increase disc height and segmental lordosis in a durable way following surgery and compare complication profiles between cage types., Study Design/setting: Retrospective cohort study conducted within a large academic health system involving 31 different spine surgeons., Patient Sample: Adults undergoing single-level TLIF for an indication other than infection, tumor, trauma, or revision instrumentation from 2021 to 2023., Outcome Measures: Our primary outcomes were changes in segmental disc height, segmental lordosis, and L4-S1 lordosis at 2 weeks, 6 months, and 1 year following surgery relative to baseline. Our secondary outcomes were frequencies of incidental durotomies, surgical site infections, readmissions, death, subsidence, and unplanned return to the operating room., Methods: Radiographic variables were collected from our institutional imaging registry. Demographics and surgical characteristics were abstracted from chart review. Generalized linear modeling was used for each primary outcome, with cage type (expandable vs. static) as our primary predictor and age, biologic sex, race, CCI, year of surgery, duration of surgery, invasiveness of surgery, surgeon specialty (Orthopedics vs. Neurosurgery), and level of surgery as covariates., Results: Our cohort consisted of 417 patients with a mean age of 62. Static cages were used in 306 patients and expandable cages in 111. Expandable cages were associated with increased changes in disc height relative to static cages at 2 weeks (1.1 mm [0.2-1.9]; p=.01) and 6 months (1.2 mm [0.2-2.3]; p=.02) following surgery, but differences were no longer significant at 1 year (0.4 mm [-0.9-1.8]; p=.4). Expandable cages were found to subside more commonly than static cages (14.1% vs. 6.6%; p=.04). No significant differences between cage types were identified in lordotic parameters at any timepoint (p=0.25 to p=0.97)., Conclusions: Expandable cages were associated with an initial increase in disc height relative to static cages, but this difference diminished with the first year of surgery, likely due to a higher rate of subsidence within the expandable cohort., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: To correlate the operative characteristics and complications of transforaminal lumbar interbody fusion (TLIF) to patient frailty status for the first time in a multicenter study., Methods: Using the American College of Surgeons National Surgical Quality Improvement (ACS-NSQIP) database, all patients who underwent TLIF in 2015-2020 were filtered for their demographics, operative characteristics, and 30-day complication outcomes. Patients were stratified into 2 cohorts, low and high frailty, based on their modified frailty index 5 score. Univariate analysis was performed between the 2 cohorts for each collected variable, and multivariable analysis was performed to observe adjusted odds ratios (OR)., Results: The frail cohort experienced more unplanned readmission (4.3 vs 6.6 %, p  < 0.001). During hospital stays, the frail cohort experienced more overall complications (9.8 vs 13.8 %, p  < 0.001). In contrast to the low frailty cohort, the high frailty patients saw longer hospital stays (3.27 vs. 3.69 days, p  < 0.001). The high frailty group saw more discharges to an institution beside their home (89.6 vs 77.9 %, p  < 0.001). Rates of superficial and deep surgical site infection, organ space infection, wound dehiscence, reintubation, renal insufficiency, urinary tract infection, stroke, cardiac arrest, DVT, sepsis, and septic shock were not significantly different. Multivariable analyses showed high frailty status as an independent predictor of unplanned readmissions, major complications, and preventing discharge to home., Conclusions: mFI-5 serves as an effective predictor of surgical outcomes following TLIF and independently predicts unplanned readmission, discharge to home, and major complications. Noninfectious outcomes were more likely to be significantly different between the high- and low frailty groups, while all infectious outcomes apart from superficial surgical site infection and pneumonia were not significantly different between the cohorts., Competing Interests: There are no declarations of interest to disclose., (© 2024 The Authors.)

Objective: The aims of this study were to 1) define the incidence of transforaminal lumbar interbody fusion (TLIF) interbody subsidence; 2) determine the relative importance of preoperative and intraoperative patient- and instrumentation-specific risk factors predictive of postoperative subsidence using CT-based assessment; and 3) determine the impact of TLIF subsidence on postoperative complications and fusion rates., Methods: All adult patients who underwent one- or two-level TLIF for lumbar degenerative conditions at a multi-institutional academic center between 2017 and 2019 were retrospectively identified. Patients with traumatic injury, infection, malignancy, previous fusion at the index level, combined anterior-posterior procedures, surgery with greater than two TLIF levels, or incomplete follow-up were excluded. Interbody subsidence at the superior and inferior endplates of each TLIF level was directly measured on the endplate-facing surface of both coronal and sagittal CT scans obtained greater than 6 months postoperatively. Patients were grouped based on the maximum subsidence at each operative level classified as mild, moderate, or severe based on previously documented < 2-mm, 2- to 4-mm, and ≥ 4-mm thresholds, respectively. Univariate and regression analyses compared patient demographics, medical comorbidities, preoperative bone quality, surgical factors including interbody cage parameters, and fusion and complication rates across subsidence groups., Results: A total of 67 patients with 85 unique fusion levels met the inclusion and exclusion criteria. Overall, 28% of levels exhibited moderate subsidence and 35% showed severe subsidence after TLIF with no significant difference in the superior and inferior endplate subsidence. Moderate (≥ 2-mm) and severe (≥ 4-mm) subsidence were significantly associated with decreases in cage surface area and Taillard index as well as interbody cages with polyetheretherketone (PEEK) material and sawtooth surface geometry. Severe subsidence was also significantly associated with taller preoperative disc spaces, decreased vertebral Hounsfield units (HU), the absence of bone morphogenetic protein (BMP) use, and smooth cage surfaces. Regression analysis revealed decreases in Taillard index, cage surface area, and HU, and the absence of BMP use predicted subsidence. Severe subsidence was found to be a predictor of pseudarthrosis but was not significantly associated with revision surgery., Conclusions: Patient-level risk factors for TLIF subsidence included decreased HU and increased preoperative disc height. Intraoperative risk factors for TLIF subsidence were decreased cage surface area, PEEK cage material, bullet cages, posterior cage positioning, smooth cage surfaces, and sawtooth surface designs. Severe subsidence predicted TLIF pseudarthrosis; however, the causality of this relationship remains unclear.

To describe a novel technique modification and evaluate initial results of pedicle screw insertion in minimally invasive transforaminal lumbar interbody fusion (MITLIF), using self-drilling self-tapping one-step screws. All patients who were operated for MITLIF using the one-step technique over the last 6 months period at a single institute, were retrospectively identified. The surgical technique is described and depicted. Outcome evaluation was performed, including screw misplacement, screw insertion time, and post-operative complications. We describe a novel technique modification in which self-drilling self-tapping navigated screws incorporate an embedded K-wire that enables a one-step insertion which obviates the need for instrument exchange. The first four patients in whom this technique was implemented were included (mean age was 55). All patients had been previously operated at the fused level. The mean surgical duration was 142 minutes and the calculated mean screw insertion time was 8.2 minutes. The mean estimated blood loss was 66 cc. An intraoperative 3D scan demonstrated no screw pedicle breach. There were no neurological complications or wound healing disturbances. The clinical course was uneventful for all patients. To our knowledge, the use of one-step navigation-assisted self-drilling self-tapping pedicle screws with an embedded K-wire has not been previously described. Our initial experience with this novel technique modification was efficient and safe. Navigated surgery allows for newer and safer techniques to be incorporated into the surgeon's toolbox. Further studies should be performed to thoroughly evaluate this technique. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective cohort.Objective: The aim of this study was to elucidate the relative influence of multiple factors on radiation usage for anterior, lateral, and posterior based lumbar interbody fusion techniques.Summary Of Background Data: There has been substantial global growth in the performance of lumbar interbody fusions, due to evolution of techniques and approaches and increased attention to sagittal alignment. Utilization of intraoperative imaging guidance has similarly expanded, with a predominance of fluoroscopy and consequent increased radiation exposure. There have been no larger-scale studies examining the role of patient and procedural factors in driving radiation exposure across different interbody techniques.Methods: We used a clinical registry to review all single-level lumbar interbody fusions performed between January 2016 and October 2020. Operative records were reviewed for the amount of radiation exposure during the procedure. Patient age, biologic sex, body mass index (BMI), operative surgeon, surgical level, surgical time, and fusion technique were recorded. Multivariable adjusted analyses using negative binomial regression were used to account for confounding.Results: We included 134 interbody fusions; 80 performed with a posterior approach (TLIF/PLIF), 43 via an anterior approach (ALIF) with posterior pedicle fixation, and 9 performed with a lateral approach (LLIF/XLIF). Average radiation per case was 136.4 mGy (SE 17.3) for ALIF, 108.6 mGy (16.9) for LLIF/XLIF, and 60.5 mGy (7.4) for TLIF/PLIF. We identified lateral approaches, increased BMI, minimally invasive techniques, and more caudal operative levels as significantly associated with increased radiation exposure.Conclusion: We identified several novel drivers of radiation exposure during interbody fusion procedures, including the relative importance of technique and the level at which the fusion is performed. More caudal levels of intervention and lateral based techniques had significantly greater radiation exposure.Level of Evidence: 4. [ABSTRACT FROM AUTHOR]

Interbody fusion at the caudal levels of long constructs for adult spinal deformity (ASD) surgery is used to promote fusion and secure a solid foundation for maintenance of deformity correction. We sought to evaluate long-term pseudarthrosis, rod fracture, and revision rates for TLIF performed at the base of a long construct for ASD. We reviewed 316 patients who underwent TLIF as a component of ASD surgery for medical comorbidities, surgical characteristics, and rate of unplanned reoperation for pseudarthrosis or instrumentation failure at the TLIF level. Fusion grading was assessed after revision surgery for pseudarthrosis at the TLIF level. Rate of pseudarthrosis at the TLIF level was 9.8% (31/316), and rate of rod fractures was 7.9% (25/316). The rate of revision surgery at the TLIF level was 8.9% (28/316), and surgery was performed at a mean of 20.4 ± 16 months from the index procedure. Current smoking status (odds ratio 3.34, P = 0.037) was predictive of pseudarthrosis at the TLIF site. At a mean follow-up of 43 ± 12 months after revision surgery, all patients had achieved bony union at the TLIF site. At 3-year follow-up, the rate of pseudarthrosis after TLIF performed at the base of a long fusion for ASD was 9.8%, and the rate of revision surgery to address pseudarthrosis and/or rod fracture was 8.9%. All patients were successfully treated with revision interbody fusion or posterior augmentation of the fusion mass, without need for further revision procedures at the TLIF level. [ABSTRACT FROM AUTHOR]

Background: Instrumented posterior lumbar fusion (IPLF) with and without transforaminal interbody fusion (TLIF) is a common treatment for low back pain when conservative interventions have failed. Certain patient comorbidities and lifestyle risk factors, such as obesity and smoking, are known to negatively affect these procedures. An advanced cellular bone allograft (CBA) with viable osteogenic cells (V-CBA) has demonstrated high fusion rates, but the rates for patients with severe and/or multiple comorbidities remain understudied. The purpose of this study was to assess fusion outcomes in patients undergoing IPLF/TLIF using V-CBA with baseline comorbidities and lifestyle risk factors known to negatively affect bone fusion.Methods: This was a retrospective study of de-identified data from consecutive patients at an academic medical center who underwent IPLF procedures with or without TLIF, and with V-CBA. Baseline patient and procedure characteristics were assessed. Radiological outcomes included fusion rates per the Lenke scale. Patient-reported clinical outcomes were evaluated via the Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) for back and leg pain. Operating room (OR) times and intraoperative blood loss rates were also assessed.Results: Data from 96 patients were assessed with a total of 222 levels treated overall (mean: 2.3 levels) and a median follow-up time of 16 months (range: 6 to 45 months). Successful fusion (Lenke A or B) was reported for 88 of 96 patients (91.7%) overall, including in all IPLF-only patients. Of 22 patients with diabetes in the IPLF+TLIF group, fusion was reported in 20 patients (90.9%). In IPLF+TLIF patients currently using tobacco (n = 19), fusion was reported in 16 patients (84.3%), while in those with a history of tobacco use (n = 53), fusion was observed in 48 patients (90.6%). Successful fusion was reported in all 6 patients overall with previous pseudarthrosis at the same level. Mean postoperative ODI and VAS scores were significantly reduced versus preoperative ratings.Conclusion: The results of this study suggest that V-CBA consistently yields successful fusion and significant decreases in patient-reported ODI and VAS, despite patient comorbidities and lifestyle risk factors that are known to negatively affect such bony healing. [ABSTRACT FROM AUTHOR]

Background: Clinical outcomes amongst Rheumatoid Arthritis (RA) patients have shown satisfactory results being reported after lumbar surgery. The increased adoption of the interbody fusion technique has been due to a high fusion rate and less invasive procedures. However, the radiographic outcome for RA patients after receiving interbody fusion has scarcely been addressed in the available literature.Methods: Patients receiving interbody fusion including ALIF, OLIF, and TLIF were examined for implant cage motion and fusion status at two-year follow-up. Parameters for the index correction level including ADH, PDH, WI, SL, FW, and FH were measured and compared at pre-OP, post-OP, and two-year follow-up.Results: We enrolled 64 RA patients at 104 levels (mean 64.0 years old, 85.9% female) received lumbar interbody fusion. There were substantial improvement in ADH, PDH, WI, SL, FW, and FH after surgery, with both ADH and PDH having significantly dropped at two-year follow up. The OLIF group suffered from a higher subsidence rate with no significant difference in fusion rate when compared to TLIF. The fusion rate and subsidence rate for all RA patients was 90.4 and 28.8%, respectively.Conclusions: We revealed the radiographic outcomes of lumbar interbody fusions towards symptomatic lumbar disease in RA patients with good fusion outcome despite the relative high subsidence rate amongst the OLIF group. Those responsible for intra-operative endplate management should be more cautious to avoid post-OP cage subsidence. [ABSTRACT FROM AUTHOR]

Intervertebral fusions in cases of reduced bone density are a tough challenge. From a biomechanical point of view, most current studies have focused on the range of motion or have shown test setups for single-component tests. Definitive setups for biomechanical testing of the primary stability of a 360° fusion using a screw-rod system and cage on osteoporotic spine are missing. The aim of this study was to develop a test stand to provide information about the bone-implant interface under reproducible conditions. After pretesting with artificial bone, functional spine units were tested with 360° fusion in the transforaminal lumbar interbody fusion technique. The movement sequences were conducted in flexion/extension, right and left lateral bending, and right and left axial rotation on a human model with osteopenia or osteoporosis under permanent maximum load with 7.5 N-m. During the testing of human cadavers, 4 vertebrae were fully tested and were inconspicuous even after radiological and macroscopic examination. One vertebra showed a subsidence of 2 mm, and 1 vertebra had a cage collapsed into the vertebra. This setup is suitable for biomechanical testing of cyclical continuous loads on the spine with reduced bone quality or osteoporosis. The embedding method is stable and ensures a purely single-level setup with different trajectories, especially when using the cortical bone trajectory. Optical monitoring provides a very accurate indication of cage movement, which correlates with the macroscopic and radiological results. [ABSTRACT FROM AUTHOR]

To examine the effect of static versus expandable polyether ether ketone (PEEK) cages on both clinical and radiographic outcomes. A retrospective cohort study was conducted on patients who underwent one-level transforaminal lumbar interbody fusion with either a static or expandable PEEK cage. Patient outcomes were obtained from chart review and radiographic outcomes were measured using standing, lateral radiographs. Recovery ratios and the proportion of patients achieving the minimally clinically important difference were calculated for Oswestry Disability Index (ODI), Physical Component Score-12, Mental Component Score-12, visual analogue scale for back, and visual analogue scale for leg at 1 year and compared between groups. Multivariate linear regression analysis was performed to determine the effect of cage type on the change in patient-reported outcome measures, controlling for demographic factors. A total of 240 patients (137 static, 103 expandable) were included in the final analysis. ΔPhysical Component Score-12 scores at 3 months were significantly greater for the static group (16.0 vs. 10.0, P = 0.043) compared with the expandable group. Multivariate regression demonstrated that use of an expandable cage was associated with greater improvements in ΔODI (β: –7.82, P = 0.048) at 1 year. No differences were found in the perioperative change in sagittal spinal alignment within or between groups at 1 year. Subsidence rates failed to show any statistically significant difference between the 2 groups. Transforaminal lumbar interbody fusion with an expandable PEEK cage is an independent predictor of improved ODI scores at 1 year. Our study showed no significant differences in subsidence rates or changes in sagittal spinal alignment between static and expandable PEEK cages. [ABSTRACT FROM AUTHOR]

Background Data: In double- and triple-segment lumbar disc herniation, a facet hypertrophy is more encountered specially in the same side of disc herniation with subsequent ipsilateral concave curve scoliosis. Lumbar fixation with interbody fusion surgery is a scientific and feasible option. Some authors believe that unilateral pedicle screw fixation can provide similar biomechanical support to the traditional bilateral pedicle screw fixation. Purpose: To assess the strategy of use of unilateral pedicle screw fixation with lumbar interbody fusion in surgical treatment of multilevel (2-3) symptomatic lumbar disc herniation syndromes. Study Design: Retrospective observational analytic study. Patients and Methods: Retrospective evaluation of 216 patients' files who underwent unilateral pedicular screws fixation for management of degenerative lumbar disc pathology, from July 2007 to June 2017. Only 24 patient’s files were selected with multilevel symptomatic lumbar disc prolapse who were managed by unilateral pedicular screw fixation with interbody fusion. All patients were presented with symptoms of nerve root compression. Patients' data included age, gender, levels of disc prolapse, preoperative and postoperative Visual Analogue Scale (VAS) for back and leg and Oswestry Disability Index (ODI) for functional outcome, presence of complications, and finally patients’ satisfaction according to Odom’s criteria. VAS and ODI were retrieved preoperatively, immediately postoperatively, and 6 months postoperatively. Results: They were 18 males (75%) and 6 females (25%) with a male-to-female ratio of 3:1 and age ranging 35–63 years with a mean age of 49±9.8 years. Double-level disc prolapse was recorded in 20 (83.3%) patients, while it was triple in 4 cases (16.7%). At the last follow-up, back pain VAS improved from 7.5±1.47 to 1.12±1.03, leg pain VAS from 8.7±1.04 to 0.33±0.63, and ODI from 78±8.3 to 11.08±4.6. Excellent and good Odom’s outcomes were reported in 95% of our patients. Conclusion: Our study suggests that unilateral pedicular screw fixation with interbody fusion for the management of multiple level ipsilateral lumbar disc disease could be considered as an effective and less invasive method with satisfying clinical outcomes. (2019ESJ191)

Objective: Traditionally surgery for degenerative lumbar pathology is performed under general anesthesia (GA). There have been several studies that have pointed to the negative cognitive effects of general anesthesia, and patients often frequently request alternatives. Considering this, it is advantageous to offer alternative anesthesia strategies. Studies have demonstrated spinal anesthesia (SA) being utilized successfully in decompressive lumbar surgeries; however, there is limited data evaluating use in fusion surgeries. This study presents a single institution’s experience with spinal anesthesia for minimally invasive transforaminal lumbar interbody fusions. Methods: This is a retrospective review of a prospectively collected database analyzing 67 patients undergoing SA for lumbar fusion surgeries. Outcomes including data on safety, adverse events, and efficacy of SA were reviewed. In addition, patient demographics, complications, length of stay (LOS), disposition, and OR utilization time were recorded. Comparison to a similar cohort undergoing GA the year prior was completed. Results: There was no difference in length of stay (GA 3.2d vs SA 2.9d, p = 0.104). More patients in the SA group were discharged home compared to the GA group (SA-76% vs GA-56%, p = 0.02). There were no occurrences of pneumonia (PNA) or deep vein thromboses/pulmonary embolus (DVT/PE). There was no difference in incidence of urinary tract infections (UTI) (GA-5% vs SA-1%, p = 0.27). Total OR time was decreased in the SA group(SA-164 min vs GA-200 min, p

Background Context: Previous studies have shown that oblique lateral interbody fusion (OLIF) can improve neurological symptoms via "indirect decompression." However, data are lacking in terms of its benefits when compared with conventional transforaminal lumbar interbody fusion (TLIF) and/or posterior lumbar interbody fusion (PLIF) approach, especially in patients with severe central canal stenosis.Purpose: To investigate the clinical outcome of OLIF without posterior decompression versus conventional TLIF and/or PLIF in severe lumbar stenosis diagnosed on preoperative magnetic resonance imaging.Study Design: Retrospective comparative study.Patient Sample: Fifty-one patients who underwent OLIF and 41 patients who underwent conventional TLIF and/or PLIF.Outcome Measures: Clinical outcome score by Japanese Orthopedic Association (JOA) score and radiographic outcomes (disc height and fusion rate on computed tomography scan).Materials/methods: We retrospectively reviewed 51 patients who underwent OLIF with supplemental percutaneous pedicle screws (55 levels; OLIF group) and 41 patients who underwent conventional TLIF and/or PLIF (47 levels; TPLIF group). The cross-sectional area of the thecal sac was measured preoperatively in OLIF and TPLIF groups, but postoperatively only in the OLIF group. All patients were diagnosed with severe stenosis based on Schizas classification (Grade C or D) on magnetic resonance imaging. We compared radiographic and clinical outcome scores (JOA score) between the 2 groups at 1 year of follow-up. The radiographic evaluation included the fusion status and disc height on computed tomography scan. Surgical data and perioperative complications were also investigated.Results: The baseline demographic data of the 2 groups were equivalent in preoperative diagnosis, JOA score, and disc height and/or angle. The cross-sectional area significantly increased postoperatively, which confirmed indirect decompressive effect in the OLIF group. The JOA score improved in both groups at the 1-year follow up (76.6% vs. 73.5% improvement rate in the OLIF and TPLIF groups, respectively). The fusion rate at the 1-year follow-up was higher in the OLIF group than in the TPLIF group (87.2% vs. 57.4%). The disc height restoration was also better in the OLIF group. The operative data demonstrated less estimated blood loss and operative time in the OLIF group.Conclusions: OLIF and conventional TLIF and/or PLIF demonstrated comparable short-term clinical outcomes in the treatment of severe degenerative lumbar stenosis. However, the surgical and radiographic outcomes were better in the OLIF group. Surgeons should choose an appropriate approach on a case by case basis, recognizing the perioperative complications specific to each fusion procedure. [ABSTRACT FROM AUTHOR]

Background Context: The number of performed instrumented lumbar spine surgeries and associated health-care-related costs has increased over the last decades, and will increase further in the future. With the consistent growth of health-care-related costs, cost-effectiveness of surgical techniques is of major relevance. Common indications for instrumented lumbar spine surgery are spondylolisthesis and degenerative disease. A commonly used technique is the open transforaminal lumbar interbody fusion (OTLIF). Nowadays, there is an increasing interest in the minimally invasive variation of this technique (minimally invasive transforaminal lumbar interbody fusion [MITLIF]). Currently available literature describes that MITLIF has comparable or even better clinical results compared to OTLIF. Cost-effectiveness of MITLIF and OTLIF is important considering the growing health-care related costs, although no consensus has been reached regarding the most cost-effective technique. In this systematic review, previous literature concerning costs and cost-effectiveness of OTLIF was compared with MITLIF in patients with lumbar spondylolisthesis or degenerative disease. Furthermore, methodological quality of included studies was assessed.Purpose: This study aims to evaluate the current literature on cost-effectiveness of OTLIF compared MITLIF to in patients with lumbar spondylolisthesis or degenerative disease.Study Design: This study is a systematic literature review and meta-analysis.Study Sample: Clinical studies reporting costs or cost-effectiveness for either OTLIF or MITLIF in patients with spondylolisthesis, lumbar instability, or degenerative disease were included.Outcome Measures: The following data items were evaluated: study design, study population, utility measurement tool, gained quality adjusted life years (QALYs), cost sources, health care and societal perspective costs, total costs, costs per QALY (cost-effectiveness) and incremental cost-effectiveness ratio (ICER).Methods: A systematic search was conducted using databases PubMed, CINAHL, EMBASE, Cochrane, Clinical Trials, Current Controlled Trials, ClinicalTrials.gov, NHS Centre for Review and Dissemination, Econlit and Web of Science on studies reporting OTLIF or MITLIF, spondylolisthesis or lumbar instability or degenerative disease, and costs. Relevant studies were selected and reviewed independently by two authors. For comparison, all costs were converted to American dollars with the reference year 2018.Results: After duplicate removal, a total of 892 studies were identified. Eventually, 32 studies were included. Nine studies compared OTLIF and MITLIF directly. All studies mentioned health care perspective costs. Seven studies mentioned societal perspective costs. Cost-effectiveness of OTLIF was mentioned in five studies, ranging from $47,303/QALY to $218,766/QALY. Cost-effectiveness of MITLIF was mentioned in one study, $121,105/QALY. Meta-analysis of hospital perspective costs showed a significant overall effect in favor of MITLIF, with a mean difference of $2,650. There was great heterogeneity in health care and societal perspective costs due to different in-, and exclusion factors, baseline characteristics, and calculation methods. Overall quality of studies was low.Conclusions: OTLIF and MITLIF appear to be expensive interventions when using a threshold of $50,000/QALY. Results of this study and previous literature suggest that MITLIF is more cost-effective compared to OTLIF. Considering the increase in health care costs of instrumented spine surgery, cost-effectiveness could be one of the factors in surgical decision-making. Prospective randomized studies directly comparing cost-effectiveness of OTLIF and MITLIF from both hospital and societal perspectives are needed to obtain higher level of evidence. [ABSTRACT FROM AUTHOR]

Purpose: The mean potential of lordosis restoration by transforaminal lumbar interbody fusion (TLIF) is supposed to be low in general. In contrast, clinical experience shows a wide range of segmental lordosis correction. In this study, the predictability of lordosis correction should be investigated. Methods: Prospectively collected register data were analyzed retrospectively. One hundred twenty-one consecutive patients (2014–2016) operated with single-level TLIF L4/5 (10°-lordotic cage). Segmental lordosis (L4/5) and overall lordosis (L1–S1) were measured on lumbar X-rays: preoperatively (pre), after 3–5 days (post), at least 24 months postoperatively (2yFU). Outcome and satisfaction of patients were assessed. Parameters were statistically compared by students t-tests (a = 0.05). In addition, predictors of correction were analyzed. Results: Age was 60.7 years, rate of 2yFU 41.3% (n = 50). Lordosis correction L4/5 was statistically significant with (post–pre) 4.9 ± 5.7° (p < 0.01), but not significant for L1–S1 (post–pre) 1.6 ± 8.0° (p = 0.3). A strong–moderate correlation of lordosis L4/5 (pre) and lordosis correction L4/5 (post–pre) was shown (r = − 0.6, p < 0,01). In a rising range of preoperative lordosis L4/5 from 15–30° the likelihood of lordosis loss increased. In 2yFU correction, L4/5 was significant with (post–pre) 5.4 ± 5.4° (p < 0.01), no significant long-term change (2yFU-postop) − 1.5 ± 4.9° (p = 0.2). No correlation (r = − 0.1) of correction and ODI. VAS-B improved by means of 2.9, VAS-L by 2.5, ODI by 19.1% (pre vs. 2yFU), each statistically significant (p < 0.01). Conclusion: Significant segmental relordosation can be performed by TLIF L4/5. The potential of correction strongly correlates with preoperative lordosis. Therefore, TLIF technique should be considered carefully in cases with a preoperative segmental lordosis of more than 15° and additional need of lordosation. [ABSTRACT FROM AUTHOR]

Purpose: Transforaminal lumbar interbody fusion (TLIF) is a widely accepted surgical procedure for degenerative disk disease. While numerous studies have analyzed complication rates and risk factors this study investigates the extent to which complications after TLIF spondylodesis alter the clinical outcome regarding pain and physical function. Methods: A prospective clinical two-center study was conducted, including 157 patients undergoing TLIF spondylodesis with 12-month follow-up (FU). Our study classified complications into three subgroups: none (I), minor (IIa), and major complications (IIb). Complications were considered "major" if revision surgery was required or new permanent physical impairment ensued. Clinical outcome was assessed using visual analog scales for back (VAS-B) and leg pain (VAS-L), and Oswestry Disability Index (ODI). Results: Thirty-nine of 157 patients (24.8%) had at least one complication during follow-up. At FU, significant improvement was seen for group I (n = 118) in VAS-B (–50%), VAS-L (–54%), and ODI (–48%) and for group IIa (n = 27) in VAS-B (–40%), VAS-L (–64%), and ODI (–47%). In group IIb (n = 12), VAS-B (–22%, P = 0.089) and ODI (–33%, P = 0.056) improved not significantly, while VAS-L dropped significantly less (–32%, P = 0.013) compared to both other groups. Conclusion: Our results suggest that major complications with need of revision surgery after TLIF spondylodesis lead to a significantly worse clinical outcome (VAS-B, VAS-L, and ODI) compared to no or minor complications. It is therefore vitally important to raise the surgeon´s awareness of consequences of major complications, and the topic should be given high priority in clinical work. [ABSTRACT FROM AUTHOR]

Introduction: The minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) procedure gains access to the disc space while avoiding major structures such as the great vessels anteriorly, spinal cord posteriorly, and lumbosacral plexus bilaterally. MIS TLIF procedures may be limited in capacity for the implanting of large interbody spacers due to the relatively small access window of Kambin’s triangle. The current study examines patients treated with an articulating expandable interbody spacer designed to address the limitations of the MIS TLIF procedure. Methods: This study is a retrospective chart review of clinical and radiographic data from 46 patients at a single site. Radiographs were measured to determine preoperative and postoperative disc height, neuroforaminal height, intervertebral angle and lumbar lordosis. Results: Anterior disc height increased significantly from 10.0 ± 3.4 mm at preoperative to 14.1 ± 2.3 mm at 3-month follow-up. Posterior disc height increased significantly (p

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. [ABSTRACT FROM AUTHOR]

Background: Minimally invasive approaches for lumbar fusion are aimed at reducing soft tissue injury in order to minimize surgical morbidity and facilitate recovery. Method: Applied to lumbar fusion, such an approach is described as a mini-open transforaminal lumbar interbody fusion (TLIF). Important anatomical landmarks are reviewed. Indications, advantages, and limitations are discussed, and a step-by-step description of the procedure is presented. Results: Decompression, fixation, and bone grafting can be achieved efficiently through this approach with lesser blood loss, shorter hospital stay, reduced rate of general complications, and infections as well as a lower readmission rate. Conclusion: The mini-open TLIF technique, as presented here, is a safe and efficient procedure to achieve lumbar fusion with a reduced rate of complications related to surgery. [ABSTRACT FROM AUTHOR]

Background Context: Expandable cages (EXP) are being more frequently utilized in transforaminal lumbar interbody fusions (TLIF). EXP were designed to reduce complications related to neurological retraction, enable better lordosis restoration, and improve ease of insertion, particularly in the advent of minimally invasive surgical (MIS) techniques, however they are exponentially more expensive than the nonexpandable (NE) alternative.Purpose: To investigate the clinical results of expandable cages in single level TLIF.Study Design/setting: Retrospective review at a single institution.Patient Sample: Two hundred and fifty-two single level TLIFs from 2012 to 2018 were included.Outcome Measures: Clinical characteristics, perioperative and neurologic complication rates, and radiographic measures.Methods: Patients ≥18 years of age who underwent single level TLIF with minimum 1 year follow-up were included.Outcome Measures: clinical characteristics, perioperative and neurologic complications. Radiographic analysis included pelvic incidence-lumbar lordosis (PI-LL) mismatch, segmental lumbar lordosis (LL) mismatch, disc height restoration, and subsidence ≥2 mm. Statistical analysis included independent t tests and chi-square analysis. For nonparametric variables, Mann-Whitney U test and Spearman partial correlation were utilized. Multivariate regression was performed to assess relationships between surgical variables and recorded outcomes. For univariate analysis significance was set at p<.05. Due to the multiple comparisons being made, significance for regressions was set at p<.025 utilizing Bonferroni correction.Results: Two hundred and fifty-two TLIFs between 2012 and 2018 were included, with 152 NE (54.6% female, mean age 59.28±14.19, mean body mass index (BMI) 28.65±5.38, mean Charlson Comorbidity Index (CCI) 2.20±1.89) and 100 EXP (48% female, mean age 58.81±11.70, mean BMI 28.68±6.06, mean CCI 1.99±1.66) with no significant differences in demographics. Patients instrumented with EXP cages had a shorter length of stay (3.11±2.06 days EXP vs. 4.01±2.64 days NE; Z=-4.189, p<.001) and a lower estimated blood loss (201.31±189.41 mL EXP vs. 377.82±364.06 mL NE; Z=-6.449, p<.001). There were significantly more MIS-TLIF cases and bone morphogenic protein (BMP) use in the EXP group (88% MIS, p<.001 and 60% BMP, p<.001) as illustrated in Table 1. There were no significant differences between the EXP and NE groups in rates of radiculitis and neuropraxia. In multivariate regression analysis, EXP were not associated with a difference in perioperative outcomes or complications. Radiographic analyses demonstrated that the EXP group had a lower PI-LL mismatch than the NE cage group at baseline (3.75±13.81° EXP vs. 12.75±15.81° NE; p=.001) and at 1 year follow-up (3.81±12.84° EXP vs. 8.23±12.73° NE; p=.046), but change in regional and segmental alignment was not significantly different between groups. Multivariate regression demonstrated that EXP use was a risk factor for intraoperative subsidence (2.729[1.185-6.281]; p=.018).Conclusions: Once technique was controlled for, TLIFs utilizing EXP do not have significantly improved neurologic or radiographic outcomes compared with NE. EXP increase risk of intraoperative subsidence. These results question the value of the EXP given the higher cost. [ABSTRACT FROM AUTHOR]

Background: A wide variety of materials are used for lumbar interbody fusion, but there is no unified consensus on the superiority of one material over another. The aim of this systematic review and network meta-analysis (NMA) is to compare and rank the various TLIF interbody materials based on fusion rates., Methods: We queried PubMed, EMBASE and Scopus from inception until August 2023, in which 2135 studies were identified. Inclusion criteria were applied based on the PRISMA guidelines. The fusion assessment employed the Bridwell's criteria with a length of follow-up of at least 12 months. The NMA was conducted to compare multiple approaches from multiple studies using the frequentist framework with STATA16., Results: In total, 13 TLIF studies involving 1919 patients with 1981 lumbar interbody levels fulfilled our eligibility criteria. Seven different cage materials were utilized: polyetheretherketone (PEEK, as the reference), allograft, autograft, PEEK with titanium coating (TiPEEK), titanium, carbon/carbon fiber reinforced polymer (CFRP) and 3D-printed titanium. The average patient age was 60.9 ( SD  = 7.5) years old. When compared to PEEK, the other six materials did not have a significantly different rate of lumbar fusion. However, the SUCRA number of the 3D-printed titanium, TiPEEK, Ti, allograft, autograft, CFRP, and PEEK were 0.8, 0.6, 0.5, 0.5, 0.4, 0.4, and 0.3 consecutively., Conclusions: Based on a network meta-analysis within the confines of our clinical study, 3D-printed titanium interbody cage may promote the highest success rate of fusion while PEEK may be the material with the least success rate of fusion in TLIF., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)

Objective: Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been demonstrated to achieve the highest rates of arthrodesis in multilevel lumbar fusion but is also associated with possible perioperative morbidity. A novel allograft (OSTEOAMP) is a differentiated allograft that retains growth factors supporting bone healing. The authors sought to compare the clinical and radiographic outcomes of rhBMP-2 and the novel allograft in lumbar interbody arthrodesis to determine if the latter may be a safer and equally effective alternative to rhBMP-2 for single- and multilevel posterior or transforaminal lumbar interbody fusion (PLIF or TLIF)., Methods: Patients who underwent single- or multilevel TLIF or PLIF using either OSTEOAMP or rhBMP-2 at the authors' institution over a 2-year period were prospectively followed for 12 months. Healthcare utilization, safety measures, patient satisfaction, physical disability (measured on the Oswestry Disability Index [ODI]), back and leg pain (on the numeric rating scale [NRS]), quality of life (on the EQ-5D scale), and return to work (RTW) were prospectively recorded. For purposes of this study, this consecutive series was retrospectively analyzed and pseudarthrosis rates were assessed at 2 years of follow-up. All patients (100%) had both 12-month patient-reported outcome follow-up and 24-month clinical and radiographic follow-up., Results: One thousand one hundred fifty-four patients (654 treated with OSTEOAMP, 500 with rhBMP-2) were prospectively enrolled in the institutional registry. After propensity score matching, there were no significant baseline differences between 330 novel allograft and 330 rhBMP-2 cases. Perioperative morbidity and 90-day hospital readmission (3.3% vs 2.4%, p = 0.485) did not significantly differ between the novel allograft and the rhBMP-2 cases. At the 2-year follow-up, symptomatic pseudarthrosis requiring revision surgery occurred in 8 patients (2.4%) with OSTEOAMP and 6 patients (1.8%) with rhBMP-2 (p = 0.589). The overall fusion rate at 2 years was similar between groups (p = 0.213). Both groups showed significant and equivalent improvement in patient-reported outcome measures (PROMs) from baseline to 12-month follow-up, with no significant difference in 1-year mean NRS leg pain score (2.5 vs 2.7), ODI (25 vs 26), quality-adjusted life years (0.73 vs 0.73), satisfaction (83% vs 80%), or RTW (6.6 vs 7 weeks)., Conclusions: In the authors' institutional experience, OSTEOAMP is a clinically viable substitute for rhBMP-2 for single- and multilevel lumbar fusion. This novel allograft provides clinically effective arthrodesis and improvements in PROMs comparable to rhBMP-2 with a similar safety profile. Additional indications and outcome assessment in longitudinal studies are needed to further characterize this allogeneic graft.

Background: Robotic-assisted, endoscopic transforaminal lumbar interbody fusion (RE-TLIF) is a promising, minimally invasive surgical option for degenerative lumbar spondylosis/spondylolisthesis; however, outcomes data and efficacy are limited, especially in multilevel disease. Here, we present the first reported series of patients that underwent either single or multilevel RE-TLIF., Methods: A retrospective review was performed on 23 consecutive patients who underwent a single level or multilevel RE-TLIF by a single surgeon. Variables included demographics, perioperative results, pain scores, and functional outcome scores., Results: Eighteen patients (78.3 %) underwent single level RE-TLIF and 5 patients (21.7 %) underwent multilevel RE-TLIF. The median reduction of visual analog scale (VAS) for low back pain (LBP) of all subjects was 6 (IQR = 4.5, 6.5) with no significant difference between single level and multilevel RE-TLIF ( p  = 0.565). The median reduction of VAS for leg pain of all subjects 7 (IQR = 6, 8) with no significant difference between single level and multilevel RE-TLIF ( p  = 0.702). Median blood loss was 25 cc (IQR = 25, 25) and 50 cc (IQR = 25, 100) for single and multilevel RE-TLIF, respectively ( p  = 0.025), whereas median length of stay was 1 (IQR = 1, 1; mean = 1.0 ± 00.18) days and 1 (IQR = 1, 2; mean = 1.4 ± 00.54) days, respectively ( p  = 0.042). One major complication was observed requiring reoperation for demineralized bone matrix migration resulting in an L5 radiculopathy., Conclusions: Single and multi-level RE-TLIF appears to be a safe and efficacious approach with comparable outcomes to open and other minimally invasive approaches. Additionally, we observed favorable accuracy in robot-assisted pedicle screw, endoscope, and interbody device placement., Competing Interests: None., (© 2024 The Authors.)