Associations of overweight/obesity with patient-reported outcome measures after oblique lumbar interbody fusion.

Background: Oblique lateral interbody fusion (OLIF) combined with transpedicular screw fixation has been practiced for degenerative spinal diseases of elderly patients for years. However, overweight patients have been shown to have longer operative times and more complications from surgery. The effect on clinical outcome is still uncertified. The objective of this study was to determine is overweight a risk factor to clinical outcome of OLIF combined with transpedicular screw fixation technique. Material and methods: A retrospective study in patients submitted to OLIF combined with transpedicular screw fixation from January 2018 to August 2019 was conducted. VAS score, ODI score and EQ5D were measured before the operation and one year after the operation. Results: A total of 111 patients were included with 48 patients in the non-obese group and 55 patients in the overweight/obese group. There was no significant difference between the two groups in gender, age, smoking history, hypertension, chronic kidney disease and diabetes mellitus. Overweight/obese group has higher BMI (28.4 vs. 22.7, p < 0.001) than non-obese group. There was no difference between the two groups in pre-operative VAS score, ODI score and EQ5D score. However, the healthy weight group improved much more than the overweight score in VAS score, ODI score and EQ5D score. Conclusion: The overweight/obese patient group had clinical outcomes worse than the non-obese group in terms of pain relief and life functions.

Transforaminal lumbar interbody fusion subsidence: computed tomography analysis of incidence, associated risk factors, and impact on outcomes.

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.

What is the early fate of adjacent segmental lordosis compensation at L3-4 and L5-S1 following a lateral versus transforaminal lumbar Interbody Fusion at L4-5?

INTRODUCTION: Degenerative spondylolisthesis causes translational and angular malalignment, resulting in a loss of segmental lordosis. This leads to compensatory adjustments in adjacent levels to maintain balance. Lateral lumbar interbody fusion (LLIF) and transforaminal lumbar interbody fusion (TLIF) are common techniques at L4-5. This study compares compensatory changes at adjacent L3-4 and L5-S1 levels six months post LLIF versus TLIF for grade 1 degenerative spondylolisthesis at L4-5. METHODS: A retrospective study included patients undergoing L4-5 LLIF or TLIF with posterior pedicle screw instrumentation (no posterior osteotomy) for grade 1 spondylolisthesis. Pre-op and 6-month post-op radiographs measured segmental lordosis (L3-L4, L4-L5, L5-S1), lumbar lordosis (LL), and pelvic incidence (PI), along with PI-LL mismatch. Multiple regressions were used for hypothesis testing. RESULTS: 113 patients (61 LLIF, 52 TLIF) were studied. TLIF showed less change in L4-5 lordosis (mean = 1.04°, SD = 4.34) compared to LLIF (mean = 4.99°, SD = 5.53) (p = 0.003). L4-5 angle changes didn't correlate with L3-4 changes, and no disparity between LLIF and TLIF was found (all p > 0.16). In LLIF, greater L4-5 lordosis change predicted reduced compensatory L5-S1 lordosis (p = 0.04), while no significant relationship was observed in TLIF patients (p = 0.12). CONCLUSION: LLIF at L4-5 increases lordosis at the operated level, with compensatory decrease at L5-S1 but not L3-4. This reciprocal loss at adjacent L5-S1 may explain inconsistent improvement in lumbar lordosis (PI-LL) post L4-5 fusion.

Full-Endoscopic Posterior Lumbar Interbody Fusion: A Review and Technical Note.

Remarkable innovations in spinal endoscopic surgery have broadened its applications over the past 20 years. Full-endoscopic fusions have been widely reported, and several full-endoscopic approaches for interbody fusion have been published. In general, full-endoscopic lumbar interbody fusion (LIF) is called Endo-LIF, and facet-preserving endo-LIF through the transforaminal route is called trans-Kambin's triangle LIF, which has a relatively longer history than facet-sacrificing endo-LIF via the posterolateral route. Both approaches can reduce intraoperative and postoperative bleeding. However, there is a higher risk of subsidence and exit nerve root injury. There is no direct decompression in either of the interbody fusions, and additional decompression is required if there is severe lumbar bony canal stenosis. However, the posterior interlaminar approach, which is a well-known standard in full-endoscopic spine surgery, has rarely been applied in the field of endoscopic lumbar fusion surgery. Full-endoscopic posterior LIF (FE-PLIF) via an interlaminar approach can accomplish direct decompression of bony canal stenosis and safe interbody fusion. FE-PLIF via an interlaminar approach demonstrated a longer operation time, less blood loss, and shorter hospitalization duration than minimally invasive transforaminal LIF. FE-PLIF, which can accomplish direct decompression for bony spinal canal stenosis, is superior to other Endo-LIFs. However, FE-PLIF requires technical dexterity to improve efficiency and reduce technical complexity.

Clinical Outcomes of the Transforaminal Lumbar Interbody Fusion Technique Among Patients With Low Back Pain Showing Type 1 Modic Changes on MRI.

Introduction The unilateral transforaminal lumbar interbody fusion (TLIF) signifies a different surgical method, circumventing both the anterior method and the method via the spinal canal. Due to the shortage of literature available for clinical outcomes and consequences post-TLIF, we undertook the current study to assess the TLIF technique's clinical outcomes among patients with low back pain showing type 1 Modic changes on MRI. Material and methods A cross-sectional study was conducted between January 2019 and March 2021. All patients included in the study had Modic type 1 change and disabling low back pain as the main complaint and/or leg pain. Data were collected on age, body mass index (BMI), gender, and other risk factors like diabetes mellitus, steroid use, and smoking. Pain intensity was evaluated using a visual analog scale (VAS) before and after surgery. A radiographic evaluation was also performed. Pre and post-operative pain scores and differences in disc height were assessed using the Wilcoxon rank sum test. A p-value of less than 0.05 was considered significant. Results The mean length of stay in the hospital was 4.3±1.61. The mean pre-operative lower back pain score was 8.78±0.79. The mean post-operative score was substantially lowered to 0.83±0.7. There was a significant difference between pre- and post-operative lumbar pain (p-value < 0.001). There was a significant increase in mean disc height from pre-operative (7.14 mm) to post-operative (11.02 mm) and also at one year (10.21 mm) with a p-value of <0.001. Of the patients, 82.14% did not have any complications, and 3.57% each had either delayed wound healing without any infection or transient post-operative radiculopathy that improved in six weeks. Conclusion TLIF procedure can be considered safe to provide anterior and posterior column support by adopting a unilateral posterior approach. The outcomes were favorable in terms of no prolonged length of stay, less blood loss, no mortality, reduction in the severity of pain, and improvement in disc height. However, the appropriate selection of patients for this technique is pivotal for the success of the procedure.

A comparison of ultrasound volume navigation, O-arm navigation, and X-ray guidance for screw placement in minimally invasive transforaminal lumbar interbody fusion: a randomized controlled trial.

OBJECTIVE: To compare the differences between Ultrasound Volume Navigation (UVN), O-arm Navigation, and conventional X-ray fluoroscopy-guided screw placement in Minimally Invasive Transforaminal Lumbar Interbody Fusion (MIS-TLIF) surgeries. METHODS: A total of 90 patients who underwent MIS-TLIF due to lumbar disc herniation from January 2022 to January 2023 were randomly assigned to the UVN group, O-arm group, and X-ray group. UVN, O-arm navigation, and X-ray guidance were used for screw placement in the respective groups, while the remaining surgical procedures followed routine MIS-TLIF protocols. Intraoperative data including average single screw placement time, total radiation dose, and average effective radiation dose per screw were recorded and calculated. On the 10th day after surgery, postoperative X-ray and CT examinations were conducted to assess screw placement accuracy and facet joint violation. RESULTS: There were no significant differences in general characteristics among the three groups, ensuring comparability. Firstly, the average single screw placement time in the O-arm group was significantly shorter than that in the UVN group and X-ray group (P<0.05). Secondly, in terms of total radiation dose during surgery, for single-level MIS-TLIF, the O-arm group had a significantly higher radiation dose compared to the UVN group and X-ray group (P<0.05). However, for multi-level MIS-TLIF, the X-ray group had a significantly higher radiation dose than the O-arm group and UVN group (P<0.05). In terms of average single screw radiation dose, the O-arm group and X-ray group were similar (P>0.05), while the UVN group was significantly lower than the other two groups (P<0.05). Furthermore, no significant differences were found in screw placement assessment grades among the three groups (P>0.05). However, in terms of facet joint violation rate, the UVN group (10.3%) and O-arm group (10.7%) showed no significant difference (P>0.05), while the X-ray group (26.7%) was significantly higher than both groups (P<0.05). Moreover, in the UVN group, there were significant correlations between average single screw placement time and placement grade with BMI index (r = 0.637, P<0.05; r = 0.504, P<0.05), while no similar significant correlations were found in the O-arm and X-ray groups. CONCLUSION: UVN-guided screw placement in MIS-TLIF surgeries demonstrates comparable efficiency, visualization, and accuracy to O-arm navigation, while significantly reducing radiation exposure compared to both O-arm navigation and X-ray guidance. However, UVN may be influenced by factors like obesity, limiting its application.

Percutaneous lumbar interbody fusion results in less perioperative opioid usage compared to minimally invasive transforaminal lumbar interbody fusion: a single institution, multi-surgeon retrospective study.

Background: Ultra-minimally invasive percutaneous lumbar interbody fusion (percLIF) has been demonstrated to further minimize tissue trauma and has been associated with improved clinical outcomes including decreased blood loss, post-operative pain and length of stay when compared to minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) surgery. A single-institution retrospective study was conducted to investigate whether 1-level percLIF is associated with decreased narcotic consumption compared to 1-level MIS-TLIF in the first 24-hour following surgery. Methods: A retrospective study of patients undergoing either single-level percLIF or MIS-TLIF from January 2018 to December 2021. Opioid consumption in the 24-hour following surgery was converted into total morphine milligram equivalents (MME). The primary outcome used univariate and multivariate regression analysis to compare MME consumption between the MIS-TLIF and percLIF groups. Secondary outcome variables included, estimated blood loss, total intraoperative MME, MME at discharge, MME at 30 days post-op, exiting nerve root injury, post-anesthesia care unit (PACU) visual analogue scale (VAS) score at handoff, time to first ambulation, distance ambulated post-operative day one and hospital length of stay. Results: A total of 51 patients (21 percLIF vs. 30 MIS-TLIF) were included in the study. Univariate regression analysis revealed that on average patients who underwent percLIF had a 24-hour postoperative MME -50.8 mg (95% CI: -91.6, -10) lower than those who had MIS-TLIF (P=0.02). On multivariable analysis, after adjusting for sex and age, 24-hour postoperative MME closely failed to meet statistical significance (P=0.06) with an average of -40.8 mg (95% CI: -83.2, 1.6) MME in percLIF patients compared to MIS-TLIF. There was no statistically significant difference in MME between MIS-TLIF and percLIF at the time of discharge and at 30 days post-op. Conclusions: In the setting of the current opioid epidemic in the United States and increased numbers of patients undergoing lumbar interbody fusion, spine surgeons must continue to do their part helping reduce the need for opioid prescriptions for postoperative pain management. New "ultra-MIS" techniques such as percLIF allow surgeons to further decrease tissue trauma, which should lead to reduced need for post-operative narcotic requirements.

Adhesive surface electrodes versus needle-based neuromonitoring in lumbar spinal surgery.

Background: The relative safety and more widespread utility of an adhesive surface electrode-based neuromonitoring (ABM) system may reduce the time and cost of traditional needle-based neuromonitoring (NBM). Methods: This retrospective cohort review included one- and two-level transforaminal lumbar interbody fusion procedures (2019-2023). The primary variables studied included were time (in minutes) from patient entry into the operating room (OR) to incision, time from patient entry into the OR to closure, and time from incision to closure. Univariate and bivariate analyses were performed to compare the outcomes between the ABM (31 patients) and NBM (51 patients) modalities. Results: We found no significant differences in the time from patient entry into the OR to incision (ABM: 71.8, NBM: 70.3, P = 0.70), time from patient entry into the OR to closure (ABM: 284.2, NBM: 301.7, P = 0.27), or time from incision to closure (ABM: 212.4, NBM: 231.4, P = 0.17) between the two groups. Further, no patients from either group required reoperation for mal-positioned instrumentation, and none sustained a new postoperative neurological deficit. The ABM approach did, however, allow for a reduction in neurophysiologist-workforce and neuromonitoring costs. Conclusion: The introduction of the ABM system did not lower surgical time but did demonstrate similar efficacy and clinical outcomes, with reduced clinical invasiveness, neurophysiologist-associated workforce, and overall neuromonitoring cost compared to NBM.

Comparison of robot-assisted versus fluoroscopy-guided transforaminal lumbar interbody fusion (TLIF) for lumbar degenerative diseases: a systematic review and meta-analysis of randomized controlled trails and cohort studies.

BACKGROUND: As an emerging technology in robot-assisted (RA) surgery, the potential benefits of its application in transforaminal lumbar interbody fusion (TLIF) lack substantial support from current evidence. OBJECTIVE: We aimed to investigate whether the RA TLIF is superior to FG TLIF in the treatment of lumbar degenerative disease. METHODS: We systematically reviewed studies comparing RA versus FG TLIF for lumbar degenerative diseases through July 2022 by searching PubMed, Embase, Web of Science, CINAHL (EBSCO), Chinese National Knowledge Infrastructure (CNKI), WanFang, VIP, and the Cochrane Library, as well as the references of published review articles. Both cohort studies (CSs) and randomized controlled trials (RCTs) were included. Evaluation criteria included the accuracy of percutaneous pedicle screw placement, proximal facet joint violation (FJV), radiation exposure, duration of surgery, estimated blood loss (EBL), and surgical revision. Methodological quality was assessed using the Cochrane risk of bias and ROBINS-I Tool. Random-effects models were used, and the standardized mean difference (SMD) was employed as the effect measure. We conducted subgroup analyses based on surgical type, the specific robot system used, and the study design. Two investigators independently screened abstracts and full-text articles, and the certainty of evidence was graded using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. RESULTS: Our search identified 539 articles, of which 21 met the inclusion criteria for quantitative analysis. Meta-analysis revealed that RA had 1.03-folds higher "clinically acceptable" accuracy than FG (RR: 1.0382, 95% CI: 1.0273-1.0493). And RA had 1.12-folds higher "perfect" accuracy than FG group (RR: 1.1167, 95% CI: 1.0726-1.1626). In the case of proximal FJV, our results indicate a 74% reduction in occurrences for patients undergoing RA pedicle screw placement compared to those in the FG group (RR: 0.2606, 95%CI: 0.2063- 0.3293). Seventeen CSs and two RCTs reported the duration of time. The results of CSs suggest that there is no significant difference between RA and FG group (SMD: 0.1111, 95%CI: -0.391-0.6131), but the results of RCTs suggest that the patients who underwent RA-TLIF need more surgery time than FG (SMD: 3.7213, 95%CI: 3.0756-4.3669). Sixteen CSs and two RCTs reported the EBL. The results suggest that the patients who underwent RA pedicle screw placement had fewer EBL than FG group (CSs: SMD: -1.9151, 95%CI: -3.1265-0.7036, RCTs: SMD: -5.9010, 95%CI: -8.7238-3.0782). For radiation exposure, the results of CSs suggest that there is no significant difference in radiation time between RA and FG group (SMD: -0.5256, 95%CI: -1.4357-0.3845), but the patients who underwent RA pedicle screw placement had fewer radiation dose than FG group (SMD: -2.2682, 95%CI: -3.1953-1.3411). And four CSs and one RCT reported the number of revision case. The results of CSs suggest that there is no significant difference in the number of revision case between RA and FG group (RR: 0.4087,95% CI 0.1592-1.0495). Our findings are limited by the residual heterogeneity of the included studies, which may limit the interpretation of the results. CONCLUSION: In TLIF, RA technology exhibits enhanced precision in pedicle screw placement when compared to FG methods. This accuracy contributes to advantages such as the protection of adjacent facet joints and reductions in intraoperative radiation dosage and blood loss. However, the longer preoperative preparation time associated with RA procedures results in comparable surgical duration and radiation time to FG techniques. Presently, FG screw placement remains the predominant approach, with clinical surgeons possessing greater proficiency in its application. Consequently, the integration of RA into TLIF surgery may not be considered the optimal choice. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42023441600.

[Oblique Lumbar Interbody Fusion Combined With 4-Screw Fixation for Treating Two-Level Degenerative Lumbar Diseases:A Finite Element Study].

Objective To demonstrate the feasibility of oblique lumbar interbody fusion (OLIF) combined with 4-screw fixation for treating two-level lumbar degenerative diseases.Methods An intact finite element model of L3-S1 (M0) was constructed and validated.Then,we constructed the M1 model by simulating OLIF surgery at L3/4 and L4/5 segments on the M0 model.By attachment of posterior 4-screw or 6-screw fixation to the M1 model,three 4-screw fixation models (M2-M4) and one 6-screw fixation model (M5) were established.The segmental and overall range of motion (ROM) and the peak von Mises stresses of superior endplate,cage,and posterior screw-rod were investigated under each implanted condition.Results Under the motion modes of forward flexion,backward extension,bilateral (left and right) flexion,and left and right rotation,the L3/4 ROM of M2 model and L4/5 ROM of M3 model increased,while the L3/4 and L4/5 ROM of M4 and M5 models significantly decreased compared with those of M1 model.Under all motion modes,the L4 superior endplate in M2 model and the L5 superior endplate in M3 model showed the maximum peak von Mises stress,and the peak von Mises stresses of L4 and L5 superior endplates in M4 and M5 models were close.The L3/4 cage in M2 model and the L4/5 cage in M3 model showcased the largest peak von Mises stress,and the peak von Mises stresses of cages in M4 and M5 models were close.The peak stresses of internal fixation in M2-M5 models were close.Conclusion Four-screw fixation can replace 6-screw fixation in the OLIF surgery for treating two-level degenerative lumbar diseases.

Transdural retrieval of retropulsed transforaminal lumbar interbody fusion cages.

Transforaminal lumbar interbody fusions (TLIFs) are performed for various lumbar spine pathologies. Posterior migration of an interbody cage is a complication that may result in neurologic injury and require reoperation. Sparse information exists regarding the safety and efficacy of a transdural approach for cage retrieval. We describe a surgical technique, in which centrally retropulsed cages were safely retrieved transdurally. A patient with prior L3-S1 posterior lumbar fusion and L4-S1 TLIFs presented with radiculopathy and weakness in dorsiflexion. Imaging revealed posterior central migration of TLIF cages causing compression of the traversing L5 nerve root. Cages were removed transdurally; the correction was performed with an all-posterior T10-pelvis fusion. Aside from temporary weakness in right-sided dorsiflexion, the patient experienced complete resolution in their radiculopathy and strength returned to its presurgical state by 3 months. The transdural approach for interbody removal can be safely performed and should be a tool in the spine surgeon's armamentarium.

A comparative cohort study of surgical approaches for adult spinal deformity at a minimum 2-year follow-up.

STUDY DESIGN: This study was a retrospective multi-center comparative cohort study. MATERIALS AND METHODS: A retrospective institutional database of operative adult spinal deformity patients was utilized. All fusions > 5 vertebral levels and including the sacrum/pelvis were eligible for inclusion. Revisions, 3 column osteotomies, and patients with < 2-year clinical follow-up were excluded. Patients were separated into 3 groups based on surgical approach: 1) posterior spinal fusion without interbody (PSF), 2) PSF with interbody (PSF-IB), and 3) anteroposterior (AP) fusion (anterior lumbar interbody fusion or lateral lumbar interbody fusion with posterior screw fixation). Intraoperative, radiographic, and clinical outcomes, as well as complications, were compared between groups with ANOVA and χ2 tests. RESULTS: One-hundred and thirty-eight patients were included for study (PSF, n = 37; PSF-IB, n = 44; AP, n = 57). Intraoperatively, estimated blood loss was similar between groups (p = 0.171). However, the AP group had longer operative times (547.5 min) compared to PSF (385.1) and PSF-IB (370.7) (p < 0.001). Additionally, fusion length was shorter in PSF-IB (11.4) compared to AP (13.6) and PSF (12.9) (p = 0.004). There were no differences between the groups in terms of change in alignment from preoperative to 2 years postoperative. There were no differences in clinical outcomes. While postoperative complications were largely similar between groups, operative complications were higher in the AP group (31.6%) compared to the PSF (5.4%) and PSF-IB (9.1) groups (p < 0.001). CONCLUSION: While there were differences in intraoperative outcomes (operative time and fusion length), there were no differences in postoperative clinical or radiographic outcomes. AP fusion was associated with a higher rate of operative complications.

Oblique Lumbar Interbody Fusion Combined with Posterior Percutaneous Pedicle Screw Internal Fixation: Does Variability in Cage Position Influence Clinical Outcomes?

OBJECTIVE: The study investigates how cage positions in oblique lumbar interbody fusion (OLIF) combined with posterior percutaneous pedicle screw internal fixation (PPSF) affect lumbar canal and foraminal decompression and postoperative outcomes, providing guidance for optimal placement and efficacy assessment. METHODS: This investigation assesses radiological outcomes and follow-up data in relation to cage position variability among 80 patients who underwent L4/5 single-segment OLIF+PPSF from 2018-2022. RESULTS: In the study, involving 80 participants, the combination of OLIF and PPSF significantly improved lower back and leg symptoms in patients, leading to positive clinical outcomes during follow-up. The intervertebral DH increased from an average of 8.10 ± 2.79 mm before surgery to 11.75 ± 2.14 mm after surgery (P < 0.001). Additionally, this surgical technique notably increased the FH (P < 0.001) and expanded the DCSA from 68.81 ± 53.89 mmˆ2 before surgery to 102.91 ± 60.46 mmˆ2 after surgery (P < 0.001). Linear results suggest that changes in the position of the cage do not affect spinal imaging parameters. There is no significant difference in the correction of spinal parameters or prognosis whether the cage is back, middle, ahead. CONCLUSION: In the OLIF+PPSF procedure, strict requirements for cage position are not necessary to achieve predetermined spinal biomechanical parameters. The practice of repeated fluoroscopy to adjust cage position post-implantation does not provide added clinical benefits to the patient.

Are the facet joint parameters risk factors for cage subsidence after TLIF in patients with lumbar degenerative spondylolisthesis?

PURPOSE: To assess whether preoperative facet joint parameters in patients with degenerative lumbar spondylolisthesis (DS) are risk factors for cage subsidence (CS) following transforaminal lumbar interbody fusion (TLIF). METHODS: We enrolled 112 patients with L4-5 DS who underwent TLIF and were followed up for > 1 year. Preoperative demographic characteristics, functional areas of paraspinal muscles and psoas major muscles (PS), total functional area relative to vertebral body area, functional cross-sectional area (FCSA) of PS and lumbar spine extensor muscles, normalized FCSA of PS to the vertebral body area (FCSA/VBA), lumbar indentation value, facet joint orientation, facet joint tropism (FT), cross-sectional area of the superior articular process (SAPA), intervertebral height index, vertebral Hounsfield unit (HU) value, lordosis distribution index, t-scores, sagittal plane parameters, visual analog scale (VAS) for low back pain, VAS for leg pain, Oswestry disability index, global alignment and proportion score and European quality of life-5 dimensions (EQ-5D) were assessed. RESULTS: Postoperative CS showed significant correlations with preoperative FO(L3-4), FT (L3 and L5), SAPA(L3-5), L5-HU, FCSA/VBA(L3-4), Pre- T-score, post-6-month VAS for back pain and EQ-5D scores among other factors. According to ROC curve analysis, the optimal decision points for FO(L3-4), L3-SAPA, FCSA/VBA(L3-4), L5-HU, and Pre- T-score were 35.88°, 43.76°,114.93, 1.73, 1.55, 136, and - 2.49. CONCLUSIONS: This study identified preoperative FO, SAPA, preoperative CT, Pre- T-score and the FCSA/VBA as independent risk factors for CS after TLIF for DS. These risk factors should enable spinal surgeons to closely monitor and prevent the occurrence of CS.

Restoring L4-S1 Lordosis Shape in Severe Sagittal Deformity: Impact of Correction Techniques on Alignment and Complication Profile.

BACKGROUND: Severe sagittal plane deformity with loss of L4-S1 lordosis is disabling and can be improved through various surgical techniques. However, data are limited on the differing ability of anterior lumbar interbody fusion (ALIF), pedicle subtraction osteotomy (PSO), and transforaminal lumbar interbody fusion (TLIF) to achieve alignment goals in severely malaligned patients. METHODS: Severe adult spinal deformity patients with preoperative PI-LL >20°, L4-S1 lordosis <30°, and full body radiographs and PROMs at baseline and 6-week postoperative visit were included. Patients were grouped into ALIF (1-2 level ALIF at L4-S1), PSO (L4/L5 PSO), and TLIF (1-2 level TLIF at L4-S1). Comparative analyses were performed on demographics, radiographic spinopelvic parameters, complications, and PROMs. RESULTS: Among the 96 included patients, 40 underwent ALIF, 27 underwent PSO, and 29 underwent TLIF. At baseline, cohorts had comparable age, sex, race, Edmonton frailty scores, and radiographic spinopelvic parameters (P > 0.05). However, PSO was performed more often in revision cases (P < 0.001). Following surgery, L4-S1 lordosis correction (P = 0.001) was comparable among ALIF and PSO patients and caudal lordotic apex migration (P = 0.044) was highest among ALIF patients. PSO patients had higher intraoperative estimated blood loss (P < 0.001) and motor deficits (P = 0.049), and in-hospital ICU admission (P = 0.022) and blood products given (P = 0.004), but were otherwise comparable in terms of length of stay, blood transfusion given, and postoperative admission to rehab. Likewise, 90-day postoperative complication profiles and 6-week PROMs were comparable as well. CONCLUSIONS: ALIF can restore L4-S1 sagittal alignment as powerfully as PSO, with fewer intraoperative and in-hospital complications. When feasible, ALIF is a suitable alternative to PSO and likely superior to TLIF for correcting L4-S1 lordosis among patients with severe sagittal malalignment.

Clinical use of quantitative computed tomography to evaluate the effect of less paraspinal muscle damage on bone mineral density changes after lumbar interbody fusion.

STUDY DESIGN: A retrospective cohort study. PURPOSE: This study aimed to assess the reliability of quantitative computed tomography (QCT) in measuring bone mineral density (BMD) of instrumented vertebrae and investigate the effect of less paraspinal muscle damage on BMD changes after lumbar interbody fusion. OVERVIEW OF LITERATURE: Patients always experience a decrease in vertebral BMD after lumbar interbody fusion. However, to the best of our knowledge, no study has analyzed the effect of paraspinal muscles on BMD changes. METHODS: This retrospective analysis included a total of 155 patients who underwent single-level lumbar fusion, with 81 patients in the traditional group and 74 patients in the Wiltse group (less paraspinal muscle damage). QCT was used to measure the volumetric BMD (vBMD), Hounsfield unit value, and cross-sectional area of the paraspinal muscles at the upper instrumented vertebrae (UIV), vertebrae one segment above the UIV (UIV+1), and the vertebrae one segment above the UIV+1 (UIV+2). Statistical analyses were performed. RESULTS: No significant differences in general data were observed between the two groups (p>0.05). Strong correlations were noted between the preoperative and 1-week postoperative vBMD of each segment (p<0.01), with no significant difference between the two time points in both groups (p>0.05). Vertebral BMD loss was significantly higher in UIV+1 and UIV+2 in the traditional group than in the Wiltse group (-13.6%±19.1% vs. -4.2%±16.5%, -10.8%±20.3% vs. -0.9%±37.0%; p<0.05). However, no statistically significant difference was observed in the percent vBMD changes in the UIV segment between the two groups (37.7%±70.1% vs. 36.1%±78.7%, p>0.05). CONCLUSIONS: QCT can reliably determine BMD in the instrumented spine after lumbar interbody fusion. With QCT, we found that reducing paraspinal muscle destruction through the Wiltse approach during surgery can help preserve the adjacent vertebral BMD; however, it does not help increase the BMD in the instrumented vertebrae.

Association between delayed ambulation and increased risk of adverse events after lumbar fusion surgery in elderly patients.

PURPOSE: The relationship between delayed ambulation (DA) and postoperative adverse events (AEs) following transforaminal lumbar interbody fusion (TLIF) in elderly patients remains elusive. The aim of our study was to evaluate the effects of DA on the postoperative AEs including complications, readmission and prolonged length of hospital stay (LOS). METHODS: This was a retrospective analysis of a prospectively established database of elderly patients (aged 65 years and older) who underwent TLIF surgery. The early ambulation (EA) group was defined as patients ambulated within 48 h after surgery, whereas the delayed ambulation (DA) group was patients ambulated at a minimum of 48 h postoperatively. The DA patients were 1:1 propensity-score matched to the EA patients based on age, gender and the number of fused segments. Univariate analysis was used to compare postoperative outcomes between the two groups, and multivariate logistic regression analysis was used to identify risk factors for adverse events and DA. RESULTS: After excluding 125 patients for various reasons, 1025 patients (≤ 48 h: N = 659 and > 48 h: N = 366) were included in the final analysis. After propensity score matching, there were 326 matched patients in each group. There were no significant differences in the baseline data and the surgery-related variables between the two groups (p > 0.05). The patients in the DA group had a significant higher incidence of postoperative AEs (46.0% vs. 34.0%, p = 0.002) and longer LOS (p = 0.001). Multivariate logistic regression identified that age, operative time, diabetes, and DA were independently associated with postoperative AEs, whereas greater age, higher international normalized ratio, and intraoperative estimated blood loss were identified as independent risk factors for DA. CONCLUSIONS: Delayed ambulation was an independent risk factor for postoperative AEs after TLIF in elderly patients. Older age, increased intraoperative blood loss and worse coagulation function were associated with delayed ambulation.

Can We Rely on Prophylactic Two-Level Vertebral Cement Augmentation in Long-Segment Adult Spinal Deformity Surgery to Reduce the Incidence of Proximal Junctional Complications?

Background and Objectives: Proximal junctional kyphosis (PJK) and failure (PJF), the most prevalent complications following long-segment thoracolumbar fusions for adult spinal deformity (ASD), remain lacking in defined preventive measures. We studied whether one of the previously reported strategies with successful results-a prophylactic augmentation of the uppermost instrumented vertebra (UIV) and supra-adjacent vertebra to the UIV (UIV + 1) with polymethylmethacrylate (PMMA)-could also serve as a preventive measure of PJK/PJF in minimally invasive surgery (MIS). Materials and Methods: The study included 29 ASD patients who underwent a combination of minimally invasive lateral lumbar interbody fusion (MIS-LLIF) at L1-2 through L4-5, all-pedicle-screw instrumentation from the lower thoracic spine to the sacrum, S2-alar-iliac fixation, and two-level balloon-assisted PMMA vertebroplasty at the UIV and UIV + 1. Results: With a minimum 3-year follow-up, non-PJK/PJF group accounted for fifteen patients (52%), PJK for eight patients (28%), and PJF requiring surgical revision for six patients (21%). We had a total of seven patients with proximal junctional fracture, even though no patients showed implant/bone interface failure with screw pullout, probably through the effect of PMMA. In contrast to the PJK cohort, six PJF patients all had varying degrees of neurologic deficits from modified Frankel grade C to D3, which recovered to grades D3 and to grade D2 in three patients each, after a revision operation of proximal extension of instrumented fusion with or without neural decompression. None of the possible demographic and radiologic risk factors showed statistical differences between the non-PJK/PJF, PJK, and PJF groups. Conclusions: Compared with the traditional open surgical approach used in the previous studies with a positive result for the prophylactic two-level cement augmentation, the MIS procedures with substantial benefits to patients in terms of less access-related morbidity and less blood loss also provide a greater segmental stability, which, however, may have a negative effect on the development of PJK/PJF.

Is endoscopic technique an effective and safe alternative for lumbar interbody fusion? A systematic review and meta-analysis.

Study design: Systematic review; meta-analysis. Purpose: Lumbar degenerative disease is frequent and has a tremendous impact on patients' disability and quality-of-life. Open and minimally invasive procedures have been used to achieve adequate decompression and fusion. Endoscopic lumbar interbody fusion (Endo-LIF) is emerging as an alternative, trying to reduce morbidity, while achieving comparable to superior clinical outcomes. The aim of this work is to perform a systematic review and meta-analysis to investigate how Endo-LIF compares to open or minimally invasive procedures. Methods: Electronic databases (MEDLINE, Scopus, Web of Science, Cochrane) were systematically reviewed using the query: '(percutaneous OR endoscop*) AND (open OR minimal* invasive) AND lumbar AND fusion'. PRISMA guidelines were followed. Results: Twenty-seven articles were included (25 cohort study, 1 quasi-experimental study, and 1 randomized control trial; for meta-analytical results, only observational studies were considered). Endo-LIF conditioned longer operative time, with significantly lower blood loss, bedtime, and hospital length of stay. Early post-operative back pain favored endoscopic techniques. Endo-LIF and non-Endo-LIF minimally invasive surgery displayed comparable results for most back and leg pain or disability outcomes, despite Endo-LIF having been associated with higher disability at late follow-up (versus Open-LIF). No differences were found regarding fusion rates, cage subsidence, or adverse events. Definitive conclusions regarding fusion rate cannot be drawn due to low number of studies and unstandardized fusion definition. Conclusion: Endo-LIF is an effective and safe alternative to conventional lumbar interbody fusion procedures. Evidence shortcomings may be addressed, and future randomized control trials may be performed to compare techniques and to validate results.