Comparison of the early results of transforaminal lumbar interbody fusion and posterior lumbar interbody fusion in symptomatic lumbar instability

Radiologic and Clinical Evaluation of Posterolateral Versus Transforaminal Interbody Fusion in Degenerative Lumbar Spondylolisthesis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The primary objective is to compare foraminal height (FH) and disk height (DH) differences in posterolateral (PLF) and transforaminal interbody fusions (TLIFs) and secondarily correlate these measurements with patient-reported outcomes.

BACKGROUND

The impact FH has on patient outcomes in degenerative lumbar spinal fusion surgery is unknown. Postoperative FH change and how it relates to patient-reported outcomes in posteriorly based procedures has not been well evaluated.

METHODS

A retrospective review of a subset of patients from a prospective cohort from the Canadian Spine Outcomes and Research Network was undertaken. Radiographic assessment preoperatively, at 3 months and 1 year, with standing lumbar spine radiographs were completed. FH and DH were recorded at each time interval, differences between groups were compared, and correlations with patient-reported outcomes were assessed.

RESULTS

One hundred nine patients were included (23 PLF and 86 TLIF). At 3-month follow-up, the change in FH was greater in the TLIF group (mean difference =2.3; 95% CI: 0.8-3.5, P =0.002). The change in FH remained significantly different at 12 months (mean difference=1.6, 95% CI: 0.2, 3.0 mm, P =0.028). The change in DH was greater in the TLIF group, with a mean difference between groups of 4.1 mm (95% CI: 2.5, 5.7, P <0.001) and 3.6 mm (95% CI: 2.0, 5.3, P <0.001). A positive change in FH correlated with less back pain, less disability, and improved physical function in the TLIF group ( P <0.05).

CONCLUSIONS

Patients treated with PLF lost FH over time. An increased difference in FH at 1 year was associated with improved function and less back pain in the TLIF group.

Load distribution on intervertebral cages with and without posterior instrumentation

BACKGROUND CONTEXT

Posterior and transforaminal lumbar interbody fusion (PLIF, TLIF) are well-established procedures for spinal fusion. However, little is known about load sharing between cage, dorsal construct, and biological tissue within the instrumented lumbar spine.

PURPOSE

The aim of this study was to quantify the forces acting on cages under axial compression force with and without posterior instrumentation.

STUDY DESIGN

Biomechanical cadaveric study.

METHODS

Ten lumbar spinal segments were tested under uniaxial compression using load cell instrumented intervertebral cages. The force was increased in 100N increments to 1000N or a force greater than 500N on one load cell. Each specimen was tested after unilateral PLIF (uPLIF), bilateral PLIF (bPLIF) and TLIF each with/without posterior instrumentation. Dorsal instrumentation was performed with 55N of compression per side.

RESULTS

Cage insertion resulted in median cage preloads of 16N, 29N and 35N for uPLIF, bPLIF, and TLIF. The addition of compressed dorsal instrumentation increased the median preload to 224N, 328N, and 317N, respectively. With posterior instrumentation, the percentage of the external load acting on the intervertebral cage was less than 25% at 100N (uPLIF: 14.2%; bPLIF: 16%; TLIF: 11%), less than 45% at 500N (uPLIF: 31.8%; bPLIF: 41.1%; TLIF: 37.9%) and less than 50% at 1000N (uPLIF: 40.3%; bPLIF: 49.7%; TLIF: 43.4%). Without posterior instrumentation, the percentage of external load on the cages was significantly higher with values above 50% at 100N (uPLIF: 55.6%; bPLIF: 75.5%; TLIF: 66.8%), 500N (uPLIF: 71.7%; bPLIF: 79.2%; TLIF: 65.4%), and 1000N external load (uPLIF: 73%; bPLIF: 80.5%; TLIF: 66.1%). For absolute loads, preloads and external loads must be added together.

CONCLUSIONS

Without posterior instrumentation, the intervertebral cages absorb more than 50% of the axial load and the load distribution is largely independent of the loading amplitude. With posterior instrumentation, the external load acting on the cages is significantly lower and the load distribution becomes load amplitude dependent, with a higher proportion of the load transferred by the cages at high loads. The bPLIF cages tend to absorb more force than the other two cage configurations.

CLINICAL SIGNIFICANCE

Cage instrumentation allows some of the compression force to be transmitted through the cage to the screws below, better distributing and reducing the overall force on the pedicle screws at the end of the construct and on the rods.

Do TLIF and PLIF Techniques Differ in Perioperative Complications? - Comparison of Complications Rates of Two High Volume Centers

STUDY DESIGN

Retrospective bicentric Cohort Study.

OBJECTIVE

Posterior (PLIF) and transforaminal lumbar interbody fusion (TLIF) have been clinically proven for the surgical treatment of degenerative spinal disorders. Despite many retrospective studies, the superiority of either technique has not been proven to date. In the literature, the complication rate of the conventional PLIF technique is reported to be significantly higher, but with inconsistent complication recording. In this retrospective bicentric study, a less invasive PLIF technique was compared with the conventional TLIF technique and complications were recorded using the validated SAVES V2 classification system.

METHODS

1142 patients underwent PLIF (702) or TLIF (n = 440) up to 3 levels in two specialized centers. Epidemiological data, intra- and postoperative complications during hospitalization and after discharge were analyzed according to SAVES V2.

RESULTS

The overall complication rate was 13.74%. TLIF-patients had slightly significant more complications than PLIF-patients (TLIF = 16.6%/PLIF = 11.9%, P = .0338). Accordingly, complications during revision surgeries were more frequent in the first cohort (TLIF = 20.9%/PLIF = 12.6%; P = .03252). In primary interventions, the surgical technique did not correlate with the complication rate (TLIF = 12.4%/PLIF = 11.7%). There were no significant differences regarding severity of complications.

CONCLUSIONS

An important component of this work is the complication recording according to a uniform classification system (SAVES V2). In contrast to previous literature, we could demonstrate that there is not a significant difference between the two surgical techniques.

Meta-analysis of the efficacy and safety of OLIF and TLIF in the treatment of degenerative lumbar spondylolisthesis

OBJECTIVE

To systematically evaluate the difference in clinical efficacy between two surgical approaches, oblique lateral approach and intervertebral foraminal approach, in the treatment of degenerative lumbar spondylolisthesis.

METHODS

English databases, including PubMed, Cochrane, Embase, and Web of Science, were systematically searched using keywords such as "oblique lumbar interbody fusion" and "transforaminal lumbar interbody fusion." Concurrently, Chinese databases, including CNKI, WanFang data, VIP, and CBM, were also queried using corresponding Chinese terms. The search spanned from January 2014 to February 2024, focusing on published studies in both Chinese and English that compared the clinical efficacy of OLIF and TLIF. The literature screening was conducted by reviewing titles, abstracts, and full texts. Literature meeting the inclusion criteria underwent quality assessment, and relevant data were extracted. Statistical analysis and a meta-analysis of the observational data for both surgical groups were performed using Excel and RevMan 5.4 software. Findings revealed a total of 14 studies meeting the inclusion criteria, encompassing 877 patients. Of these, 414 patients were in the OLIF group, while 463 were in the TLIF group. Meta-analysis of the statistical data revealed that compared to TLIF, OLIF had a shorter average surgical duration (P < 0.05), reduced intraoperative bleeding (P < 0.05), shorter average hospital stay (P < 0.05), better improvement in postoperative VAS scores (P < 0.05), superior enhancement in postoperative ODI scores (P < 0.05), more effective restoration of disc height (P < 0.05), and better correction of lumbar lordosis (P < 0.05). However, there were no significant differences between OLIF and TLIF in terms of the incidence of surgical complications (P > 0.05) and fusion rates (P > 0.05).

CONCLUSION

When treating degenerative lumbar spondylolisthesis, OLIF demonstrates significant advantages over TLIF in terms of shorter surgical duration, reduced intraoperative bleeding, shorter hospital stay, superior improvement in postoperative VAS and ODI scores, better restoration of disc height, and more effective correction of lumbar lordosis.

Application of self-anchored lateral lumbar interbody fusion in lumbar degenerative diseases

STUDY DESIGN

This is a retrospective study.

OBJECTIVE

The aim of the study was to evaluate the efficacy of self-anchored lateral lumbar interbody fusion (SA-LLIF) in lumbar degenerative diseases.

METHODS

Forty-eight patients with lumbar degenerative disease between January 2019 and June 2020 were enrolled in this study. All patients complained of low back and leg pain, which were aggravated during standing activities and alleviated or disappeared during lying. After general anesthesia, the patient was placed in the right decubitus position. The anterior edge of the psoas major muscle was exposed through an oblique incision of approximately 6 cm, using an extraperitoneal approach. The psoas major muscle was then properly retracted dorsally to expose the disc. After discectomy, a suitable cage filled with autogenous bone graft from the ilium was implanted. Two anchoring plates were inserted separately into the caudal and cranial vertebral bodies to lock the cage. Clinical efficacy was evaluated using the visual analog scale (VAS) and Oswestry Disability Index (ODI). Lumbar lordosis, intervertebral disc height, spondylolisthesis rate, cage subsidence and fusion rate were also recorded.

RESULTS

A total of 48 patients were enrolled in this study, including 20 males and 28 females, aged 61.4 ± 7.3 (range 49-78) years old. Surgery was successfully performed in all patients. Lumbar stenosis and instability were observed in 22 cases, disc degenerative disease in eight cases, degenerative spondylolisthesis in nine cases, degenerative scoliosis in six cases, and postoperative revision in three cases. In addition, five patients were diagnosed with osteoporosis. The index levels included L2-3 in three patients, L3-4 in 13 patients, L4-5 in 23 patients, L2-4 in three patients, and L3-5 in six patients. The operation time was 81.1 ± 6.4 (range 65-102) min. Intraoperative blood loss was 39.9 ± 8.5 (range 15-72) mL. No severe complications occurred, such as nerve or blood vessel injuries. The patients were followed up for 11.7 ± 2.3 (range 4-18) months. At the last follow-up, the VAS decreased from 6.2 ± 2.3 to 1.7 ± 1.1, and the ODI decreased from 48.4% ± 11.2% to 10.9% ± 5.5%. Radiography showed satisfactory postoperative spine alignment. No cage displacement was found, but cage subsidence 2-3 mm was found in five patients without obvious symptoms, except transient low back pain in an obese patient. The lumbar lordosis recovered from 36.8° ± 7.9° to 47.7° ± 6.8°, and intervertebral disc height recovered from 8.2 ± 2.0 mm to 11.4 ± 2.5 mm. The spondylolisthesis rate decreased from 19.9% ± 4.9% to 9.4% ± 3.2%. The difference between preoperative and last follow-up was statistically significant (P<0.05).

CONCLUSION

SA-LLIF can provide immediate stability and good results for lumbar degenerative diseases with a standalone anchored cage without posterior internal fixation.

A Prospective Study of Lumbar Facet Arthroplasty in the Treatment of Degenerative Spondylolisthesis and Stenosis: Results from the Total Posterior Spine System (TOPS) IDE Study

STUDY DESIGN

Prospective randomized Food and Drug Administration investigational device exemption clinical trial.

OBJECTIVE

The purpose of the present study is to report the 1-year clinical and radiographic outcomes and safety profile of patients who underwent lumbar facet arthroplasty through implantation of the Total Posterior Spine System (TOPS) device.

SUMMARY OF BACKGROUND DATA

Lumbar facet arthroplasty is one proposed method of dynamic stabilization to treat grade-1 spondylolisthesis with stenosis; however, there are currently no Food and Drug Administration-approved devices for facet arthroplasty.

METHODS

Standard demographic information was collected for each patient. Radiographic parameters and patient-reported outcome measures were assessed preoperatively and at regular postoperative intervals. Complication and reoperation data were also collected for each patient.

RESULTS

At the time of this study, 153 patients had undergone implantation of the TOPS device. The mean surgical time was 187.8 minutes and the mean estimated blood loss was 205.7cc. The mean length of hospital stay was 3.0 days. Mean Oswestry Disability Index, Visual Analog Score leg and back, and Zurich Claudication Questionnaire scores improved significantly at all postoperative time points ( P >0.001). There were no clinically significant changes in radiographic parameters, and all operative segments remained mobile at 1-year follow-up. Postoperative complications occurred in 11 patients out of the 153 patients (7.2%) who underwent implantation of the TOPS device. Nine patients (5.9%) underwent a total of 13 reoperations, 1 (0.6%) of which was for device-related failure owing to bilateral L5 pedicle screw loosening.

CONCLUSIONS

Lumbar facet arthroplasty with the TOPS device demonstrated a statistically significant improvement in all patient-reported outcome measures and the ability to maintain motion at the index level while limiting sagittal translation with a low complication rate.

Oblique versus Transforaminal Lumbar Interbody Fusion in Degenerative Spondylolisthesis: A Systematic Review and Meta-analysis

BACKGROUND: This meta-analysis compared transforaminal interbody fusion (TLIF) and oblique lumbar interbody fusion (OLIF) techniques for degenerative lumbar spondylolisthesis. AIM: The aim is to evaluate Oswestry Disability Index (ODI), Japanese Orthopedic Association Back Pain Evaluation Questionnaire, visual analog scale improvement for back and leg pain, disc height, slipped percentage, blood loss, surgical time, and complication rates in both groups. METHODS: A systematic literature search was carried out to obtain a study that compared OLIF and TLIF for degenerative lumbar spondylolisthesis. A literature search was performed using PubMed, Scopus, EuropePMC, and EBSCOHost. While the intervention was the OLIF technique, the control was the TLIF technique. The primary outcome was clinical outcome (ODI, Japanese Orthopaedic Association Back Pain Evaluation Questionnaire [JOABPEQ], visual analog scale [VAS] improvement for back, and leg pain). The Newcastle-Ottawa Scale was used to assess the quality of the studies. RESULTS: Total of 384 patients from four studies were included in this study. OLIF group was better than TLIF group in terms of disc height, slipped percentage, and blood loss. ODI, JOABPEQ, VAS improvement for back pain (standardized mean difference [SMD] 0.06 [−0.18, 0.29], p = 0.63, I2 = 0%, p = 0.87) and leg pain (SMD 0.12 [−0.36, 0.60], p = 0.63, I2 = 74%, p = 0.02), surgical time, and complication rates were similar in both groups. CONCLUSION: OLIF technique was better than TLIF technique in terms of radiologic outcome and surgical blood loss. Both techniques showed similar outcomes in clinical outcome, complication, and surgical time.

Clinical and Patient-reported Outcomes After Posterior Versus Transforaminal Lumbar Interbody Fusion-A Propensity Score-matched Cohort Study on 422 Patients with 2-year Follow-up

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.

The Effect of the Severity of Preoperative Disability on Patient-Reported Outcomes and Patient Satisfaction Following Minimally Invasive Transforaminal Lumbar Interbody Fusion

OBJECTIVE

To compare patient-reported outcomes (PROMs), satisfaction, and minimum clinically important difference (MCID) achievement following minimally invasive transforaminal lumbar interbody fusion stratified by preoperative disability.

METHODS

Minimally invasive transforaminal lumbar interbody fusions were grouped by preoperative Oswestry Disability Index (ODI) score: ODI <41 or ODI ≥41. PROMs administered pre/postoperatively included Patient-Reported Outcomes Measurement Information System physical function (PROMIS-PF), visual analog scale (VAS) back/leg, ODI, and 12-Item Short-Form Physical Composite Score (SF-12 PCS)/12-Item Short-Form Mental Composite Score (SF-12 MCS). Satisfaction scores were collected for VAS back/leg and ODI. Coarsened exact match controlled for differences between cohorts. T tests compared mean PROMs and postoperative improvement/satisfaction between cohorts. Simple logistic regression compared MCID achievement.

RESULTS

After coarsened exact matching, there were 118 patients in the ODI ≤41 and 377 patients in the ODI >41 cohort. The ODI >41 cohort saw greater postoperative inpatient VAS pain score and narcotic consumption on days 0/1 (P < 0.018, all). PROMs differed between cohorts: PROMIS-PF, SF-12 PCS, ODI, VAS back/leg at all postoperative time points and SF-12 MCS at 6 weeks/12 weeks/6 months/1 year (P < 0.045, all). Patients in the ODI >41 cohort demonstrated greater proportion achieving MCID for ODI at all postoperative time points and for SF-12 MCS 6-week/12-week/6-month/1-year (P < 0.040, all). The ODI ≤41 cohort demonstrated greater MCID achievement for overall PROMIS-PF and SF-12 PCS 6 months (P < 0.047, all). Postoperative satisfaction was greater in the ODI ≤41 cohort for VAS leg 6 weeks/12 weeks, VAS back 6 weeks/12 weeks, and ODI all postoperative time points (P < 0.048, all).

CONCLUSIONS

Preoperative disability associated with worse postoperative PROMs and patient satisfaction for disability, back/leg pain at multiple time points. MCID achievement rates across cohorts were similar for most PROMs at most postoperative time points. Patients with severe disability may have unrealistic expectations for surgical benefits, influencing corresponding postoperative satisfaction.

A Prospective Randomized Study of the Safety and Efficacy of Transforaminal Lumbar Interbody Fusion Versus Posterior Lumbar Interbody Fusion in the Treatment of Lumbar Spondylolisthesis: A Cost utility from a Lower-middle-income Country Perspective and Review of Literature

BACKGROUND: The safety and efficacy of transforaminal lumbar interbody fusion (TLIF) and posterior lumbar interbody fusion (PLIF) in lumbar spondylolisthesis have not been validated in many prospective randomized trials. AIM: We aimed to validate the safety and efficacy of TLIF and PLIF surgery in lumbar spondylolisthesis using the clinical, radiographic, and cost-utility outcomes. METHODS: The data of surgically treated single-level spondylolisthesis patients were randomized prospectively into two groups. The groups were compared regarding demographics, perioperative complications, hospital stay, total expenditure, fusion rate, and clinical outcomes (visual analog scale, Oswestry disability index, Zurich claudication scale, and Odom’s criteria). A review of literature was done to compare the outcomes with the ones from higher-income nations. RESULTS: Thirty-three patients underwent prospective randomization. The improvement in the clinical outcomes at 12-month follow-up showed improvement in the TLIF group more than the PLIF group but with no significant difference. The mean operative time was significantly longer in the PLIF (p < 0.05), also, the blood loss was significantly less in the TLIF (p < 0.001). The complications frequency did not show any statistical significance between both groups and no significant difference in the patient’s post-operative patient satisfaction (p = 0.6). The mean hospital stay was non-significantly longer in the PLIF (p = 0.7). At 12-month follow-up, 93.3% of the TLIF patients were fused versus 86.7% of the PLIF (p = 0.5). The total cost of the TLIF was significantly less (p < 0.001). CONCLUSION: Both PLIF and TLIF could achieve similar fusion rates and clinical satisfaction in the management of lumbar spondylolisthesis. The TLIF group was significantly better in terms of financial burden, operative time, and blood loss.

Lordosis Restoration With Midline Minimally Invasive Cortical Trajectory Screws (MidLF) and Transforaminal Interbody Fusion: A Safe Technique With a Short Stay

BACKGROUND

The minimally invasive cortical trajectory screw (MidLF) technique has been described accompanied with posterolateral interbody fusion (PLIF). We present our 2-year results of a hybrid technique to show that using transforaminal interbody fusion (TLIF) rather than PLIF in conjunction with MidLF is a less invasive and safe technique.

METHODS

We retrospectively identified 25 patients who underwent MidLF with TLIF from July 2015 through September 2017. The surgical technique was the same for each, with radiological, clinical, and patient-reported outcome data collected and analyzed at a 2-year follow-up.

RESULTS

The cohort showed a mean age of 55 (35-85) years. The length of hospital stay was between 1 and 4 days, with an average of 2.7 days. Postoperatively, lordosis across the motion segment fused increased by a mean of 7.3° (0°-24°), mean pelvic incidence was 53°(31°-80°), and pelvic tilt reduced by an average of 3.5° (0°-11°). The Oswestry Disability Index improved from 34 preoperatively to 19 postoperatively. Visual analogue pain score-leg improved by 4.7 points, from 6 down to 1. One patient showed delayed wound healing. There were no incidences of neurological injury or durotomy.

CONCLUSIONS

Our data suggests that MidLF with TLIF is both less invasive than traditional techniques and safe. It restores lordosis, requires less exposure and retraction of neural elements than the more widely used PLIF, and shows early discharge and satisfactory medium-term patient-reported outcomes.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

The MidLF technique with PLIF is less invasive than traditional techniques, restores alignment and shows satisfactory medium term results.

Comparison of (Partial) economic evaluations of transforaminal lumbar interbody fusion (TLIF) versus Posterior lumbar interbody fusion (PLIF) in adults with lumbar spondylolisthesis: A systematic review

Introduction

The demand for spinal fusion surgery has increased over the last decades. Health care providers should take costs and cost-effectiveness of these surgeries into account. Open transforaminal lumbar interbody fusion (TLIF) and posterior lumbar interbody fusion (PLIF) are two widely used techniques for spinal fusion. Earlier research revealed that TLIF is associated with less blood loss, shorter surgical time and sometimes shorter length of hospital stay, while effectiveness of both techniques on back and/or leg pain are equal. Therefore, TLIF could result in lower costs and be more cost-effective than PLIF. This is the first systematic review comparing direct and indirect (partial) economic evaluations of TLIF with PLIF in adults with lumbar spondylolisthesis. Furthermore, methodological quality of included studies was assessed.

Methods

Searches were conducted in eight databases for reporting on eligibility criteria; TLIF or PLIF, lumbar spondylolisthesis or lumbar instability, and cost. Costs were converted to United States Dollars with reference year 2020. Study quality was assessed using the bias assessment tool of the Cochrane Handbook for Systematic Reviews of Interventions, the Level of Evidence guidelines of the Oxford Centre for Evidence-based Medicine and the Consensus Health Economic Criteria (CHEC) list.

Results

Of a total of 693 studies, 16 studies were included. Comparison of TLIF and PLIF could only be made indirectly, since no study compared TLIF and PLIF directly. There was a large heterogeneity in health care and societal perspective costs due to different in-, and exclusion criteria, baseline characteristics and the use of costs or charges in calculations. Health care perspective costs, calculated with hospital costs, ranged from $15,867-$43,217 in TLIF-studies and $32,662 in one PLIF-study. Calculated with hospital charges, it ranged from $8,964-$51,469 in TLIF-studies and $21,838-$93,609 in two PLIF-studies. Societal perspective costs and cost-effectiveness, only mentioned in TLIF-studies, ranged from $5,702/QALY-$48,538/QALY and $50,092/QALY-$90,977/QALY, respectively. Overall quality of studies was low.

Conclusions

This systematic review shows that TLIF and PLIF are expensive techniques. Moreover, firm conclusions about the preferable technique, based on (partial) economic evaluations, cannot be drawn due to limited studies and heterogeneity. Randomized prospective trials and full economical evaluations with direct TLIF and PLIF comparison are needed to obtain high levels of evidence. Furthermore, development of guidelines to perform adequate economic evaluations, specified for the field of interest, will be useful to minimize heterogeneity and maximize transferability of results.

Trial registration

Prospero-database registration number: CRD42020196869.

A comparison of the bilateral decompression via unilateral approach versus conventional approach transforaminal lumbar interbody fusion for the treatment of lumbar degenerative disc disease in the elderly

Background

Bilateral decompression via unilateral approach (BDUA) is an effective surgical approach for treating lumbar degenerative diseases. However, no studies of prognosis, especially the recovery of the soft tissue, have reported using BDUA in an elderly population. The aims of these research were to investigate the early efficacy of the bilateral decompression via unilateral approach versus conventional approach transforaminal lumbar interbody fusion (TLIF) for the treatment of lumbar degenerative disc disease in the patients over 65 years of age, especially in the perioperative factors and the recovery of the soft tissue.

Methods

The clinical data from 61 aging patients with lumbar degenerative disease who received surgical treatment were retrospectively analyzed. 31 cases who received the lumbar interbody fusion surgery with bilateral decompression via unilateral approach (BDUA) were compared with 30 cases who received conventional approach transforaminal lumbar interbody fusion. The radiographic parameters were measured using X-ray including lumbar lordosis angle and fusion rate. Japanese Orthopedic Association (JOA), Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) scores were used to evaluate the clinical outcomes at different time points. Fatty degeneration ratio and area of muscle/vertebral body were used to detect recovery of soft tissue.

Results

The BDUA approach group was found to have significantly less intraoperative blood loss(p < 0.05) and postoperative drainage(p < 0.05) compared to conventional approach transforaminal lumbar interbody fusion group. Symptoms of spinal canal stenosis and nerve compression were significantly relieved postoperatively, as compared with the preoperative state. However, the opposite side had a lower rate of fatty degeneration (9.42 ± 3.17%) comparing to decompression side (11.68 ± 3.08%) (P < 0.05) six months after surgery in the BDUA group. While there were no significant differences (P > 0.05) in two sides of conventional transforaminal lumbar interbody fusion approach group six months after surgery.

Conclusions

Bilateral decompression via unilateral approach (BDUA) is able to reduce the intraoperative and postoperative body fluid loss in the elderly. The opposite side of decompression in BDUA shows less fatty degeneration in 6 months, which indicates better recovery of the soft tissue of the aging patients.

Full Endoscopic Lumbar Transforaminal Interbody Fusion in DDD Lumbar Degenerative Disc Disease: A Latest Technique

BACKGROUND

Lumbar interbody fusion has long been used in the treatment of degenerative disc disease. Lumbar spinal interbody fusion surgery traditionally is an open surgical technique. Although lumbar spinal interbody fusions using endoscopy have been reported, the endoscope was used partially for the interbody fusion. We are reporting a case where lumbar interbody fusion with discectomy was entirely done through direct visualization with the endoscope.

METHODS

We report a case of a 55-year-old woman who underwent the transforaminal percutaneous full-endoscopic lumbar interbody fusion technique (FELTIF) under continuous and direct visualization at the L5-S1 level. To facilitate the interbody fusion, a foraminoplasty with complete resection of the superior articular process (SAP) and a partial pediculectomy of the S1 pedicle was performed. End plate sparing decortication techniques were used under direct video endoscopic visualization. The cage and bone graft insertion occurred through the endoscopic working cannula, thereby protecting the retracted traversing and exiting nerve roots at the surgical level. Posterior supplemental fixation with percutaneous pedicle screws was performed to complete the circumferential fusion.

RESULT

The VAS leg score was reduced to 2 from preoperative score of 7 and the VAS back score reduced 3 from preoperative score of 9. Her neurogenic symptom score improved from 8 before surgery to 1 at the last follow-up. The fusion is assessed by plain radiographs in follow up.

CONCLUSIONS

We concluded that the insertion of an interbody fusion cage device directly through an endoscopic working cannula was technically feasible. Future research should focus on examining the clinical outcomes of this technique.

LEVEL OF EVIDENCE

4.

Trends in lumbar spinal fusion-a literature review

Over the past several decades, there has been an upward trend in the total number of spinal fusion procedures worldwide. Advanced spinal fusion techniques with or without internal fixation, additional innovations in surgical approaches, innovative implants including a wide variety of interbody devices, and new alternatives in bone grafting materials are some reasons for the increasing number of spine fusion procedures. Moreover, the indications for spinal fusion have broadened over time. Initially developed for the treatment of instability and deformity due to tuberculosis, scoliosis, and traumatic injury, spinal fusion surgery has now a wide range of indications like spondylolisthesis, congenital or degenerative deformity, spinal tumors, and pseudarthrosis, with degenerative disorders as the most common indication. This review emphasizes current lumbar fusion techniques and their development in the past decades.

A retrospective controlled study protocol of transforaminal lumbar interbody fusion compared with posterior lumbar interbody fusion for spondylolisthesis

BACKGROUND

In the current literature, for adult lumbar spondylolisthesis, the direct comparison of clinical outcomes and perioperative complications between transforaminal lumbar interbody fusion (TLIF) and posterior lumbar interbody fusion (PLIF) is limited. Whether the therapeutic effect of TLIF is better than that of PLIF is still controversial. In this retrospective controlled study, our aim was to compare their clinical outcomes and radiological results of the above two stabilization approaches after 1-year follow-up period.

METHODS

This investigation was approved via the Institutional Review committee of China-Japan friendship hospital. This was a retrospective single-center analysis of subjects. We reviewed the patients with spondylolisthesis treated with TLIF or PLIF between July 2016 and February 2019 in our hospital. Patients with these conditions will be included: with the radiological evidence of degenerative lumbar spondylolismia with leg pain and/or low back pain, or the neurogenic claudication after failure of conventional conservative treatment for more than 6 months. The patients who received 3 levels or more intervertebral fusion levels were excluded. Patients without a completed medical history were excluded. Patients who had a history of lumbar spine surgery were also excluded. Clinical outcomes in our follow-up included functional outcomes, complications, and radiographic such as spondylolisthesis degree. The radiographs were obtained at 1, 3, 6, and 12 months during the outpatient follow-up.

RESULTS

This protocol will provide a solid theoretical basis for exploring which technique is better in treatment of spondylolisthesis.

TRIAL REGISTRATION

This study protocol was registered in Research Registry (number: researchregistry6032).

Assessment of Great Vessels for Anterior Access of L5/S1 Using Patient Positioning

STUDY DESIGN

This was a prospective cross-sectional study.

PURPOSE

The aim was to describe the effect of patient positioning, from supine to lateral decubitus position, on the width of the L5/S1 anterior disk space defined by the great vessels.

OVERVIEW OF LITERATURE

The application of the lateral decubitus position interbody fusion has been rapidly increasing; however, there are concerns regarding the access to the lumbosacral region due to the great vessels, which necessitates further morphometric data.

METHODS

A total of 20 consecutive live patients awaiting lumbar surgery were subjected to two magnetic resonance imaging scans on the same day in both supine and lateral decubitus positions at a single center to investigate the anterior L5/S1 disk space.

RESULTS

The bare anterior L5/S1 disk window was present in all patients of this study population, and the mean width was 27 mm in the supine and 22 mm in the lateral decubitus position, with a mean reduction of 5.2 mm between the positions. The oblique corridor angle was measured at a mean of 33°.

CONCLUSIONS

The bare window of L5/S1 disk space was present within this population group, and it was found to be mobile and changed significantly with patient positioning. Therefore, the spine surgeon or the access surgeon must consider the increased potential vascular risk during disk access in lateral decubitus anterior lumbar interbody spinal fusion surgery.

Interbody Fusions in the Lumbar Spine: A Review

BACKGROUND

Lumbar interbody fusion is among the most common types of spinal surgery performed. Over time, the term has evolved to encompass a number of different approaches to the intervertebral space, as well as differing implant materials. Questions remain over which approaches and materials are best for achieving fusion and restoring disc height.

QUESTIONS/PURPOSES

We reviewed the literature on the advantages and disadvantages of various methods and devices used to achieve and augment fusion between the disc spaces in the lumbar spine.

METHODS

Using search terms specific to lumbar interbody fusion, we searched PubMed and Google Scholar and identified 4993 articles. We excluded those that did not report clinical outcomes, involved cervical interbody devices, were animal studies, or were not in English. After exclusions, 68 articles were included for review.

RESULTS

Posterior approaches have advantages, such as providing 360° support through a single incision, but can result in retraction injury and do not always restore lordosis or correct deformity. Anterior approaches allow for the largest implants and good correction of deformities but can result in vascular, urinary, psoas muscle, or lumbar plexus injury and may require a second posterior procedure to supplement fixation. Titanium cages produce improved osteointegration and fusion rates but also increase subsidence caused by the stiffness of titanium relative to bone. Polyetheretherketone (PEEK) has an elasticity closer to that of bone and shows less subsidence than titanium cages, but as an inert compound PEEK results in lower fusion rates and greater osteolysis. Combination PEEK-titanium coating has not yet achieved better results. Expandable cages were developed to increase disc height and restore lumbar lordosis, but the data on their effectiveness have been inconclusive. Three-dimensionally (3D)-printed cages have shown promise in biomechanical and animal studies at increasing fusion rates and reducing subsidence, but additive manufacturing options are still in their infancy and require more investigation.

CONCLUSIONS

All of the approaches to spinal fusion have plusses and minuses that must be considered when determining which to use, and newer-technology implants, such as PEEK with titanium coating, expandable, and 3D-printed cages, have tried to improve upon the limitations of existing grafts but require further study.

A Bayesian network meta-analysis of 5 different fusion surgical procedures for the treatment of lumbar spondylolisthesis

Lumbar fusion has been widely used to treat lumbar spondylolisthesis, which can be classified into 5 types according to its approach, including posterolateral fusion (PLF), posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), posterolateral fusion plus anterior lumbar interbody fusion (PLFplusALIF), and posterolateral fusion plus posterior lumbar interbody fusion (PLFplusPLIF). Theoretically, each approach has its own advantages and disadvantages, however, no studies are available to compare them.A network meta-analysis (NMA) was performed in this study and the results were illustrated by the mean difference (MD) or odds ratio (OR). Meanwhile, the preferable treatments were indicated using the surface under the cumulative ranking curve (SUCRA). All data were analyzed and graphs were plotted using R 3.4.1.A total of 28 literatures were included in this meta-analysis. PLIF was the most effective treatment for pain relief. Conversely, TLIF was the most effective method for reducing vertebral slippage. For patients with isthmic spondylolisthesis (IS), PLIF performed the best in terms of Visual Analogue Scale (VAS) score, Oswestry Disability Index (ODI) score, fusion rate, blood loss, and complication rate. For patients with degenerative spondylolisthesis (DS), TLIF was the best from the points of view of VAS, complication rate, and vertebral slippage reduction.PLIF and TLIF are identified as the optimal treatments for all lumbar spondylolisthesis cases, among which, PLIF may be the preferred choice for pain relief, while TLIF can offer the best outcomes in terms of vertebral slippage reduction. Furthermore, TLIF has displayed the best clinical outcomes and tolerability for DS patients.

Factors Influencing Early Disc Height Loss Following Lateral Lumbar Interbody Fusion

Study Design

Retrospective radiological analysis.

Purpose

To analyze the factors influencing early disc height loss following lateral lumbar interbody fusion (LLIF).

Overview of Literature

Postoperative disc height loss can occur naturally as a result of mechanical loading. This phenomenon is enabled by the yielding of the polyaxial screw heads and settling of the cage to the endplates. When coupled with cage subsidence, there can be significant reduction in the foraminal space which ultimately compromises the indirect decompression achieved by LLIF.

Methods

Seventy-two cage levels in 37 patients aged 62±10.2 years who underwent single or multilevel LLIF for degenerative spinal conditions were selected. Their preoperative and postoperative follow-up radiographs were used to measure the anterior disc height (ADH), posterior disc height (PDH), mean disc height (MDH), disc space angle (DSA), and segmental angle. Correlations between the loss of disc height and several factors, including age, construct length, preoperative lordosis, postoperative lordosis, disc height, cage dimensions, and cage position, were analyzed.

Results

We found that the lateral interbody cages significantly increased ADH, PDH, MDH, and DSA after surgery (p <0.0001). However, there was a loss of disc height over time. All postoperative disc height parameters, especially the amount of increase in MDH (r =0.413, p <0.0001) after surgery, showed a significant positive association with early disc height loss. The levels demonstrating a significant (≥25%) height loss were those that exhibited a substantial height increase (128.3%, 4.6±3.0 to 10.5±5.6 mm) postoperatively. However, the levels that showed less than 25% height loss were those that exhibited, on average, only a 57.4% height increase post-operatively.

Conclusions

The greater the postoperative increase in disc height, the greater the disc height loss throughout early follow-up. Therefore, achieving an optimal disc height rather than overcorrection is an important surgical strategy to adopt when performing LLIF.

[Early effectiveness of oblique lateral interbody fusion combined with pedicle screw fixation via small incision Wiltse approach for lumbar spondylolisthesis]

OBJECTIVE

To investigate the early effctiveness of oblique lateral interbody fusion (OLIF) combined with pedicle screw fixation via small incision Wiltse approach for the treatment of lumbar spondylolisthesis.

METHODS

Between January 2016 and December 2016, 21 patients with lumbar spondylolisthesis were treated with OLIF and pedicle screw fixation via small incision Wiltse approach. There were 9 males and 12 females, aged 57-73 years, with an average age of 64.5 years. The disease duration was 24-60 months, with an average of 34.6 months. All cases were spondylolisthesis at L 4 (15 cases of degreeⅠ, 6 cases of degreeⅡ); 1 case had vertebral arch isthmus, and 20 cases had spinal stenosis. Japanese Orthopaedic Association (JOA) scoring system was used to evaluate the effectiveness before operation and at last follow-up. Before operation and at 2 days after operation, anteroposterior and lateral X-ray films and CT were taken to measure the sagittal diameter and cross-sectional area of the spinal canal, and calculate the intervertebral height and degree of spondylolisthesis. At 6 months after operation, the intervertebral fusion was evaluated by CT.

RESULTS

The operation time was 120-180 minutes, with an average of 155 minutes; the intraoperative blood loss was 100-340 mL, with an average of 225.5 mL. One patient had slight injury of lower endplate, 1 patient had numbness of thigh and weakness of hip flexion after operation, 1 patient had sympathetic nerve trunk injury. All the cases were followed up 12-18 months, with an average of 14.3 months. The symptoms of low back pain, leg pain, and numbness of lower limbs significantly relieved after operation, and there was no complication such as protrusion of fusion cage, screw breakage, and endplate collapse. At 2 days after operation, the intervertebral height, degree of spondylolisthesis, sagittal diameter of spinal canal, and cross-sectional area of spinal canal significantly improved compared with preoperative ones ( P<0.05). At 6 months after operation, CT showed that 1 patient had poor interbody fusion (grade Ⅲ), the other 20 patients had good interbody fusion (grade Ⅰ and Ⅱ), and the interbody fusion rate was 95.2%. At last follow-up, JOA score of lumbar spine significantly increased compared with that before operation ( t=24.980, P=0.000).

CONCLUSION

OLIF combined with pedicle screw fixation via small incision Wiltse approach for the lumbar spondylolisthesis has minimally invasive features, such as less trauma, fewer complications, and higher intervertebral fusion rate. It is a safe and effective method.

Minimally invasive surgery for degenerative spondylolisthesis: transforaminal or oblique lumbar interbody fusion

Aim: To compare the outcomes of minimally invasive surgery (MIS) for degenerative spondylolisthesis transforaminal lumbar interbody fusion (TLIF) and oblique lumbar interbody fusion (OLIF). Materials & methods: The clinical and surgical characteristics and outcomes of 38 patients with MIS-OLIF and 55 with MIS-TLIF were retrospectively evaluated. Results: Procedures and hospital stay were shorter and blood loss was less, with MIS-OLIF than with MIS-OLIF. The clinical and radiographic outcomes were similar. Postoperative changes in disk height and foraminal dimension were greater and patient satisfaction was better with MIS-OLIF than with MIS-TLIF. Conclusion: The clinical findings associated with the two procedures were similar; but patients preferred MIS-OLIF, which is less invasive, to MIS-TLIF. Clinical trial registration number: ChiCTR1800019443.

[Comparison of the effectiveness of vertebral arch replantation and laminectomy in the treatment of mild to moderate isthmic spondylolisthesis]

OBJECTIVE

To compare the effectiveness of vertebral arch replantation and laminectomy in the treatment of mild to moderate isthmic spondylolisthesis.

METHODS

The clinical data of 66 patients with isthmic spondylolisthesis treated with vertebral arch replantation or laminectomy between March 2014 and July 2016 were retrospectively analyzed. They were divided into trial group (34 cases, treated with complete replantation of vertebral arch, intervertebral fusion, and internal fixation) and control group (32 cases, treated with laminectomy with intervertebral fusion and internal fixation) according to different surgical methods. There was no significant difference in general data of gender, age, disease duration, lesion segment, Meyerding grade, and preoperative visual analogue scale (VAS) score, Oswestry disability index (ODI) score, Japanese Orthopaedic Association (JOA) score between the two groups ( P>0.05). The operation time, intraoperative blood loss, complications, vertebral arch fusion of trial group, and epidural scar formation of the two groups were recorded. The VAS score, JOA score, and ODI score were evaluated at preoperation, 3, 6, 12 months after operation, and at last follow-up. The effectiveness was evaluated according to HOU Shuxun's criteria.

RESULTS

All the patients successfully completed the surgery, without any aggravation of nerve injury, dural tear, infection, etc. There was no significant difference in the operation time between the two groups ( t=0.583, P=0.562), but the intraoperative blood loss was significantly lower in the trial group than that in the control group ( t=2.134, P=0.037). All the 66 patients were followed up 13-18 months (mean, 16.2 months). Postoperative clinical symptoms of all patients were significantly improved. In the control group, 7 cases were found to have symptoms of spinal canal stenosis with postoperative posture changes at 3 months after operation, and 5 cases showed mild lower limb numbness at 18 months after operation. No complication such as infection and nerve injury occurred in other patients. In the trial group, 34 cases of epidural scar tissue were completely blocked outside the replantation vertebral arch, while in the control group, 11 cases of epidural scar tissue invaded the spinal canal. At last follow-up, the fusion rate of intervertebral bone grafting and vertebral arch replantation in the trial group was 100%, and the fusion rate of intervertebral bone grafting in the control group was also 100%. The VAS score, ODI score, and JOA score were significantly improved at each time point after operation ( P<0.01). The ODI score and JOA score of the trial group were significantly better than those of the control group at 3 months after operation and at last follow-up ( P<0.05), and there was no significant difference in scores between the two groups at other time points ( P>0.05). According to HOU Shuxun's criteria, the excellent and good rate was 91.2% in the trial group and 84.4% in the control group, showing no significant difference ( χ 2=1.092, P=0.573).

CONCLUSION

Compared with laminectomy, vertebral arch replantation can better improve postoperative neurological symptoms, maximize the reconstruction of the bone spinal canal, restore the stability of the intraspinal environment, and it is a better surgical method for lumbar isthmic spondylolisthesis.

Assessing the Difference in Clinical and Radiologic Outcomes Between Expandable Cage and Nonexpandable Cage Among Patients Undergoing Minimally Invasive Transforaminal Interbody Fusion: A Systematic Review and Meta-Analysis

BACKGROUND

Minimally invasive transforaminal interbody fusion (MIS-TLIF) has been shown to have excellent outcomes for surgical management of degenerative disc disease. However, the challenge is in addressing coronal imbalance and restoring lumbar lordosis and sagittal alignment. Use of expandable cages in MIS-TLIF has been hypothesized to circumvent this disadvantage. An indirect meta-analysis of the evidence is presented comparing outcomes from expandable cages with those from nonexpandable cages, in patients undergoing MIS-TLIF.

METHODS

PRISMA guidelines were used to conduct a systematic review and meta-analysis to compare the clinical and radiologic outcomes of expandable cages and nonexpandable cages in patients undergoing MIS-TLIF.

RESULTS

Twelve studies (706 patients) were included in the meta-analysis. The mean increase in disc height was found to be significantly greater for the nonexpandable cages group than for the expandable cages group (1.33 mm; 95% confidence interval [CI], 1.28-1.38 vs. 1.14 mm,; 95% CI, 1.06-1.23; P < 0.001). No significant difference was found regarding change in lumbar lordosis at last follow-up between the 2 groups (P = 0.34). The mean change in segmental lordosis was found to be significantly higher for the expandable cage group (5.04°, 95% CI, 3.89-6.20 vs. 2.08°, 95% CI, 1.93-2.22; P < 0.001). We did not detect any significant difference in fusion rate (P = 0.33), subsidence rate (P = 0.41) or in reoperations (P = 0.56) at last follow-up between the 2 groups.

CONCLUSIONS

Our results indicate that there may not be a significant difference in clinical and radiologic parameters between expandable cages and nonexpandable cages among patients undergoing MIS-TLIF, and it is unclear if the higher cost of the expandable cages is justified.

The diagnostic accuracy of somatosensory evoked potentials in evaluating neurological deficits during 1057 lumbar interbody fusions

BACKGROUND

Lumbar interbody spinal fusion (LIF) surgeries are performed to treat or prevent back pain in patients with degenerated intervertebral discs and a variety of spinal diseases. However, post-operative neurological complications may ensue. Intraoperative monitoring techniques have been used to predict and potentially reduce the risk of complications.

METHODS

This study examined the diagnostic accuracy of significant changes of somatosensory evoked potentials (SSEPs) to evaluate and predict post-operative neurological deficits after LIF. All patients underwent LIF at UPMC from 2010 to 2012. One thousand fifty-seven patients had pre-operative baseline and continuous intraoperative SSEP monitoring. Statistical analysis was completed using SPSS version 22. No relevant disclosure.

RESULTS

Patient outcomes were not significantly affected by age over 65, gender, obesity, and abnormal baselines. Lower extremity (LE) significant changes in SSEPs and LE loss of responses resulted in a sensitivity/specificity of 0.03/0.99 and 0.03/0.99; they had an AUC of 0.54/0.73 with a 95% confidence interval (CI) of [0.34, 0.74]/[0.29, 1.00].

CONCLUSIONS

Significant SSEP changes during LIF are a very specific but poorly sensitive indicator of perioperative neurological deficits. The odds ratio for LE loss of responses was 29.14 with a 95% CI of 1.79-475.5, so LE SSEP loss of responses can serve as a biomarker of perioperative neurological deficits after LIF.

Evaluation of the discal height gain and lumbar lordosis variation obtained by the techniques of transforaminal and posterior lumbar intersomatic fusion

Objective

Evaluate the discal height and lumbar lordosis gains, comparatively, according to the two lumbar arthrodesis techniques, transforaminal lumbar interbody fusion (TLIF) and posterior lumbar interbody fusion (PLIF), used in the treatment of spinal degenerative diseases.

Methods

The present study, retrospective, was done with 60 patients who underwent decompression and 1 level lumbar arthrodesis in the Hospital Santa Casa de Misericórdia de Vitória (HSCMV), between January 2010 and December 2015. The patients were divided in two groups of 30 each, according to the utilized intersomatic arthrodesis technique: TLIF or PLIF. All patients presented pathologies at the L4-L5 level. In this study, the discal height gain and lumbar lordosis variation were evaluated by analyzing spinal radiographies of the pre and post-operatory periods from patients of the two groups, measured by the software Surgimap^®. In addition, the pain intensity in the post-operatory period was estimated by the Visual Analog Scale for Pain (VAS Pain).

Results

Both techniques presented a gain in the discal height in the post-operatory. There was no statistically significant difference between the discal height variation obtained with the PLIF technique when compared to the TLIF technique (p = 0.139). In the same way, there was no statistically significant difference in the lumbar lordosis variation between the two studied groups (p = 0.184). By the EVA Pain analysis, there was no significant difference in the pain intensity in the post-operatory period between both arthrodesis surgeries.

Conclusion

There is no difference in the discal height gain and lumbar lordosis variation, as well as in the pain intensity in the post-operatory periods, in patients who underwent 1 level intersomatic arthrodesis when comparing the PLIF and TLIF techniques.

Biomechanical comparison of transdiscal fixation and posterior fixation with and without transforaminal lumbar interbody fusion in the treatment of L5-S1 lumbosacral joint

Transdiscal screw fixation is generally performed in the treatment of high-grade L5-S1 spondylolisthesis. The main thought of the study is that the biomechanical performances of the transdiscal pedicle screw fixation can be identical to standard posterior pedicle screw fixations with or without transforaminal lumbar interbody fusion cage insertion. Lumbosacral portions and pelvises of 45 healthy lambs' vertebrae were dissected. Animal cadavers were randomly and equally divided into three groups for instrumentation. Three fixation systems, L5-S1 posterior pedicle screw fixation, L5-S1 posterior pedicle screw fixation with transforaminal lumbar interbody fusion cage insertion, and L5-S1 transdiscal pedicle screw fixation, were generated. Axial compression, flexion, and torsion tests were conducted on test samples of each system. In axial compression, L5-S1 transdiscal fixation was less stiff than L5-S1 posterior pedicle screw fixation with transforaminal lumbar interbody fusion cage insertion. There were no significant differences between groups in flexion. Furthermore, L5-S1 posterior fixation was stiffest under torsional loads. When axial compression and flexion loads are taken into consideration, transdiscal fixation can be alternatively used instead of posterior pedicle screw fixation in the treatment of L5-S1 spondylolisthesis because it satisfies enough stability. However, in torsion, posterior fixation is shown as a better option due to its higher stiffness.

Comparison of rigid and semi-rigid instrumentation under acute load on vertebrae treated with posterior lumbar interbody fusion/transforaminal lumbar interbody fusion procedures: An experimental study

Rigid and semi-rigid fixations are investigated several times in order to compare their biomechanical stability. Interbody fusion techniques are also preferable for maintaining the sagittal balance by protecting the disk height. In this study, the biomechanical comparison of semi-rigid and rigid fixations with posterior lumbar interbody fusion or transforaminal lumbar interbody fusion procedures is conducted under trauma. There were four different test groups to analyze the effect of acute load on treated ovine vertebrae. First and second groups were fixed with polyetheretherketone rods and transforaminal lumbar interbody fusion and posterior lumbar interbody fusion cages, respectively. Third and fourth groups were fixed with titanium rods and posterior lumbar interbody fusion and transforaminal lumbar interbody fusion cages, respectively. The drop tests were conducted with 7 kg weight. There were six samples in each group so the drop test repeated 24 times in total. The test samples were photographed and X-rayed (laterally and anteroposteriorly) before and after drop test. Two fractures were observed on group 1. Conversely, there were no fractures observed for group 2. There were no anterior element fractures for both groups 1 and 2. However, one fracture seen on group 3 was anterior element fracture, whereas the other three were posterior element fractures. All three fractures were anterior element fractures for group 4. Treated vertebrae with polyetheretherketone rods and posterior lumbar interbody fusion cages showed the best durability to the drop tests among the groups. Semi-rigid fixation gave better results than rigid fixation according to failed segments. Posterior lumbar interbody fusion cages seem to be better option for semi-rigid fixation, however mentioned surgical disadvantages must be considered.

Transforaminal lumbar interbody fusion (TLIF) versus posterior lumbar interbody fusion (PLIF) in lumbar spondylolisthesis: a systematic review and meta-analysis

BACKGROUND CONTEXT

Transforaminal lumbar interbody fusion (TLIF) and posterior lumbar interbody fusion (PLIF) are both frequently used as a surgical treatment for lumbar spondylolisthesis. Because of the unilateral transforaminal route to the intervertebral space used in TLIF, as opposed to the bilateral route used in PLIF, TLIF could be associated with fewer complications, shorter duration of surgery, and less blood loss, whereas the effectiveness of both techniques on back or leg pain is equal.

PURPOSE

The objective of this study was to compare the effectiveness of both TLIF and PLIF in reducing disability, and to compare the intra- and postoperative complications of both techniques in patients with lumbar spondylolisthesis.

STUDY DESIGN/SETTING

A systematic literature review and meta-analysis were carried out.

METHODS

We conducted a Medline (using PubMed), Embase (using Ovid), Cochrane Library, Current Controlled Trials, ClinicalTrials.gov and NHS Centre for Review and Dissemination search for studies reporting TLIF, PLIF, lumbar spondylolisthesis and disability, pain, complications, duration of surgery, and estimated blood loss. A meta-analysis was performed to compute pooled estimates of the differences between TLIF and PLIF. Forest plots were constructed for each analysis group.

RESULTS

A total of 192 studies were identified; nine studies were included (one randomized controlled trial and eight case series), including 990 patients (450 TLIF and 540 PLIF). The pooled mean difference in postoperative Oswestry Disability Index (ODI) scores between TLIF and PLIF was -3.46 (95% confidence interval [CI] -4.72 to -2.20, p≤.001). The pooled mean difference in the postoperative VAS scores was -0.05 (95% CI -0.18 to 0.09, p=.480). The overall complication rate was 8.7% (range 0%-25%) for TLIF and 17.0% (range 4.7-28.8%) for PLIF; the pooled odds ratio was 0.47 (95% CI 0.28-0.81, p=.006). The average duration of surgery was 169 minutes for TLIF and 190 minutes for PLIF (mean difference -20.1, 95% CI -33.5 to -6.6, p=.003). The estimated blood loss was 350 mL for TLIF and 418 mL for PLIF (mean difference -43.9 mL, 95% CI -71.2 to -16.6, p=.002).

CONCLUSIONS

TLIF has advantages over PLIF in the complication rate, blood loss, and operation duration. The clinical outcome is similar, with a slightly lower postoperative ODI score for TLIF.

Retrospective Comparison of Radiological and Clinical Outcomes of PLIF and TLIF Techniques in Patients Who Underwent Lumbar Spinal Posterior Stabilization

Degenerative disc disease and spinal stenosis lead to various symptoms. Degeneration of facet joints is added to this degenerative process with aging.Seventy-four patients who were admitted to the Spinal Column Outpatient Clinic of the Neurosurgery Department with a diagnosis of degenerative narrow spinal canal and lumbar spondylolisthesis between 2011 and 2013 and who underwent surgery were included in the study.Our study was conducted with 74 patients of whom 73.0% (n = 54) were female and 27.0% (n = 20) were male. Mean age was 54.86 ± 7.87 years (range 34-74).Although we did not detect a difference between the two surgical methods with regard to clinical improvement, transforaminal lumbar interbody fusion (TLIF) is preferred due to radiological advantages observed one year later, ease of application, and the development of fewer complications.

An effect comparison of teriparatide and bisphosphonate on posterior lumbar interbody fusion in patients with osteoporosis: a prospective cohort study and preliminary data

PURPOSE

Our purpose was to evaluate the efficacy of teriparatide for posterior lumbar interbody fusion (PLIF) in osteoporotic women.

METHODS

Forty-seven osteoporotic patients underwent PLIF with pedicle screw fixation for degenerative lumbar stenosis and instability. Patients were divided into two groups. The teriparatide group (n = 23) was injected subcutaneously with teriparatide (20 μg daily) for 3-month cycles alternating with 3-month periods of oral sodium alendronate for 12 months. The bisphosphonate group (n = 24) was administered oral sodium alendronate (91.37 mg/week) for ≥1 year. Serial plain radiography, computed tomography, and bone mineral densitometry (BMD) evaluations were performed. Fusion rate, bony fusion duration, and T score changes were evaluated. Clinical data [pain scores, Prolo's functional scale, and Oswestry disability index (ODI)] were also serially evaluated.

RESULTS

The teriparatide group showed earlier fusion than the bisphosphonate group. The average period of bone fusion was 6.0 ± 4.8 months in the teriparatide group but 10.4 ± 7.2 months in the bisphosphonate group. The bone fusion rate in the teriparatide group was higher than that in the bisphosphonate group at 6 months; however, there was no difference 12 and 24 months after surgery. Pain scores and ODI were not significantly different between groups. BMD scores in the teriparatide group were significantly improved compared with the bisphosphonate group 2 years after surgery.

CONCLUSIONS

There was no significant improvement in overall fusion rate and clinical outcome in our patients after injection of teriparatide, but the teriparatide group showed faster bony union and highly improved BMD scores.

Lumbar interbody fusion: techniques, indications and comparison of interbody fusion options including PLIF, TLIF, MI-TLIF, OLIF/ATP, LLIF and ALIF

Degenerative disc and facet joint disease of the lumbar spine is common in the ageing population, and is one of the most frequent causes of disability. Lumbar spondylosis may result in mechanical back pain, radicular and claudicant symptoms, reduced mobility and poor quality of life. Surgical interbody fusion of degenerative levels is an effective treatment option to stabilize the painful motion segment, and may provide indirect decompression of the neural elements, restore lordosis and correct deformity. The surgical options for interbody fusion of the lumbar spine include: posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), minimally invasive transforaminal lumbar interbody fusion (MI-TLIF), oblique lumbar interbody fusion/anterior to psoas (OLIF/ATP), lateral lumbar interbody fusion (LLIF) and anterior lumbar interbody fusion (ALIF). The indications may include: discogenic/facetogenic low back pain, neurogenic claudication, radiculopathy due to foraminal stenosis, lumbar degenerative spinal deformity including symptomatic spondylolisthesis and degenerative scoliosis. In general, traditional posterior approaches are frequently used with acceptable fusion rates and low complication rates, however they are limited by thecal sac and nerve root retraction, along with iatrogenic injury to the paraspinal musculature and disruption of the posterior tension band. Minimally invasive (MIS) posterior approaches have evolved in an attempt to reduce approach related complications. Anterior approaches avoid the spinal canal, cauda equina and nerve roots, however have issues with approach related abdominal and vascular complications. In addition, lateral and OLIF techniques have potential risks to the lumbar plexus and psoas muscle. The present study aims firstly to comprehensively review the available literature and evidence for different lumbar interbody fusion (LIF) techniques. Secondly, we propose a set of recommendations and guidelines for the indications for interbody fusion options. Thirdly, this article provides a description of each approach, and illustrates the potential benefits and disadvantages of each technique with reference to indication and spine level performed.

A comparative study of perioperative complications between transforaminal versus posterior lumbar interbody fusion in degenerative lumbar spondylolisthesis

BACKGROUND

Both posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) are accepted surgical techniques for the treatment of degenerative lumbar spondylolisthesis (DLS). However, it is still unclear one technique offers distinct advantages over the other.

OBJECTIVE

A retrospective study was performed to compare perioperative complications and functional outcomes of patients undergoing TLIF versus PLIF for DLS.

METHODS

A total of 226 consecutive patients who underwent surgery for treatment of DLS at three institutions were evaluated from January 2012 to December 2014. In this series, 125 patients underwent PLIF and 101 received TLIF. The operative time, blood loss, allogeneic blood transfusion rate and perioperative complications (including re-operative rate, nerve root injury, dural tear, wound infection) were compared between the two groups. Pain (VAS) and functional outcomes of patients (Kirkaldy-Willis criteria) were quantified before surgery and 1 week after surgery.

RESULTS

Patients involved in the two groups had similar baseline demographic, clinical and radiographic characteristics. The PLIF group was associated with a higher incidence of post-operative iatrogenic nerve root dysfunction [12 cases (9.6 %) versus 2 cases (1.9 %), P = 0.018] and dural tears [15 cases (12 %) versus 4 cases (3.9 %), P = 0.030]. The re-operation rate was significantly higher in patients undergoing PLIF [13 cases (10.4 %) versus 2 cases (1.9 %), P = 0.011]. In addition, intra-operative blood loss, operative times, and allogeneic blood transfusion rates were higher in the PLIF group when compared to the TLIF group (P < 0.05). The wound infection rate of the PLIF group was similar to that of the TLIF group (7.2 versus 5.0 %, P = 0.486). VAS scores were decreased from 7.08 ± 1.13 to 2.84 ± 0.89 in the PLIF group, and from 7.18 ± 1.09 to 2.84 ± 0.91 in the TLIF group, respectively (P = 0.32). 85.6 % of patients in the TLIF group had good or excellent functional outcomes within the first post-operative week compared to 83.2 % in the PLIF group (P = 0.64).

CONCLUSION

Both PLIF and TLIF were equally beneficial in improving short-term functional outcomes for patients with DLS. However, PLIFs were associated with statistically significant higher incidences of nerve root injury, dural tears, allogeneic blood transfusion, increased intra-operative times, blood loss and re-operations. Therefore, caution should be exercised when considering PLIFs.

Accidental Durotomy in Minimally Invasive Transforaminal Lumbar Interbody Fusion: Frequency, Risk Factors, and Management

Purpose. To assess the frequency, risk factors, and management of accidental durotomy in minimally invasive transforaminal lumbar interbody fusion (MIS TLIF). Methods. This single-center study retrospectively investigates 372 patients who underwent MIS TLIF and were mobilized within 24 hours after surgery. The frequency of accidental durotomies, intraoperative closure technique, body mass index, and history of previous surgery was recorded. Results. We identified 32 accidental durotomies in 514 MIS TLIF levels (6.2%). Analysis showed a statistically significant relation of accidental durotomies to overweight patients (body mass index ≥25 kg/m²; P = 0.0493). Patient age older than 65 years tended to be a positive predictor for accidental durotomies (P = 0.0657). Mobilizing patients on the first postoperative day, we observed no durotomy-associated complications. Conclusions. The frequency of accidental durotomies in MIS TLIF is low, with overweight being a risk factor for accidental durotomies. The minimally invasive approach seems to minimize durotomy-associated complications (CSF leakage, pseudomeningocele) because of the limited dead space in the soft tissue. Patients with accidental durotomy can usually be mobilized within 24 hours after MIS TLIF without increased risk. The minimally invasive TLIF technique might thus be beneficial in the prevention of postoperative immobilization-associated complications such as venous thromboembolism. This trial is registered with DRKS00006135.

Minimally Invasive Versus Open Lumbar Fusion: A Comparison of Blood Loss, Surgical Complications, and Hospital Course

BACKGROUND

Perioperative blood loss is a frequent concern in spine surgery and often necessitates the use of allogeneic transfusion. Minimally invasive technique (MIS) is an option that minimizes surgical trauma and therefore intra-operative bleeding. The purpose of this study is to evaluate the blood loss, surgical complications, and duration of inpatient hospitalization in patients undergoing open posterolateral lumbar fusion (PLF), open posterior lumbar interbody fusion (PLIF) with PLF, or MIS transforaminal lumbar interbody fusion (MIS TLIF).

METHODS

Operative reports and perioperative data of patients undergoing single-level, primary open PLF (n=41), open PLIF/PLF (n=42), and MIS TLIF (n=71) were retrospectively evaluated. Patient demographics, operative blood loss, use of transfusion products, complications, and length of stay were tabulated. Patient data was controlled for age, BMI, and gender for statistical analysis.

RESULTS

Patients undergoing open PLF and open PLIF/PLF respectively experienced a significantly higher blood loss (p<0.001), higher volume of blood transfusion (p<0.001), higher volume of cell saver transfusion (p<0.001), and more surgical complications (dural injury, wound infections, screw malposition) (p=0.02) than those undergoing MIS TLIF. There was no statistically significant difference in duration of hospital stay (p=0.11).

CONCLUSIONS

MIS TLIF provides interbody fusion with less intraoperative blood loss and subsequently a lower transfusion rate compared to open techniques, but this did not influence length of hospital stay. MIS TLIF is at least as safe as open techniques with respect to dural tear, wound infection, and screw placement.

LEVEL OF EVIDENCE

Level III, Therapeutic.

A comparison of posterior lumbar interbody fusion and transforaminal lumbar interbody fusion: a literature review and meta-analysis

Background

We compared the perioperative results and complications associated with PLIF and TLIF, and collected evidence for choosing the better fusion method.

Methods

A literature survey of the MEDLINE and EMBASE databases identified 7 comparative observational studies that met our inclusion criteria. Checklists by Cowley were used to evaluate the risk of bias of the included studies. A database including patient demographic information, perioperative results, and complications was established. The summary odds ratio and weighed mean difference with 95% confidence interval were calculated with a random-effects model.

Results

We found that PLIF had a higher complication rate (P <0.00001), and TLIF reduced the rate of durotomy (P = 0.01). No statistical difference was found between the two groups with regard to clinical satisfaction (P = 0.54), blood loss (P = 0.14), vertebral root injury (P = 0.08), graft malposition (P = 0.06), infection (P = 0.36), or rate of radiographic fusion (P = 0.27). The evidence indicated that PLIF required longer operative time (P = 0.03).

Conclusions

The evidence indicated that TLIF could reduce the complication rate and durotomy. Neither TLIP nor PLIF was found superior in terms of clinical satisfaction or radiographic fusion rate. PLIF might result in longer time in surgery.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-367) contains supplementary material, which is available to authorized users.

Instrumented transforaminal lumbar interbody fusion in surgical treatment of recurrent disc herniation

BACKGROUND

The incidence of recurrence in patients undergoing primary discectomy due to lumbar disc herniation (LDH), is regularly reported as 5-15%. In this study we aimed to evaluate surgical outcome of instrumented transforaminal lumbar interbody fusion (TLIF) in the patients suffering from recurrent LDH.

METHODS

We retrospectively studied 51 patients (30 female, 21 male) from August 2007 to October 2011. The mean age and follow-up of the patients was 46.4±14.8 (ranged; 29-77 years old) and 31.4±6.8 (ranged; 25-50 months), respectively. Clinical improvement was assessed by Oswestry Disability Index (ODI), visual analogue scale (VAS), and subjective satisfaction rate, while fusion was appraised radiologically. Data analysis was by one sample Kolmogorov-Smirnov, paired t, and Mann-Whitney tests.

RESULTS

Surgery could significantly improve mean leg and lumbar VAS and ODI from preoperative 7.4±2.5, 7.8±3.1, and 72.1±21.5 to postoperative 3.4±3.6, 3.5±2.6, and 27.5±18.0, respectively at the last follow-up visit. Subjective satisfaction rate was excellent in 24 patients (47.1%), good in 14 (27.5%), fair 11 (21.6%), and poor in two (3.9%). We had one patient with iatrogenic partial L5 nerve root injury and one with unknown late onset refractory postoperative back pain. Fusion rate was 100% and instrument failure was nil.

CONCLUSION

In surgical treatment of the patients with recurrent LDH, bilaterally instrumented TLIF is a relatively safe and effective procedure and can be associated with least instrument failure and highest fusion rate while no postoperative bracing is also needed.

The efficacy and perioperative complications associated with lumbar spinal fusion surgery, focusing on geriatric patients in the republic of Korea

Objective

The purpose of this study was to examine the efficacy and perioperative complications associated with lumbar spinal fusion surgery, focusing on geriatric patients in the Republic of Korea.

Methods

We retrospectively investigated 485 patients with degenerative spinal diseases who had lumbar spinal fusion surgeries between March 2006 and December 2010 at our institution. Age, sex, comorbidity, American Society of Anesthesiologists (ASA) class, fusion segments, perioperative complications, and outcomes were analyzed in this study. Risk factors for complications and their association with age were analyzed.

Results

In this study, 81 patients presented complications (16.7%). The rate of perioperative complications was significantly higher in patients 70 years or older than in other age groups (univariate analysis, p=0.015; multivariate analysis, p=0.024). The perioperative complications were not significantly associated with the other factors tested (sex, comorbidity, ASA class, and fusion segments). Post-operative outcomes of lumbar spinal fusion surgeries for the patients were determined on the basis of MacNab's criteria (average follow up period : 19.7 months), and 412 patients (85.0%) were classified as having "excellent" or "good" results.

Conclusion

Increasing age was an important risk factor for perioperative complications in patients undergoing lumbar spinal fusion surgery, whereas other factors were not significant. However, patients' satisfaction or return to daily activities when compared with younger patients did not show much difference. We recommend good clinical judgment as well as careful selection of geriatric patients for lumbar spinal fusion surgery.