The impact of interbody approach and lumbar level on segmental,adjacent, and sagittal alignment in degenerative lumbar pathology: a radiographic analysis six months following surgery

BACKGROUND CONTEXTInterbody fusion, including: transforaminal (TLIF), posterior (PLIF), anterior (ALIF), and lateral (LLIF); effectively treat lumbar degenerative pathology and provide spinopelvic balance. Although the decision on surgical approach and technique are multifactorial and patient specific, the impact of the interbody approach on segmental and adjacent level lordosis could be an important factor to consider during pre-operative planning to achieve pre-specified alignment goals.PURPOSEThe purpose of this study is to compare the 6-month postoperative radiographic outcomes in the lumbar spine following 1 to 2 level transforaminal (TLIF), posterior (PLIF), anterior (ALIF), and lateral (LLIF) interbody fusions at the L3-4, L4-5, and L5-S1 levels. As our primary outcome, we evaluated the change in segmental lordosis at the level of fusion in ALIF/LLIF approaches compared to TLIF/PLIF. Secondarily, we evaluated the pelvic incidence to lumbar lordosis (PI-LL) mismatch and examined the compensatory lordotic changes at the adjacent levels 6 months following surgery.STUDY DESIGNRetrospective cohort.PATIENT SAMPLEThis retrospective study included 18 centers of various practice settings across the United States. Patients were included in the study if they underwent a one- or two-level primary lumbar fusion for degenerative pathology.OUTCOMES MEASURESMeasurements of the pre-operative and 6-month post-operative lumbar AP and lateral lumbar plain radiographs included: pelvic incidence (PI), pelvic tilt, lumbar lordosis from L1-S1 (LL), as well as segmental lordosis (SL) of each segment between L1-S1.METHODSDue to there being 2 evaluated time points, patients were then grouped based on alignment into categories of preserved, restored, not corrected, and worsened.RESULTS474 patients underwent 608 levels of fusion. ALIF/LLIF resulted in significantly more segmental lordosis compared to TLIF/PLIF procedures at both L4-5 and L5-S1 (p<.001). Overall, ALIF/LLIF resulted in significantly more global lumbar lordotic alignment change compared to TLIF/PLIF (p=.01). Whether patients’ alignment was preserved versus worsened was not significantly predicted by type of procedure. Similarly, whether patients’ alignment was restored versus not corrected was not significantly predicted by type of procedure. Finally, anterior approaches resulted in decreased lordosis at adjacent levels, thus resulting in a more neutral position.CONCLUSIONIn this large multicenter retrospective study of 1 to 2 level interbody fusion surgeries, we identified that A/LLIF procedures at L4-L5 and L5-S1 resulted in greater segmental lordosis restoration and PI-LL mismatch improvement compared to T/PLIF procedures. A/LLIF may also significantly reduce lordosis (compared to T/PLIF) at the adjacent levels in a fashion that serves to reduce the lumbar lordosis that may have been increased at the fused level.     

Outcomes of stand-alone anterior lumbar interbody fusion of L5–S1 using a novel implant with anterior plate fixation

Background ContextCompared with other approaches, anterior lumbar interbody fusion (ALIF) is believed to be more effective at restoring segmental lordosis and reducing risks of adjacent-segment disease. It remains controversial, however, whether ALIF improves global lumbar lordosis or influences pelvic parameters, possibly because of the heterogeneity of implants and levels studied.PurposeTo report clinical outcomes of stand-alone ALIF with anterior plate fixation for L5–S1 and to determine the effect on global lumbar lordosis and pelvic parameters.Study DesignThis is a retrospective case series.Patient SamplePatients that underwent isolated mini-ALIF with anterior plate fixation for L5–S1.Outcome MeasuresOswestry Disability Index (ODI), Short Form 12, lower back and legs pain on Visual Analog Scale, as well as spino-pelvic parameters.MethodsThe authors reviewed the records of all patients that underwent retroperitoneal mini-ALIF for single-level L5–S1 fusion between August 2012 and December 2016. A total of 129 patients were included, but 9 patients had incomplete preoperative radiographic data, and one patient had schizophrenia and was unable to respond to outcome questionnaires, leaving 119 patients eligible for outcome assessment. At a minimum follow-up of 1 year, seven patients refused to participate in the study or could not be reached, which left a final cohort of 112 patients.ResultsNine patients were reoperated without implant removal (four pseudarthrosis, two hematomas, one sepsis, one L4–L5 disc hernia, and one L4–L5 disc degeneration). At a mean of 20±9 months, all scores improved significantly from baseline values, with net improvement in ODI of 23.3±19.9. Multivariable analyses confirmed better postoperative ODI in patients that received 18° cages (β=−9.0, p=.017), but revealed no significant trends for net improvement in ODI. Comparison of preoperative and last follow-up radiographs revealed that global lumbar lordosis increased by 4.2±7.1° (p<.001), L5–S1 segmental lordosis increased by 11.8±6.7° (p<.001), and L4–L5 segmental lordosis decreased by 1.9±3.3° (p<.001). All pelvic parameters changed: pelvic incidence increased by 0.6±2.7° (p=.003), pelvic tilt decreased by 2.5±4.1° (p<.001) and sacral slope increased by 3.3±4.7° (p<.001).ConclusionsStand-alone mini-ALIF with anterior plate fixation for L5–S1 can change pelvic parameters while improving global and segmental lumbar lordosis. The procedure resulted in a fusion rate of 96% and comparable improvements in ODI to other studies.     

Anterior lumbar interbody fusion in comparison with transforaminal lumbar interbody fusion: implications for the restoration of foraminal height, local disc angle, lumbar lordosis, and sagittal balance

OBJECT: A primary consideration of all spinal fusion procedures is restoration of normal anatomy, including disc height, lumbar lordosis, foraminal decompression, and sagittal balance. To the authors' knowledge, there has been no direct comparison of anterior lumbar interbody fusion (ALIF) with transforaminal lumbar interbody fusion (TLIF) concerning their capacity to alter those parameters. The authors conducted a retrospective radiographic analysis directly comparing ALIF with TLIF in their capacity to alter foraminal height, local disc angle, and lumbar lordosis. METHODS: The medical records and radiographs of 32 patients undergoing ALIF and 25 patients undergoing TLIF from between 2000 and 2004 were retrospectively reviewed. Clinical data and radiographic measurements, including preoperative and postoperative foraminal height, local disc angle, and lumbar lordosis, were obtained. Statistical analyses included mean values, 95% confidence intervals, and intraobserver/interobserver reliability for the measurements that were performed. RESULTS: Our results indicate that ALIF is superior to TLIF in its capacity to restore foraminal height, local disc angle, and lumbar lordosis. The ALIF procedure increased foraminal height by 18.5%, whereas TLIF decreased it by 0.4%. In addition, ALIF increased the local disc angle by 8.3 degrees and lumbar lordosis by 6.2 degrees, whereas TLIF decreased the local disc angle by 0.1 degree and lumbar lordosis by 2.1 degrees. CONCLUSIONS: The ALIF procedure is superior to TLIF in its capacity to restore foraminal height, local disc angle, and lumbar lordosis. The improved radiographic outcomes may be an indication of improved sagittal balance correction, which may lead to better long-term outcomes as shown by other studies. Our data, however, demonstrated no difference in clinical outcome between the two groups at the 2-year follow-up.     

Fusion techniques for adult isthmic spondylolisthesis: a systematic review

Introduction

Various fusion techniques have been used to treat lumbar spine isthmic spondylolisthesis (IS) in adults, including anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), posterolateral fusion (PLF), and circumferential fusion. The objective of this study was to evaluate which fusion technique provides the best clinical and radiological outcome for adult lumbar IS.

Materials and methods

A systematic review was performed. MEDLINE databases and reference lists of selected articles were searched. Inclusion criteria stated that the studies had to be controlled and that they compared clinical and radiological outcomes of various fusion techniques for treating adult IS. Exclusion criteria were use of only one treatment and non-English language articles. Two reviewers independently extracted relevant data from each included study. Statistical comparisons were made when appropriate.

Results

Nine studies that compared two surgical approaches to IS were included in this systematic review. Three were prospective studies, and six were retrospective studies. Two studies compared ALIF with instrumented PLF and ALIF with percutaneous pedicle screw fixation, two studies compared ALIF and TLIF, and five studies compared PLIF and PLF. ALIF was superior to other techniques regarding restoration of disc height, segmental lordosis, and whole lumbar lordosis. TLIF had lower complication rates. ALIF combined with PLF showed lower nonfusion rates than other techniques. However, there were no significant differences in clinical outcomes between any two techniques.

Conclusion

Compared to other fusion techniques, TLIF shows fewer complications, ALIF shows better sagittal alignment, and circumferential fusion showed better fusion rates. It was difficult to make recommendations about the optimal approach because of the methodological variance in the publications.     

Does approach matter? A comparative radiographic analysis of spinopelvic parameters in single-level lumbar fusion

Background Context

Lumbar fusion is a popular and effective surgical option to provide stability and restore anatomy. Particular attention has recently been focused on sagittal alignment and radiographic spinopelvic parameters that apply to lumbar fusion as well as spinal deformity cases. Current literature has demonstrated the effectiveness of various techniques of lumbar fusion; however, comparative data of these techniques are limited.

Hybrid construct for two levels disc disease in lumbar spine

Prospective study. To study the validity of Hybrid construction (Anterior Lumbar Interbody Fusion) ALIF at one level and total disc arthroplasty (TDA) at adjacent, for two levels disc disease in lumbar spine as surgical strategy. With growing evidence that fusion constructs in the treatment of degenerative disc disease (DDD) may alter sagittal balance and contribute to undesirable complications in the long-term, total disc arthroplasty (TDA) slowly becomes an accepted treatment option for a selected group of patients. Despite encouraging early and intermediate term results of single-level total disc arthroplasty reported in the literature, there is growing evidence that two-level arthroplasty does not fare as well. Hybrid fusion is an attempt to address two-level DDD by combining the advantages of a single-level ALIF with those of a single-level arthroplasty. 42 patients (25 females and 17 males) underwent Hybrid fusion and had a median follow-up of 26.3 months. The primary functional outcomes were assessed before and after surgery with Oswestry Disability Index and the visual analogue score of the back and legs. Patients were divided into four groups according to the percentage improvement between preop and postop ODI scores. A total of 42 patients underwent a hybrid fusion as follows: 35 L5-S1 ALIF/L4-5 prosthesis, 3 L4-5 ALIF/L3-4 prosthesis, 2 L5-S1 ALIF/L4-5 prosthesis/L3-4 prosthesis, 1 L5-S1 prosthesis/L4-5 ALIF, and 1 L5-S1 ALIF/L4-5 ALIF/L3-4 prosthesis. At 2-years clinical outcomes, mean reduction in ODI is 24.9 points (53.0% improvement compared to preop ODI). The visual analogue score for the back is 64.6% improvement. At 2-year clinical outcomes, Hybrid fusion is a viable surgical alternative for the treatment of two-level DDD in comparison with two-level TDA and with two-level fusion.     

Which procedure is better for lumbar interbody fusion: anterior lumbar interbody fusion or transforaminal lumbar interbody fusion?

Introduction

Both anterior lumbar interbody fusion (ALIF) and transforaminal lumbar interbody fusion (TLIF) surgeries are performed to obtain a solid fusion to treat lumbar spondylosis. This systematic review investigated whether surgical complications, nonfusion rate, radiographic outcome, and clinical outcome of ALIF were significantly different from those of TLIF.

Method

A computerized search of the electronic databases MEDLINE was conducted. Only therapeutic studies with a prospective or retrospective comparative design were considered for inclusion in the present investigation. Two reviewers independently extracted relevant data from each included study. Statistical comparisons were made when appropriate.

Results

Nine studies were determined to be appropriate for the systematic review, and all studies were retrospective comparative studies. Blood loss and operative time in ALIF was greater than in TLIF. There was no significant difference in the complication rate between ALIF and TLIF. The restoration of disc height, segmental lordosis, and whole lumbar lordosis in ALIF was superior to TLIF. However, clinical outcomes in ALIF were similar with TLIF, and there was no significant difference in nonfusion rate between the two techniques. Costs of ALIF were greater than those of TLIF.

Conclusion

Clinical outcomes and nonfusion rate in ALIF were similar to TLIF. However, the restoration of disc height, segmental lordosis, and whole lumbar lordosis in ALIF were superior to those in TLIF, while blood loss, operative time, and costs in ALIF were greater than in TLIF.     

Single position lateral decubitus anterior lumbar interbody fusion (ALIF) and posterior fusion reduces complications and improves perioperative outcomes compared with traditional anterior-posterior lumbar fusion

BACKGROUND CONTEXTLateral decubitus single position anterior-posterior (AP) fusion utilizing anterior lumbar interbody fusion and percutaneous posterior fixation is a novel, minimally invasive surgical technique. Single position lumbar surgery (SPLS) with anterior lumbar interbody fusion (ALIF) or lateral lumbar interbody fusion (LLIF) has been shown to be a safe, effective technique. This study directly compares perioperative outcomes of SPLS with lateral ALIF vs. traditional supine ALIF with repositioning (FLIP) for degenerative pathologies.PURPOSETo determine if SPLS with lateral ALIF improves perioperative outcomes compared to FLIP with supine ALIF.STUDY DESIGN/SETTINGMulticenter retrospective cohort study.PATIENT SAMPLEPatients undergoing primary AP fusions with ALIF at 5 institutions from 2015 to 2020.OUTCOME MEASURESLevels fused, inclusion of L4-L5, L5-S1, radiation dosage, operative time, estimated blood loss (EBL), length of stay (LOS), perioperative complications. Radiographic analysis included lumbar lordosis (LL), pelvic incidence (PI), and PI-LL mismatch.METHODSRetrospective analysis of primary ALIFs with bilateral percutaneous pedicle screw fixation between L4-S1 over 5 years at 5 institutions. Patients were grouped as FLIP or SPLS. Demographic, procedural, perioperative, and radiographic outcome measures were compared using independent samples t-tests and chi-squared analyses with significance set at p <.05. Cohorts were propensity-matched for demographic or procedural differences.RESULTSA total of 321 patients were included; 124 SPS and 197 Flip patients. Propensity-matching yielded 248 patients: 124 SPLS and 124 FLIP. The SPLS cohort demonstrated significantly reduced operative time (132.95±77.45 vs. 261.79±91.65 min; p <0.001), EBL (120.44±217.08 vs. 224.29±243.99 mL; p <.001), LOS (2.07±1.26 vs. 3.47±1.40 days; p <.001), and rate of perioperative ileus (0.00% vs. 6.45%; p =.005). Radiation dose (39.79±31.66 vs. 37.54±35.85 mGy; p =.719) and perioperative complications including vascular injury (1.61% vs. 1.61%; p =.000), retrograde ejaculation (0.00% vs. 0.81%, p =.328), abdominal wall (0.81% vs. 2.42%; p =.338), neuropraxia (1.61% vs. 0.81%; p =.532), persistent motor deficit (0.00% vs. 1.61%; p =.166), wound complications (1.61% vs. 1.61%; p =.000), or VTE (0.81% vs. 0.81%; p =.972) were similar. No difference was seen in 90-day return to OR. Similar results were noted in sub-analyses of single-level L4-L5 or L5-S1 fusions. On radiographic analysis, the SPLS cohort had greater changes in LL (4.23±11.14 vs. 0.43±8.07 deg; p =.005) and PI-LL mismatch (-4.78±8.77 vs. -0.39±7.51 deg; p =.002).CONCLUSIONSSingle position lateral ALIF with percutaneous posterior fixation improves operative time, EBL, LOS, rate of ileus, and maintains safety compared to supine ALIF with prone percutaneous pedicle screws between L4-S1.     

Comparison of the mini-open versus laparoscopic approach for anterior lumbar interbody fusion: a retrospective review

OBJECTIVE: The anterior lumbar interbody fusion (ALIF) procedure has become an accepted fusion technique for treating patients with degenerative disorders of the lumbar spine. Many consider laparoscopic ALIF to be the least invasive approach. A modification of the open laparotomy--the "mini-open" approach--is an attractive alternative. In this retrospective review, a comparison of these two ALIF approaches is presented. METHODS: We conducted a retrospective review of 98 patients who underwent ALIF procedures between 1996 and 2001 in which either a mini-open or a laparoscopic approach was used. Patient demographics, intraoperative parameters, length of hospitalization, and technique-related complications associated with the use of these two approaches were compared. The subset of patients who underwent L5-S1 ALIF procedures was analyzed separately. Statistical analysis was conducted with chi2 and Student's paired t tests. RESULTS: Between 1996 and 2001, a total of 98 patients underwent ALIF. A laparoscopic approach was used in 47 of these patients, and the mini-open technique was used in the other 51 patients. Operative preparation and procedure time were longer with the use of a laparoscopic approach, and significantly greater during L5-S1 ALIF procedures (P < 0.05). A marginal but significant increase in length of stay was observed after mini-open ALIF procedures (P < 0.05). The immediate postoperative complication rate was greater after mini-open ALIF procedures, 17.6 versus 4.3% (P < 0.05); however, the rate of retrograde ejaculation was higher in the laparoscopic group, 45 versus 6% (P < 0.05). CONCLUSION: Both the laparoscopic and mini-open techniques are effective approaches to use when performing ALIF procedures. On the basis of the data obtained in this retrospective review, the laparoscopic approach does not seem to have a definitive advantage over the mini-open exposure, particularly in an L5-S1 ALIF procedure. In our opinion, the mini-open approach possesses a number of theoretical advantages; however, the individual surgeon's preference ultimately is likely to be the dictating factor.     

单节段后路椎间融合内固定术对腰椎前凸角度变化的影响

目的探讨L4/L5单节段后路椎间融合器置入椎弓根内固定术对患者腰椎前凸角度变化的影响。方法回顾性随访分析43例L4/L5单节段后路椎间融合器置入配合使用椎弓根内固定术的患者,对患者术前、术后总腰椎前凸角度、L4/L5节段前凸角、骶骨倾斜角进行比较。结果 L4/L5单节段后路椎间融合术后患者总腰椎前凸角度与术前对比平均增加8.4°（P〈0.01）;L4/L5节段前凸角与术前对比平均增加3.5°（P〈0.05）;骶骨倾斜角与术前对比平均增加4.2°（P〈0.05）。结论 L4/L5单节段后路椎间融合器置入椎弓根内固定术可以明显改善患者腰椎前凸角度,对于改善腰椎序列和缓解患者术后腰痛症状以及延缓邻近节段退变均有积极意义。     

Segmental lumbar lordosis: manual versus computer-assisted measurement using seven different techniques

OBJECTIVES: Obliteration of end-plate landmarks by interbody fusion has made the traditional measurement of segmental lumbar lordosis nearly impossible. Because the L4-L5 and L5-S1 levels are most likely to be subjected to fusion procedures or arthroplasty and contribute to more than half of normal lumbar lordosis, it is crucial to identify a reproducible and accurate means of measuring segmental lordosis at these levels. METHODS: Twelve spinal surgeons measured lordosis at L4-L5 and L5-S1 on 10 separate radiographs using three techniques for L4-L5 and four techniques for L5-S1. With use of identical radiographs, measurements first were made using a manual method and then were repeated with a computer-assisted method. Measurements were analyzed for both intraobserver and interobserver error. RESULTS: The individual data demonstrated an intraobserver variance of 9.56 and a standard deviation of 3.092 for computerized measurements compared with 7.742 and 2.782 for manual measurements. The interobserver variance was 4.107 with a standard deviation of 2.027 for the computerized group compared with 4.221 and 2.055 for manual measurements. When analyzed as a group to evaluate interobserver error, the pooled data yielded variance of 19.235 for the computerized group and 19.117 for the manual measurements. CONCLUSIONS: Variance calculations identified the Cobb technique and the posterior vertebral body technique as the least variable measurement techniques for the L4-L5 and L5-S1 levels, respectively; however, there was no statistical significance. In direct comparison, the manual and computer-assisted techniques were found to be statistically equivalent with similar degrees of variance. We believe that the anterior vertebral technique, which did not demonstrate a significant difference from other techniques, will prove to be the most reliable method of assessing segmental lumbar lordosis in patients before surgery, after interbody fusion, and after motion-sparing disc arthroplasty.     

Mini-Open ALIF for Degenerative Spine and Adult Deformity: Surgical Technique and the Evidence

With advances in surgical technique and spinal instrumentation, the mini-open anterior approach has become increasingly utilized for lumbar interbody placement. The anterior approach is not only less disruptive regarding muscular dissection, but also provides excellent visualization of the entire disc space and a large bed for fusion. Anterior lumbar interbody fusion (ALIF) provides indirect decompression through restoration of foraminal height and has been found to produce the most potential segmental correction. Although ALIF is associated with some unique complications, it is now routinely used in cases of degenerative and isthmic spondylolisthesis, pseudarthrosis after posterior fusions, adult spinal deformity, and cases of degenerative disc disease.     

Effect of intraoperative position used in posterior lumbar interbody fusion on the maintenance of lumbar lordosis

OBJECT: The objective in this study was to compare retrospectively the use of different operating tables with different positions for posterior lumbar interbody fusion (PLIF) and the effect on intraoperative and postoperative lumbar lordosis and segmental lordosis. METHODS: One hundred seventy-two patients with degenerative disease of the lumbar spine who underwent posterior decompression and PLIF in which a 0 degrees polyetheretherketone cage and pedicle screw fixation were used were evaluated. Ninety-one patients underwent surgery on a Wilson table (Group I) and 81 patients were treated on an OSI Jackson spinal table (Group II). Preoperative standing, intraoperative prone, and postoperative standing lateral radiographs were obtained in each patient. The total lumbar and segmental lordosis were compared and analyzed according to the position in which the patients were placed for their operation. RESULTS: The intraoperative total lumbar lordosis was significantly decreased compared with the preoperative value. The postoperative total lumbar lordosis was similar, however, to the preoperative values in both groups. In Group I, the intraoperative segmental lordosis of L2-3 and L3-4 was significantly decreased compared with the pre-operative segmental lordosis. In Group II, the intraoperative segmental lordosis of L3-4, L4-5, L5-S1, and L4-S1 was significantly decreased compared with the preoperative segmental lordosis. The postoperative segmental lordosis of L4-5 was significantly decreased and L2-3 was significantly increased compared with the preoperative lordosis in both groups. CONCLUSIONS: Intraoperative position does not affect postoperative total lumbar lordosis and segmental lordosis in short-segment PLIF of the lumbar spine in a retrospective analysis of the surgical procedure to maintain lordosis.     

Anterior lumbar interbody fusion in patients with a previous discectomy: minimum 2-year follow-up

OBJECTIVE: A retrospective review was conducted to determine the availability of anterior lumbar interbody fusion (ALIF) in selected patients who presented with recurrent lumbar disc herniation. METHODS: A total of 22 patients who underwent ALIF were studied clinically and radiographically. The patients were 11 men and 11 women, with a mean age of 46 years (range 23-60 years) at the time of ALIF. The mean follow-up duration was 35 months (range 30-42 months). The fused level at which the ALIF was performed was as follows: L3-L4 (1 patient), L4-L5 (14 patients), and L5-S1 (7 patients). Back pain, leg pain, and functional outcomes were measured both before surgery and at the last follow-up visit. Patient satisfaction index was also assessed. RESULTS: Leg pain, back pain, and functional status all demonstrated statistically significant improvements between preoperative and postoperative scores by 86%, 77%, and 82%, respectively (P < 0.001). Nineteen of 22 patients (86.3%) were satisfied with their clinical results. Solid fusion was found in all patients. CONCLUSIONS: The authors found ALIF to be an effective procedure with satisfactory clinical results in selected patients with a recurrent disc herniation in the lumbar spine.     

Effect of lordosis angle change after lumbar/lumbosacral fusion on sacrum angular displacement: a finite element study

Purpose

To assess and characterize the sacrum angular displacements in response to lumbar lordosis after lumbar/lumbosacral fusion.

Methods

A finite element model of the lower lumbar spine-pelvis was established and used to simulate the posterior fusion at L3–L5 and L4–S1. The lordosis angle in the fusion segments was set to five different conditions with respect to the intact model: 10° less than intact, 5° less than intact, same as intact, 5° more than intact, and 10° more than intact. Variations of the sacrum angular displacements with lordosis changes were analyzed under loading setting of axial compression, flexion, extension, lateral bending, and axial rotation.

Results

Compared with the intact lordosis, both increased and decreased lumbar lordosis angles caused the sacrum angular displacements to be increased. The lordosis angle increased by 10° induced the most substantial increase in sacrum angular displacements. In addition, the sacrum angular displacements of the L4–S1 fusion model at different lordosis angles were higher than those of the L3–L5 fusion model.

Conclusion

The sacrum angular displacements occur as a result of the fusion surgery (L4–S1) and the changes in lumbar lordosis.     

Microscopic anterior foraminal decompression combined with anterior lumbar interbody fusion

Background context

Anterior lumbar interbody fusion (ALIF) with percutaneous pedicle screw fixation (PPF) provides successful surgical outcomes to isthmic spondylolisthesis patients with indirect decompression through foraminal volume expansion. However, indirect decompression through ALIF followed by PPF may not obtain a successful surgical outcome in patients with isthmic spondylolisthesis accompanied by foraminal stenosis caused by a posterior osteophyte or foraminal sequestrated disc herniation. Thus far, there has been no report of foraminal decompression through anterior direct access in the lumbar spine.

Purpose

This study aims to describe the new surgical technique of microscopic anterior foraminal decompression and to analyze the clinical outcomes and radiologic results of the microscopic anterior decompression during ALIF followed by PPF.

Study design/Setting

We conducted a multisurgeon, retrospective, clinical series from a single institution.

Patient sample

This study was carried out from March 2007 to July 2010 and included 40 consecutive patients with isthmic spondylolisthesis accompanied by foraminal stenosis caused by posterior osteophyte or foraminal sequestrated disc herniation undergoing microscopic anterior foraminal decompression during ALIF followed by PPF.

Outcome measures

The visual analog scales (VAS) of back and leg pain and the Oswestry disability index were measured preoperatively and at the last follow-up.

Methods

Postoperative computed tomography and magnetic resonance imaging measured whether decompression of neural structure had been made and morphometric change of the foramen and the amount of resected bone. Moreover, segmental lordosis, whole lumbar lordosis, disc height, and degree of listhesis were measured through X-ray examination before the operation and at the last follow-up; we also verified whether fusion had been achieved.

Results

Successful decompression was confirmed in both patients with foraminal stenosis caused by posterior osteophyte and those with foraminal sequestrated disc herniation. Clinically, compared with before the surgery, the VAS (leg and back) and the Oswestry disability index significantly decreased at the last follow-up (p=.000). With regard to radiology, at the last follow-up all patients had bone fusion on X-ray examination, and an increase in disc height, a reduction in the degree of listhesis, an increase in segmental lordosis, and an increase in whole lumbar lordosis were significant in both groups (p=.000) compared with before the surgery. Foraminal volume, foraminal width, and foraminal height also significantly increased postoperatively compared with before the operation (p=.000). The height, width, and dimension of resected body were 4.61±1.05 mm, 7.92±1.42 mm, 17.15±4.96 mm², respectively, in patients with foraminal stenosis caused by a posterior osteophyte, and 3.88±0.92 mm, 6.8±1.29 mm, and 13.12±2.25 mm², respectively, in patients with foraminal sequestrated disc.

Conclusions

The microscopic anterior foraminal approach provides successful foraminal decompression. Combined with ALIF and PPF, this approach shows a good surgical outcome in patients with isthmic spondylolisthesis accompanied by foraminal stenosis caused by a posterior osteophyte or those with foraminal sequestrated disc herniation.     

The effect of Harrington rod contouring on lumbar lordosis

The effect of Harrington rod sagittal plane contouring, or lack of it, on total lumbar, segmental lumbar, and lumbosacral lordosis was studied retrospectively in a series of 36 patients operated on for idiopathic scoliosis. Regardless of contouring, there was a decrease in total lumbar lordosis and lordosis above L4, with an increase in lordosis below L5. Although not statistically significant, patients with contoured rods had less loss of segmental (L1-4) lordosis and less increase in segmental lumbosacral lordosis (L4-S1) than the noncontoured group. Although helpful, additional steps beyond concave rod contouring appear to be necessary to consistently preserve lumbar lordosis.     

A case report of a rare complication of bowel perforation in extreme lateral interbody fusion

Over the past decade, extreme lateral interbody fusion (XLIF) has gained in popularity as a minimally invasive alternative to direct anterior lumbar interbody fusion (ALIF), and ALIF’s associated morbidity. Most notably, XLIF largely avoids vascular and visceral structures that are required to be mobilized in ALIF. In this case report, the authors describe a rare complication of a bowel injury in a 70-year-old male who underwent an L3–4 and L4–5 lateral transpsoas approach for interbody fusion.     

Comparison of Lumbosacral Fusion Grade in Patients after Transforaminal and Anterior Lumbar Interbody Fusion with Minimum 2-Year Follow-Up

Objective

Generally, anterior lumbar interbody fusion (ALIF) was believed superior to transforaminal lumbar interbody fusion (TLIF) in induction of fusion. However, many studies have reported comparable results in lumbosacral fusion rate between the two approaches. This study aimed to evaluate the realistic lumbosacral arthrodesis rates following ALIF and TLIF in patients with degenerative spondylolisthesis as measured by CT and radiology.

Methods

Ninety-six patients who underwent single-level L5-S1 fusion through ALIF (n = 48) or TLIF (n = 48) for degenerative spondylolisthesis at the Spine Center, University of California San Francisco, between October 2014 and December 2017 were retrospectively evaluated. Fusion was independently evaluated and categorized as solid fusion, indeterminate fusion, or pseudarthroses by two radiologists using the modified Brantigan–Steffee–Fraser (mBSF) grade. Clinical data on sex, age, body mass index, Meyerding grade, smoking status, follow-up times, complications, and radiological parameters including disc height, disc angle, segmental lordosis, and overall lumbar lordosis were collected. The fusion results and clinical and radiographic data were statistically compared between the ALIF and TLIF groups by using t-test or chi-square test.

Results

The mean follow-up period was 37.5 (ranging from 24 to 51) months. Clear, solid radiographic fusions were higher in the ALIF group compared with the TLIF group at the last follow-up (75% vs 47.9%, p = 0.006). Indeterminate fusion occurred in 20.8% (10/48) of ALIF cases and in 43.8% (21/48) of TLIF cases (p = 0.028). Radiographic pseudarthrosis was not significantly different between the TLIF and ALIF groups (16.7% vs 8.3%; p = 0.677). In subgroup analysis of the patients without bone morphogenetic protein (BMP), the solid radiographic fusion rate was significantly higher in the ALIF group than that in the TLIF group (78.6% vs 45.5%; p = 0.037). There were no differences in sex, age, body mass index, Meyerding grade, smoking status, or follow-up time between the two groups (p > 0.05). The ALIF group had more improvement in disc height (7.8 mm vs 4.7 mm), disc angle (5.2° vs 1.5°), segmental lordosis (7.0° vs 2.5°), and overall lumbar lordosis (4.7° vs 0.7°) compared with the TLIF group (p < 0.05). Overall complication rates were similar between the TLIF and ALIF groups (10.4% vs 8.33%; p > 0.999).

Conclusions

With a minimum 2-year radiographic analysis of arthrodesis at lumbosacral level by radiologists, the rate of solid radiographic fusions was higher in the ALIF group compared with the TLIF group, whereas the TLIF group had a higher rate of indeterminate fusion. Radiographic pseudarthrosis did not differ significantly between the TLIF and ALIF groups.