Extreme lateral interbody fusion in spinal revision surgery: clinical results and complications

Preoperative Multifidus Muscle Quality is Associated With Patient Reported Outcomes After Lateral Lumbar Interbody Fusion

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

Lateral lumbar interbody fusion (LLIF) commonly involves a transpsoas approach. Despite the association between LLIF, postoperative iliopsoas weakness, and iatrogenic neuropraxia, no study has yet examined the effect of psoas or multifidus muscle quality on patient-reported outcomes (PROs).

METHODS

This study retrospectively reviewed patients who underwent LLIF with 1-year minimum follow-up. Psoas and multifidus muscle qualities were graded on preoperative magnetic resonance imaging using two validated classification systems for muscle atrophy. Average muscle quality was calculated as the mean score from all levels (L1-2 through L5-S1). Univariate and multivariate statistics were utilized to investigate the relationship between psoas/multifidus muscle quality and preoperative, 6-weeks postoperative, and final postoperative PROs.

RESULTS

74 patients (110 levels) with a mean follow-up of 18.71 ± 8.02 months were included for analysis. Greater multifidus atrophy was associated with less improvement on ODI, SF12, and VR12 (P < .05) on univariate analysis. On multivariate analysis, worse multifidus atrophy predicted less improvement on SF12 and VR12 (P < .05).

CONCLUSION

Despite the direct manipulation of the psoas muscle inherent to LLIF, preoperative psoas muscle quality did not affect postoperative outcomes. Rather, the extent of preoperative multifidus fatty infiltration and atrophy was more likely to predict postoperative pain and disability. These findings suggest that multifidus atrophy may be more pertinent than psoas atrophy in its association with patient-reported outcome measures after LLIF.

Adjacent segment degeneration after posterolateral lumbar fusion: results and complications of posterior revision surgery

BACKGROUND

Lumbar fusion is an important technique for the treatment of degenerative pathologies. Adjacent segment degeneration is a known complication after lumbar fusion that causes significant morbidity. Our objective was to evaluate the demographics, risk factors, type of surgery, and surgical complications in patients who underwent reoperation through a posterior route due to adjacent segment degeneration.

METHODS

We performed a retrospective analysis of all patients who underwent instrumented posterolateral fusion in the lumbar spine for the treatment of degenerative diseases from January 2000 to December 2015 at a single institution. Patients who developed symptomatic adjacent segment degeneration requiring a second surgery were noted and compared with patients who did not develop adjacent segment degeneration.

RESULTS

A total of 750 patients with degenerative pathologies who underwent fusion with instrumentation were identified. Forty-five patients (6%) required a second surgery for symptomatic adjacent segment degeneration. The average onset of adjacent segment degeneration symptoms after fusion was 5.89 years. Adjacent segment degeneration occurred above the level of fusion in 40 cases and below in 5 cases. The risk factor identified in our series was L5-S1 fusion. The main complication seen after the second surgery was infection in 5 cases (11%).

CONCLUSIONS

This study identifies the L5-S1 fusion as a possible risk factor for adjacent segment degeneration. Reoperation through a posterior route is a therapeutic option but is associated with considerable morbidity. Further studies are necessary to elucidate this pathology and the best options for its management.

Establishing a Standardized Clinical Consensus for Reporting Complications Following Lateral Lumbar Interbody Fusion

Background and Objectives: Mitigating post-operative complications is a key metric of success following interbody fusion. LLIF is associated with a unique complication profile when compared to other approaches, and while numerous studies have attempted to report the incidence of post-operative complications, there is currently no consensus regarding their definitions or reporting structure. The aim of this study was to standardize the classification of complications specific to lateral lumbar interbody fusion (LLIF). Materials and Methods: A search algorithm was employed to identify all the articles that described complications following LLIF. A modified Delphi technique was then used to perform three rounds of consensus among twenty-six anonymized experts across seven countries. Published complications were classified as major, minor, or non-complications using a 60% agreement threshold for consensus. Results: A total of 23 articles were extracted, describing 52 individual complications associated with LLIF. In Round 1, forty-one of the fifty-two events were identified as a complication, while seven were considered to be approach-related occurrences. In Round 2, 36 of the 41 events with complication consensus were classified as major or minor. In Round 3, forty-nine of the fifty-two events were ultimately classified into major or minor complications with consensus, while three events remained without agreement. Vascular injuries, long-term neurologic deficits, and return to the operating room for various etiologies were identified as important consensus complications following LLIF. Non-union did not reach significance and was not classified as a complication. Conclusions: These data provide the first, systematic classification scheme of complications following LLIF. These findings may improve the consistency in the future reporting and analysis of surgical outcomes following LLIF.

The leptomeninges as a critical organ for normal CNS development and function: First patient and public involved systematic review of arachnoiditis (chronic meningitis)

BACKGROUND & IMPORTANCE

This patient and public-involved systematic review originally focused on arachnoiditis, a supposedly rare "iatrogenic chronic meningitis" causing permanent neurologic damage and intractable pain. We sought to prove disease existence, causation, symptoms, and inform future directions. After 63 terms for the same pathology were found, the study was renamed Diseases of the Leptomeninges (DLMs). We present results that nullify traditional clinical thinking about DLMs, answer study questions, and create a unified path forward.

METHODS

The prospective PRISMA protocol is published at Arcsology.org. We used four platforms, 10 sources, extraction software, and critical review with ≥2 researchers at each phase. All human sources to 12/6/2020 were eligible for qualitative synthesis utilizing R. Weekly updates since cutoff strengthen conclusions.

RESULTS

Included were 887/14286 sources containing 12721 DLMs patients. Pathology involves the subarachnoid space (SAS) and pia. DLMs occurred in all countries as a contributor to the top 10 causes of disability-adjusted life years lost, with communicable diseases (CDs) predominating. In the USA, the ratio of CDs to iatrogenic causes is 2.4:1, contradicting arachnoiditis literature. Spinal fusion surgery comprised 54.7% of the iatrogenic category, with rhBMP-2 resulting in 2.4x more DLMs than no use (p<0.0001). Spinal injections and neuraxial anesthesia procedures cause 1.1%, and 0.2% permanent DLMs, respectively. Syringomyelia, hydrocephalus, and arachnoid cysts are complications caused by blocked CSF flow. CNS neuron death occurs due to insufficient arterial supply from compromised vasculature and nerves traversing the SAS. Contrast MRI is currently the diagnostic test of choice. Lack of radiologist recognition is problematic.

DISCUSSION & CONCLUSION

DLMs are common. The LM clinically functions as an organ with critical CNS-sustaining roles involving the SAS-pia structure, enclosed cells, lymphatics, and biologic pathways. Cases involve all specialties. Causes are numerous, symptoms predictable, and outcomes dependent on time to treatment and extent of residual SAS damage. An international disease classification and possible treatment trials are proposed.

Single-position prone transpsoas fusion for the treatment of lumbar adjacent segment disease: early experience of twenty-four cases across three tertiary medical centers

PURPOSE

Prone transpsoas fusion (PTP) is a minimally invasive technique that maximizes the benefit of lateral access interbody surgery and the prone positioning for surgically significant adjacent segment disease. The authors describe the feasibility, reproducibility and radiographic efficacy of PTP when performed for cases of lumbar ASD.

METHODS

Adult patients undergoing PTP for treatment of lumbar ASD at three institutions were retrospectively enrolled. Demographic information was recorded, as was operative data such as adjacent segment levels, operative time, blood loss, laterality of approach, open versus percutaneous pedicle screw instrumentation and need for primary decompression. Radiographic measurements including segmental and global lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope and sagittal vertical axis were recorded both pre- and immediately post-operatively.

RESULTS

Twenty-four patients met criteria for inclusion. Average age was 60.4 ± 10.4 years and average BMI was 31.6 ± 5.0 kg/m². Total operative time was 204.7 ± 83.3 min with blood loss of 187.9 ± 211 mL. Twenty-one patients had pedicle screw instrumentation exchanged percutaneously and 3 patients had open pedicle screw exchange. Two patients suffered pulmonary embolism that was treated medically with no long-term sequelae. One patient had transient lumbar radicular pain and all patients were discharged home with an average length of stay of 3.0 days (range 1-6). Radiographically, global lumbar lordosis improved by an average of 10.3 ± 9.0 degrees, segmental lordosis by 10.1 ± 13.3 degrees and sagittal vertical axis by 3.2 ± 3.2 cm.

CONCLUSION

Single-position prone transpsoas lumbar interbody fusion is a clinically reproducible minimally invasive technique that can effectively treat lumbar adjacent segment disease.

Development and Initial Internal Validation of a Novel Classification System for Perioperative Expectations Following Minimally Invasive Degenerative Lumbar Spine Surgery

STUDY DESIGN

This was a prospective consecutive clinical cohort study.

OBJECTIVE

The purpose of our study was to develop and provide an initial internal validation of a novel classification system that can help surgeons and patients better understand their postoperative course following the particular minimally invasive surgery (MIS) and approach that is utilized.

SUMMARY OF BACKGROUND DATA

Surgeons and patients are often attracted to the option of minimally invasive spine surgery because of the perceived improvement in recovery time and postsurgical pain. A classification system based on the impact of the surgery and surgical approach(es) on postoperative recovery can be particularly helpful.

METHODS

Six hundred thirty-one patients who underwent MIS lumbar/thoracolumbar surgery for degenerative conditions of the spine were included. Perioperative outcomes-operative time, estimated blood loss, postsurgical length of stay (LOS), 90-day complications, postoperative day zero narcotic requirement [in Morphine Milligram Equivalent (MME)], and need for intravenous patient-controlled analgesia (IV PCA).

RESULTS

Postoperative LOS and postoperative narcotic use were deemed most clinically relevant, thus selected as primary outcomes. Type of surgery was significantly associated with all outcomes (P<0.0001), except intraoperative complications. Number of levels for fusion was significantly associated with operative time, in-hospital complications, 24 hours oral MME, and the need for IV PCA and LOS (P<0.0001). Number of surgical approaches for lumbar fusion was significantly associated with operative time, 24 hours oral MME, need for IV PCA and LOS (P<0.001). Based on these parameters, the following classification system ("Qureshi-Louie classification" for MIS degenerative lumbar surgery) was devised: (1) Decompression-only; (2) Fusion-1 and 2 levels, 1 approach; (3) Fusion-1 level, 2 approaches; (4) Fusion-2 levels, 2 approaches; (5) Fusion-3+ levels, 2 approaches.

CONCLUSIONS

We present a novel classification system and initial internal validation to describe the perioperative expectations following various MIS surgeries in the degenerative lumbar spine. This initial description serves as the basis for ongoing external validation.

Comparison of Posterior Unilateral Vertebral Column Resection Versus Posterior Vertebral Column Resection for Severe Thoracolumbar Angular Kyphosis as a Revision Surgical Modality: A Retrospective Cohort Study

OBJECTIVE

The objective of this study was to determine the safety and efficacy of posterior unilateral vertebral column resection (PUVCR) as revision surgery for severe thoracolumbar angular kyphosis.

PATIENTS AND METHODS

This is a retrospective cohort study. Adult patients undergoing revision surgery for severe thoracolumbar angular kyphosis in 2010-2016 with ≥2-year follow-up at our institution were assessed. Perioperative complications and clinical outcomes, including blood loss, operation time, Visual Analog Scale score, Oswestry Disability Index, and preoperative and postoperative kyphotic angles, were analyzed.

RESULTS

This study included 58 patients who were divided into the PUVCR group and the posterior vertebral column resection (PVCR) group. Age ( P =0.810), sex distribution ( P =0.500), and vertebrae that underwent surgery ( P =0.638) were similar in the 2 groups. Shorter mean operation time was observed in the PUVCR group as compared with the PVCR group ( P <0.001). In addition, less blood loss was recorded in the PUVCR group as compared with the PVCR group ( P =0.001). There were no significant differences between the 2 groups in a change of Visual Analog Scale scores postoperation versus preoperation ( P =0.961), and at postoperative 3 months ( P =0.906), 12 months ( P =0.752), and 24 months ( P =0.811) versus postoperation, respectively. There were no significant differences between the 2 groups in Oswestry Disability Index changes postoperation versus preoperation ( P =0.157), and at postoperative 3 months ( P =0.899), 12 months ( P =0.947), and 24 months ( P =0.811) versus postoperation, respectively. PUVCR and PVCR were comparable in deformity correction ( P =0.434) and final angle correction ( P =0.790). Complication rates in the PUVCR and PVCR groups were 7.1% and 36.7%, respectively.

CONCLUSION

PUVCR has comparable safety and efficacy to PVCR in treating severe thoracolumbar angular kyphosis, with the advantages of the shorter operation time, less blood loss, and fewer complications.

Intraoperative Computed Tomography-Based Navigation with Augmented Reality for Lateral Approaches to the Spine

Background. Lateral approaches to the spine have gained increased popularity due to enabling minimally invasive access to the spine, less blood loss, decreased operative time, and less postoperative pain. The objective of the study was to analyze the use of intraoperative computed tomography with navigation and the implementation of augmented reality in facilitating a lateral approach to the spine. Methods. We prospectively analyzed all patients who underwent surgery with a lateral approach to the spine from September 2016 to January 2021 using intraoperative CT applying a 32-slice movable CT scanner, which was used for automatic navigation registration. Sixteen patients, with a median age of 64.3 years, were operated on using a lateral approach to the thoracic and lumbar spine and using intraoperative CT with navigation. Indications included a herniated disc (six patients), tumors (seven), instability following the fracture of the thoracic or lumbar vertebra (two), and spondylodiscitis (one). Results. Automatic registration, applying intraoperative CT, resulted in high accuracy (target registration error: 0.84 ± 0.10 mm). The effective radiation dose of the registration CT scans was 6.16 ± 3.91 mSv. In seven patients, a control iCT scan was performed for resection and implant control, with an ED of 4.51 ± 2.48 mSv. Augmented reality (AR) was used to support surgery in 11 cases, by visualizing the tumor outline, pedicle screws, herniated discs, and surrounding structures. Of the 16 patients, corpectomy was performed in six patients with the implantation of an expandable cage, and one patient underwent discectomy using the XLIF technique. One patient experienced perioperative complications. One patient died in the early postoperative course due to severe cardiorespiratory failure. Ten patients had improved and five had unchanged neurological status at the 3-month follow up. Conclusions. Intraoperative computed tomography with navigation facilitates the application of lateral approaches to the spine for a variety of indications, including fusion procedures, tumor resection, and herniated disc surgery.

Benefits of Early Ambulation in Elderly Patients Undergoing Lumbar Decompression and Fusion Surgery: A Prospective Cohort Study

Objective

To evaluate the effects of early ambulation on elderly patients’ postoperative physical functional outcomes, complications, 90‐day readmission rate, and the length of postoperative hospital stay.

Methods

This is a prospective cohort study conducted between June 2019 and December 2019. The study enrolled 86 elderly patients (39 males) with newly diagnosed lumbar degenerative disease undergoing single‐segment decompression and fusion surgerywere enrolled. Of all 86 patients, 39 voluntarily joined the early ambulation group, and 47 joined the regular ambulation group. The early ambulation group included patients ambulated within 4 h postoperatively, whereas the regular ambulation group included patients who were ambulatory at a minimum of 24 h after surgery. Participants’ baseline characteristics, surgical information, ambulation ability, degree of pain, functional scores, postoperative complications, 90‐day readmission rate, and length of postoperative hospital stay were recorded.

Results

Participants’ baseline demographic characteristics were balanced between the early ambulation group and the regular ambulation group. The operative time and blood loss were similar between groups. The time before the first‐time ambulation was 4 ± 0.5 h in the early ambulation group and 28 ± 4.5 h in the regular ambulation group. Ambulating distance was significantly longer in the early ambulation group compared with the regular ambulation group on the 1st (63 ± 45 vs 23 ± 60 m), the 2nd (224 ± 100 vs 101 ± 130 m), and the 3rd (280 ± 102.5 vs 190 ± 170 m) ambulation days based on generalized estimating equation analyses. Generalized estimating equation analyses also demonstrated that the ambulating time was longer in the early ambulation group compared with the regular ambulation group on the 1st (10 ± 5 vs 10 ± 5 min), the 2nd (19 ± 7 vs 15 ± 5 min), and the 3rd (22 ± 16.5 vs 27 ± 12 min) ambulation days. Patients in the regular ambulation group experienced a higher degree of pain than the early ambulation group patients, with an odds ratio of 1.627 (P = 0.002). Short‐term functional independence was superior in the early ambulation group, with a lower Roland–Morris disability questionnaire score (P = 0.008) and Oswestry disability index (P < 0.001). The incidences of postoperative urinary retention (early ambulation group: 7.7%, regular ambulation group: 25.5%, P = 0.030) and ileus (early ambulation group: 0%, regular ambulation group: 12.8%, P = 0.030) were significantly higher in the regular ambulation group. The prevalence of at least one complication rate was significantly lower in the early ambulation group than in the regular ambulation group (early ambulation group, 23.1%; regular ambulation group, 46.8%, P = 0.022). The duration of indwelling of the drainage catheter was shorter in the early ambulation group (early ambulation group, 68 ± 24 h; regular ambulation group, 78 ± 20 h, P = 0.001), and the length of the postoperative hospital stay was also shorter in the early ambulation group (early ambulation group, 4 ± 0 days; regular ambulation group: 5 ± 2 days, P < 0.001). However, there was no statistical difference in the 90‐day readmission rate between groups.

Conclusion

Early ambulation improved patients’ postoperative functional status, decreased the incidence of complications, and shortened postoperative hospital stay in elderly patients undergoing lumbar decompression and fusion surgery.

Extreme lateral interbody fusion and percutaneous pedicle screw fixation in the minimally invasive treatment of thoracic tuberculosis

OBJECTIVE

As a minimally invasive intervertebral fusion technique popularized in recent years, extreme lateral interbody fusion (XLIF) has various advantages. In this study, we describe the application and efficacy of XLIF for the treatment of thoracic tuberculosis (TB), as this may be an emerging treatment option for thoracic TB in the future.

METHODS

We present the case of a 75-year-old man who had suffered from chest and back pain for 1 month. Imaging studies showed destruction of the T12 and L1 vertebral bodies and the T12-L1 intervertebral disc, accompanied by formation of a paravertebral abscess. After 2 weeks of standard anti-TB treatment, the patient underwent debridement of the lesions, XLIF, and percutaneous pedicle screw fixation.

RESULTS

The patient's chest and back pain were significantly alleviated after the operation. The patient recovered well, and as of the most recent follow-up had no obvious limitation in thoracolumbar spine function.

CONCLUSIONS

XLIF combined with percutaneous pedicle screw fixation for the treatment of thoracic TB can allow for TB lesion debridement, discectomy, and interbody fusion under direct visualization, and can effectively improve patient prognosis.

State of the art advances in minimally invasive surgery for adult spinal deformity

Adult spinal deformity (ASD) can be associated with substantial suffering due to pain and disability. Surgical intervention for achieving neural decompression and restoring physiological spinal alignment has shown to result in significant improvement in pain and disability through patient-reported outcomes. Traditional open approaches involving posterior osteotomy techniques and instrumentation are effective based on clinical outcomes but associated with high complication rates, even in the hands of the most experienced surgeons. Minimally invasive techniques may offer benefit while decreasing associated morbidity. Minimally invasive surgery (MIS) for ASD has evolved over the past 20 years, driven by improved understanding of open procedures along with novel technique development and technologic advancements. Early efforts were hindered due to suboptimal outcomes resulting from high pseudarthrosis, inadequate correction, and fixation failure rates. To address this, multi-center collaborative groups have been established to study large numbers of ASD patients which have been vital to understanding optimal patient selection and individualized management strategies. Different MIS decision-making algorithms have been described to better define appropriate candidates and interbody selection approaches in ASD. The purpose of this state of the review is to describe the evolution of MIS surgery for adult deformity with emphasis on landmark papers, and to discuss specific MIS technology for ASD, including percutaneous pedicle screw instrumentation, hyperlordotic grafts, three-dimensional navigation, and robotics.

ALIF in the correction of spinal sagittal misalignment. A systematic review of literature

PURPOSE

We aim at analysing the impact of anterior lumbar interbody fusion (ALIF) in restoring the main spinopelvic parameters, along with its potentials and limitations in correcting sagittal imbalance.

MATERIALS AND METHODS

The 2009 PRISMA flow chart was used to systematically review the literature; 27 papers were eventually selected. The following spinopelvic parameters were observed: pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), segmental lumbar lordosis (LLseg) and sagittal vertical axis (SVA). Papers reporting on hyperlordotic cages (HLC) were analysed separately. The indirect decompression potential of ALIF was also assessed. The clinical outcome was obtained by collecting visual analogue scale (VAS) for back and leg pain and Oswestry Disability Index (ODI) scores. Global fusion rate and main complications were collected.

RESULTS

PT, SS, LL, LLseg and SVA spinopelvic parameters all improved postoperatively by - 4.3 ± 5.2°, 3.9 ± 4.5°, 10.6 ± 12.5°, 6.7 ± 3.5° and 51.1 ± 44.8 mm, respectively. HLC were statistically more effective in restoring LL and LLseg (p < 0.05). Postoperative disc height, anterior disc height, posterior disc height and foraminal height, respectively, increased by 58.5%, 87.2%, 80.9% and 18.1%. Postoperative improvements were observed in VAS back and leg and ODI scores (p < 0.05). The global fusion rate was 94.5 ± 5.5%; the overall complication rate was 13%.

CONCLUSION

When managing sagittal imbalance, ALIF can be considered as a valid technique to achieve the correct spinopelvic parameters based on preoperative planning. This technique permits to obtain an optimal LL distribution and a solid anterior column support, with lower complications and higher fusion rates when compared to posterior osteotomies.

Lateral lumbar interbody fusion in revision surgery for restenosis after posterior decompression

OBJECTIVE

The purpose of this study was to compare the clinical results of revision interbody fusion surgery between lateral lumbar interbody fusion (LLIF) and posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF) with propensity score (PS) adjustments and to investigate the efficacy of indirect decompression with LLIF in previously decompressed segments on the basis of radiological assessment.

METHODS

A retrospective study of patients who underwent revision surgery for recurrence of neurological symptoms after posterior decompression surgery was performed. Postoperative complications and operative factors were evaluated and compared between LLIF and PLIF/TLIF. Moreover, postoperative improvement in cross-sectional areas (CSAs) in the spinal canal and intervertebral foramen was evaluated in LLIF cases.

RESULTS

A total of 56 patients (21 and 35 cases of LLIF and PLIF/TLIF, respectively) were included. In the univariate analysis, the LLIF group had significantly more endplate injuries (p = 0.03) and neurological deficits (p = 0.042), whereas the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), surgical site infections (SSIs) (p = 0.02), and estimated blood loss (EBL) (p < 0.001). After PS adjustments, the LLIF group still showed significantly more endplate injuries (p = 0.03), and the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), EBL (p < 0.001), and operating time (p = 0.04). The PLIF/TLIF group showed a trend toward a higher incidence of SSI (p = 0.10). There was no statistically significant difference regarding improvement in the Japanese Orthopaedic Association scores between the 2 surgical procedures (p = 0.77). The CSAs in the spinal canal and foramen were both significantly improved (p < 0.001).

CONCLUSIONS

LLIF is a safe, effective, and less invasive procedure with acceptable complication rates for revision surgery for previously decompressed segments. Therefore, LLIF can be an alternative to PLIF/TLIF for restenosis after posterior decompression surgery.

Lateral Lumbar Interbody Fusion: What Is the Evidence of Indirect Neural Decompression? A Systematic Review of the Literature

BACKGROUND

In the past decade, lateral lumbar interbody fusion (LLIF) has gained in popularity. A proposed advantage is the achievement of indirect neural decompression. However, evidence of the effectiveness of LLIF in neural decompression in lumbar degenerative conditions remains unclear.

QUESTIONS/PURPOSES

We sought to extrapolate clinical and radiological results and consequently the potential benefits and limitations of LLIF in indirect neural decompression in degenerative lumbar diseases.

METHODS

We conducted a systematic review of the literature in English using the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and checklist. Scores on the Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain were extracted, as were data on the following radiological measurements: disc height (DH), foraminal height (FH), foraminal area (FA), central canal area (CA).

RESULTS

In the 42 articles included, data on 2445 patients (3779 levels treated) with a mean follow-up of 14.8 ± 5.9 months were analyzed. Mean improvements in VAS back, VAS leg, and ODI scale scores were 4.1 ± 2.5, 3.9 ± 2.2, and 21.9 ± 7.2, respectively. Post-operative DH, FH, FA, and CA measurements increased by 68.6%, 21.9%, 37.7%, and 29.3%, respectively.

CONCLUSION

Clinical results indicate LLIF as an efficient technique in indirect neural decompression. Analysis of radiological data demonstrates the effectiveness of symmetrical foraminal decompression. Data regarding indirect decompression of central canal and lateral recess are inconclusive and contradictory. Bony stenosis appears as an absolute contraindication. The role of facet joint degeneration is unclear. This systematic review provides a reference for surgeons to define the potential and limitations of LLIF in indirect neural elements decompression.

Fusion rate and influence of surgery-related factors in lumbar interbody arthrodesis for degenerative spine diseases: a meta-analysis and systematic review

The aim of this meta-analysis and systematic review is to summarize and critically analyze the influence of surgery-related factors in lumbar interbody fusion for degenerative spine diseases. A systematic review of the literature was carried out with a primary search being performed on Medline through PubMed. The 2009 PRISMA flowchart and checklist were taken into account. Sixty-seven articles were included in the analysis: 48 studies were level IV of evidence, whereas 19 were level III. All interbody fusion techniques analyzed have proved to reach a good fusion rate. An overall mean fusion rate of 93% (95% CI 92-95%, p < 0.001) was estimated pooling the selected studies. The influence of sagittal parameters and cages features in fusion rate was not clear. Autograft is considered the gold standard material. The use of synthetic bone substitutes and biological factors alone or combined with bone graft have shown conflicting results. Low level of evidence studies and high heterogeneity (χ² = 271.4, df = 72, p < 0.001; I² = 73.5%, τ² = 0.05) in data analysis could result in the risk of bias. Further high-quality studies would better clarify these results in the future.

Association Between Surgical Level and Early Postoperative Thigh Symptoms Among Patients Undergoing Standalone Lateral Lumbar Interbody Fusion

BACKGROUND

Lateral lumbar interbody fusion (LLIF) has often been associated with postoperative lumbar plexus symptoms, including pain, paresthesia, and motor deficits in the lower extremities, especially the anterior thigh regions. Previous studies have suggested that LLIF procedures at L4-L5 will be associated with a greater motor deficit rate than other levels. However, it is unclear which level has the greatest risk of pain and paresthesia. The purpose of the present retrospective observational study was to investigate the difference in the incidence of early postoperative thigh symptoms (pain and paresthesia) stratified by procedure level among patients who had undergone standalone LLIF.

METHODS

We reviewed the data from consecutive patients who had undergone LLIF at a single academic institution. A total of 285 standalone LLIF cases without preoperative motor deficits were identified. The incidence of postoperative thigh pain and paresthesia at the 6-week postoperative follow-up examination was assessed at all levels from T12-L1 to L4-L5.

RESULTS

A total of 81 patients (28.4%) had anterior thigh pain and 62 (21.8%) had anterior thigh paresthesia. The presence of ≥3 levels fused (odds ratio [OR], 2.96; P = 0.004) and surgery at L2-L3 (OR, 2.59; P = 0.001) were significant risk factors for postoperative anterior thigh paresthesia on univariate analysis but were not associated with anterior thigh pain. Multivariate analyses demonstrated that only surgery L2-L3 was an independent risk factor for anterior thigh paresthesia (OR, 2.09; P = 0.049).

CONCLUSIONS

Our results have demonstrated that standalone LLIF at the L2-L3 was significantly associated with a greater incidence of postoperative anterior thigh paresthesia but that the incidence of postoperative thigh pain showed no significant association with any operative level.

Risks of Colon Injuries in Extreme Lateral Approaches to the Lumbar Spine: An Anatomical Study

Introduction


The extreme lateral interbody fusion technique (XLIF) is a modification of the retroperitoneal approach to the lumbar spine. This is a minimally invasive technique allowing direct access to the disc space without peritoneal or posterior paraspinal musculature damage. Nevertheless, the retroperitoneal part of the colon can be injured in this operative technique. To our knowledge, a study analyzing the anatomical considerations of the extreme lateral interbody fusion technique with regards to potential colon injuries has not been previously performed. Therefore, the aim of this study was to evaluate the potential risk of colon injuries during the extreme lateral approach to the lumbar spine.

Materials and Methods


The extreme lateral approach to the lumbar spine was performed on four fresh-frozen cadaveric sides. K-wires were placed into the intervertebral discs and positioned at L1/L2, L2/L3, L3/L4, and L4/L5 levels. Next, the distances from the wires to the most posterior aspect of the adjacent ascending or descending colon were measured.


Results


The mean distance from the intervertebral disc space to the ascending or descending colon was 23.2 mm at the L2/L3 level, 29.5 mm at the L3/L4 level, and 40.3 mm at the L4/L5 level. The L1/L2 level was above the colon on both sides.


Conclusion


Our study quantified the relationship of the retroperitoneal colon during an extreme lateral interbody fusion approach. Our results, as well as previously described cases of bowel perforations, suggest a greater risk for colon injuries at the L2/3 and L3/4 levels.​​​​​​​

Anatomical Study of the Extreme Lateral Transpsoas Lumbar Interbody Fusion with Application to Minimizing Injury to the Kidney

Objective Since the extreme lateral lumbar interbody fusion procedure was first reported by Ozgur in 2006, a large number of clinical studies have been published. Anatomical studies which explore methods to avoid visceral structures, such as the kidney, with this approach have not been examined in detail. We dissected the retroperitoneal space to analyze how the extreme lateral transpsoas approach to the lumbar spine could damage the kidney and related structures. Methods Eight sides from four fresh Caucasian cadavers were used for this study. The latissimus dorsi muscle and the thoracolumbar fascia were dissected to open the retroperitoneum. The fat tissue was removed. Steel wires were then put into the intervertebral disc spaces. Finally, the closest distance between kidney and wires on each interdiscal space was measured. Results The closest distance from the wire in the interdiscal space on L1/2, L2/3 and L3/4 to the kidney ranged from 13.2 mm to 32.9 mm, 20.0 mm to 27.7 mm, and 20.5 mm to 46.6 mm, respectively. The distance from the kidney to the interdiscal space at L4/5 was too great to be considered applicable to this study. Conclusions The results of this study might help surgeons better recognize the proximity of the kidney and avoid injury to it during the extreme lateral transpsoas approach to the lumbar spine.

Salvage Strategy for Failed Spinal Fusion Surgery Using Lumbar Lateral Interbody Fusion technique: A Technical Note

INTRODUCTION

Failed spinal fusion surgery sometimes requires salvage surgery when symptomatic, especially with postsurgical decrease in intervertebral disc height followed by foraminal stenosis. For such cases, an anterior approach to lumbar lateral interbody fusion (LLIF) provides safe, direct access to the pathological disc space and a potential improvement in the fusion rate. One LLIF approach, oblique lateral interbody fusion (OLIF), targets the oblique lateral window of the intervertebral discs to achieve successful lateral interbody fusion. The current technical note describes spinal revision surgery using the OLIF procedure.

TECHNICAL NOTE

The subjects were patients with leg pain and/or lower back pain derived from decreased intervertebral height followed by foraminal stenosis due to failed spinal fusion surgery. These patients underwent additional OLIF surgery and posterior fusion with no additional posterior direct decompression. Their outcomes were evaluated using the Japanese Orthopaedic Association (JOA) scores at baseline and final follow-up. Bony union was also evaluated using computed tomography images at final follow-up. Six subjects were evaluated, with two representative cases described in detail. Four patients had an adjacent segment disorder, and the other two patients had pseudarthrosis due to postoperative infection. The mean JOA score improved from 5.7 ± 5.4 to 21.2 ± 2.3, with a mean recovery rate of 65.0%. All cases showed intervertebral bony union.

CONCLUSIONS

We introduced a salvage strategy for failed posterior spine fusion surgery cases using the OLIF procedure. Patients effectively achieved recovered intervertebral and foraminal height with no additional posterior direct decompression.