An updated classification of the anatomical variations of the internal iliac venous drainage system: Surgical implications for anterior lumbar spinal approaches.

BACKGROUND: Advanced pelvic surgery is associated with potential vascular risks. The aim of this study was to complete the existing classification of the anatomical variations of the internal iliac veins encountered on a series of preoperative angio CT with a view to performing anterior lumbar spine surgery. MATERIALS AND METHODS: In this monocentric retrospective study conducted between 2010 and 2020, all preoperative angio CT performed before an anterior lumbar surgery were systematically analyzed. All the abnormalities of the iliac veins were referenced in an updated classification system. RESULTS: 910 patients (431 men and 479 women) with a mean age of 49 years [16-88] were included. Apart from the most common variant in the population (type I), 64 anatomical variations (7.0%) in the iliac veins were reported and classified according to our new classification. The percentage of coverage of the L4-L5 intervertebral disc is 52%, including 32% by the inferior vena cava before the confluence of the common iliac veins. At the level of the L5-S1 intervertebral disc, the coverage is 30% (same distribution between left and right). CONCLUSIONS: Variations of the iliac veins are frequent, and contrary to what one might think, and even if they can represent an anatomical trap during surgery, certain variations do not limit anterior lumbar spine surgery and are not more associated with vascular complications. Nevertheless, these anatomical variations must be known before any advanced pelvic surgery. Depending on their distribution, level L5-S1 is more suitable for ALIF, level L4-L5 for OLIF approaches.

Fractured cervical spine, dissected vertebral artery, and life-threatening stroke: A challenging case report and literature review.

INTRODUCTION: Vertebral artery injury (VAI) following blunt trauma can lead to acute or delayed life-threatening posterior fossa ischemic stroke. Its management raises controversial issues and is still open to debate. MATERIAL & METHOD: We report the case of a 48-year-old male who presented a life-threatening posterior circulation ischemic stroke, secondary to a vertebral artery dissection caused by a cervical spine fracture. This case was successfully managed through intravenous thrombolysis and endovascular thrombectomy followed by antiplatelet therapy and an anterior cervical discectomy and fusion. At the one-year follow-up, the patient had no persisting deficit and was back working as a policeman. CONCLUSION: Rapid management of patients with dramatic clinical presentation can lead to full recovery. Implications include a systematic screening of blunt trauma VAI through computed tomography angiography when dealing with high-risk cervical spine fractures; patients harboring both a cervical spine fracture and a VAI must be transferred to a tertiary referral hospital able to deal both with strokes and cervical spine surgery to ensure responsiveness in case of stroke.

Primary intradural Extraosseous Ewing's sarcoma of the cauda equina: A case report and literature review.

Intradural Extraosseous Ewing sarcoma (IEES) is an infrequent occurrence. We report a case of a 66-year-old male who presented with a 2-month history of low back pain and bilateral S1 sciatica, with acute sphincter dysfunction. Imaging studies revealed an intradural extramedullary lesion in the cauda equina spanning from level L4 to S1. The patient underwent partial removal of the intradural lesion. Histopathological examination showed the presence of small round cells, which were consistent with Ewing Sarcoma. The patient was then treated with targeted radiation therapy and chemotherapy. The rarity of IEES in this specific location underscores the significance of evaluating and managing patients with intradural spinal tumors with careful consideration of this diagnosis. To further investigate this condition, we conducted a thorough review of the literature on IEES involving the lumbar spine and cauda equina. Our analysis revealed that patients with this condition frequently exhibit rapidly progressive neurological symptoms likely attributed to hemorrhagic transformation. This characteristic may serve as a distinguishing factor from other lesion types, particularly benign ones. Our study provides a comprehensive summary that can offer direction for clinical management in comparable uncommon and novel cases.

Efficacy of the immediate adipose-derived stromal vascular fraction autograft on functional sensorimotor recovery after spinal cord contusion in rats.

BACKGROUND: Spinal cord injuries (SCI) lead to functional alteration with important consequences such as motor and sensory disorders. The repair strategies developed to date remain ineffective. The adipose tissue-derived stromal vascular fraction (SVF) is composed of a cocktail of cells with trophic, pro-angiogenic and immunomodulatory effects. Numerous therapeutic benefits were shown for tissue reconstitution, peripheral neuropathy and for the improvement of neurodegenerative diseases. Here, the therapeutic efficacy of SVF on sensorimotor recovery after an acute thoracic spinal cord contusion in adult rats was determined. METHOD: Male Sprague Dawley rats (n = 45) were divided into 3 groups: SHAM (without SCI and treatment), NaCl (animals with a spinal lesion and receiving a saline injection through the dura mater) and SVF (animals with a spinal lesion and receiving a fraction of fat removed from adipocytes through the dura mater). Some animals were sacrificed 14 days after the start of the experiment to determine the inflammatory reaction by measuring the interleukin-1ß, interleukin-6 and Tumor Necrosis Factor-α in the lesion area. Other animals were followed once a week for 12 weeks to assess functional recovery (postural and locomotor activities, sensorimotor coordination). At the end of this period, spinal reflexivity (rate-dependent depression of the H-reflex) and physiological adjustments (ventilatory response to metabosensitive muscle activation following muscle fatigue) were measured with electrophysiological tools. RESULTS: Compared to non-treated animals, results indicated that the SVF reduced the endogenous inflammation and increased the behavioral recovery in treated animals. Moreover, H-reflex depression and ventilatory adjustments to muscle fatigue were found to be comparable between SHAM and SVF groups. CONCLUSION: Our results highlight the effectiveness of SVF and its high therapeutic potential to improve sensorimotor functions and to restore the segmental sensorimotor loop and the communication between supra- and sub-lesional spinal cord regions after traumatic contusion.

The "Bevel drilling" for degenerative cervical myelopathy: A technical note with illustrative video.

Degenerative cervical myelopathy is a pathology frequently encounterd in the neurosurgical practice. Posterior ostophytes located at the posterior part of the vertebral endplate are frequently involved in the reduction of the cervical canal. We propose a description of the technique used in our department to drill this posterior part of the endplate safely with the help of modern instruments and microscope magnification.The bony resection being performed with diamond burr, we believe this technique less traumatic on the spinal cord than repeated insertions of rongeur. Radiological result shows a nice enlargment of the cervical canal. This technique offers a less invasive alternative to corporectomy in cases of two-level stenosis.

Iatrogenic vertebral fracture in ankylosed spine during liver transplantation: a case report and biomechanical study using finite element method.

PURPOSE: The occurrence of an iatrogenic vertebral fracture during non-spinal digestive surgery is an exceptional event that has not been previously documented. Our study aims to explain the occurrence of this fracture from a biomechanical perspective, given its rarity. Using a finite element model of the spine, we will evaluate the strength required to induce a vertebral fracture through a hyperextension mechanism, considering the structure of the patient's spine, whether it is ossified or healthy. METHODS: A 70-year-old patient was diagnosed T12 fracture during a liver transplantation on ankylosed spine. We use a finite element model of the spine. Different mechanical properties were applied to the spine model: first to a healthy spine, the second to a osteoporotic ossified spine. The displacement and force imposed at the Sacrum, the time and location of fractures initiation were recorded and compared between the two spine conditions. RESULTS: A surgical treatment is done associating decompression with posterior fixation. After biomechanical study, we found that the fracture initiation occurred for the ossified spine after a sacrum displacement of 29 mm corresponding to an applied force of 65 N. For the healthy spine it occurred at a sacrum displacement of 52 mm corresponding to an applied force of 350 N. CONCLUSION: The force required to produce a type B fracture in an ankylosed spine is 5 times less than in a healthy spine. These data enable us to propose several points of management to avoid unexpected complications with ankylosed spines during surgical procedures. LEVEL OF EVIDENCE: IV.

Da Vinci Robotic Assistance for Anterolateral Lumbar Arthrodesis: Results of a French Multicentric Study.

BACKGROUND: The da Vinci robot (DVR) is the most widely used robot in abdominal, urological, and gynecological surgery. Due to its minimally invasive approach, the DVR has demonstrated its effectiveness and improved safety in these different disciplines. The aim of our study was to report its use in an anterior approach of complex lumbar surgery. METHODS: In a retrospective multicenter observational study, 10 robotic-assisted procedures were performed from March 2021 to May 2022. Six oblique lumbar interbody fusion procedures and 4 lumbar corpectomies were performed by anterolateral approach assisted by the DVR. The characteristics of the patients and the intraoperative and postoperative data were recorded. RESULTS: Six men and 4 women underwent surgery (mean age 50.5 years; body mass index 28.6 kg/m2). No vascular injuries were reported, and no procedures required conversion to open surgery. Mean surgical time were 219 minutes for 1-level oblique lumbar interbody fusion (3 patients), 286 minutes for 2-level oblique lumbar interbody fusion (3 patients), and 390 minutes for corpectomy (4 patients). Four patients experienced nonserious adverse events due to lumbar plexus nerve damage. One patient had a vertebral body plate fracture requiring posterior revision surgery, and 1 patient had a psoas hematoma requiring transfusion. No abdominal wall complications or surgical site infection were found. Seven patients were reviewed at 12 months, none had complications, and all showed radiological evidence of fusion. CONCLUSIONS: The use of the DVR in lumbar surgery allows a safe minimally invasive transperitoneal approach, but to date, only hybrid procedures have been performed.

Cirq® robotic assistance for percutaneous kyphoplasty of C1: report on feasibility.

BACKGROUND: To report the feasibility and safety of C1 kyphoplasty using the Cirq® robotic assistance coupled to the AIRO® intraoperative computed tomography (iCT)-scan and BrainLab® navigation system. METHODS: A 47-year-old woman with C1 osteolytic lesion responsible of intractable left-sided suboccipital pain was admitted. She underwent a percutaneous kyphoplasty of left lateral mass of C1 using Cirq® robotic assistance. She reported postoperative substantial pain relief. CT scan showed adequate filling of the osteolytic lesion without obvious leakage of cement. CONCLUSION: Percutaneous kyphoplasty of C1 using Cirq® robotic assistance is a safe and effective alternative in selected patients with C1 lateral mass metastasis.

Management of Spinal Metastasis by Minimally Invasive Surgical Techniques: Surgical Principles and Indications-A Literature Review.

BACKGROUND: Spinal metastasis is becoming more frequent. This raises the topics of pain and neurological complications, which worsen the functional and survival prognosis of oncological population patients. Surgical treatment must be as complete as possible in order to decompress and stabilize without delaying the management of the oncological disease. Minimally invasive spine surgical techniques inflict less damage on the musculocutaneous plan than opened ones. METHODS: Different minimally invasive techniques are proposed in this paper for the management of spinal metastasis. We used our experience, developed degenerative and traumatic pathologies, and referred to many authors, establishing a narrative review of our local practice. RESULTS: Forty-eight articles were selected, and these allowed us to describe the different techniques: percutaneous methods such as vertebro/kyphoplasty, osteosynthesis, mini-open surgery, or that through a posterior or anterior approach. Also, some studies detail the contribution of new technologies, such as intraoperative CT scan and robotic assistance. CONCLUSIONS: It seems essential to offer a lasting solution to a spinal problem, such as in the form of pain relief, stabilization, and decompression. Our department has embraced a multidisciplinary and multidimensional approach to MISS, incorporating cutting-edge technologies and evidence-based practices.

Variation of cervical sagittal alignment parameters according to age and pelvic incidence in degenerative spinal deformity patients.

INTRODUCTION: In asymptomatic subjects, variations of cervical sagittal alignment parameters according to age and spinopelvic organization have been reported. A large range of compensation phenomena has been observed in degenerative spinal deformity in order to maintain horizontal gaze, but it remains unclear how age and spinopelvic morphology could additionally influence cervical alignment. The aim of this observational retrospective study was to describe the distribution of cervical sagittal alignment parameters according to age and pelvic incidence in subjects with and without degenerative spinal deformity in order to precisely evaluate cervical compensation phenomena in adult spinal deformity (ASD). MATERIAL AND METHODS: Radiographs of 478 subjects (327 females and 151 males) were distributed into 235 asymptomatic and 243 deformed subjects. Occipito-cervical parameters were McGregor-C1, McGregor-C2, C1-C2 and occipito-C2 angles. The cervicothoracic inflection point (CTIP) was determined. Caudal cervical sagittal alignment parameters were: C2-C7 lordosis, C2-apex (superior arch), apex-CTIP (inferior arch), occipito-C3 and occipito-C4 angles, C7-slope and T1-slope. The distribution of parameters was analyzed using a Bayesian inference (significant when Pr > 0.975 or Pr < 0.025). Comparisons between asymptomatic and deformed subjects were done after matching on age (40-60 years; > 60 years) and on PI (< 45°; 45-60°; > 60°). RESULTS: Among occipito-cervical parameters, there was no significant change in McGregor-C1 angle. However, McGregor-C2 angle was significantly higher in the ASD group (Pr = 0.0029), with influence of age (Pr = 0.023), but PI influence. C1-C2 lordosis was significantly higher in the ASD group compared to the asymptomatic group (Pr < 0.0007), without influence of age or PI noticed. C2-C7 lordosis was also higher in the ASD group (Pr < 0.025) with a role of age and PI (Pr < 0.025). Cervical lordosis in the superior arch was significantly higher in the ASD group (Pr > 0.999), without influence of age or PI. In the inferior arch, the lordosis angle was not modified according to the group, but there was an influence of age (Pr < 0.0007). C7-slope and T1-slope were higher according the age group (Pr < 0.0012), without influence of the group or PI. CONCLUSION: This observational study highlights cervical sagittal alignment adaptations in degenerative spinal deformity, matched on age and pelvic incidence. The inferior cervical spine seemed to be modified with a higher lordosis, increasing with age responding to the age-related thoracic kyphosis increase. In addition to that, the superior cervical spine hyperextends more in adult degenerative deformity to maintain horizontal gaze. LEVEL OF EVIDENCE: III.

Da Vinci robotic-assisted anterolateral lumbar arthrodesis: operative technique.

BACKGROUND: Minimally invasive approaches for lumbar fusion are aimed at reducing soft tissue injury in order to minimize surgical morbidity and facilitate recovery. METHOD: Applied to oblique lateral lumbar interbody fusion (OLIF), Da Vinci® robot (DVR) assistance can help specially in obese patients. Positioning and important anatomical landmarks are reviewed. Indications, advantages, and limitations are discussed, and a step-by-step description of the procedure is presented. OLIF can be achieved efficiently through this approach with lesser blood loss, shorter hospital stays, and reduced rate of general complications. CONCLUSION: The use of DVR assistance for OLIF is a promising new technique.

Anterolateral versus posterior minimally invasive lumbar interbody fusion surgery for spondylolisthesis: comparison of outcomes from a global, multicenter study at 12-months follow-up.

BACKGROUND CONTEXT: Several minimally invasive lumbar interbody fusion techniques may be used as a treatment for spondylolisthesis to alleviate back and leg pain, improve function and provide stability to the spine. Surgeons may choose an anterolateral or posterior approach for the surgery however, there remains a lack of real-world evidence from comparative, prospective studies on effectiveness and safety with relatively large, geographically diverse samples and involving multiple surgical approaches. PURPOSE: To test the hypothesis that anterolateral and posterior minimally invasive approaches are equally effective in treating patients with spondylolisthesis affecting one or two segments at 3-months follow-up and to report and compare patient reported outcomes and safety profiles between patients at 12-months post-surgery. DESIGN: Prospective, multicenter, international, observational cohort study. PATIENT SAMPLE: Patients with degenerative or isthmic spondylolisthesis who underwent 1- or 2-level minimally invasive lumbar interbody fusion. OUTCOME MEASURES: Patient reported outcomes assessing disability (ODI), back pain (VAS), leg pain (VAS) and quality of life (EuroQol 5D-3L) at 4-weeks, 3-months and 12-months follow-up; adverse events up to 12-months; and fusion status at 12-months post-surgery using X-ray and/or CT-scan. The primary study outcome is improvement in ODI score at 3-months. METHODS: Eligible patients from 26 sites across Europe, Latin America and Asia were consecutively enrolled. Surgeons with experience in minimally invasive lumbar interbody fusion procedures used, according to clinical judgement, either an anterolateral (ie, ALIF, DLIF, OLIF) or posterior (MIDLF, PLIF, TLIF) approach. Mean improvement in disability (ODI) was compared between groups using ANCOVA with baseline ODI score used as a covariate. Paired t-tests were used to examine change from baseline in PRO for both surgical approaches at each timepoint after surgery. A secondary ANCOVA using a propensity score as a covariate was used to test the robustness of conclusions drawn from the between group comparison. RESULTS: Participants receiving an anterolateral approach (n=114) compared to those receiving a posterior approach (n=112) were younger (56.9 vs 62.0 years, p <.001), more likely to be employed (49.1% vs 25.0%, p<.001), have isthmic spondylolisthesis (38.6% vs 16.1%, p<.001) and less likely to only have central or lateral recess stenosis (44.9% vs 68.4%, p=.004). There were no statistically significant differences between the groups for gender, BMI, tobacco use, duration of conservative care, grade of spondylolisthesis, or the presence of stenosis. At 3-months follow-up there was no difference in the amount of improvement in ODI between the anterolateral and posterior groups (23.2 ± 21.3 vs 25.8 ± 19.5, p=.521). There were no clinically meaningful differences between the groups on mean improvement for back- and leg-pain, disability, or quality of life until the 12-months follow-up. Fusion rates of those assessed (n=158; 70% of the sample), were equivalent between groups (anterolateral, 72/88 [81.8%] fused vs posterior, 61/70 [87.1%] fused; p=.390). CONCLUSIONS: Patients with degenerative lumbar disease and spondylolisthesis who underwent minimally invasive lumbar interbody fusion presented statistically significant and clinically meaningful improvements from baseline up to 12-months follow-up. There were no clinically relevant differences between patients operated on using an anterolateral or posterior approach.

Spinal Fractures during Touristic Motorboat Sea Cruises: An Underestimated and Avoidable Phenomenon.

PURPOSE: Each summer, many vacationers enjoy the Mediterranean Sea shores. Among the recreational nautical activities, motorboat cruise is a popular choice that leads to a significant number of thoracolumbar spine fractures at our clinic. This phenomenon seems to be underreported, and its injury mechanism remains unclear. Here, we aim to describe the fracture pattern and propose a possible mechanism of injury. METHODS: We retrospectively reviewed the clinical, radiological, and contextual parameters of all motorboat-related spinal fracture cases during a 14-year period (2006-2020) in three French neurosurgical level I centers bordering the Mediterranean Sea. Fractures were classified according to the AOSpine thoracolumbar classification system. RESULTS: A total of 79 patients presented 90 fractures altogether. Women presented more commonly than men (61/18). Most of the lesions occurred at the thoracolumbar transition region between T10 and L2 (88.9% of the levels fractured). Compression A type fractures were seen in all cases (100%). Only one case of posterior spinal element injury was observed. The occurrence of neurological deficit was rare (7.6%). The most commonly encountered context was a patient sitting at the boat's bow, without anticipating the trauma, when the ship's bow suddenly elevated while crossing another wave, resulting in a "deck-slap" mechanism hitting and propelling the patient in the air. CONCLUSIONS: Thoracolumbar compression fractures are a frequent finding in nautical tourism. Passengers seated at the boat's bow are the typical victims. Some specific biomechanical patterns are involved with the boat's deck suddenly elevating across the waves. More data with biomechanical studies are necessary to understand the phenomenon. Prevention and safety recommendations should be given before motorboat use to fight against these avoidable fractures.

Surgical management of isthmic spondylolisthesis: A comparative study of postoperative outcomes between ALIF and TLIF.

INTRODUCTION: Circumferential fusion by the anterior (ALIF) or transforaminal (TLIF) approach combined with posterior instrumentation is currently used for the surgical treatment of low-grade isthmic spondylolisthesis. But few studies have compared the clinical and radiological outcomes of various interbody fusion techniques. The objective of this study was to compare the clinical and radiological results at 2 years postoperative of two fusion techniques-TLIF versus ALIF plus posterior instrumentation-for low-grade isthmic spondylolisthesis in adults. MATERIALS AND METHODS: This was an observational multicenter study done at nine French healthcare facilities specialized in spine surgery. The inclusion criteria were minimum age of 18 years, grade 1-3 isthmic spondylolisthesis, ALIF+posterior fixation (ALIF+PS) or TLIF, minimum follow-up of 2 years. Clinical and radiological evaluations were done preoperatively and at 2 years of follow-up. A lumbar CT scan was done at 1 year postoperative to evaluate fusion. RESULTS: The cohort consisted of 89 patients (50 women, 39 men) with a mean age of 47.7±12.3 (18-79) years. The patients in the ALIF groups (n=71) had a significantly longer hospital stay than those in the TLIF group (n=18): 5.7 days versus 4.6 days (p=.04). However, their medical leave from work was significantly shorter: 31.0 weeks versus 40.7 (p=.003). Lumbar pain VAS diminished faster in the ALIF groups, with a significantly larger drop than the TLIF group in the first 3 months postoperative. Only the increase in lumbar disc lordosis was larger in the ALIF group: 11.7°±12.0° versus 6.0°±11.7° (p=.036). There was a significant correlation between the increase in global lordosis and reduction in lumbar VAS at 2 years postoperative (ρ=-0.3295; p=.021). CONCLUSION: ALIF+PS provides a faster relief of postoperative low back pain than TLIF but there are no significant clinical differences between techniques at 2 years of follow-up. Despite better restoration of disc lordosis in the ALIF+PS group, there was no difference in the restoration of global lordosis. LEVEL OF EVIDENCE: III; multicenter comparative study.

Thoracolumbar vertebral fracture in unoperated idiopathic scoliosis.

INTRODUCTION: Traumatic fractures of the thoracolumbar spine are common. Their management considers the fracture type according to the various classifications in existence, as well as the patient's background and age. In some cases, the occurrence of a fracture on a spine with an unoperated scoliotic deformity can be observed. This entity, not described in the literature, can pose a therapeutic challenge and is not present in any existing treatment algorithm. The main objective of this work was to describe the characteristics and management of vertebral fractures in patients with unoperated idiopathic scoliosis. MATERIAL AND METHODS: We carried out a monocentric retrospective study in all patients operated on for a spinal fracture between May 2011 and August 2020, with a history of unoperated adolescent idiopathic scoliosis. We collected epidemiological data including the surgical course of each patient and the final result. The patients were categorized according to the surgical strategy (extensive fusion and correction of the deformity, short osteosynthesis without considering the scoliosis, vertebroplasty and orthopedic treatment) and the final clinical and radiological result evaluated at the last follow-up. RESULTS: Ten patients were included in this study with a total number of 16 fractured vertebrae. The population was 80% female, with an average age of 36.3 years. The majority of fractures were type A, at the thoracolumbar junction. The curves were classified as Lenke 1A in 5 cases, 1B in 2 cases, 1C in 1 case and 5C for 2 patients. Ultimately, 3 patients underwent extended fusion with correction of scoliosis, 6 localized osteosynthesis and 1 percutaneous vertebroplasty. In 50% of cases, a change of surgical strategy had to be made, due to worsening of the deformity or hyperalgesia. The last follow-up was at 19.7 months on average. Five patients had a good final clinical result, 5 patients had persistence of significant pain (lower back pain or cruralgia). CONCLUSION: This is the first study investigating the association of vertebral fractures and the presence of unoperated idiopathic scoliosis. The results of our study highlight the management challenges and difficulties in therapeutic decision-making. The presence of a pre-existing curve is thus an important parameter to consider and should lead to the discussion of performing an extended fusion secondarily in view of the risk of poor results from localized surgery. LEVEL OF EVIDENCE: IV.

Radiological analysis of minimally invasive treatment of type A thoracolumbar fractures based on a series of 135 fractures.

INTRODUCTION: Although the reduction of traumatic fractures of the thoracolumbar spine is of good quality during conventional so-called open procedures, the alternative minimally invasive approach also appears to confer good results. The aim of this study was to measure the radiological parameters before and after minimally invasive surgery, in order to assess the quality of the reduction of thoracolumbar compression fractures. MATERIALS AND METHODS: This retrospective, monocentric study included 112 patients with a mean age of 48.9years, presenting with 135 type A thoracolumbar compression fractures treated by a posterior minimally invasive surgical approach comprising vertebral augmentation or posterior osteosynthesis or a mixed procedure. RESULTS: The parameters analyzed were significantly lower whatever the procedure in the immediate postoperative period. Mean regional and local kyphosis, posterior wall displacement, and mean vertebral height were significantly lower (p<0.01). Fracture reduction was better when osteosynthesis was associated with vertebral augmentation. In the osteosynthesis subgroup with osteosynthesis hardware removal but without vertebral augmentation, we found a significant worsening of the regional kyphosis (p<0.05). CONCLUSION: The management of thoracolumbar compression fractures by a posterior minimally invasive approach allows excellent fracture reduction with a restoration of the spinal canal, vertebral height and kyphosis. LEVEL OF EVIDENCE: IV.

Fusion and clinical outcomes of lumbar interbody fusion for low-grade isthmic spondylolisthesis.

INTRODUCTION: Low-grade isthmic spondylolisthesis (ISPL) is generally treated by circumferential fusion with interbody graft, although there is no consensus on technique. HYPOTHESIS: The various interbody fusion strategies provide satisfactory fusion rates and clinical results. METHODS: A multicenter retrospective study analyzed lumbar interbody fusion for low-grade ISPL performed between March 2016 and March 2019. Techniques comprised: circumferential fusion on a posterior or a transforaminal approach (PLIF, TLIF: n=57), combined anterior (ALIF)+posterolateral fusion (ALIF+PLF: n=60), and ALIF+percutaneous posterior fixation (ALIF+PPF: n=55). Function was assessed on a lumbar and a radicular visual analog scale (AVS-L, VAS-R), Oswestry Disability Index (ODI) and Short Form 12 (SF12). RESULTS: Among the 129 patients, 85.3% showed fusion (Lenke 1 or 2), with no significant differences between the ALIF-PLF or ALIF-PPF groups and the PLIF or TLIF groups (p=0.3). Likewise, there was no difference in fusion rates between the ALIF-PPF and ALIF-PLF subgroups (p=0.28). VAS-L (p<0.001) and VAS-R (p<0.0001), ODI (p<0.001) and SF12 physical (PCS) (p<0.01) and mental component sores (MCS) (p<0.001) all showed significant improvement at 12months. Combined approaches provided greater clinical efficacy than TLIF or PLIF for lumbar (p<0.0001) and radicular pain (p<0.05), ODI (p<0.0001) and SF12 PCS (p<0.01). At 12months, there was no clinical difference between the ALIF-PPF and ALIF-PLF subgroups. However, patents with interbody non-union (Lenke 3 or 4) had lower SF12 PCS scores (p<0.004) and VAS-L ratings (p<0.001) than Lenke 1-2 patients. CONCLUSION: Low-grade ISPL treated by circumferential arthrodesis and interbody graft showed 85.3% consolidation at 2years, with equivalent outcomes between anterior and posterior techniques. Successful fusion was associated with better clinical results. LEVEL OF EVIDENCE: IV.