Murine models of posterolateral spinal fusion: A systematic review.

BACKGROUND: Rodent models are commonly used experimentally to assess treatment effectiveness in spinal fusion. Certain factors are associated with better fusion rates. The objectives of the present study were to report the protocols most frequently used, to evaluate factors known to positively influence fusion rate, and to identify new factors. METHOD: A systematic literature search of PubMed and Web of Science found 139 experimental studies of posterolateral lumbar spinal fusion in rodent models. Data for level and location of fusion, animal strain, sex, weight and age, graft, decortication, fusion assessment and fusion and mortality rates were collected and analyzed. RESULTS: The standard murine model for spinal fusion was male Sprague Dawley rats of 295g weight and 13 weeks' age, using decortication, with L4-L5 as fusion level. The last two criteria were associated with significantly better fusion rates. On manual palpation, the overall mean fusion rate in rats was 58% and the autograft mean fusion rate was 61%. Most studies evaluated fusion as a binary on manual palpation, and only a few used CT and histology. Average mortality was 3.03% in rats and 1.56% in mice. CONCLUSIONS: These results suggest using a rat model, younger than 10 weeks and weighing more than 300 grams on the day of surgery, to optimize fusion rates, with decortication before grafting and fusing the L4-L5 level.

Factors influencing complications after 3-columns spinal osteotomies for fixed sagittal imbalance from multiple etiologies: a multicentric cohort study about 286 cases in 273 patients.

PURPOSE: Spinal osteotomies performed to treat fixed spinal deformities are technically demanding and associated with a high complications rate. The main purpose of this study was to analyze complications and their risk factors in spinal osteotomies performed for fixed sagittal imbalance from multiple etiologies. METHODS: The study consisted of a blinded retrospective analysis of prospectively collected data from a large multicenter cohort of patients who underwent 3-columns (3C) spinal osteotomy, between January 2010 and January 2017. Clinical and radiological data were compared pre- and post-operatively. Complications and their risk factors were analyzed. RESULTS: Two hundred eighty-six 3C osteotomies were performed in 273 patients. At 1 year follow-up, both clinical (VAS pain, ODI and SRS-22 scores) and radiological (SVA, SSA, loss of lordosis and pelvic version) parameters were significantly improved (p < 0.001). A total of 164 patients (59.2%) experienced at least 1 complication (277 complications). Complications-free survival rates were only 30% at 5 years. Most of those were mechanical (35.2%), followed by general (17.6%), surgical site infection (17.2%) and neurological (10.9%). Pre-operative neurological status [RR = 2.3 (1.32-4.00)], operative time (+ 19% of risk each additional hour) and combined surgery [RR = 1.76 (1.08-2.04)] were assessed as risk factors for overall complication (p < 0.05). The use of patient-specific rods appeared to be significantly associated with less overall complications [RR = 0.5 (0.29-0.89)] (p = 0.02). CONCLUSION: Spinal 3C osteotomies were efficient to improve both clinical and radiological parameters despite high rates of complication. Efforts should be made to reduce operative time which appears to be the strongest predictive risk factor for complication.

Coexistence of flavum ligament ossification with diffuse idiopathic skeletal hyperostosis in the cervical spine: Review of literature and technical note starting from a rare case.

BACKGROUND: Cervical flavum ligament ossification (C-OLF) is very rare source of myeloradiculopathy. Less than 100 cases have been reported in modern English literature up to 2020. Association between C-OLF and Diffuse Idiopathic Skeletal Hyperostosis (DISH) at cervical level has never been described. METHODS: In this article we performed a systematic review about epidemiology, physiopathology, clinical and surgical management of C-OLF. Moreover, we research its possible association with other cervical spine ligament ossification and in particular with anterior longitudinal ligament ossification. We report a case of 73 years-old woman experiencing mild cervical myeloradiculopathy caused by C6-C7 C-OLF compression and coexistence of DISH at cervico-thoracic level. A brief technical note about intraoperative management of C-OLF has also been described. RESULT: Our research found 81 previous reported case of C-OLF. The coexistence of Posterior longitudinal ligament ossification has been reported in 21.3% of C-OLF case. Conversely, we reported the first case describing the association between DISH and C-OLF. Posterior surgical decompression is the only useful treatment providing good long-term functional outcome. Instrumentation should be tailored according to pre-operative findings. CONCLUSIONS: C-OLF is a rare source of myeloradiculopathy and it may coexists with DISH probably due to alteration in the cervical mechanical stress and tendency of bone formation in patients harboring coexistent ligament ossifications. According to our result, skip en-bloc microsurgical laminectomy is safe and less invasive method to avoid complication and to provide optimal cervical spinal cord and nerve decompression avoiding CSF-leak.

Personalized bacteriophage therapy to treat pandrug-resistant spinal Pseudomonas aeruginosa infection.

Bone and joint infections (BJI) are one of the most difficult-to-treat bacterial infection, especially in the era of antimicrobial resistance. Lytic bacteriophages (phages for short) are natural viruses that can selectively target and kill bacteria. They are considered to have a high therapeutic potential for the treatment of severe bacterial infections and especially BJI, as they also target biofilms. Here we report on the management of a patient with a pandrug-resistant Pseudomonas aeruginosa spinal abscess who was treated with surgery and a personalized combination of phage therapy that was added to antibiotics. As the infecting P. aeruginosa strain was resistant to the phages developed by private companies that were contacted, we set up a unique European academic collaboration to find, produce and administer a personalized phage cocktail to the patient in due time. After two surgeries, despite bacterial persistence with expression of small colony variants, the patient healed with local and intravenous injections of purified phages as adjuvant therapy.

Prognostic factors for progression-free survival of the filum terminale ependymomas in adults.

OBJECTIVE: To define the prognostic factors for progression and to determine the impact of the histological grading (according to the World Health Organization) on the progression-free survival (PFS) of filum terminale ependymomas. METHODS: A retrospective chart review of 38 patients with ependymoma of the filum terminale was performed, focusing on demographic data, preoperative symptoms, tumor size, quality of resection, presence of a tumor capsule, and histological grade. RESULTS: Gross total resection (GTR) was achieved in 30 patients (78.9%). Histopathological analysis found 21 (55.3%) myxopapillary grade I ependymoma (MPE), 16 (42.1%) ependymoma grade II (EGII), and 1 (2.6%) ependymoma grade III. There was no significant difference between the mean±SD volume of MPE (5840.5±5244.2mm3) and the one of EGII (7220.3±6305.9mm3, p=0.5). The mean±SD follow-up was 54.1±38.4 months. At last follow-up, 30 (78.9%) patients were free of progression. In multivariate analysis, subtotal resection (p=0.015) and infiltrative tumor (p=0.03) were significantly associated with progression. The PFS was significantly higher in patients with encapsulated tumor than in patients with infiltrative tumor (log-rank p=0.01) and in patients who had a GTR in comparison with those who had an incomplete resection (log-rank p=0.05). There was no difference in PFS between patient with MPE and EGII (p=0.1). CONCLUSION: The progression of ependymoma of the filum terminale highly depends on the quality of resection, and whether the tumor is encapsulated. Except for anaplastic grade, histopathological type does not influence progression.

Anterior approach to remove a pre-medullary meningioma in the cervical spine: Technical case report.

BACKGROUND: Regarding their relation to the spinal cord (SC), resection of pre-medullary meningiomas may be technically challenging. Anterior approach via corpectomy represents a nice option reducing the need for mobilization of the SC. CASE DESCRIPTION: We describe the case of a patient presenting with a cervical meningioma, located anterior to the SC and operated on through an anterior approach. Surgery consisted of a 2-levels discectomy and C7 corpectomy, midline opening of the dura and then microsurgical resection of the tumor. After coagulation of the implantation base, the dura was then closed in a watertight fashion. Finally, the anterior column was reconstructed using a titanium mesh-cage and anterior plating. CONCLUSION: In the case of cervical meningioma located anterior to the SC, anterior approach may be considered as an alternative option to remove the tumor.

C1-C2 Injury: Factors influencing mortality, outcome, and fracture healing.

BACKGROUND: C1-C2 injury represents 25-40% of cervical injuries and predominantly occurs in the geriatric population. METHODS: A prospective multicentre study was conducted under the aegis of the french spine surgery society (SFCR) investigating the impact of age, comorbidities, lesion type, and treatment option on mortality, complications, and fusion rates. RESULTS: A total of 417 patients were recruited from 11 participating centres. The mean ± SD age was 66.6 ± 22 years, and there were 228 men (55%); 5.4% presented a neurological deficit at initial presentation. The most frequent traumatic lesion was C2 fracture (n = 308). Overall mortality was 8.4%; it was 2.3% among those aged ≤ 60 years, 5.0% 61-80 years, and 16.0% > 80 years (p < 0.001). Regarding complications, 17.8% of patients ≤ 70 years of age presented with ≥ 1 complication versus 32.3% > 70 years (p = 0.0009). The type of fracture did not condition the onset of complications and/or mortality (p > 0.05). The presence of a comorbidity was associated with a risk factor for both death (p = 0.0001) and general complication (p = 0.008). Age and comorbidities were found to be independently associated with death (p < 0.005). The frequency of pseudoarthrosis ranged from 0 to 12.5% up to 70 years of age and then constantly and progressively increased to reach 58.6% after 90 years of age. CONCLUSIONS: C1-C2 injury represents a serious concern, possibly life-threatening, especially in the elderly. We found a major impact of age and comorbidities on mortality, complications, and pseudarthrosis; injury pattern or treatment option seem to have a minimal effect.

Correction to: Sagittal balance of the spine.

The Fig. 20 is not from the study by Shiba et al., but is a courtesy from Dr. Stéphane Armand, Laboratory of Kinesiology, Geneva University Hospitals, Geneva, Switzerland.

Sagittal balance of the spine.

The static sagittal balance of the normal spine is a physiological alignment of the spine in the most efficient manner by the muscular forces. During gait, this balance is constantly thwarted by single-foot support. This analysis involves the study of parameters which are now well defined. The pelvic incidence is constant, and the sacral slope and the pelvic tilt are positional. The cervical parameters are the upper (O-C2) and lower cervical curvatures (C2-C7), the C7 slope, the spino-cranial angle and the vertical cervical offset. At the thoracic and lumbar level, they are, respectively, kyphosis and lordosis. The OD-HA (odontoid hip axis) angle is the most efficient parameter to analyse the global balance. The average values of these parameters are reported with the new 3D measurements by Le Huec et al. The relationship between these different parameters was analysed, and Roussouly proposed his classification of the different spine shape. Ageing makes it possible to show compensation mechanisms at three levels: spinal, pelvic and lower limbs. Understanding these different data allows for better planning of the surgical management of the patients. Global evaluation of the entire spine and the measurement of the aforementioned parameters allow to determine the extent of the correction to be performed during surgery. Taking these parameters into account also enables us to understand the complications involved in this type of surgery: transitional syndromes or junctional syndromes. Integration of these parameters into the study of gait is an area still under investigation. These slides can be retrieved under Electronic Supplementary Material .

Thoracic spine intra- and extradural dumbbell-shaped meningioma: Case report and extensive review of the literature with 21 cases.

INTRODUCTION: Spinal dumbbell-shaped meningioma is a rare condition usually mistaken preoperatively for schwannoma. The present study reported a case of dumbbell-shaped meningioma, with an extensive review of literature. METHODS: A documented case of thoracic spine dumbbell-shaped meningioma is reported, followed by an extensive review of the literature to analyze epidemiological features, pathogenesis, histopathological diagnosis, location, Eden classification, surgical treatment and outcome in such tumors. RESULTS: Case report: A 55 year-old woman was admitted with paraparesis and paresthesia of lower limbs. MRI showed a dumbbell-shaped meningioma of the thoracic spine. The tumor was totally removed via a posterolateral approach. REVIEW OF THE LITERATURE: Twenty-one spinal dumbbell-shaped meningiomas were reported in the last twenty years (1997-2017). Mean patient age was 46.57 years, with female predominance. Mean disease progression was 23.11 months. The thoracic spine was the predominant site (38.09%), followed by the cervical spine (33.33%). Eden type-3 was the most frequent tumor type, accounting for 66.67% of cases. In all cases, meningiomas were classified as WHO grade I. Complete removal (Simpson I-II) was achieved in 75% of cases. There was recurrence in 3 patients (14%), including 1 case of malignant transformation leading to death at 12 years post-surgery. CONCLUSION: Spinal dumbbell-shaped meningioma is mainly of the benign subtype. Long-term follow-up shows low rates of morbidity and mortality.

[The efficacy of multimodal treatment for symptomatic vertebral hemangiomas: A report of 27 cases and a review of the literature]. / Intérêt d'une prise en charge multimodale des hémangiomes vertébraux symptomatiques : à propos de 27 cas et revue de la littérature.

INTRODUCTION: Vertebral hemangiomas (VH) represent the most common primary bone tumor of the spine and are rarely symptomatic. Currently, there is no consensus for treatment and many therapeutic options are available, alone or in combination including cementoplasty, sclerotherapy, surgery, embolization and/or radiotherapy. OBJECTIVE: To evaluate the clinical and radiological outcome of a multimodal management for symptomatic VH. METHODS: A consecutive prospective and retrospective multicenter study was conducted to review cases of symptomatic VHs between 2005 and 2015. Clinical and radiological aspects, treatment modalities and complications were evaluated preoperatively; postoperatively and at last follow-up. We also reviewed the literature of studies concerning case series of VH, published after 1990 and involving more than 10 patients. RESULTS: Twenty-seven VHs were included in our series (mean age at diagnosis: 47.9 years), out of which 26 were symptomatic. Ten presented with neurologic deficit (37%). An epidural extension was noted in 13 patients (48%). Eleven patients (41%) underwent multimodal treatments. In the multimodal group, eradication was observed in 6 patients (54%), stable residue in 5 cases (46%) with no recurrence versus 3 eradication (23%), 9 stable residue (69%) and no recurrence in the monomodal group, (P>0.05). The literature comprised 14 studies including 458 patients. Only 4 studies were focused on multimodal treatments. CONCLUSION: Based on this study, the multimodal management of symptomatic VHs appeared safe and effective. Finally, we propose an algorithm for symptomatic VHS management based on the severity of epidural extension and fracture risk.

[A continuous series of 27 adult patients treated for L5-S1 isthmic spondylolisthesis by combined approach: Clinical and radiological outcomes at 1 year follow-up]. / Une série continue de 27 patients adultes opérés d'un spondylolisthésis isthmique L5-S1 par voie combinée : résultats cliniques et radiologiques à 1 an de suivi.

Through this single-center consecutive prospective study, we evaluated the results of a combined approach for L5-S1 isthmic spondylolisthesis, using a polyetheretherketone (PEEK) interbody lordotic cage during anterior approach and pedicle screw-based posterior fixation. Between 2010 and 2014, 27 adult patients were treated for L5-S1 isthmic spondylolisthesis (high and low grades) by a combined approach with a minimum follow-up of one year. Clinical outcome was assessed before surgical treatment and at four months and one year after surgery by: VAS, Oswestry Index (ODI) and Rolland-Morris scores. Two observers evaluated the following radiological parameters: pelvic incidence, pelvic tilt, lumbar lordosis, segmental lordosis L5-S1, anterior and posterior disc height, spinal vertical axis (SVA), SVA/sacro-femoral distance (SFD) ratio. Fusion was evaluated on the CT scan at one-year follow-up. Blood loss, surgery time and complications were also collected. The mean age was 47.7 years (±16.9). The VAS, ODI and Rolland-Morris scores were significantly improved postoperatively, decreased from 7.5 (±1.45); 48 (±19.25); 15.3 (±4.67) before the surgery to 3.8 (±2.55); 28.7 (±19.58) and 7.76 (±7.21) respectively at one year after the surgery (P=0.05). The mean follow-up was 3.3 years. Mean surgery time was 193.7min (±37). Fusion was obtained in 100% of cases. Segmental lordosis L5-S1, pelvic tilt, slippage, anterior and posterior L5-S1 disc height were significantly improved postoperatively, they passed from 20.1; 22.6; 35.3%; 26.4%; 17.9% to 29.5; 20.6; 20.3%; 64.4%; 36.3% respectively. Combined surgical procedure meets the required goals of surgery in the treatment of adults L5-S1 isthmic spondylolisthesis.

Bicortical facet screws as a new option for posterior C2 fixation: anatomical study and clinical experience.

PURPOSE: C2 fixation is a demanding procedure, particularly in patients with variants of C1-C2 anatomy. The inferior articular process (IAP) of the axis can be an alternative for screw placement. We report the results of a CT study of C2 IAP anatomy and we present the clinical experience of 28 patients operated with this technique. METHODS: Anatomical study: 50 CT angiographies of the vertebral arteries (VA) were used for this study and, therefore, 100 IAPs were considered. We measured on the axial and sagittal planes the length, height and width of the facet, the distance between the anterior cortex and the VA and the distance between the screw entry point and the VA. We also measured the angle between the sagittal plane and the external tangent line of the VA. CLINICAL REPORT: 28 patients were treated with C2 IAP screws at the Spine Surgery Department of the University Hospital in Lyon, France, from January 2014 to January 2016. RESULTS: Anatomical study: the mean length of C2 IAP was 12 ± 2 mm, the mean distance between the anterior cortical layer and the VA was 5.2 ± 1.4 mm, and the mean angle we found was 0.2° ± 5.3°. CLINICAL REPORT: 16 of the 28 patients presented post-traumatic C1-C2 instability, 8 patients presented degenerative disease, 1 patient was treated for pseudoarthrosis, 1 for tumour, 1 for OPLL and 1 for rheumatoid arthritis. All the screws were correctly positioned and there was no VA injury. CONCLUSION: IAP screws can represent a safe alternative option for C2 fixation.

[Surgical correction of post-vertebroplasty kyphosis by pedicle substraction osteotomy. Regarding three cases]. / Correction chirurgicale de la cyphose post-vertébroplastie par ostéotomie trans-pédiculaire. À propos de trois observations.

We report a case of three patients treated with pedicle subtraction osteotomy for post-vertebroplasty kyphosis. These patients were initially treated with a vertebroplasty for vertebral fracture (two cases) and spinal lymphoma (1 case). All of these patients worsened progressively on a clinical and radiographic level with progression of the spinal deformity in the form of kyphosis. The surgery consisted of transpedicular osteotomy instrumented at the level of the vertebra cemented with maximum removal of intra-corporeal cement. One of the three patients required a supplementary anterior approach to achieve good quality bone fusion. In all three cases the post-vertebroplasty kyphosis was able to be reduced by at least 50 % emphasizing the feasibility and relevance of the pedicle subtraction osteotomy in a context of cemented vertebra.

C1-C2 stabilization by Harms arthrodesis: indications, technique, complications and outcomes in a prospective 26-case series.

INTRODUCTION: C1-C2 arthrodesis is a surgical challenge due to the proximity of neurovascular structures (vertebral arteries and spinal cord) and the wide range of motion of the joint, hampering bone fusion. A variety of techniques have been successively recommended to reduce anatomic risk and improve results in terms of biomechanical stability and fusion rates. Recently, Harms described a new technique using polyaxial screws in the C1 lateral masses and C2 pedicles. MATERIAL AND METHOD: The present study reports our experience in a consecutive series of 26 patients operated on by C1-C2 arthrodesis using the Goel and Harms technique, and details technical aspects step by step. Routine systematic immediate postoperative CT and 6-month CT controlled screw positioning and assessed fusion. Follow-up was at least 1 year, except in 2 cases (10 months). RESULTS: Twenty-six patients with a mean age of 57 years were included. Indications comprised: C2 non-union (n=11), C1-C2 fracture and/or dislocation (n=11), inflammatory pathology (n=2) and tumoral pathology (n=2). The results showed the technique to be reliable (no neurovascular complications and 85% of screws with perfect positioning) and an excellent rate of fusion (100% at 6 months). CONCLUSION: Anatomic and biomechanical considerations, combined with the present clinical and radiological outcomes, indicate that Goel and Harms fusion is to be considered the first-line attitude of choice for posterior C1-C2 arthrodesis. LEVEL OF EVIDENCE: Level IV prospective study.

Surgical management of multilevel lumbar spondylolysis: a case report and review of the literature.

Multilevel lumbar spondylolysis accounts for less than 6% of the cases of lumbar spondylolysis and its treatment, as reported in the literature, has not been consistent. Fewer than ten cases presenting triple lumbar spondylosis have been published. We describe the case of a 33-year-old male presenting bilateral L3, L4, and L5 isthmic lysis with no spondylolisthesis or disc degeneration. The MRI and CT of the lumbar spine were decisive elements in the therapeutic choice and the surgical treatment performed was bilateral L3 and L4 isthmic repair via a combined anterior and posterior L5S1 approach. The clinical and radiological results were good at the last follow-up visit.

Lumbar-sacral fusion by a combined approach using interbody PEEK cage and posterior pedicle-screw fixation: clinical and radiological results from a prospective study.

INTRODUCTION: This prospective series evaluated the clinical and radiological results of a circumferential lumbar fusion achieved by a combined approach in one stage (anterior then posterior) using interbody PEEK cages and posterior pedicle-screw fixation. HYPOTHESIS: The combined approach in one stage is a safe and efficient technique with few complications to achieve a fusion with a satisfying clinical and radiological outcome. MATERIALS AND METHODS: Thirty-nine consecutive patients were prospectively included, with a one-year clinical and radiological minimum follow-up, from December 2008 to July 2011. All patients suffering from degenerative disc disease or low-grade isthmic spondylolisthesis requiring L5S1, L4L5 or L4S1 spinal fusions were included. Clinical outcome was assessed using VAS, ODI and Rolland-Morris scores. Radiological outcome was assessed by analyzing PI, PT, lumbar lordosis, segmental lordosis, disc height, C7/CSFD ratio on full spine radiographies and the quality of bone fusion on a CT scan at 1-year follow-up. Blood loss, surgery time and adverse events were also recorded. RESULTS: Twenty-nine patients (74%) were operated for a lumbar degenerative disc disease and 10 patients (26%) for an isthmic spondylolisthesis. Mean age was 46 (± 10.1) years old. Clinical outcome were satisfactory. VAS, ODI and Rolland-Morris scores substantially improved. Mean follow-up was 22.5 months (± 8.7). Mean surgery time was 227 min (± 41.4) for complete surgical procedure time. Mean blood loss was 308 mL (± 179.2) for total surgery. Fusion was assessed in all cases. Disc height and segmental lordosis significantly improved in postoperative. The segmental lordosis at operated level(s) increased by 8.5° (± 5) regardless of the level, and by 11.6° (± 6) for L5-S1. CONCLUSION: The combined procedure meets the requested criteria for a lumbar fusion in terms of clinical and functional results, fusion rates, and restoration of segmental lordosis. It cumulates the advantages of the anterior and posterior approach performed alone and should be considered by surgeons before realizing a lumbar fusion.

One-stage combined lumbo-sacral fusion, by anterior then posterior approach: clinical and radiological results.

INTRODUCTION: We intended to prospectively evaluate the clinical and radiological results of lumbo-sacral fusion achieved by a combined approach, anterior then posterior. MATERIAL AND METHODS: 62 patients were consecutively treated at L5-S1, L4-L5 or L4-S1 for degenerative disc disease or low-grade isthmic spondylolisthesis by combined surgery. RESULTS: Mean operative time and blood loss were 209 min and 308 ml, respectively, including the two approaches. VAS, ODI and Roland-Morris scores significantly improved postoperatively at 1 year (p < 0.005) and fusion was obtained in all cases on the CT scan at 1-year follow-up. Segmental lordosis significantly improved postoperatively (p < 0.05) with a mean gain of 10.2° at L5-S1 and 5.5° at L4-L5. CONCLUSION: The combined procedure meets the requested criteria for a lumbar fusion in terms of clinical results, functional outcomes, fusion rates while restoring segmental lordosis and disc height. It cumulates the advantages of the anterior and posterior approach performed alone, especially for L5-S1.