A Case of U-shaped Sacral Fracture After Longstanding Spinopelvic Fixation Treated With Percutaneous Sacroiliac Joint Fusion and Iliosacral Osteosynthesis.

Sacral fractures are pelvic ring injuries that usually occur following a fall from height and may present with neurological injury. They are divided into several subtypes based on the pattern and location of injury. Certain subtypes require operative management due to the risk of neural compromise and inadequate axial load transfer, limiting mobility. Spinopelvic fixation has been reported as an efficient surgical treatment to restore the stability of U-shaped sacral fractures and to accelerate healing by relieving sacral stress. It is unclear if low-velocity sacral fractures occurring after longstanding lumbosacral fusion with pelvic fixation require additional surgical intervention. An elderly female with osteoporosis and prior T4-pelvis instrumented fusion sustained a fragility sacral fracture and was treated conservatively. At follow-up, she developed a symptomatic U-shaped sacral fracture. The increased fracture displacement and nonunion were chiefly attributed to sacroiliac joint hypermobility. A percutaneous osteosynthesis at the S1 and S2 levels was performed with a novel type of implant to achieve concomitant sacroiliac joint stabilization and fusion. Implants were placed with the help of intraoperative three-dimensional imaging and image-guided navigation to avoid the previously installed pelvic hardware. In summary, U-shaped fractures can develop nonunion despite pre-existing spinopelvic fixation and can be treated adequately with percutaneous iliosacral osteosynthesis. A sacroiliac joint fixation and fusion should be considered in the same setting as sacroiliac joint instability may contribute to or exacerbate nonunion.

Single Level Spondylolisthesis Associated Sagittal Plane Imbalance Corrected by Pre-Psoas Interbody Fusion Using Anterior Column Release with 30° Expandable Hyperlordotic Cage.

Background: Loss of lumbar lordosis caused by single level degenerative spondylolisthesis can trigger significant sagittal plane imbalance and failure to correct lumbopelvic parameters during lumbar fusion can lead to poor outcome or worsening deformity. Anterior column release (ACR) through a pre-psoas approach allows the placement of a hyperlordotic cage (HLC) to improve lumbar lordosis, but it is unclear if the amount of cage lordosis affects radiological outcomes in real-life patient conditions. Methods: Three patients were treated with ACR and 30° expandable HLC for positive sagittal imbalance secondary to single-level spondylolisthesis. Patients reported baseline and post-operative Oswestry Disability Index (ODI) and Numeric Pain Score (NRS). Radiographic parameters of sagittal balance included lumbar lordosis (LL), sagittal vertical axis (SVA) and pelvic incidence-lumbar lordosis mismatch (PI-LL). Results: Surgical indications were sagittal plane imbalance caused by L4-L5 degenerative spondylolisthesis (n = 2) and L3-L4 spondylolisthesis secondary to adjacent segmental degeneration (n = 1). Average post-operative length of stay was 3 days (range 2-4) and estimated blood loss was 266 mL (range 200-300). NRS and ODI improved in all patients. All experienced improvements in LL (x¯preop = 33°, x¯postop = 56°), SVA (x¯preop = 180 mm, x¯postop = 61 mm) and PI-LL (x¯preop = 26°, x¯postop = 5°). Conclusion: ACR with expandable HLC can restore sagittal plane balance associated with single-level spondylolisthesis. Failure to perform ACR with HLC placement during pre-psoas interbody fusion may result in under correction of lordosis and poorer outcome for these patients.

Does the L5 spinal nerve move? Anatomical evaluation with implications for postoperative L5 nerve palsy.

PURPOSE: While palsy of the L5 nerve root due to stretch injury is a known complication in complex lumbosacral spine surgery, the underlying pathophysiology remains unclear. The goal of this cadaveric study was to quantify movement of the L5 nerve root during flexion/extension of the hip and lower lumbar spine. METHODS: Five fresh-frozen human cadavers were dissected on both sides to expose the lumbar vertebral bodies and the L5 nerve roots. Movement of the L5 nerve root was tested during flexion and extension of the hip and lower lumbar spine. Four steps were undertaken to characterize these movements: (1) removal of the bilateral psoas muscles, (2) removal of the lumbar vertebral bodies including the transforaminal ligaments from L3 to L5, (3) opening and removing the dura mater laterally to visualize the rootlets, and (4) removal of remaining soft tissue surrounding the L5 nerve root. Two metal bars were inserted into the sacral body at the level of S1 as fixed landmarks. The tips of these bars were connected to make a line for the ruler that was used to measure movement of the L5 nerve roots. Movement was regarded as measurable when there was an L5 nerve excursion of at least 1 mm. RESULTS: The mean age at death was 86.6 years (range 68-89 years). None of the four steps revealed any measurable movement after flexion/extension of the hip and lower lumbar spine on either side (< 1 mm). Flexion of the hip and lower lumbar spine revealed lax L5 nerve roots. Extension of the hip and lower lumbar spine showed taut ones. CONCLUSION: Significant movement or displacement of the L5 nerve root could not be quantified in this study. No mechanical cause for L5 nerve palsy could be identified so the etiology of the condition remains unclear.

Management of human resources of a pharmacy department during the COVID-19 pandemic: Take-aways from the first wave.

The coronavirus disease 2019 (COVID-19) is the biggest public health threat the world has seen in many years and poses new challenges and opportunities to healthcare systems. The new reality imposed by the pandemic requires a modification of practices to ensure the health and safety of patients and medical teams. The purpose of this article is to share the experiences of the pharmacy department of the Centre hospitalier de l'Université de Montréal (CHUM) in response to the COVID-19 pandemic. Seven of the most important issues will be addressed: crisis management, internal communications, employee stress, reorganisation of workspaces, reorganisation of pharmacist workforce, telework and schedule management. Some of the changes made in human resources deployment will likely remain even post-pandemic.

N6-Methyladenosine Demethylase FTO Contributes to Neuropathic Pain by Stabilizing G9a Expression in Primary Sensory Neurons.

Nerve injury-induced change in gene expression in primary sensory neurons of dorsal root ganglion (DRG) is critical for neuropathic pain genesis. N6-methyladenosine (m6A) modification of RNA represents an additional layer of gene regulation. Here, it is reported that peripheral nerve injury increases the expression of the m6A demethylase fat-mass and obesity-associated proteins (FTO) in the injured DRG via the activation of Runx1, a transcription factor that binds to the Fto gene promoter. Mimicking this increase erases m6A in euchromatic histone lysine methyltransferase 2 (Ehmt2) mRNA (encoding the histone methyltransferase G9a) and elevates the level of G9a in DRG and leads to neuropathic pain symptoms. Conversely, blocking this increase reverses a loss of m6A sites in Ehmt2 mRNA and destabilizes the nerve injury-induced G9a upregulation in the injured DRG and alleviates nerve injury-associated pain hypersensitivities. FTO contributes to neuropathic pain likely through stabilizing nerve injury-induced upregulation of G9a, a neuropathic pain initiator, in primary sensory neurons.

Catheter-based Minimally Invasive Evacuation of Extensive Spinal Epidural Abscess: A Technical Report.

Surgical treatment of extensive spinal epidural abscess (SEA) usually involves multilevel exposure of the dural sac with subsequent risk for iatrogenic instability. A minimally invasive technique using an epidural catheter inserted through a limited approach for distant irrigation and drainage of the abscess represents an interesting alternative. Most described techniques involve blind placement of the catheters, with the potential risk of damage to the spinal cord and incomplete abscess drainage. We present and analyze a new technique used in two cases of SEA. Those were successfully treated using a minimally invasive approach supplemented with fluoroscopically-guided catheter drainage. We suggest that fluoroscopic placement of the catheter is a safe and effective method that offers a more focused and potentially safer way to proceed to this technique.

Sphenopalatine Ganglion Block and Radiofrequency Ablation: Technical Notes and Efficacy.

Background: Sphenopalatine ganglion (SPG) blockade or lesioning can offer significant pain relief for cluster headaches (CHs) and a variety of other pain syndromes involving the head and face. Methods: We reviewed the literature on the efficacy of SPG block and radiofrequency ablation (RFA) using PubMed and Google Scholar. Results: The infrazygomatic technique can be used to directly access the SPG for injection of local anesthetic or lesioning using RFA. Important technical points to achieve these procedures are described. SPG blockade efficacy is supported by randomized controlled studies but SPG RFA is not. Conclusion: Targeting the SPG is a promising treatment option for refractory CHs. RFA and neuromodulation have the potential to offer long-term significant pain relief, but more randomized studies are needed to demonstrate their efficacy.

Laminoplasty for Cervical Spinal Cord Stimulator Implantation in Patients With Cervical Spondylosis and Fusion: A Technical Note.

Background: Epidural spinal cord stimulator (SCS) implantation is a commonly used strategy for treating refractory neuropathic pain, but the literature on the technical aspects of cervical SCS surgery remains scarce. Degenerative cervical stenosis and prior fusion surgery are relatively frequent conditions in this population, and the optimal method for cervical lead placement among such patients has not been established. Decompressive laminectomy may be required for cervical SCS placement in the presence of spinal stenosis. However, extensive decompression may increase the rate of lead migration and destabilize the spine, especially when performed above an existing fusion. Case Series: We present a surgical technique for cervical SCS implantation and the cases of 3 patients with significant spinal stenosis and/or prior fusion. In these patients, the paddle lead placement was safely achieved using cervical laminoplasty techniques. Conclusion: In addition to stabilizing the epidural paddle lead, laminoplasty offers several potential advantages compared to decompression alone.

Minimally invasive repair of a pseudomeningocele caused by a sheared intrathecal catheter following implantation of a drug delivery system.

BACKGROUND: Shearing of an intrathecal catheter during implantation of a drug delivery system is an underreported complication that can be challenging to manage. CASE DESCRIPTION: A 53-year-old man with refractory cancer pain had an intrathecal pump system implanted. The procedure was complicated with catheter shear and retention in the intrathecal space. A second catheter was successfully placed but formation of a painful pseudomeningocele and ineffective pain relief complicated the outcome. A minimally invasive approach through a tubular retractor was employed to access the spinal canal via a laminotomy, the sheared catheter was removed and the dural defect repaired. Complete resolution of the pseudomeningocele and efficient pain control were observed at follow-up. CONCLUSION: Minimally invasive approach to the spine is demonstrated as a safe and effective alternative in this case of retained catheter induced cerebrospinal fluid (CSF) leak.

Minimally invasive surgery for lumbar synovial cysts with coexisting degenerative spondylolisthesis.

BACKGROUND: About one third of lumbar synovial cysts are associated with degenerative spondylolisthesis. Segmental instability is thought to contribute to the pathogenesis and recurrence of synovial cysts and lumbar fusion has been advocated as a treatment of choice in the presence of spondylolisthesis. In patients with spondylolisthesis, minimally invasive resection of lumbar synovial cysts, without fusion, could minimize surgically induced segmental instability while providing good pain relief. METHODS: Clinical and radiological outcomes of lumbar synovial cyst patients with and without spondylolisthesis were retrospectively compared. Pain outcomes were assessed with modified Macnab criteria. RESULTS: Fifty-three patients (18 with grade 1 spondylolisthesis) underwent minimally invasive synovial cyst resection and all had either excellent or good pain outcome at ≤ 8 post- operative weeks (P = 1.000, n = 53). At > 8 post-operative weeks (mean (SD) follow-up of 200 (175) weeks), excellent or good outcomes were noted in 89% of patients without spondylolisthesis and in 75% of patients with spondylolisthesis (P = 0.425, n = 40). Four patients developed a new grade 1 spondylolisthesis at a mean follow-up of 2.6 ± 2.1 years. Nine patients were assessed for spondylolisthesis measurements at 1.2 ± 1.3 years of follow up and no significant difference was observed (5 ± 0 vs 5 ± 1 mm; P = 0.791). Two patients without spondylolisthesis and none of the patients with spondylolisthesis had a synovial cyst recurrence. CONCLUSION: Patients with concomitant lumbar degenerative spondylolisthesis and synovial cyst can have good short- and long-term clinical outcomes with minimally invasive surgery without fusion. Post-operative segmental instability does not appear to be significant in patients with spondylolisthesis. All patients included in this article signed an informed consent for the use of their medical information for research.

Resection of an oculomotor nerve cavernous angioma.

BACKGROUND: Cavernous angiomas (CAs) of cranial nerves are rare, and their occurrence on the third cranial nerve is particularly rare. Surgical management of such CAs involving the third nerve is controversial. We describe a case of a symptomatic CA of the oculomotor nerve and review the literature in order to ascertain the relevance of surgical intervention. CASE DESCRIPTION: A 71-year-old male patient presented with a 2-month history of progressive oculomotor nerve paralysis. CA of the oculomotor nerve was suspected on magnetic resonance imaging (MRI). The patient underwent complete resection of the CA through a subtemporal approach, preserving the integrity of the nerve. Histopathological analysis confirmed the diagnosis of CA. Despite optimal resection, the patient did not improve postoperatively. CONCLUSION: CAs of cranial nerves can cause rapid or progressive neurological deterioration. Whereas delayed treatment often leads to irreversible deficits, early nerve-sparing surgical excision of the CAs may potentially restore function.

Short-term outcomes of purely endoscopic endonasal resection of orbital tumors: a systematic review.

BACKGROUND: The purpose of this review was to evaluate outcomes in transnasal endoscopic approaches for the management of extraconal and intraconal orbital tumors. METHODS: A systematic review of studies on purely endoscopic endonasal orbital tumor resections was conducted using the MEDLINE database. Data extracted and analyzed from selected studies included study type, sample size, demographics, symptomatology, tumor characteristics, complications, follow-up time, and recurrence. RESULTS: Thirty-nine studies were identified and included, containing patient data for 71 cases. Mean patient age was 47 years (range, 1-75 years), and 53.5% of patients were male. Primary site of the tumor was orbital in 69.0% of the cases, of which 51.0% were intraconal and 30.6% were extraconal. The most common reported histopathology was cavernous hemangioma (45.1%). Intraoperative complications were reported in 5.6% of cases. Postoperative complications were noted in 29.6% of cases, the majority of which were transient (76.2%). There was no significant difference in postoperative complication rate between intraconal and extraconal primary site tumors (p = 0.302). Recurrence rate was 4.2%. CONCLUSION: Purely endoscopic endonasal resection of orbital tumors is a viable alternative technique to traditional external procedures, with the inherent advantages of minimally invasive surgery. This study of 71 cases represents the largest pooled sample size to date, and the increasing use of endoscopic procedures will allow for future analyses with greater statistical power.

Cervical spondylosis: a rare and curable cause of vertebrobasilar insufficiency.

BACKGROUND: Spondylotic vertebral artery (VA) compression is a rare cause of vertebrobasilar insufficiency and stroke. CASE DESCRIPTION: A 53-year-old man experienced multiple brief vertebrobasilar transient ischemic attacks (TIAs) and strokes, not apparently triggered by neck movements. Brain magnetic resonance imaging (MRI) documented consecutive infarcts, first in the left then right medial posterior inferior cerebellar artery (PICA) territories. Angiography showed two extracranial right vertebral artery (VA) stenoses, left VA hypoplasia, absence of left PICA and a dominant right PICA. Computed tomography angiography revealed right VA compression by osteophytes at C5-C6 and C6-C7 levels. No further vertebrobasilar insufficiency symptoms occurred in the 65 months following VA surgical decompression. Our literature review found 49 published surgical cases with vertebrobasilar symptoms caused by cervical spondylosis. Forty cases had one or more brief TIAs frequently triggered by neck movements. Three cases presented with stroke without prior TIA, with symptoms suggesting a top of the basilar artery embolic infarcts (one combined with a PICA infarct). Six cases had both TIAs and minor stroke. VA compression by uncovertebral osteophytes at the C5-C6 level was common. Dynamic angiography done in 38 cases systematically revealed worsening of VA stenosis or complete occlusion with either neck extension or rotation (ipsilateral when specified). Contralateral VA incompetence was found in 14 patients. CONCLUSION: Spondylotic VA stenosis can cause hemodynamic TIAs and watershed strokes, especially when contralateral VA insufficiency is combined to specific neck movements. Low-amplitude neck movement may suffice in severe cases. Embolic vertebrobasilar events are less frequent. VA decompression from spondylosis may prevent recurrent ischemic episodes.

Inflammatory myofibroblastic tumors of the central nervous system that express anaplastic lymphoma kinase have a high recurrence rate.

BACKGROUND: Inflammatory myofibroblastic tumors (IMTs) of the central nervous system (CNS) are rare entities with diverse histopathological features and varying propensities to recur. CASE DESCRIPTION: A 26 year-old male with an IMT of the CNS of the left tentorium had tumor progression 2 months after partial surgical resection. Histopathological studies confirmed expression of ALK. Macroscopic total resection was performed followed by radiotherapy. A recurrence occurred 20 months after the second surgery that necessitate reoperation. Including the present case, we identified 30 cases of IMT of the CNS corresponding to our search criteria in the literature. The extent of resection was reported in 26 of these cases. Gross total resection was done in 75% of ALK-positive and in 61% of ALK-negative cases. Recurrence rate after gross total resection for ALK-positive and ALK-negative cases was 33% and 9%, respectively. Every recurrence in ALK-positive patients occurred within 2 years after surgery. CONCLUSION: IMT of the CNS are a heterogeneous group of tumors and the treatment of choice is complete surgical resection. Because of the high recurrence rate reported for IMT of the CNS expressing ALK, a closed follow-up is recommended. When faced with an early recurrence, a surgical resection followed by radiotherapy may be advised.

Tentorial branch of the superior cerebellar artery.

BACKGROUND: The tentorial branch of the superior cerebellar artery (SCA) is not well known and is underreported in the literature. In the present study, the authors report and describe a dural branch arising from the SCA that was encountered during the surgical treatment of a tentorial dural arteriovenous fistula (DAVF). The clinical relevance of this branch is discussed. CASE DESCRIPTION: A 53-year-old patient suffered a third recurrent right thalamic hemorrhage within 2 weeks rendering him comatose. Computed tomography scan revealed a right thalamic hematoma extending into the ventricles, producing acute hydrocephalus and midline shift. Cerebral angiography revealed a right-sided tentorial Borden type III DAVF fed primarily by the tentorial artery of Bernasconi and Cassinari and, to a lesser extent, the petrous branch of the middle meningeal artery. A small dural feeder originating from the SCA was suspected. Venous drainage was via the lateral mesencephalic vein, through an aneurysmal dilated basal vein of Rosenthal, to the straight sinus. The DAVF was approached surgically via a right subtemporal approach. Intraoperatively, after division of the tentorium, a tentorial branch originating from the SCA was identified. This artery was sectioned while preserving the SCA. The draining vein was ligated adjacent to the sinus. Postoperatively, the patient's neurological status improved and postoperative angiography demonstrated complete obliteration of the tentorial DAVF. CONCLUSION: Knowledge of the tentorial branch of the SCA is important as it may potentially be sectioned during division of the tentorium or avulsed from its origin in the SCA during surgical manipulation in the ambient cistern.

The early origins and development of the scatterplot.

Of all the graphic forms used today, the scatterplot is arguably the most versatile, polymorphic, and generally useful invention in the history of statistical graphics. Its use by Galton led to the discovery of correlation and regression, and ultimately to much of present multivariate statistics. So, it is perhaps surprising that there is no one widely credited with the invention of this idea. Even more surprising is that there are few contenders for this title, and this question seems not to have been raised before. This article traces some of the developments in the history of this graphical method, the origin of the term scatterplot, the role it has played in the history of science, and some of its modern descendants. We suggest that the origin of this method can be traced to its unique advantage: the possibility to discover regularity in empirical data by smoothing and other graphic annotations to enhance visual perception.