Comparative Study Between M6-C and Mobi-C Cervical Artificial Disc Replacement: Biomechanical Outcomes and Comparison with Normative Data.

OBJECTIVE: Cervical spondylosis affects a huge proportion of the middle-aged population. Degenerative changes can occur in multiple regions of the cervical spine typically affecting the joints, intervertebral discs and endplates. These changes lead to compression of adjacent nervous structures, which results in radiculopathic and myelopathic pain. Various treatment modalities are currently available with non-surgical approaches the initial go to if there is no symptomatic cord compression. Anterior cervical discectomy and fusion, or arthroplasty are the two common surgical approaches if non-surgical treatments fail to relieve symptoms of the patients or there are signs of central cord compression. However, studies have shown that there is an increased risk of adjacent segment disease related to fusion. Cervical disc arthroplasty aims to restore normal range of motion (ROM) in patients with pain and disability due to degenerative disc disease resistant to conservative care. Two common disc prostheses used include M6-C and Mobi-C. Both prostheses comprise a mobile polymer segment sandwiched between two metal endplates with mechanisms resembling an actual intervertebral disc. This study aims to compare the kinematics associated with these prostheses, against the normal range of motion in the non-degenerative population. METHOD: Patients who underwent M6-C or Mobi-C disc replacements by the senior author from 2012 to 2015 were identified at a single tertiary institution. Routine 3-month postoperative lateral radiographs were analyzed for flexion and extension ROM angles at the involved vertebral level by two independent authors. Data was compared to previous published studies investigating cervical spine ROM of asymptomatic patients. RESULTS: There was no statistical significance in the difference of overall flexion range between M6-C and Mobi-C prostheses. However, overall range of extension of Mobi-C was greater compared to M6-C (P = 0.028). At C5-6 , the range of flexion for both implants were similar but lesser compared to asymptomatic patients (P < 0.001). Range of extension was greater in the Mobi-C group (14.2° ± 5.1°) compared to the M6-C (7.3° ± 4.6°) (P = 0.0009). At C6-7 , there were no statistical differences in both range of flexion and extension between the two prostheses and asymptomatic patients (P > 0.05). CONCLUSION: The early results regarding restoration of ROM following cervical arthroplasty using either M6-C or Mobi-C prosthesis are encouraging. Long-term follow-up studies are necessary to observe the change in ROM over time with physiological loading and wear patterns.

A Direct Aspiration First Pass Technique vs Standard Endovascular Therapy for Acute Stroke: A Systematic Review and Meta-Analysis.

BACKGROUND: The direct aspiration first pass technique (ADAPT) is a recent endovascular treatment for ischemic stroke due to large vessel occlusion that has been gaining popularity due to the rapidity of the technique and the potential for cost savings in comparison to standard thrombectomy methods such as stent retrievers. However, few studies have directly compared these 2. OBJECTIVE: To compare ADAPT with stent retrievers for thrombectomy via systematic review and meta-analysis. METHODS: Ovid Medline, PubMed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, ACP Journal Club, and Database of Abstracts of Review of Effectiveness limited to English through September 2016 were systematically searched. Eligible studies included those in which patient cohorts underwent ADAPT for acute stroke. Recanalization efficiency, clinical outcomes, and complication rates of ADAPT were compared with the current standard of endovascular thrombectomy techniques. RESULTS: Seventeen studies on ADAPT and 5 randomized controlled trials on endovascular therapy were included. ADAPT achieved higher rates of complete revascularisation (89.4% vs 71.7%, P < .001) but similar clinical outcomes compared to front-line endovascular therapy. Seventy-one point four percent of ADAPT cases were successfully recanalized with aspiration alone, and a trend towards reduced time from groin puncture to recanalization time was noted (44.77 vs 61.46 min, P = .088). CONCLUSION: The pooled results are comparable with recent randomized studies that demonstrate the benefit of endovascular therapy over intra-arterial medical therapy. Future direct comparative studies and randomized trials are required to confirm the benefit of the ADAPT strategy compared to standard endovascular therapy for acute ischemic stroke.

A systematic review and meta-analysis of the prevalence of norovirus in cases of gastroenteritis in developing countries.

BACKGROUND: While norovirus (NoV) is well known as a leading causal pathogen for acute gastroenteritis in developed countries,structured data on prevalence in developing countries are not available thus far. This review aims to estimate the prevalence of NoV in cases of gastroenteritis in developing countries based on recently published reports. METHODS: Relevant studies were identified by searching PubMed and Web of Science for the period January 1, 1990 through March 31, 2016. We included studies performed in developing countries with a study period of at least 12 months and which provided information on polymerase chain reaction (PCR)-confirmed NoV prevalence in patients diagnosed with acute gastroenteritis. A metaanalysis was conducted on NoV prevalence, focused on viral genogroups GI and GII, in cases of acute gastroenteritis. RESULTS: Using evidence from 178 articles, the estimated NoV prevalence among 148,867 patients with acute gastroenteritis was 17% (95% confidence interval [CI]: 15-18%). The prevalence decreased from 18% (95% CI: 16-20%) for upper middle-income countries to 15% (13-18%) and 6% (3-10%) for lower middle- and low-income countries, respectively. There were no significant differences in NoV prevalence by age group (under 5 years, 5 years and over, and mixed ages) or severity of symptoms as defined by community, outpatient, or inpatient setting. The pooled prevalence of NoV GII (15%, 95% CI: 13-17%) was significantly higher than that of NoV GI (1%, 95% CI: 1-1%) in patients with acute gastroenteritis. CONCLUSION: From the evidence considered in this review, the estimated prevalence of NoV in patients with acute gastroenteritis in developing countries was 17%. This estimate can be used to evaluate the burden of NoV-associated acute gastroenteritis in developing countries, which is currently unclear due to poor diagnosis and surveillance systems, and the estimation may enhance the development of human NoV vaccines.

A novel technique for placement of sacro-alar-iliac (S2AI) screws by K-wire insertion using intraoperative navigation.

Sacral-iliac fixation techniques may be indicated in the management of various lumbosacral pathologies including spinal degeneration, infection, tumour resection, fracture, pseudarthrosis, correction of spinal deformities involving long fusion constructs to the sacrum and cases with poor sacral fixation. There are a number of options for lumbosacral fixation each with their own advantages and disadvantages. Though S2-alar-iliac (S2AI) have demonstrated promising advantages over alternatives, the complex anatomy of the spinopelvic region demands precise insertion of the screws to create a biomechanically robust construct safely. As such, we present a novel technique of using intra-operative CT navigation and K-wires to establish and secure a planned trajectory, thereby ensuring solid spinopelvic fixation with S2AI screws. This was performed as part of a long fusion construct for correction of kyphosis deformity in a male patient.

A meta-analysis comparing ALIF, PLIF, TLIF and LLIF.

INTRODUCTION: Lumbar interbody fusions have been widely used to treat degenerative lumbar disease that fails to respond to conservative treatment. This procedure is divided according to its approach: anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF) and lateral lumbar interbody fusion (LLIF). Each approach has its own theoretical advantages and disadvantages; however, there have been no studies that compared these. METHODS: Various full-text databases were systematically searched through December 2015. Data regarding the radiological, operative and clinical outcomes of each lumbar interbody fusion were extracted. All outcomes were pooled using random effects meta-analysis, with the relative risk (RR) and/or weighted mean difference (WMD) as the summary statistic. RESULTS: Thirty studies met the inclusion criteria. The ALIF procedure has been studied most intensively, followed by PLIF, TLIF and LLIF respectively. All four approaches had similar fusion rates (p=0.320 & 0.703). ALIF has superior radiological outcome, achieving better postoperative disc height (p=0.002 & 0.005) and postoperative segmental lordosis (p=0.013 & 0.000). TLIF had better Oswestry Disability Index scores (p=0.025 & 0.000) while PLIF had the greatest blood loss (p=0.032 & 0.006). Complication rates were similar between approaches. Other comparisons were either inconclusive or lacked data. There was marked less studies comparing against LLIF. CONCLUSIONS: Each approach has their own risks and benefits but similar fusion rates. Despite the large number of studies, there is little data overall when comparing specific aspects of lumbar interbody fusions. More studies, especially RCTs are needed to further explore this topic.

Treatment of Lumbar Spinal Stenosis by Microscopic Unilateral Laminectomy for Bilateral Decompression: A Technical Note.

Lumbar spinal stenosis is typically a degenerative condition that leads to compression of the spinal canal and lateral recess, resulting in leg pain and walking disability. Surgical management is indicated after failure of non-surgical management or rapidly worsening neurological impairment. The traditional approach is a laminectomy with foraminotomy and partial facetectomy but a newer minimally invasive option, unilateral laminectomy for bilateral decompression (ULBD), seems to demonstrate the better postoperative outcomes due to its unilateral exposure. ULBD involves a midline incision, opening the thoracolumbar fascia, retracting the paravertebral muscles unilaterally, then a hemilaminectomy, flavectomy, and decompression of the spinal canal with foraminotomy or partial facetectomy. The clinical decision on which side to approach spinal stenosis with ULBD has not been discussed in the literature. We have come up with an algorithm to decide which side to approach for ULBD based on position of spinous process and angulation, side of maximal compression, and surgeon handedness.

Ultra-Early Angiographic Vasospasm After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis.

OBJECTIVE: After aneurysmal subarachnoid hemorrhage (aSAH), prognosis is affected heavily by the presence of delayed cerebral ischemia (DCI). There is growing recognition of ultra-early angiographic vasospasm (UEAV) occurring within 48 hours of aSAH; however, its relationship with DCI and ultimately prognosis remains unclear. METHODS: Various databases limited to the English language through September 2016 were searched systematically. Eligible studies were those comparing UEAV with control non-UEAV outcomes and follow-up. Two independent reviewers evaluated the quality of studies and abstracted the data, with discrepancies resolved by a third. We calculated odds ratios (ORs) and 95% confidence intervals for all outcomes by using random-effects meta-analyses and performed a heterogeneity analysis. RESULTS: Four comparative studies were selected for analysis. Pooled analysis demonstrated that UEAV compared with no-UEAV was associated with greater proportion of rupture aneurysms sized greater than 12 mm (38.3% vs. 24.3%, P < 0.00001). A significantly greater number of patients with UEAV had ruptured MCA aneurysms compared with patients without UEAV (29.7% vs. 19.9%, P = 0.005). Compared with no-UEAV, patients with UEAV were significantly associated with symptomatic cerebral vasospasm (OR 2.07, P = 0.05) and DCI/infarction (OR 2.52, P = 0.02). A significant association also was found between UEAV and an unfavorable outcome at follow-up (OR 1.64, P = 0.03) and greater mortality (OR 2.65, P < 0.00001). CONCLUSIONS: UEAV was significantly associated with symptomatic cerebral vasospasm, DCI/infarction, unfavorable outcome at follow-up, and greater mortality. Patients with intracerebral hematoma, intraventricular hemorrhage (Fisher Grade IV), larger ruptured aneurysms >12 mm, and an MCA location were more likely to have UEAV.

Orbital Approaches for Treatment of Carotid Cavernous Fistulas: A Systematic Review.

BACKGROUND: Carotid cavernous fistulas (CCFs) are abnormal connections between the carotid arteries and the cavernous sinus. CCFs often present with double vision, reduced visual acuity, and conjunctivitis. Deteriorating ocular symptoms caused by abnormal fistula drainage can cause permanent blindness, and so urgent interventional treatment is necessary. Transvenous embolization of the fistula is the primary treatment option for most patients with symptomatic CCFs. Orbital approaches are considered to be risky compared with the traditional approach via the inferior petrosal sinus and are thus used as a secondary option. These approaches include embolization via the superior ophthalmic vein, inferior ophthalmic vein, and medial ophthalmic vein and direct transorbital puncture. This study aims to assess the merits and risks of orbital approaches in transvenous embolization of CCFs. METHODS: A systematic review of 30 studies assessing the radiographic and clinical outcomes of this approach was conducted. Outcomes of interest included successful fistula closure, postoperative improvement of ocular symptoms, and complications from the procedure. Weighted averages were calculated for all outcomes. RESULTS: Transvenous embolization via an orbital approach had a high success rate (89.9%). Improvement in visual acuity and proptosis was found in 93.4% and 88.1% of patients, respectively. There were no major complications. Minor complications found included subconjunctival hemorrhage (n = 4), intraorbital hemorrhage (n = 1), eyelid hematoma (n = 1), and foreign-body granuloma (n = 3). CONCLUSIONS: All orbital approaches for transvenous embolization of CCFs are effective and safe.

Attitudes and knowledge of medical practitioners to hereditary cancer clinics and cancer genetic testing.

Genetic testing for susceptibility for common cancers is widely available. Thus, doctors have a role in identifying and referring patients who would benefit from a consultation with a specialist in genetics. This study aims to assess doctors' referral rates, knowledge and attitudes towards cancer genetic testing, broken down by specialty (gastrointestinal, breast/ovarian, other specialties and General Practitioners-GPs). A 4-page questionnaire was mailed out to the GPs of all patients seen in 2012 in the Hereditary Cancer Clinic of St. Vincent's Hospital Sydney (n = 128) and all the specialists in St. Vincent's Hospital Sydney that might refer to the HCC (n = 33). 50 questionnaires were returned (31 %). Most doctors had referred a patient for cancer genetic testing (90 %). The average proportion of patients referred was 1 in 68.5 patients with breast/ovarian specialists referring the most, followed by gastrointestinal specialists and GPs. There was suboptimal knowledge of cancer genetic testing amongst doctors. Breast/ovarian specialists were most knowledgeable, followed by gastrointestinal specialists, other specialists and GPs. There were indications of inappropriate referral amongst doctors. Most (77.6 %) doctors were willing to receive further information on cancer genetics. Nearly all (94 %) doctors believe that it is their duty to inform an individual at high risk for hereditary cancer that cancer genetic counselling and testing is available. The majority of doctors have positive attitudes towards cancer genetic testing. Defective knowledge scores, however, indicate that doctors need further training or tools to enable them to refer patients appropriately for cancer genetic testing.

Asymmetric requirement of surface epithelial ß-catenin during the upper and lower jaw development.

BACKGROUND: Intercellular communication between epithelial and mesenchymal cells is central to mammalian craniofacial development. ß-catenin is the gateway of canonical Wnt signaling, one of the major evolutionarily conserved cell-cell communication pathways in metazoa. In this study, we report an unexpected stage- and tissue-specific function of ß-catenin during mammalian jaw development. RESULTS: Using a unique mouse genetic tool, we have discovered that epithelial ß-catenin is essential for lower jaw formation, while attenuation of ß-catenin is required for proper upper jaw development. Changes in ß-catenin in vivo alter major epithelial Fgf8, Bmp4, Shh, and Edn1 signals, resulting in partial transcriptional reprogramming of the neural crest-derived mesenchyme, the primary source of jawbones. CONCLUSIONS: The Wnt/ß-catenin signal coordinates expression of multiple epithelial signals and has stage-specific asymmetric functions during mammalian upper and lower jaw development. In addition, these findings suggest that evolutionary changes of the canonical Wnt/ß-catenin signaling pathway may lead to innovation of jaws.