Quantitative evaluation for cervical foraminal bony stenosis based on angled sagittal slices along a nerve root on computed tomography

Cervical foraminal canal stenosis is a common disease, but any relationships between the measurement values of cervical foraminal canals and clinical symptoms have yet to be explored. We aim to determine a numerical cutoff point of cervical foraminal bony canal size that does not lead to radiculopathy so as to establish criteria for the surgical indication. We reconstructed angled sagittal slices along a nerve root on computed tomography (CT) on a workstation from pre-operative CT data and measured 1152 cervical foraminal canals (144 patients) from Cervical (C) 4/5 to C7/Thoracic (Th) 1. We evaluated the relationship between the size of foraminal canals and clinical manifestations. Receiver operating characteristic (ROC) analysis was used to calculate cutoff points of each foraminal canal size with positive neurologic manifestations. Of the 144 patients’ 1152 nerve roots, 286 nerve roots (24.8%) were diagnosed as radiculopathy by neurological examinations. The mean measured value of all foraminal canals on angled sagittal CT imagery was 3.39 ± 1.37 mm. The cutoff point of foraminal canal sizes without radiculopathy was 2.7 mm (sensitivity 0.680, specificity 0.591) overall. A cutoff point ascertained by quantitative evaluation of cervical foraminal canal size is useful for making diagnosis of cervical foraminal canal bony stenosis.     

The impact of walking devices on kinematics in patients with spastic bilateral cerebral palsy

Increased anterior pelvic and trunk tilt is a common finding in patients with bilateral cerebral palsy especially during walking with assistive devices. As previous studies demonstrate various gait alterations when using assistive devices, the assessment of surgical interventions may be biased when the patients become independent of (or dependent on) assistive devices after therapy. Furthermore, some of these patients in fact are able to walk without devices even though in daily life they prefer to use them. Consequently, for such patients the classification into GMFCS level II or III may be ambiguous. The specific aim of this study was therefore to assess the influence of the use of forearm crutches and posterior walker during walking and to set this influence in relation to outcome effects of surgical intervention studies.26 ambulatory patients with spastic bilateral CP (GMFCS II–III) were included who underwent 3D gait analysis. All patients used forearm crutches or posterior walkers in everyday life even though they were able to walk without assistive devices for short distances.Independent of the type of assistive devices, the patients walk on average with more anterior trunk tilt and pelvic tilt (7° ± 6° and 3° ± 2°) and with a maximum ankle dorsiflexion decreased by 2° (±3°) when walking with assistive devices, enhancing the mal-positioning present without device. Oppositely, the knees on average are more extended by 6° (±4°) when using the assistive devices.These effects have to be taken into account when assessing gait patterns or when monitoring the outcome after intervention as assistive devices may partially hide or exaggerate therapeutic effects.     

Elevation of serum lactate dehydrogenase at posterior reversible encephalopathy syndrome onset in chemotherapy-treated cancer patients

The pathophysiology of posterior reversible encephalopathy syndrome (PRES) is incompletely understood; however, an underlying state of immune dysregulation and endothelial dysfunction has been proposed. We examined alterations of serum lactate dehydrogenase (LDH), a marker of endothelial dysfunction, relative to the development of PRES in patients receiving chemotherapy. A retrospective Institutional Review Board approved database of 88 PRES patients was examined. PRES diagnosis was confirmed by congruent clinical diagnosis and MRI. Clinical features at presentation were recorded. Serum LDH values were collected at three time points: prior to, at the time of, and following PRES diagnosis. Student’s t-test was employed. LDH values were available during the course of treatment in 12 patients (nine women; mean age 57.8 years [range 33–75 years]). Chemotherapy-associated PRES patients were more likely to be normotensive (25%) versus the non-chemotherapy group (9%). LDH levels at the time of PRES diagnosis were higher than those before and after (p = 0.0263), with a mean difference of 114.8 international units/L. Mean time intervals between LDH measurement prior to and following PRES diagnosis were 44.8 days and 51.4 days, respectively. Mean elapsed time between last chemotherapy administration and PRES onset was 11.1 days. In conclusion, serum LDH, a marker of endothelial dysfunction, shows statistically significant elevation at the onset of PRES toxicity in cancer patients receiving chemotherapy. Our findings support a systemic process characterized by endothelial injury/dysfunction as a factor, if not the prime event, in the pathophysiology of PRES.     

Bone bridge fixation has superior biomechanics on posterior knees to bone plug fixation after lateral meniscal allograft transplantation – A biomechanical study simulating partial weight-bearing conditions

BackgroundIt remains unknown how biomechanics change in posterior lateral knee using different fixation techniques in lateral meniscal allograft transplantation (MAT) during simulated toe-touch partial weight-bearing. This study aimed to compare the biomechanical effects on posterior knee between bridge and bone plug fixation in lateral MAT.MethodsIntact knee, bone bridge fixation, and bone plug fixation were tested with 500 N of axial load during knee flexion at 0°, 30°, and 60°, which simulated toe-touch partial weight-bearing. Contact area and peak pressure were assessed on posterior knee and the shift of peak pressure position were measured.ResultsOn the posterior lateral compartment, the contact mechanics of bone bridge fixation were similar to those of the intact knee (all P-values > 0.05), but its peak pressure was higher than that of intact knee at 60° (P = 0.002). For bone plug fixation, the contact area of the posterior lateral knee was significantly lower than those of intact knee and bone bridge fixation at 30° and 60° (all P-values < 0.05). The peak pressure of the posterior lateral knee was higher than that of the intact knee at all flexions and higher than that of bone bridge fixation at 30° and 60° (all P-values < 0.05). The peak pressure position of bone plug fixation shifted more laterally and posteriorly compared with intact knee and bone bridge fixation during knee flexion.ConclusionBone bridges could maintain posterior knee biomechanics better than bone plug fixation during knee bending during partial weight-bearing.     

Cephalometric and three-dimensional assessment of the posterior airway space and imaging software reliability analysis before and after orthognathic surgery

PurposeThis study aimed to compare the reliability of three different imaging software programs for measuring the PAS and concurrently to investigate the morphological changes in oropharyngeal structures in mandibular prognathic patients before and after orthognathic surgery by using 2D and 3D analyzing technique.Material and methodsThe study consists of 11 randomly chosen patients (8 females and 3 males) who underwent maxillomandibular treatment for correction of Class III anteroposterior mandibular prognathism at the University Hospital in Zurich. A set of standardized LCR and CBCT-scans were obtained from each subject preoperatively (T0), 3 months after surgery (T1) and 3 months to 2 years postoperatively (T2). Morphological changes in the posterior airway space (PAS) were evaluated longitudinally by two different observers with three different imaging software programs (OsiriX^® 64-bit, Switzerland; Mimics^®, Belgium; BrainLab^®, Germany) and manually by analyzing cephalometric X-rays.ResultsA significant increase in the upper airway dimensions before and after surgery occurred in all measured cases. All other cephalometric distances showed no statistically significant alterations. Measuring the volume of the PAS showed no significant changes in all cases. All three software programs showed similar outputs in both cephalometric analysis and 3D measuring technique.ConclusionA 3D design of the posterior airway seems to be far more reliable and precise phrasing of a statement of postoperative gradients than conventional radiography and is additionally higher compared to the corresponding manual method. In case of Class III mandibular prognathism treatment with bilateral split osteotomy of the mandible and simultaneous maxillary advancement, the negative effects of PAS volume decrease may be reduced and might prevent a developing OSAS.     

Single-centre comparison of procedural complications,clinical outcome,and angiographic follow-up between coiling and stent-assisted coiling for posterior communicating artery aneurysms

Aneurysm recurrence is a principle limitation of endovascular coiling procedures, especially in posterior communicating artery aneurysms, with reported recurrence rates of >30%. The adjunctive use of self-expandable stents has revolutionised the treatment of intracranial aneurysms, especially for complex morphologies, wide necks, or unfavourable dome-to-neck ratios. However, there are limited data concerning a direct comparison between simple coiling and stent-assisted coiling in posterior communicating artery aneurysms. This study aimed to compare the durability and outcomes of coiling versus stent-assisted coiling procedures. Imaging data of patients with posterior communicating artery aneurysms treated with coiling or stent-assisted coiling between January 2008 and October 2012 were retrospectively analysed. The initial angiographic results, procedural complications, and clinical outcomes were assessed at discharge. Imaging follow-up was performed with cerebral angiography. Complete aneurysm occlusion was achieved on initial angiography in 23/56 (41.1%) stent and 83/235 (35.3%) non-stent patients. At the latest follow-up (mean follow-up 14.3 ± 10.4 months for stent and 13.2 ± 9.5 months for non-stent patients), aneurysms had recurred in 5/47 (10.6%) stent and 57/203 (28.1%) non-stent patients (p = 0.014). Procedural complications occurred in 6/56 (10.7%) stent and 27/235 (11.5%) non-stent aneurysms. No rebleeding occurred during clinical follow-up (mean duration, 46.7 months). Recurrence rates at the latest follow-up were significantly lower in patients undergoing stent-assisted coiling than those undergoing simple coiling. Thus, use of the stent-assisted neck remodelling technique in the treatment of wide-necked posterior communicating artery intracranial aneurysms appears to improve the long-term clinical outcome.     

小儿后颅窝囊肿特点和治疗探讨

目的探讨小儿后颅窝囊肿的临床特点、手术方式及疗效。方法回顾分析近10年内治疗的38例后颅窝囊肿病变患儿的临床资料。这38例患儿中行单纯囊肿一腹腔分流治疗13例，囊肿剥离开窗治疗14例（其中显微镜下剥离13例，内镜下剥离1例），神经内镜辅助下第三脑室底造瘘术结合分流术或囊肿剥离开窗治疗（联合手术组）11例（均为巨大囊肿合并脑积水者）。结果分流组再次手术率15．4％（2113），囊肿剥离开窗组再次手术率7．1％（1／14），联合手术组再手术率18．2％（2111）。术后平均随访3年以上，所有病人的囊肿均缩小。结论对小儿后颅窝囊肿治疗应根据囊肿部位、大小和脑脊液吸收功能情况制定以显微镜下囊肿剥离术为首选，配合内镜和分流术的个体化手术方案。