Influence of hinge position on the effectiveness of expansive open-door laminoplasty for cervical spondylotic myelopathy.

STUDY DESIGN: A prospective study. OBJECTIVE: To assess the influence of different hinge positions on the clinical results of expansive open-door laminoplasty (EOLP) for cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA: EOLP is currently the most widely adopted surgical treatment for CSM, although many long-term clinical follow-up studies have reported that most patients recover satisfactorily after EOLP, there have been numerous reports regarding postoperative complications, such as stubborn axial symptoms and segmental motor paralysis. The hinge position in EOLP plays a decisive role in determining the openness of the door so that affect clinical outcomes, whereas no thorough studies on the hinge positions have been published. METHODS: A total of 102 consecutive CSM patients who underwent EOLP from February 2006 to February 2007 were enrolled in this randomized controlled trial and assigned alternatively to 1 of 2 treatment groups. Using a random digits table, 57 patients with the hinge located at the inner margin of the lateral mass were classified as wide-open group, whereas 45 patients with the hinge positioned at the lamina margin served as narrow-open group. All patients were followed up over 24 months, clinical results including operation duration, intraoperative bleeding volume, Japanese Orthopaedic Association scores, axial symptoms assessment, and C5 palsy, and radiologic examinations like C2-C7 angle, cervical curvature index, and range of motion were analyzed statistically. RESULTS: In this study, there were no significant differences in terms of operation duration, intraoperative bleeding volume, neural function recovery rate, curvature index, and range of motion. The neural functions were satisfactorily improved after EOLP in both groups (Japanese Orthopaedic Association score developed from 7.2 ± 1.1 to 14.3 ± 1.2 and 8.1 ± 0.9 to 15.1 ± 1.6 with P = 0.01 and 0.02, respectively), whereas the severity of axial symptoms was significantly lower in narrow-open group than in wide-open group (P<0.01). The incidence of C5 palsy in wide-open group was higher than that in narrow-open group (5.3% vs. 0%), even though the difference did not reach statistical significance (1-tailed Fisher exact test, P = 0.17). CONCLUSIONS: Our results indicate that proper inward shift of the hinge can ensure effectiveness of surgical decompression, avoid an excessive backward shift of the spinal cord, reduce the incidence of C5 palsy, and alleviate the severity of axial symptoms. In addition, an inward shift should be cautious and contraindicated in patients with fluorosis cervical stenosis, ossification of posterior longitudinal ligament, and ossification of ligament flavum.

A comparison of computed tomography with magnetic resonance imaging for the diagnosis of thoracic extramedullary hemopoiesis in patients with leukemia: A non-inferiority retrospective diagnostic study.

At present, MRI is the primary choice of examination for the diagnosis of thoracic extramedullary hemopoiesis. When thoracic extramedullary hemopoiesis presents as posterior mediastinum masses in specific clinical contexts, the diagnosis is not challenging. Other radiological presentations may be more difficult for diagnosis and require biopsy. Needle biopsy is typically preferred for the diagnosis of extramedullary hemopoiesis however, the high vascularization of tissues is one of the complications of this method thus, it is avoided. The aim of the present study was to compare the diagnostic parameters of CT with MRI for the diagnosis of thoracic extramedullary hemopoiesis in patients with leukemia, with an open lung biopsy as a reference standard. Chest CT, chest MRI and open lung biopsy data from a total of 912 patients with leukemia with a sign(s) and symptoms of suspected paravertebral and/or pulmonary extramedullary hemopoiesis were reviewed. In the present study, thoracic extramedullary hemopoiesis was defined as diffusivity of both lung fields being increased compared with the blood pool and no other abnormal focal of lungs being increased compared with the blood pool. The beneficial score was calculated for CT and MRI and plotted for the decision making of irradiation. With respect to open lung biopsy, MRI had a higher sensitivity compared with CT (0.865 vs. 0.809; P<0.0001; q=1691) however, CT had a higher accuracy compared with MRI (0.833 vs. 0.733; P<0.0001; q=3020). The low rate of overdiagnosis was observed for both methods for the detection of thoracic extramedullary hemopoiesis however, the working area for detecting thoracic extramedullary hemopoiesis at least once in images was higher for MRI compared with CT. CT and MRI both have diagnostic importance in the detection of thoracic extramedullary hemopoiesis in patients with leukemia however, chest MRI misdiagnoses the condition while CT can confirm it (level of evidence, 3).

[Epidemiological characteristics of severe acute respiratory syndrome in Tianjin and the assessment of effectiveness on measures of control].

OBJECTIVE: To analyze the epidemiologic characteristics of severe acute respiratory syndrome (SARS) and to evaluate the effectiveness on its major control measures in Tianjn. METHODS: Adopting two case reports 1 and 2, designed by the Tianjin Centers for Disease Control and Prevention to develop a unified case-tracing table including the map of the distribution of close contacts to SARS patients. With those methods, investigation on patients and their close contacts at hospital wards, families, communities and institutions of the patients were carried out. RESULTS: From April 13 through May 8, 2003, there were 175 SARS cases including imported ones, were identified with an incidence rate of 1.9 cases per 100,000. Among them, 14 died with a fatality of 8.0%. The whole process of epidemic in Tianjin was less than one month with the following features: (1) 93.7% of the total SARS cases in Tianjin were directly or indirectly transmitted by a super-spreader. (2) 68.6% of the total SARS patients were concentrated in 3 hospitals A, B and C which was menifastated in 'clustering'. Through study on the rest of the SARS patients, results showed that 16.8% of them were transmitted through family close contact and 2.3% due to contact to colleagues. However, 12.6% of the patients were not able to show evidence that they had any contact to a diagnosed SARS patient. At the early stage of the epidemic, a number of medical practitioners were infected, taking up 38.2% of the total SARS cases. Among the total number of 1 975 medical workers who participated in the SARS medical cares and treatments, 3.4% of them got infected. During the outbreak, all index cases and chains of transmission seemed to be clear, with only 3 patients not able to be traced for the source of infection, taking up 2% of the total SARS patients in Tianjin. Among the 10 index cases, only the super spreader and another one index case transmitted the virus to their contacts but the rest of index cases did not cause any secondary infection. CONCLUSION: Though SARS is clinically severe and can be spreaded quickly, the epidemic can be under control within a short period of time if chains of SARS transmission are broken down and effective measures as isolation and quarantine against patients as well as underscoring awareness among the publics in a scientific way, being carried out.