Genomic Elucidation of a COVID-19 Resurgence and Local Transmission of SARS-CoV-2 in Guangzhou, China.

While China experienced a peak and decline in coronavirus disease 2019 (COVID-19) cases at the start of 2020, regional outbreaks continuously emerged in subsequent months. Resurgences of COVID-19 have also been observed in many other countries. In Guangzhou, China, a small outbreak, involving less than 100 residents, emerged in March and April 2020, and comprehensive and near-real-time genomic surveillance of SARS-CoV-2 was conducted. When the numbers of confirmed cases among overseas travelers increased, public health measures were enhanced by shifting from self-quarantine to central quarantine and SARS-CoV-2 testing for all overseas travelers. In an analysis of 109 imported cases, we found diverse viral variants distributed in the global viral phylogeny, which were frequently shared within households but not among passengers on the same flight. In contrast to the viral diversity of imported cases, local transmission was predominately attributed to two specific variants imported from Africa, including local cases that reported no direct or indirect contact with imported cases. The introduction events of the virus were identified or deduced before the enhanced measures were taken. These results show the interventions were effective in containing the spread of SARS-CoV-2, and they rule out the possibility of cryptic transmission of viral variants from the first wave in January and February 2020. Our study provides evidence and emphasizes the importance of controls for overseas travelers in the context of the pandemic and exemplifies how viral genomic data can facilitate COVID-19 surveillance and inform public health mitigation strategies.

[Design of three-dimensional foraminal guide device and application in percutaneous endoscopic lumbar discectomy].

OBJECTIVE: To explore clinical application of the new three-dimensional foramen guide in percutaneous endoscopic lumbar discectomy. METHODS: Based on the principle of reverse positioning, a new three-dimensional foramen guide was designed. From May 2016 to May 2018, totally 40 patients with segmental lumbar disc herniation were underwent percutaneous endoscopic lumbar discectomy. The patients were divided into guide and control group, and 20 patients in each group. In guide group, there were 9 males and 11 females with an average age of (46.0±11.0) years old;5 patients on L3,4, 15 patients on L4,5; BMI was (25.4±3.2) kg /m2;three dimensional foramen guide was used to assist the operation. While in control group, there were 10 males and 10 females with an average age of (51.8±9.8) years old;4 patients on L3,4, 16 patients on L4,5;BMI was (24.8±3.5) kg /m2;the operation was completed with bare hands according to the experience. The puncture time, times of fluoroscopy and puncture between two groups were compared, as well as the preoperative and postoperative visual analogue scale (VAS) score and Japanese Orthopaedic Association (JOA) were compared. RESULTS: All patients had no serious complications, and successfully completed operation. Operation time, the times of fluoroscopy and puncture in guide group were better than those of control group (P<0.05). VAS score and JOA score between two groups were significantly relieved after operation (P<0.05), but there was no significant difference between two groups (P>0.05). CONCLUSION: The three dimensional foramen guide is compact in structure, simple in operation, which could reduce the time of puncture and damage of radiation, shorten the learning curve of puncture for beginners, and has certain clinical feasibility.

Comparison of the sagittal profiles among thoracic idiopathic scoliosis patients with different Cobb angles and growth potentials.

BACKGROUND: Previous studies have demonstrated that pelvic incidence and sacral slope are significantly greater in idiopathic scoliosis patients compared with normal adolescents. However, whether these sagittal parameters are related to the progression of scoliosis remain unknown. The present was designed to determine the differences in the sagittal profiles among thoracic idiopathic scoliosis patients with different potentials for curve progression. METHODS: Ninety-seven outpatient idiopathic scoliosis patients enrolled from June 2008 to June 2011 were divided to three groups according to different Cobb angles and growth potentials: (1) non-progression of thoracic curve group, Risser sign of 5 and Cobb's angle < 40°; (2) moderate progression of thoracic curve group, Risser sign of 5 and Cobb's angle ≥ 40°; and (3) severe progression of thoracic curve group, Risser sign ≤ 3 and Cobb's angle ≥ 40°. All patients underwent whole spinal anteroposterior and lateral X-ray in standing position, and the sagittal parameters were measured, including thoracic kyphosis, lumbar lordosis, sacral slope, pelvic incidence, and pelvic tilt. RESULTS: The average thoracic scoliosis Cobb's angle in the non-progression group was significantly less than that in the moderate progression group (P < 0.01) and severe progression group (P < 0.01), but there was no statistical difference in the average thoracic scoliosis Cobb's angle between the severe progression group and moderate progression group. The average thoracic kyphosis angle in the severe progression group (9° ± 4°) was significantly smaller than that in the non-progression group (18° ± 6°, P < 0.01) and moderate progression group (14° ± 5°, P < 0.05). No statistical differences were present in the average lumbar lordosis, sacral slope, pelvic incidence, and pelvic tilt among the three groups. CONCLUSIONS: Thoracic hypokyphosis is strongly related with the curve progression in thoracic idiopathic scoliosis patients, but not pelvic sagittal profiles.

[Posterior interbody fusion versus improved transforaminal lumbar interbody fusion in segmental spinal fixation for aged spondylolisthesis with lumbar spinal canal stenosis].

OBJECTIVE: To assess the clinical and radiographic outcomes of posterior lumbar fixation and posterior interbody fusion or improved transforaminal lumbar interbody fusion for Meyerding grade II/III spondylolisthesis so as to address the suitability of a dynamic stabilization. METHODS: A total of 28 consecutive patients underwent posterior lumbar fixation and posterior interbody fusion or improved transforaminal lumbar interbody fusion for Meyerding grade II/III spondylolisthesis. Among them, 13 patients underwent posterior interface fusion (PLIF) and pedicle screw fixation. And improved transforaminal lumbar interbody fusion (ITLIF) and placement of the same system were performed in 15 patients. Their clinical, economic, functional, and radiographic data were recorded both pre- and postoperatively. RESULTS: The average changes of economic and functional scores on the Prolo scale were 1.36 and 1.48 respectively. In patients with posterior interbody fusion; the average preoperative vertebral slippage was 46.9% (range: 25 - 75%) versus 14.6% (range: 15 - 25%) postoperatively. In patients with ITLIF, the average changes in economic and functional scores were 1.75 and 1.63 respectively. And the average preoperative vertebral slippage was 45.2% (range: 28 - 78%) compared with 26.3% (range: 14 - 28%) postoperatively. When two fusion techniques were compared, an overall superior reliability and resistance of systems was associated with the ITLIF procedure. But their clinical outcomes did not differ greatly (P > 0.05). CONCLUSIONS: The application of a segmental pedicle screw fixation is both feasible and efficacious.

[Comparison between bipedicular approach and uni-extrapedicular approach in application of vertebroplasty].

OBJECTIVE: To analyze the advantages and disadvantages of bipedicular approach and uni-extrapedicular approach of vertebroplasty in treating osteoporotic vertebral compression fractures (OVCFs). METHODS: From January 2008 to December 2010,53 patients with OVCFs were retrospectively analyzed. There were 24 males, 30 females with an average age of 66.9 years (ranged,59 to 88 years). Among them, 26 cases were treated with bipedicular approach, 28 cases were treated with uni-extrapedicular approach. The data of bone cement injection, radiology exposure times, operation time, bone cement leakage and vessels nerve complications were observed. Cobb angle, vertebral compression ration were observed by imaging data, and evaluate recovery of deformity. RESULTS: The data of bone cement injection, radiology exposure times, operation time, VAS score were (6.6 +/- 0.8) ml and (6.8 +/- 1.5) ml, (21.7 +/- 4.0) times and (17.9 +/- 3.6) times, (40.5 +/- 5.5) min and (31.6 +/- 9.1) min, (2.8 +/- 0.6) scores and (3.1 +/- 0.5) scores respectively. Cobb angle,vertebral compression ration were (7.6 +/- 2.0) degrees and (6.9 +/- 2.6) degrees, (18.1 +/- 5.8)% and (16.5 +/- 6.1)%. There were no vascular nerve complications occurred. For bone cement leakage, 3 cases (11%) in bipedicular approach and 3 cases (11%)in uni-extrapedicular approach. There was no significant differences between two groups in VAS score, recovery of vetebral body, Cobb angle, bone cement injection and bone cement leakage, but had significant differences in radiology exposure times and operation time (P<0.05). CONCLUSION: Both of two approaches can treat OVCFs well, especially extropedicle approach which could reduce operation time and radiation shoot frequency.

[Treatment of upper cervical spine instability with posterior fusion plus atlantoaxial pedicle screw].

OBJECTIVE: To evaluate the clinical efficacies, indications and application values of posterior fusion plus pedicle screw fixation in the treatment of upper cervical spine instability. METHODS: From May 2006 to December 2010, a total of 24 patients with atlantoaxial instability were treated with C1-2 pedicle screws and rod fixation under general anesthesia. There were 18 males and 6 females with a mean age of 49.8 years old (range: 17 - 69). RESULTS: The postoperative radiographs verified a good position of all screws with satisfactory atlantoaxial reduction. A mean follow-up period of 23 months (range: 3 - 45) showed no injury of spinal cord and vertebral artery or inter fixation failure. Atlantoaxial alignment and stability were restored without instrumentation-related complications. CONCLUSION: Posterior atlantoaxial pedicle screw and rod fixation provide immediate three-dimensional rigid fixation of atlantoaxial joint. It is a more effective technique than with previously reported techniques.

Surgery for thoracic myelopathy caused by ossification of the ligamentum flavum.

Between January 1996 and December 2003, our department treated 16 patients (10 men and 6 women; average age 57.5 years) by performing a laminectomy for thoracic myelopathy caused by ossification of the ligamentum flavum (OLF). We followed up all patients for 36 to 86 months (mean follow-up time, 57.3 months). The mean (+/-standard deviation) Japanese Orthopaedic Association score increased from 5.0+/-1.4 points before the operation to 7.7+/-1.9 points at the last follow-up (p<0.01). The average values for pre-operative and post-operative kyphosis of the involved vertebrae were 5.8 degrees +/-4.1 degrees and 8.8 degrees +/-6.0 degrees , respectively; the mean increase in kyphosis was only 3.0 degrees +/-2.4 degrees . An intraoperative dural tear was the main complication and none of the patients developed severe neurological complications. We conclude that laminectomy was both effective and safe in the treatment of thoracic OLF, but it must be performed with great care because of frequent dural adhesions to the OLF. The increase in kyphosis after the laminectomy was minimal when most of the facet joints were left intact and when the patient followed a back extensor exercise program post-operatively.