Coronal deformity in ankylosing spondylitis with concomitant thoracolumbar kyphosis: patterns, manifestations and surgical strategies.

PURPOSE: To evaluate different patterns of coronal deformity secondary to ankylosing spondylitis (AS), to propose relevant treatment strategies, and to assess efficacy of asymmetrical pedicle subtraction osteotomy (APSO). METHODS: Coronal deformity was defined as coronal Cobb angle over 20º or coronal balance distance (CBD) more than 3 cm. 65 consecutive AS patients with concomitant coronal and sagittal deformity who underwent PSO were included. The average follow-up time was 40.4 months. Radiographic evaluation included coronal Cobb angle and CBD. Furthermore, sagittal parameters were used to assess magnitude and maintenance of kyphosis correction. RESULTS: Based on curve characteristics, coronal deformity caused by AS included four different radiologic patterns: Pattern I: lumbar scoliosis; Pattern II: C-shaped thoracolumbar curve; Pattern III: trunk shift without major curve; Pattern IV: proximal thoracic scoliosis. APSO was performed for patients in Pattern I to III while conventional PSO was applied for patients in Pattern IV. Significant improvement in all the sagittal parameters were noted in 65 patients without obvious correction loss at the last follow-up. Besides, significant and sustained correction of coronal mal-alignment was identified in 59 APSO-treated patients. Rod fracture occurred in four cases and revision surgery was performed for one case. CONCLUSION: According to radiologic manifestations, coronal deformity caused by AS could be categorized into four patterns. APSO proved to be a feasible and effective procedure for correction of Pattern I to III patients. Coronal deformity pattern, apex location, sagittal profile of lumbar spine and preoperative hip function should be considered for osteotomy level selection in APSO.

Engineering and characterizing porcine reproductive and respiratory syndrome virus with separated and tagged genes encoding the minor glycoproteins.

Porcine reproductive and respiratory syndrome virus (PRRSV) is a major pathogen affecting pigs and belongs to the enveloped plus-stranded RNA virus family Arteriviridae. A unique feature of Arteriviruses is that the genes encoding the structural proteins overlap at their 3` and 5` ends. This impedes mutagenesis opportunities and precludes the binding of short peptides for antibody detection, as this would alter the amino acids encoded by the overlapping gene. In this study, we aimed to generate infectious PRRSV variants with separated genes encoding the minor glycoproteins Gp2, Gp3, and Gp4, accompanied by appended tags for detection. All recombinant genomes facilitate the release of infectious virus particles into the supernatant of transfected 293 T cells, as evidenced by immunofluorescence of infected MARC-145 cells using anti-nucleocapsid antibodies. Furthermore, expression of Gp2-Myc and Gp3-HA was confirmed through immunofluorescence and western blot analysis with tag-specific antibodies. However, after two passages of Gp2-Myc and Gp3-HA viruses, the appended tags were completely removed as indicated by sequencing the viral genome. Recombinant viruses with separated Gp2 and Gp3 genes remained stable for at least nine passages, while those with Gp3 and Gp4 genes separated reverted to wild type after only four passages. Notably, this virus exhibited significantly reduced titers in growth assays. Furthermore, we introduced a tag to the C-terminus of Gp4. The Gp4-HA virus was consistently stable for at least 10 passages, and the HA-tag was detectable by western blotting and immunofluorescence.

Brachial plexus palsy caused by halo traction before posterior correction in patients with severe scoliosis / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To explore the clinical features and treatment results of brachial plexus palsy caused by halo traction before posterior correction in patients with severe scoliosis.</p><p><b>METHODS</b>A total of 300 cases of severe scoliosis received halo traction before posterior correction in our department from July 1997 to November 2004. Among them, 7 cases were complicated with brachial plexus palsy. The average Cobb angle was 110 degree (range, 90 degree-135 degree). Diagnoses were made as idiopathic scoliosis in 1 case, congenital scoliosis in 3 cases, and neuromuscular scoliosis in 3 cases. Additionally, diastematomyelia and tethered cord syndrome were found in 3 cases and thoracolumbar kyphosis in 2 cases. Weight of traction was immediately reduced when the patient developed any abnormal neurological symptoms in the upper extremity, and rehabilitation training was undertaken. Simultaneously, neurotrophic pharmacotherapy was applied, and the neurological function restoration of the upper limbs and the recovery time were documented.</p><p><b>RESULTS</b>Traction was used for an average of 3.5 weeks (range, 2-6 weeks) before spinal fusion for these 7 patients. The average traction weight was 8 kg, which was 19% on average (range, 13%-26%) of the average body weight (40.2 kg). These 7 patients had long and thin body configuration with a mean height of 175 cm. The duration between symptoms of brachial plexus paralysis and the diagnosis was 1-3 hours. All of these 7 patients presented various degrees of numbness in the ulnar side of the hand and forearm. Median nerve paresis was found in 3 cases and ulnar nerve paresis in 4 cases. Complete recovery of the neurological function had been achieved by the end of three months.</p><p><b>CONCLUSIONS</b>The clinical features of brachial plexus palsy caused by halo traction include median nerve paresis, ulnar nerve paralysis, and numbness in the ulnar side of the hand and forearm, which may be due to the injury of the inferior part of the brachial plexus, i.e., damage of C8 and T1 nerve roots. Complete recovery of neurological function can be expected when the patient is kept under careful observation for recognizing this complication as soon as possible, then immediately reducing or removing the traction weight, and adopting rehabilitation training and neurotrophic pharmaceutical treatment.</p>