As a proven and comprehensive molecular technique, metagenomic next-generation sequencing (mNGS) has shown its potential in the diagnosis of pathogens in patients with periprosthetic joint infection (PJI), using a single type of specimen. However, the optimal use of mNGS in the management of PJI has not been explored. In this study, we evaluated the diagnostic value of mNGS using three types of specimen with the aim of achieving a better choice of specimen for mNGS in these patients. In this prospective study, 177 specimens were collected from 59 revision arthroplasties, including periprosthetic tissues, synovial fluid, and prosthetic sonicate fluid. Each specimen was divided into two, one for mNGS and one for culture. The criteria of the Musculoskeletal Infection Society were used to define PJI (40 cases) and aseptic failure (19 cases).Aims
Methods
The development of T-smart tomosynthesis has greatly improved the imaging quality of THA by reducing the peri-implant artifacts. In order to find out whether these improvements could lead to diagnostic advantages on stability of cementless THA arthroplasty components, we conducted a diagnostic research by comparing T-smart tomosynthesis, X-ray, and computed tomography. We retrospectively included 48 patients who undergone THA revisions in our center between Aug, 2013 and Mar, 2014. For patients with hybrid fixation as their primary prosthesis, the femoral or acetabular components with cement fixation were excluded. There were 41 cementless femoral stems and 35 cementless acetabular cups remained for evaluation. All patients took anterior-posterior and lateral view x-ray examination, anterior-posterior T-smart tomosynthesis scan, and computed tomography before revision surgery. As the gold standard, intraoperative pull-out tests and twisting tests were done for every patient to examine the stability of all implants. 7 orthopedic surgeons evaluated the preoperative images independently, who were divided into the senior group (3 doctors with 6∼13 years’ clinical experience) and the junior group (4 doctors with 2∼4 years’ clinical experience). The x-rays were evaluated first, followed by computed tomography 4 weeks later, and after another 4 weeks’ interval the T-smart tomosynthesis were assessed. All doctors used the same criteria for diagnosis. Diagnostic accuracy for each imaging examination was calculated by comparing with the results of intraoperative tests. The diagnostic accuracy, kappa values between 3 imaging techniques were calculated, and chi-square tests were conducted to examine the difference between the senior and junior groups for each technique.Background
Methods
To observe the safety and efficacy of a minimally destructive decompressive technique without fusion in patients with lumbar stenosis secondary to degenerative spondylolisthesis. 30 patients with degenerative spondylolisthesis (DS) were consecutively managed by a single consultant spinal surgeon. All patients presented with neurogenic claudication secondary to DS. All patients were managed operatively with lumbar decompression utilising an approach technique of “spinous process osteotomy” (1). Briefly, this approach requires only unilateral muscle stripping with preservation of the interspinous ligament. A standard centrolateral decompression is then performed. Data consisting of VAS back and leg pain and ODI were collected pre and post-operatively.Purpose
Methods
Prosthetic reconstruction of high-riding hips is technically demanding. Insufficient bony coverage and osteopenic bone stock frequently necessitate transacetabular screw fixation to augment primary stability of the metal shell. We sought to determine the validity of the previously reported quadrant system, and if needed, to define a specialized safe zone for augmentation of screw fixation to avoid vascular injuries in acetabular cup reconstruction for high-riding hips. Volumetric data from computed tomography enhancement scanning and CT angiography of eighteen hips (twelve patients) were obtained and input into a three-dimensional image-processing software. Bony and vascular structures were reconstructed three-dimensionally; we virtually reconstructed a cup in the original acetabulum and dynamically simulated transacetabular screw fixation. We mapped the hemispheric cup into several areas and, for each, measured the distance between the virtual screw and the blood vessel. We found that the rotating centers of the cups shifted more anterior-inferiorly in high-riding hips than those in ordinary cases, and thus the safe zone shifted as well. Screw fixation guided by the quadrant system frequently injured the obturator blood vessels in high-riding hips. We then defined a specialized safe zone for transacetabular screw fixation for high-riding hips. We conclude that the quadrant system can be misleading and of less value in guiding screw insertion to augment metal shells for high-riding hips. A new safe zone specific to high-riding hips should be used to guide transacetabular screw fixation in these cases.
Our aims were to describe the distribution of α-smooth muscle actin (SMA)-containing cells in Dupuytren’s tissue in vivo and to determine the effects of selected agents in regulating the expression of SMA in Dupuytren’s cells in vitro. In selected hypercellular zones of Dupuytren’s nodules up to 40% of the cells contained SMA, as shown by immunohistochemistry. A lower percentage (20%) of SMA-containing cells was found in regions of lower cellularity. A notable finding was that treatment in vitro of Dupuytren’s cells with platelet-derived growth factor significantly reduced the content of SMA. Cells from the same patients showed a significant increase in expression of SMA in response to treatment with transforming growth factor, which confirmed recent findings. In addition, interferon-γ, which has been previously used as a treatment for Dupuytren’s disease in a clinical study, had no reproducible effect on the expression of this actin isoform. Our findings are of significance for the conservative management of contractures.
