Mapping of Pelvic Ring Injuries From High-Energy Trauma Using Unfolded CT Image Technology.

OBJECTIVES: High-energy pelvic ring injuries are associated with significant morbidity and mortality, elevating the importance of injury pattern identification. The purpose of this study was to use a novel 3D computed tomography (CT) unfolding process to both evaluate high-energy pelvic ring injures and to produce injury frequency maps based on injury patterns. METHODS: Patients 18-65 years of age presenting to a level 1 trauma center with pelvic ring injuries between 2016 and 2020 were identified. Of the 482 patients reviewed, 355 were excluded primarily due to having a low energy mechanism, inadequate radiographs, or an isolated fracture. Unfolded pelvic CT images were created using syngo.via CT Bone Reading software. Pelvic ring injury frequency maps were created using the unfolded pelvic CT images and a previously described mapping technique. RESULTS: One hundred twenty-seven patients analyzed had a mean age of 32.7 years. The most common mechanisms of injury (MOI) were motor vehicle collision (30.7%) and fall from height (23.6%). The breakdown of pelvic ring injuries included LC1 = 44.1%, LC2 = 7.1%, LC3 = 14.2%, APC1 = 2.4%, APC2 = 15.0%, APC3 = 5.5%, and VS = 11.8%, with OTA/AO-61B = 74.0% and OTA/AO-61C = 26.0%. Pelvic ring mapping revealed that articular and bony injuries varied markedly between the different types of pelvic ring disruptions, both in type and location. CONCLUSIONS: Pelvic ring injury frequency maps created from unfolded CT images reflect consistent injury patterns providing distinctive information based on force vector mechanisms. Unfolded CT images allow for a novel way to visualize pelvic ring injuries which yield greater comprehension of failure patterns with implications for treatment.

Short cephalomedullary nail toggle: a closer examination.

OBJECTIVES: In patients with wide femoral canals, an undersized short nail may not provide adequate stability, leading to toggling of the nail around the distal interlocking screw and subsequent loss of reduction. The purpose of this study was to identify risk factors associated with nail toggle and to examine whether increased nail toggle is associated with increased varus collapse. DESIGN: Retrospective cohort study. SETTING: Level 1 and level 3 trauma center. PATIENTS/PARTICIPANTS: Seventy-one patients with intertrochanteric femur fractures treated with short cephalomedullary nails (CMN) from October 2013 to December 2017. INTERVENTION: Short CMN. MAIN OUTCOME MEASUREMENTS: Nail toggle and varus collapse were measured on intraoperative and final follow-up radiographs. Risk factors for nail toggle including demographics, fracture classification, quality of reduction, Dorr type, nail/canal diameter ratio, lag screw engaging the lateral cortex, and tip-apex distance (TAD) were recorded. RESULTS: On multivariate regression analysis, shorter TAD (P = .005) and smaller nail/canal ratio (P < .001) were associated with increased nail toggle. Seven patients (10%) sustained nail toggle >4 degrees. They had a smaller nail/canal ratio (0.54 vs 0.74, P < .001), more commonly Dorr C (57% vs 14%, P = .025), lower incidence of lag screw engaging the lateral cortex (29% vs 73%, P = .026), shorter TAD (13.4 mm vs 18.5 mm, P = .042), and greater varus collapse (6.2 degrees vs 1.3 degrees, P < .001) compared to patients with nail toggle < 4 degrees. CONCLUSIONS: Lower percentage nail fill of the canal and shorter TAD are risk factors for increased nail toggle in short CMNs. Increased nail toggle is associated with increased varus collapse.Level of evidence: Therapeutic Level III.

Management of complications of forearm fractures.

Forearm fractures may be complicated by the disruption of the distal radioulnar, proximal radioulnar, or radiocapitellar joints. The key principles in treating this unique subset of fractures include early recognition and management of the injury and restoration and maintenance of the anatomic alignment. This articles addresses radial diaphyseal fractures with distal radioulnar joint disruption, proximal ulnar fractures with radiocapitellar disruption, and disruption of the forearm longitudinal axis and how to properly recognize and manage these forearm fracture-dislocations.

High-level expression of biologically active glycoprotein hormones in Pichia pastoris strains--selection of strain GS115, and not X-33, for the production of biologically active N-glycosylated 15N-labeled phCG.

The methylotrophic yeast Pichia pastoris is widely used for the production of recombinant glycoproteins. With the aim to generate biologically active 15N-labeled glycohormones for conformational studies focused on the unravelling of the NMR structures in solution, the P. pastoris strains GS115 and X-33 were explored for the expression of human chorionic gonadotropin (phCG) and human follicle-stimulating hormone (phFSH). In agreement with recent investigations on the N-glycosylation of phCG, produced in P. pastoris GS115, using ammonia/glycerol-methanol as nitrogen/carbon sources, the N-glycosylation pattern of phCG, synthesized using NH4Cl/glucose-glycerol-methanol, comprised neutral and charged, phosphorylated high-mannose-type N-glycans (Man8-15GlcNAc2). However, the changed culturing protocol led to much higher amounts of glycoprotein material, which is of importance for an economical realistic approach of the aimed NMR research. In the context of these studies, attention was also paid to the site specific N-glycosylation in phCG produced in P. pastoris GS115. In contrast to the rather simple N-glycosylation pattern of phCG expressed in the GS115 strain, phCG and phFSH expressed in the X-33 strain revealed, besides neutral high-mannose-type N-glycans, also high concentrations of neutral hypermannose-type N-glycans (Manup-to-30GlcNAc2). The latter finding made the X-33 strain not very suitable for generating 15N-labeled material. Therefore, 15N-phCG was expressed in the GS115 strain using the new optimized protocol. The 15N-enrichment was evaluated by 15N-HSQC NMR spectroscopy and GLC-EI/MS. Circular dichroism studies indicated that 15N-phCG/GS115 had the same folding as urinary hCG. Furthermore, 15N-phCG/GS115 was found to be similar to the unlabeled protein in every respect as judged by radioimmunoassay, radioreceptor assays, and in vitro bioassays.