Attention to Detail: The Effect of Fluoroscopic Parallax on Limb Alignment Assessment During Corrective Osteotomy.

BACKGROUND: The accuracy of a corrective osteotomy is dependent on many factors. One error rarely considered is using noncentered fluoroscopic imaging to assess intraoperative alignment. This study quantified the coronal alignment error produced by visual parallax per interval changes in vertical and horizontal positioning of the C-arm and alignment rod during intraoperative evaluation. METHODS: Unilateral hip, ankle, and knee fluoroscopic images were obtained from a single intact cadaveric specimen. A center-center fluoroscopic image was obtained by moving the C-arm appeared in the center square of the nine-box grid. With the base of the C-arm stationary, the radiograph generator/intensifier portion of the C-arm was translated medially until the target bone appeared on the edge of the fluoroscopic image. RESULTS: One hundred eight images were obtained. Measurement error increased by an average of 14% per 10 mm of horizontal C-arm offset. Minimal effect was seen if the obtained image was within 5 mm of the true center; however, once 55 mm of offset was reached, all experimental conditions resulted in at least 10 mm of parallax error. CONCLUSION: Our results demonstrate that small variations in C-arm positioning can create statistically significant inaccuracies when assessing limb alignment using intraoperative fluoroscopy.

Platelet-Rich Plasma Augmentation of Meniscal Repair in the Setting of Anterior Cruciate Ligament Reconstruction.

BACKGROUND: The increasing incidence of anterior cruciate ligament (ACL) and meniscal injuries has led to strong interest in discovering new methods to enhance the biological healing response of these tissues. Platelet-rich plasma (PRP) contains various growth factors associated with a positive healing response, but few existing clinical studies are available to determine the risks and benefits of these therapies. PURPOSE: To determine the effects of intraoperative PRP on postoperative knee function and complications at 2 years after ACL reconstruction with meniscal repair. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective matched case-control study was conducted between 2013 and 2017 using a single surgeon database of 1014 patients undergoing primary ACL reconstruction with concomitant meniscal repair, resulting in 324 patients (162 PRP patients and 162 control patients) who met the study criteria. Patients were matched by age, sex, graft type, and meniscal injury. The Single Assessment Numeric Evaluation (SANE) was administered at 2 years, and injury surveillance was conducted. Secondary outcomes included the time to return to activity (months), self-reported knee function (International Knee Documentation Committee [IKDC] score), functional performance testing (knee range of motion, single-leg balance, single-leg hopping, agility testing), and postoperative complications (graft failure, infection, loss of motion [requiring repeat arthroscopy for lysis of adhesions], venous thrombosis, etc). Univariate models were used for between-group comparisons, and alpha was set at .05 for all analyses. RESULTS: No differences were found in SANE knee function scores between the PRP and matched-control groups at 2 years (91.6 ± 11.2 vs 92.4 ± 10.6, respectively; P = .599). Additionally, no differences were reported between groups for self-reported function (IKDC score, 87.6 ± 13.3 vs 88.1 ± 12.6; P = .952), functional performance testing (P > .05), and timing of return to activity (7.8 ± 1.9 vs 8.0 ± 1.9 months; P = .765). The PRP group demonstrated a higher rate of postoperative knee motion loss compared with the control group (13.6% vs 4.6%; P < .001). No other differences were observed in postoperative complications (P > .05). CONCLUSION: The added use of intraoperative PRP did not improve self-reported knee function, functional performance, and timing of return to activity for patients undergoing ACL reconstruction with meniscal repair. Furthermore, the use of PRP may have negative consequences for regaining knee range of motion after surgery. On the basis of these data, surgeons should cautiously consider the application of PRP when planning surgery for intra-articular injuries of the knee. REGISTRATION: NCT03704376 (ClinicalTrials.gov identifier).

Using Interactive 3D Visualisations in Neuropsychiatric Education.

Obsessive compulsive disorder (OCD) is a neuropsychiatric disorder with a global prevalence of 2-3%. OCD can have an enormous impact on the lives of those with the disorder, with some studies suggesting suicidal ideation is present in over 50% of individuals with OCD, and other data showing a significant number of individuals attempt suicide. It is therefore important that individuals with OCD receive the best possible treatment. A greater understanding of the underlying pathophysiology of neuropsychiatric disorders among professionals and future clinicians can lead to improved treatment. However, data suggests that many students and clinicians experience "neurophobia", a lack of knowledge or confidence in cases involving the nervous system. In addition, research suggests that the relationship many students have with neurological conditions deteriorates over time, and can persist into practice.If individuals living with conditions such as OCD are to receive the best possible treatment, it is crucial that those administering care are equipped with a thorough understanding of such disorders. While research has shown that the use of interactive 3D models can improve anatomy education and more specifically neurology education, the efficacy of using of such models to engage with neuropsychiatric conditions, specifically OCD, has not been assessed. This study seeks to address this gap.In this study an interactive application for Android devices was designed using standardised software engineering methods in order to improve neuropsychiatry literacy by empowering self-pace learning through interactive 3D visualisations and animations of the neural circuitry involved in OCD. A pilot test and a usability assessment were conducted among five postgraduate life science students. Findings relating to user experience were promising, and pre-test vs. post-test evaluation suggested encouraging outcomes regarding the effectiveness of the application in improving the knowledge and understanding of OCD. In short, this study suggests that interactive 3D visualisations can improve neuropsychiatry education. For this reason, more efforts should be made to construct similar applications in order to ensure patients always receive the best possible care. Fig. 2.1 A diagrammatic representation of the CSTC circuit, based on a similar diagram by Robertson et al. (2017).

Ninety-Five Degree Angled Blade Plate Fixation of High-Energy Unstable Proximal Femur Fractures Results in High Rates of Union and Minimal Complications.

OBJECTIVES: To describe the surgical technique and clinical outcomes of high-energy proximal femur fractures treated with a 95-degree angled blade plate. DESIGN: Retrospective case series. SETTING: Single academic Level I trauma center. PATIENT/PARTICIPANTS: Forty-five consecutive patients from March 2012 to April 2017 who sustained a high-energy, unstable proximal femur fracture including (OTA/AO 31-A1, 31-A2, 31-A3, 31-B3, 32-A1a, and 32-C3i). INTERVENTION: Open reduction internal fixation with a 95-degree angled blade plate used in conjunction with an articulated tensioning device. MAIN OUTCOME MEASUREMENTS: Nonunion, malunion, secondary operations, and postoperative infection. RESULTS: Twenty six patients were available for follow-up. The mean age was 43.8 (range 22-86) years, and 81% (21/26) were men. The most common fracture pattern was OTA/AO 31-A3.3. Two fractures were open. The articulated tensioner was used in 100% of cases. Average clinical follow-up was 19.2 (range 7-40) months. Twenty-four of 26 patients (92%) achieved osseous union after the index procedure. One patient underwent nonunion repair, and 2 patients had the blade plate removed as it was symptomatic laterally. No other secondary procedures were performed, and no instances of implant failure were seen. No patients had evidence of a superficial or deep infection. CONCLUSIONS: We found that high-energy proximal femur fractures treated with a 95-degree condylar blade plate and articulated tensioning device had a high rate of union with minimal postoperative complications. Although intramedullary nailing of these fractures remains a preferred treatment modality, the angled blade plate with articulated tensioning device is an excellent option to restore anatomical alignment and obtain bony union in certain highly comminuted fracture patterns. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Formation processes for large ejecta and interactions with melt pool formation in powder bed fusion additive manufacturing.

Ejecta with a size much larger than the mean particle size of feedstock powder have been observed in powder bed fusion additive manufacturing, both during post-process sieving and embedded within built components. However, their origin has not been adequately explained. Here, we test a hypothesis on the origin of large (much larger than the mass-median-diameter of feedstock powder) ejecta-that, in part, they result from stochastic, inelastic collisions of ejecta and coalescence of partially-sintered agglomerates. The hypothesis is tested using direct observation of ejecta behavior, via high-speed imaging, to identify interactions between ejecta and consequences on melt pool formation. We show that stochastic collisions occur both between particles which are nearly-simultaneously expelled from the laser interaction zone and between particles ejected from distant locations. Ejecta are also shown to perturb melt pool geometry, which is argued to be a potential cause of lack-of-fusion flaws.