Musculoskeletal Injuries in Cross-Country Skiing.

Cross-country skiing, one of the oldest forms of skiing, is enjoyed widely as a recreational activity and as a competitive sport. It is practiced in regions with snow-covered landscapes, particularly in the Nordic countries and with increasing popularity in non-Nordic countries of Europe as well as in the United States, Canada, Australia, and New Zealand, among others. Cross-country skiing is a fairly safe activity, and historically the risk of injury has been relatively low. However, advances in equipment development, together with increasing speeds, more demanding trails, and growing numbers of participants, have all contributed to a larger report of injuries, although still comparatively low versus other skiing modalities. Injuries in cross-country skiing can occur either after a single traumatic event or in the setting of chronic repetitive microtrauma (i.e., overuse injuries).

Magnetic resonance imaging of the knee: An overview and update of conventional and state of the art imaging.

Magnetic resonance imaging (MRI) has become the preferred modality for imaging the knee to show pathology and guide patient management and treatment. The knee is one of the most frequently injured joints, and knee pain is a pervasive difficulty that can affect all age groups. Due to the diverse pathology, complex anatomy, and a myriad of injury mechanisms of the knee, the MRI knee protocol and sequences should ensure detection of both soft tissue and osseous structures in detail and with accuracy. The knowledge of knee anatomy and the normal or injured MRI appearance of these key structures are critical for precise diagnosis. Advances in MRI technology provide the imaging necessary to obtain high-resolution images to evaluate menisci, ligaments, and tendons. Furthermore, recent advances in MRI techniques allow for improved imaging in the postoperative knee and metal artifact reduction, tumor imaging, cartilage evaluation, and visualization of nerves. As treatment and operative management techniques evolve, understanding the correct application of these advancements in MRI of the knee will prove to be valuable to clinical practice. LEVEL OF EVIDENCE: 5 J. MAGN. RESON. IMAGING 2017;45:1257-1275.

Ligamentous Reconstruction of the Knee: What Orthopaedic Surgeons Want Radiologists to Know.

Knee ligament injuries are common, and treatment methods are continually evolving. Accurate clinical diagnosis with imaging confirmation is critical to support appropriate treatment. Several imaging pearls allow for improved recognition of injuries. Stress radiographs may be obtained to quantify knee laxity. Magnetic resonance imaging allows assessment of the complex anatomy of the knee and has excellent sensitivity and specificity for many injuries.

Concentration and volume effects in thermochemical ablation in vivo: results in a porcine model.

PURPOSE: To explore the effects of volume and concentration in thermochemical ablation using an in vivo porcine model. METHODS: Twelve swine 60-75 kg were used in this institutionally approved study. A needle design prototype coaxial device for reagent injections and a thermocouple were inserted into surgically exposed liver. Simultaneously, an acid and base (acetic acid and NaOH) were injected at 4 mL/min based on a 3 × 3 matrix with concentration (5, 10, and 15 mol/L) and volume on the axes (total volumes of 1, 2, and 4 mL). Three animals (centre grid position) strengthened the statistical analysis. Each animal received four identical injections (total 48). Temperatures and heart rate were recorded. Livers were formalin-fixed after sacrifice. After sectioning, coagulation zones were analysed by two observers. Area and slice thickness were used to calculate the volume, surface area, and sphericity for each treatment. RESULTS: Coagulation volumes ranged from 2.95 ± 0.29 to 14.72 ± 1.42 mL with a maximum of 18.3 mL. Highest peak temperature was 105°C with temperatures ranging 43.5 ± 2.6°C to 91.0 ± 6.5°C. There was no association between conditions and sphericity or heart rate. CONCLUSIONS: The method can be used successfully to ablate tissue in vivo. By neutralising acid in situ and releasing heat and a salt, this technique improves considerably upon the use of acetic acid used alone. Peak temperatures exceeded accepted coagulation thresholds even if the only mechanism operating was hyperthermia. Reagent concentrations and volumes increased the amount of the coagulum but not in a linear fashion.

In vivo comparison of simultaneous versus sequential injection technique for thermochemical ablation in a porcine model.

PURPOSE: To investigate simultaneous and sequential injection thermochemical ablation in a porcine model, and compare them to sham and acid-only ablation. MATERIALS AND METHODS: This IACUC-approved study involved 11 pigs in an acute setting. Ultrasound was used to guide placement of a thermocouple probe and coaxial device designed for thermochemical ablation. Solutions of 10 M acetic acid and NaOH were used in the study. Four injections per pig were performed in identical order at a total rate of 4 mL/min: saline sham, simultaneous, sequential, and acid only. Volume and sphericity of zones of coagulation were measured. Fixed specimens were examined by H&E stain. RESULTS: Average coagulation volumes were 11.2 mL (simultaneous), 19.0 mL (sequential) and 4.4 mL (acid). The highest temperature, 81.3°C, was obtained with simultaneous injection. Average temperatures were 61.1°C (simultaneous), 47.7°C (sequential) and 39.5°C (acid only). Sphericity coefficients (0.83-0.89) had no statistically significant difference among conditions. CONCLUSIONS: Thermochemical ablation produced substantial volumes of coagulated tissues relative to the amounts of reagents injected, considerably greater than acid alone in either technique employed. The largest volumes were obtained with sequential injection, yet this came at a price in one case of cardiac arrest. Simultaneous injection yielded the highest recorded temperatures and may be tolerated as well as or better than acid injection alone. Although this pilot study did not show a clear advantage for either sequential or simultaneous methods, the results indicate that thermochemical ablation is attractive for further investigation with regard to both safety and efficacy.

Knee Ligament Imaging: Preoperative and Postoperative Evaluation.

Preoperative and postoperative imaging of knee ligament injury hinges on the appropriate use of available modalities. Knowledge of injury patterns as well as the surgical significance of certain image findings enhances injury detection and supports appropriate preoperative planning. The radiologist must be familiar with the strengths and weaknesses of each modality for evaluating specific aspects of ligamentous pathology. This article focuses on preoperative and postoperative imaging of knee ligament injury. Basic topics pertaining to preoperative image modality selection and isolated injury detection are addressed. More advanced areas including ligamentous injury patterns, surgical indications, and postoperative imaging are also discussed.

A parametric study of freezing injury in BPH1CAFTD-2 human prostate tumor cells.

Freeze injury in BPH1(CAFTD)-2 cells frozen/thawed in suspension was studied through a two-level four-parameter (2(4)) experimental design and analysis. The four parameters considered were end temperature, hold time, TNFalpha concentration, and thawing rate. Thermal parameter values chosen were based on the approximate thermal history cells would experience in the peripheral region of a cryosurgical iceball. Cell suspensions were frozen at a constant 10 degree C/min on a directional solidification stage and viability was assessed within 1 hr post-thaw using a dye exclusion assay. The parameters affecting cell survival were determined through calculation of the individual parameter effects (E) and interactions (I) according to factorial design guidelines; data set curvature (C) was also determined. Cell viability ranged from a maximum of 87.6 percent to a minimum of 17.6 percent indicating trends in cell survival were sensitive to the parameters chosen. Survival was affected by the following parameters in order: lowering the end temperature, increasing the hold time, adding TNFalpha, and reducing the thawing rate. In addition, all 2-way parameter interactions except TNFalpha hold time were statistically significant. Curvature analysis showed that cell viability at the midpoint of the data was nearly 20 percent lower than predicted based on linear interpolation. These results were verified and extended using analysis of variance (ANOVA). We conclude that cryoinjury in this tumor line can be influenced by multiple interacting thermal parameters, most importantly end-temperature and hold time, as well as the presence of the cytokine TNFalpha. Finally, although the cell type is tumorigenic results suggest the possibility of using freezing to control benign prostatic hyperplasia (BPH) in addition to cancer within the prostate.

Comprehensive Clinical Evaluation of Femoroacetabular Impingement: Part 3, Magnetic Resonance Imaging.

Radiologic imaging is an essential supplement to the physical examination in the evaluation of a patient with femoroacetabular impingement. Plain radiographs are the initial modality of choice for the evaluation of bony anatomy and pathology. Magnetic resonance imaging supplements the physical examination and standard radiographs by enabling qualitative and quantitative evaluation of both articular cartilage and soft tissues about the hip. Magnetic resonance imaging also provides improved 3-dimensional characterization of the bony anatomy owing to the multiplanar nature of this technique. This article describes a comprehensive approach to interpretation of magnetic resonance examination of the hip.

Comprehensive Clinical Evaluation of Femoroacetabular Impingement: Part 2, Plain Radiography.

The use of hip arthroscopy to treat various forms of hip pathology continues to grow. As part of a standard evaluation for eligibility for hip arthroscopy, we routinely obtain standard radiographs to assess the hip joint. These include orthogonal projections of the acetabulum and proximal femur, which can be obtained with a standing false profile, supine anteroposterior pelvis, and a lateral view of the proximal femur (either Dunn 45° or 90°, frog-leg lateral, or cross-table lateral). A comprehensive analysis of the radiographs is of utmost importance in order to indicate a patient for hip arthroscopy, for preoperative planning, and to determine prognosis. The purpose of this Technical Note is to provide a comprehensive guide of how our group performs qualitative and quantitative analysis of hip radiographs in a potential candidate for hip arthroscopy.

Electronic Health Record-Driven Workflow for Diagnostic Radiologists.

In most settings, radiologists maintain a high-throughput practice in which efficiency is crucial. The conversion from film-based to digital study interpretation and data storage launched the era of PACS-driven workflow, leading to significant gains in speed. The advent of electronic health records improved radiologists' access to patient data; however, many still find this aspect of workflow to be relatively cumbersome. Nevertheless, the ability to guide a diagnostic interpretation with clinical information, beyond that provided in the examination indication, can add significantly to the specificity of a radiologist's interpretation. Responsibilities of the radiologist include, but are not limited to, protocoling examinations, interpreting studies, chart review, peer review, writing notes, placing orders, and communicating with referring providers. Most of the aforementioned activities are not PACS-centric and require a login to one or more additional applications. Consolidation of these tasks for completion through a single interface can simplify workflow, save time, and potentially reduce the incidence of errors. Here, the authors describe diagnostic radiology workflow that leverages the electronic health record to significantly add to a radiologist's ability to be part of the health care team, provide relevant interpretations, and improve efficiency and quality.