Baseline knee joint effusion and medial femoral bone marrow edema,in addition to MRI-based T2 relaxation time and texture measurements of knee cartilage,can help predict incident total knee arthroplasty 4–7 years later: data from the Osteoarthritis Initiative

Skeletal Radiology - To evaluate if baseline pathological knee conditions as assessed via single features of the MR-based Whole-Organ Magnetic Resonance Imaging Scoring (WORMS), standard T2, and T2...     

Factors Associated with Osteoid Osteoma Recurrence after CT-Guided Radiofrequency Ablation

PurposeTo identify clinical and imaging variables associated with symptomatic recurrence of osteoid osteomas (OOs) treated with computerized tomography (CT)–guided radiofrequency (RF) ablation.Materials and MethodsSeventy-one patients treated with the use of CT-guided RF ablation for OO at a single institution from July 2005 to May 2018 were included in this retrospective cohort analysis. Clinical data, including patient age, sex, race, and clinical outcomes, were collected from institutional electronic health records and telephone follow-up. Imaging variables regarding tumor characteristics were gathered from imaging reports and a blinded review of preprocedural images by an experienced musculoskeletal radiologist. Logistic regression, Cox proportional hazards, and Kaplan-Meier analyses were used to identify variables that are significantly associated with symptomatic recurrence, which was defined as pain occurring > 2 weeks after RF ablation.ResultsTen patients (14.1%) experienced symptomatic recurrence at a median of 21.5 months after RF ablation. Univariable logistic regression classified young age (≤ 13 years), female sex, maximum tumor length, and “eccentricity index” (EI) ≥ 3 as predictive variables significantly associated with symptomatic recurrence. Multivariable logistic regression identified female sex and EI ≥ 3 to be significant predictors for symptomatic recurrence. A multivariable proportional hazards Cox regression of time to recurrence revealed EI ≥ 3 to be the only significant predictor of symptomatic recurrence.ConclusionsFemale patients with OOs with an EI ≥ 3 have a greater risk of symptomatic recurrence following RF ablation. The EI is a useful tool to identify OOs with elongated 3-dimensional morphology, which may warrant more extensive ablation.     

Treatment of brain metastases from melanoma

Brain metastases from malignant melanoma have a poor prognosis, and treatment can be difficult because of rapid progression of the disease. To help define the treatment of this disease, we reviewed the published literature on brain metastases from melanoma. If a solitary metastasis is present, surgery might be beneficial, especially if systemic disease is absent. Stereotactic radiosurgery is a less invasive, attractive option for solitary or oligometastatic (up to 6) lesions. External beam whole-brain radiation therapy can produce responses and frequently palliates symptoms, but as the sole therapy, it is unlikely to eradicate brain metastases. Chemotherapy may be gaining a role with newer agents that penetrate the blood-brain barrier. Combined modality therapy appears to be the future direction of treatment of multiple metastases.     

Miniplatten als Ergänzungsimplantat bei der Osteosynthese komplexer distaler Radiusfrakturen

The problem

Dislocated intra-articular fractures of the distal radius are operatively treated to achieve anatomical reconstruction of the joint. In complex distal radial fractures with multiple joint fragments, fixation with angular stable plates alone may be technically challenging. Smaller fragments, such as the lip of ulnopalmar joint, are often difficult to control.

The solution

The supplementary application of mini plates, as employed in maxillofacial surgery, is a helpful tool for reduction and fixation.

Result

In this article the operative technique, clinical and radiographic results of 4 complex distal intra-articular radial fractures are presented.

     

Zonal differences in meniscus MR relaxation times in response to in vivo static loading in knee osteoarthritis

This study assessed the effects of static loading on MRI relaxation times of menisci in individuals with and without radiographic knee OA. High‐resolution fast spin‐echo (FSE) and T_1ρ/T₂ relaxation time MR sequences were obtained with and without loading at 50% body weight in 124 subjects. T_1ρ/T₂ relaxation times were calculated in menisci, and meniscus lesions were assessed through clinical grading. Student's t‐test compared OA and control unloaded relaxation times as well as within‐group changes with loading, Generalized Linear Models evaluated zonal variation, and ANCOVA compared loading response between groups. Unloaded T_1ρ and T₂ in the middle and inner zones of the lateral anterior horn and outer zone of the medial posterior horn were significantly higher in OA and suggest that meniscal OA change occurs unevenly. Zonal T_1ρ and T₂ showed differing patterns between anterior and posterior horns, suggesting differences in macromolecular organization. Significant increases with loading were seen largely in the T₂ of controls and less frequently in subjects with OA. In the medial posterior horn, T_1ρ and T₂ decreased with loading in OA but changed negligibly in controls; these significantly different loading responses between groups may indicate load transmission failure in OA menisci. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:249–261, 2016.     

Latency analysis of single auditory evoked M100 responses by spatio-temporal filtering

Appropriate spatial filtering followed by temporal filtering is well suited for the single-trial analysis of multi-channel magnetoencephalogram or electroencephalogram recordings. This is demonstrated by the results of a single-trial latency analysis obtained for auditory evoked M100 responses from nine subjects using two different stimulation frequencies. Spatial filters were derived automatically from the data via noise-adjusted principle component analysis, and single-trial latencies were estimated from the signal phase after complex bandpass filtering. For each of the two stimulation frequencies, estimated single-trial latencies were consistent with results obtained from a standard approach using averaged evoked responses. The quality of the estimated single-trial latencies was additionally assessed by their ability to separate between the two different stimulation frequencies. As a result, more than 80% of the single trials can be classified correctly by their estimated latencies.     

Testosterone and oxandrolone, a nonaromatizable androgen, specifically amplify the mass and rate of growth hormone (GH) secreted per burst without altering GH secretory burst duration or frequency or the GH half-life

We investigated the mechanisms by which androgens increase mean circulating GH concentrations in boys. We tested two hypotheses: 1) testosterone increases serum GH concentrations at least in part via an androgen receptor-mediated mechanism, rather than exclusively by way of aromatization to estrogen; 2) androgen augments one or more specific features to GH secretion (secretory burst number, amplitude, and/or duration) and/or prolongs the half-life of GH removal. To examine these hypotheses, prepubertal boys with constitutionally delayed development and/or growth were given injections of testosterone (100 mg monthly; n = 7) or treated with oral oxandrolone, a nonaromatizable androgen (1.25 mg twice daily; n = 5). Pulsatile GH release was studied before and during androgen administration by sampling blood at 20-min intervals for 24 h. The immunoreactive GH time series were subjected to a novel deconvolution technique, which revealed that 1) testosterone and oxandrolone each increased mean (24-h) serum GH concentrations significantly; 2) both androgens augmented the daily endogenous GH secretory rate significantly; 3) increased GH production resulted from a higher mass of GH secreted per burst and a higher maximal rate of GH secretion within each burst; and 4) androgens amplified the magnitude of the nyctohemeral rhythm in the mass (but not frequency) of GH secretory pulses. The observed effects of androgen were specific, since the number and duration of GH secretory bursts and the subject-specific GH half-life were unaltered by androgen treatment. We conclude that androgen acting apart from conversion to estrogen is capable of specifically activating the somatotropic axis via distinct neuroendocrine secretory mechanisms.