Changes in chondrolabral mechanics, coverage, and congruency following peri-acetabular osteotomy for treatment of acetabular retroversion: A patient-specific finite element study.

Unlabelled: Using a validated finite element (FE) protocol, we quantified cartilage and labrum mechanics, congruency, and femoral coverage in five male patients before and after they were treated for acetabular retroversion with peri-acetabular osteotomy (PAO). Three-dimensional models of bone, cartilage, and labrum were generated from computed tomography (CT) arthrography images, acquired before and after PAO. Walking, stair-ascent, stair-descent, and rising from a chair were simulated.

Accuracy of 3D dual echo steady state (DESS) MR arthrography to quantify acetabular cartilage thickness.

Purpose: To deploy and quantify the accuracy of 3D dual echo steady state (DESS) MR arthrography with hip traction to image acetabular cartilage. Clinical magnetic resonance imaging (MRI) sequences used to image hip cartilage often have reduced out-of-plane resolution and may lack adequate signal-to-noise to image cartilage.

Materials And Methods: Saline was injected into four cadaver hips placed under traction.

A new discrete element analysis method for predicting hip joint contact stresses.

Quantifying cartilage contact stress is paramount to understanding hip osteoarthritis. Discrete element analysis (DEA) is a computationally efficient method to estimate cartilage contact stresses. Previous applications of DEA have underestimated cartilage stresses and yielded unrealistic contact patterns because they assumed constant cartilage thickness and/or concentric joint geometry.

Anatomic changes in the inguinal region after hip arthroscopy: implications for femoral nerve block.

Patients may experience significant pain after hip arthroscopy. Two patients who experienced severe pain after arthroscopic hip surgery, despite receiving multimodal pharmacologic therapy, are presented. In both cases, ultrasound-guided femoral nerve block provided excellent analgesia.

Range-wide reproductive consequences of ocean climate variability for the seabird Cassin's Auklet.

We examine how ocean climate variability influences the reproductive phenology and demography of the seabird Cassin's Auklet (Ptychoramphus aleuticus) across approximately 2500 km of its breeding range in the oceanographically dynamic California Current System along the west coast of North America. Specifically, we determine the extent to which ocean climate conditions and Cassin's Auklet timing of breeding and breeding success covary across populations in British Columbia, central California, and northern Mexico over six years (2000-2005) and test whether auklet timing of breeding and breeding success are similarly related to local and large-scale ocean climate indices across populations. Local ocean foraging environments ranged from seasonally variable, high-productivity environments in the north to aseasonal, low-productivity environments to the south, but covaried similarly due to the synchronizing effects of large-scale climate processes.