No abstract

As indications for total hip arthroplasty (THA) have expanded, the incidence of THA has increased among younger patients, who live longer and tend to place more strain on implants via higher activity levels. This demographical shift accentuates the importance of advancing innovation to ensure implant longevity for younger and more active patients. Future innovation, as it pertains to THA components, is likely to focus on modifying implant designs and tribology in conjunction with identification and application of newer biomaterials. By reviewing the literature for development status of various materials and novel design advancements in THA component outside of the standard highly cross-linked polyethylene, this investigation provided an update on the current and future status of design initiatives as they pertain to THA. Though the highlighted alternative bearing surfaces have shown promising and limited, yet encouraging clinical data, they lack larger and longer-term clinical trial results. Further research and innovation is warranted to identify the optimal bearing surface to most effectively accommodate for the trend of younger and more active patients undergoing THA. Implant longevity is crucial if the clinical success of THA is to be maintained.

The brain processes many aspects of the visual world separately and in parallel, yet we perceive a unified world populated by objects. In order to create such a "bound" percept, the visual system must construct object-centered representations out of separate features and then maintain the representations across changes in space and time. Here, we examine the role of features themselves in maintaining and disambiguating the representations of the objects to which they belong. In three experiments, we measure how the perceived motion of two objects traversing ambiguous trajectories is affected by the contrast between the features and surrounding fields, by the contrast between features, and by changes to orientation of texture within objects. We report that the maintenance and disambiguation of object representations depend on the contrast of the features relative to their surrounds and on the extent of feature differences between the two objects. These feature dependencies indicate that object representation relies on relative response to many stimulus dimensions.

Although surgical techniques pertaining to adult spinal deformity (ASD) have advanced over the last decade, proximal junctional kyphosis (PJK) is still a complication following surgery for ASD that continues to significantly challenge clinicians. This article aimed to report on the prevalence of PJK as well as enhance understanding of surgically modifiable and non-modifiable risk factors of PJK to guide management of this postoperative complication of ASD. As the understanding of the pathogenesis as well as surgical modifications aimed at reducing the incidence of PJK have advanced, so too should clinicians' ability to implement more patient-specific operative plans and improve outcomes following realignment surgery for ASD.