The Three-Dimensional Relationship of the Axes of the Capitate and Third Metacarpal.

Purpose: We quantified the morphology and angulation of the third metacarpal (MC3) relative to the capitate using three-dimensional computed tomography data to inform surgical procedures such as total wrist arthroplasty and wrist arthrodesis. Specifically, we report the three-dimensional location of the intersections of the long axis of MC3 axis with the capitate cortical surface, the sagittal and coronal angles between the MC3 and capitate axes, and the MC3 shaft angle in the sagittal plane. We tested the hypothesis that these metrics did not differ between women and men.

Effectiveness of Deep Brain Stimulation in Improving Balance in Parkinson's Disease: A Systematic Review and Meta-Analysis.

Background: Balance dysfunction is a debilitating feature of advanced Parkinson's disease (PD), potentially improved by deep brain stimulation (DBS). This systematic review and meta-analysis pooled evidence from randomized controlled trials (RCTs) on DBS effectiveness in improving balance in PD.

Methods: A systematic search was conducted to identify eligible RCTs investigating the effectiveness of DBS on improving balance in people with PD.

Development of an implantable trapezium carpal bone replacement for measuring in vivo loads at the base of the thumb.

Understanding the loads that occur across musculoskeletal joints is critical to advancing our understanding of joint function and pathology, implant design and testing, as well as model verification. Substantial work in these areas has occurred in the hip and knee but has not yet been undertaken in smaller joints, such as those in the wrist. The thumb carpometacarpal (CMC) joint is a uniquely human articulation that is also a common site of osteoarthritis with unknown etiology.

Bone morphological changes of the trapezium and first metacarpal with early thumb osteoarthritis progression.

Background: Thumb carpometacarpal osteoarthritis is characterized by osteophyte growth and changes in the curvature of the articular surfaces of the trapezium and first metacarpal. The aim of this longitudinal study was to quantify in-vivo bone morphology changes with osteoarthritis progression.

Methods: The study analyzed an observational dataset of 86 subjects with early thumb osteoarthritis and 22 age-matched asymptomatic controls.

Total Wrist Arthroplasty Alignment and Its Potential Association with Clinical Outcomes.

 There is a lack of quantitative research that describes the alignment and, more importantly, the effects of malalignment on total wrist arthroplasty (TWA). The main goal of this pilot study was to assess the alignment of TWA components in radiographic images and compare them with measures computed by three-dimensional analysis. Using these measures, we then determined if malalignment is associated with range of motion (ROM) or clinical outcomes (PRWHE, PROMIS, QuickDash, and grip strength).

Biomechanics of the Distal Radioulnar Joint During In Vivo Forearm Pronosupination.

 Ulnar variance (UV) and center of rotation (COR) location at the level of the distal radioulnar joint (DRUJ) change with forearm rotation. Nevertheless, these parameters have not been assessed dynamically during active in vivo pronosupination. This assessment could help us to improve our diagnosis and treatment strategies.

In vivo articular contact pattern of a total wrist arthroplasty design.

Total wrist arthroplasty (TWA) designs suffer from relatively high complication rates when compared to other arthroplasties. Understanding the contact pattern of hip and knee replacement has improved their design and function; however, the in vivo contact pattern of TWA has not yet been examined and is thus the aim of this study. We hypothesized that the center of contact (CoC) is located at the geometric centers of the carpal component and radial component in the neutral posture and that the CoC moves along the principal arcs of curvature throughout primary anatomical motions.

Optical motion capture accuracy is task-dependent in assessing wrist motion.

Optical motion capture (OMC) systems are commonly used to capture in-vivo three-dimensional joint kinematics. However, the skin-based markers may not reflect the underlying bone movement, a source of error known as soft tissue artifact (STA). This study examined STA during wrist motion by evaluating the agreement between OMC and biplanar videoradiography (BVR).

Biplanar Videoradiography to Study the Wrist and Distal Radioulnar Joints.

Accurate measurement of skeletal kinematics in vivo is essential for understanding normal joint function, the influence of pathology, disease progression, and the effects of treatments. Measurement systems that use skin surface markers to infer skeletal motion have provided important insight into normal and pathological kinematics, however, accurate arthrokinematics cannot be attained using these systems, especially during dynamic activities. In the past two decades, biplanar videoradiography (BVR) systems have enabled many researchers to directly study the skeletal kinematics of the joints during activities of daily living.

Proximal-distal shift of the center of rotation in a total wrist arthroplasty is more than twice of the healthy wrist.

Reproduction of healthy wrist biomechanics should minimize the abnormal joint forces that could potentially result in the failure of a total wrist arthroplasty (TWA). To date, the in vivo kinematics of TWA have not been measured and it is unknown if TWA preserves healthy wrist kinematics. Therefore, the purpose of this in vivo study was to determine the center of rotation (COR) for a current TWA design and to compare its location to the healthy wrist.

Accuracy of an electrogoniometer relative to optical motion tracking for quantifying wrist range of motion.

Methods for capturing wrist range of motion (RoM) vary in complexity, cost, and sensitivity. Measures by manual goniometer, though an inexpensive modality, provide neither dynamic nor objective motion data. Conversely, optical motion capture systems are widely used in three-dimensional scientific motion capture studies but are complex and expensive.

Osteophyte volume calculation using dissimilarity-excluding Procrustes registration of archived bone models from healthy volunteers.

Osteophytes are associated with later stage osteoarthritis and are most commonly described using semiquantitative radiographic grading systems. A detailed understanding of osteophyte formation is, in part, limited by the ability to quantify bone pathology. Osteophytes can be quantified relative to pre-osteoarthritic bone, or to the contralateral bone if it is healthy; however, in many cases, neither are available as references.

Accuracy of biplane videoradiography for quantifying dynamic wrist kinematics.

Accurately assessing the dynamic kinematics of the skeletal wrist could advance our understanding of the normal and pathological wrist. Biplane videoradiography (BVR) has allowed investigators to study dynamic activities in the knee, hip, and shoulder joint; however, currently, BVR has not been utilized for the wrist joint because of the challenges associated with imaging multiple overlapping bones. Therefore, our aim was to develop a BVR procedure and to quantify its accuracy for evaluation of wrist kinematics.

Kinematic Accuracy in Tracking Total Wrist Arthroplasty With Biplane Videoradiography Using a Computed Tomography-Generated Model.

Total wrist arthroplasty (TWA) for improving the functionality of severe wrist joint pathology has not had the same success, in parameters such as motion restoration and implant survival, as hip, knee, and shoulder arthroplasty. These other arthroplasties have been studied extensively, including the use of biplane videoradiography (BVR) that has allowed investigators to study the in vivo motion of the total joint replacement during dynamic activities. The wrist has not been a previous focus, and utilization of BVR for wrist arthroplasty presents unique challenges due to the design characteristics of TWAs.

Operator Bias Errors Are Reduced Using Standing Marker Alignment Device for Repeated Visit Studies.

When optical motion capture is used for motion analysis, reflective markers or a digitizer are typically used to record the location of anatomical landmarks identified through palpation. The landmarks are then used to construct anatomical coordinate systems. Failure to consistently identify landmarks through palpation over repeat tests creates artifacts in the kinematic waveforms.

Mild leg length discrepancy affects lower limbs, pelvis and trunk biomechanics of individuals with knee osteoarthritis during gait.

Background: Leg length discrepancy greater than 1cm increases odds of progressive knee osteoarthritis in the shorter limb.

Methods: Biomechanical data of 15 knee osteoarthritis participants were collected while they walked under two conditions: (1) control - wearing thick sandals; (2) short limb - wearing a thin sandal on the osteoarthritic limb and a thick sandal on the contralateral limb. The thick and thin sandals had 1.

Why don't most runners get knee osteoarthritis? A case for per-unit-distance loads.

Unlabelled: Peak knee joint contact forces ("loads") in running are much higher than they are in walking, where the peak load has been associated with the initiation and progression of knee osteoarthritis. However, runners do not have an especially high risk of osteoarthritis compared with nonrunners. This paradox suggests that running somehow blunts the effect of very high peak joint contact forces, perhaps to provide a load per unit distance (PUD) traveled that is relatively low.

Breastfeeding: looking beyond the debate.

A Patchwork text is typically a series of short pieces of writing relating to one topic from different perspectives (Winter 2003). For example: critique of an article; detailed analytical accounts of personal experience; appraisal of culture and society within practice. The pieces are written over a period of time and discussed with peers for review to encourage reflection in an attempt to move away from surface learning.

Tracking lymphocytes in vivo.

The ability to track antigen (Ag)-specific lymphocyte populations in vivo has greatly increased our understanding of the location and functional status of these cells throughout the course of an immune response. Recent technical advances have enhanced researchers' capability to follow migration, activation and cellular interactions of Ag-specific lymphocytes in situ. It is now possible to monitor changes in T cell subsets, co-stimulatory molecules, and chemokine expression within the physiological context of secondary lymphoid organs.