Publications by authors named "Christopher Bui"
Objectives: To evaluate axial fracture obliquity and posterior inferior comminution in vertically oriented femoral neck fractures (FNFs) in the physiologically young patient. A biomechanical investigation was designed to evaluate the impact of these fracture elements on torque to failure using cannulated screw (CS) and sliding hip screw fixation.
Methods: Four Pauwels III FNF models were established in synthetic femurs: (1) vertically oriented in the coronal plane (COR), (2) coronal plane with axial obliquity (AX), (3) coronal plane with posterior inferior comminution (CCOM), and (4) coronal plane with axial obliquity and posterior inferior comminution (ACOM).
Volar radiocarpal instability is often seen after loss of fixation of volar lunate facet fragments. The pathogenesis of post-traumatic volar radiocarpal instability is poorly understood. The purpose of this study was to determine if injury to the dorsal wrist extrinsic carpal ligaments contributes to volar radiocarpal instability.
View Article and Find Full Text PDFBackground: Biomechanical and clinical success of the superior capsule reconstruction (SCR) using fascia lata (FL) grafts has been reported. In the United States, human dermal (HD) allograft has been used successfully for SCRs; however, the biomechanical characteristics have not been reported.
Methods: Eight cadaveric shoulders were tested in 5 conditions: (1) intact; (2) irreparable supraspinatus tear; (3) SCR using FL allograft with anterior and posterior suturing; (4) SCR using HD allograft with anterior and posterior suturing; and (5) SCR using HD allograft with posterior suturing.
Background: Acute Hill-Sachs reduction represents a potential alternative method to remplissage for the treatment of an engaging Hill-Sachs lesion. This study biomechanically compared the stabilizing effects of an acute Hill-Sachs reduction technique and remplissage.
Methods: Six cadaveric shoulders were tested.
Background: A general consensus has been formed that glenoid bone loss greater than 20% to 25% is the critical amount at which bony augmentation procedures are needed; however, recent clinical results suggest that the critical levels must be reconsidered to lower values.
Purpose: This study aimed to find the critical value of anterior glenoid bone loss when a soft tissue repair is not adequate to restore anterior-inferior glenohumeral translation, rotational range of motion, or humeral head position using a biomechanical anterior shoulder instability model.
Study Design: Controlled laboratory study.
Purpose: To validate the glenoid track concept in a cadaveric bipolar bone loss model and to test whether "on-track" and "off-track" lesions can be stabilized with Bankart repair (BR) with or without Hill-Sachs remplissage (HSR).
Methods: Eight fresh-frozen cadaveric shoulders were tested in a custom apparatus with passive axial rotation and then progressive translational loading (10 to 40 N) at mid-range (60°) and end-range external rotation (90°). Injury conditions included glenoid bone loss of 15% with on-track (15%) and off-track (30%) Hill-Sachs lesions.
Purpose: To compare the biomechanical properties of a fibula cross-tunnel technique for posterolateral corner (PLC) reconstruction with those of intact knees.
Methods: Seven fresh-frozen cadaveric knees were tested while intact, after PLC tear, and after reconstruction. Testing of the parameters listed above was performed at 0°, 30°, 60°, and 90° of knee flexion.
Background: Articular-sided partial-thickness rotator cuff tears are common injuries in throwing athletes. The superior shoulder capsule beneath the supraspinatus and infraspinatus tendons works as a stabilizer of the glenohumeral joint.
Purpose: To assess the effect of articular-sided partial-thickness rotator cuff tear and repair on shoulder biomechanics.
Purpose: To compare the effect of 2 common rotator cuff repair techniques, for smaller tears limited to the use of a single anchor, on tendon morphology in relation to the footprint.
Methods: Six matched pairs of human shoulders were dissected, and a standardized 10-mm supraspinatus tendon tear was created. Two single-anchor repairs were performed: simple repair with the anchor on the footprint or inverted-mattress repair with the anchor 1 cm distal-lateral to the footprint.
Background and Aims. This report demonstrates the utility of a pudendal nerve block by pulsed radiofrequency ablation (RFA) for the treatment of male pelvic pain and urinary urgency and hesitancy. Methods.
View Article and Find Full Text PDFArticle Synopsis
- The study investigates chronic hepatitis B (CHB) among Vietnamese Americans in California, focusing on its prevalence, risk factors, and the level of disease knowledge among this population.
- Out of 717 participants, 13.8% tested positive for hepatitis B, with higher rates observed in those aged 31-40, and many remained susceptible despite some history of vaccination.
- Key risk factors for HBsAg positivity included lack of healthcare coverage, family history of CHB, and prior occupational exposure, while patient awareness of treatment options and follow-up care was notably inadequate.
Background: Although deviations in scapular orientation are thought to predispose to shoulder injuries in throwing athletes, the biomechanical mechanism underlying shoulder injuries in throwing athletes with an altered scapular orientation remains unclear.
Methods: Seven fresh-frozen cadaveric shoulders were evaluated at 90° of abduction, with the humerus externally rotated from 90° to the maximum angle, to simulate the late cocking phase of the throwing motion. Loads were applied to the deltoid, pectoralis major, latissimus dorsi, teres major, and all rotator cuff muscles.
Biomechanical effects of joint line elevation in total knee arthroplasty.
Clin Biomech (Bristol)
October 2012
Background: Inadequate restoration of the knee joint line after total knee arthroplasty may lead to a poor clinical outcome. The purpose of this study was to quantitatively assess the effects of joint line elevation following total knee arthroplasty with increased joint volume on patellofemoral contact kinematics.
Methods: Six cadaveric specimens were tested.
Study Design: Controlled laboratory study.
Objective: To evaluate the biomechanical characteristics of a new expandable interbody cage in single-segment posterior lumbar interbody fusion (PLIF) using cadaveric lumbar spines.
Summary Of Background Data: One of the popular methods of treating lumbar spine pathologies involves a posterior lumbar interbody fusion using bilateral interbody nonexpandable cages.
Background: Multiple techniques have been reported to treat chronic acromioclavicular joint injuries. However, many have failed to restore native stability, and few have addressed reconstructing the acromioclavicular ligaments.
Hypothesis: An intramedullary free semitendinosus graft reconstruction of the acromioclavicular ligaments will demonstrate joint stability comparable with that of the intact acromioclavicular joint.
Study Design: This study evaluates the biomechanical characteristics of spinal instrumentation constructs in a human unstable thoracolumbar burst fracture model simulated by corpectomy.
Objective: To compare the biomechanical characteristics of short-segment posterior instrumentation, with and without crosslinks, in a human unstable burst fracture model simulated by corpectomy.
Summary Of Background Data: Unstable thoracolumbar burst fractures are serious injuries, and their management remains controversial.