Biomechanical Comparison of Two Surgical Repair Techniques of the Distal Biceps Tendon.

Purpose: This study aimed to characterize the relationship between the distal biceps tendon force and the supination and flexion rotations during the initiation phase and to compare the functional efficiency of anatomic versus nonanatomic repairs.

Methods: Seven matched pairs of fresh-frozen cadaver arms were dissected to expose the humerus and elbow while preserving the biceps brachii, elbow joint capsule, and distal radioulnar soft tissue complex. For each pair, the distal biceps tendon was severed with a scalpel and then repaired with bone tunnels placed at either the anterior (anatomic) or the posterior (nonanatomic) aspect of the bicipital tuberosity on the proximal radius.

Biomechanical Evaluation of Transverse Patella Fracture Fixation Using Headless Screws: A Comparison of Suture Versus Cable as a Tension Band.

Objectives: To explore the performance of headless screws with FiberWire Suture as a tension band and headless screws with a mini-cable tension band in patella fixation.

Methods: A transverse osteotomy was created in 6 matched pairs of fresh-frozen cadaver knee joints. One knee was randomly assigned to receive fixation with headless screws plus a cable tension band while the other was fixed with headless screws plus a suture tension band.

Effect of age on femur whole-bone bending strength of mature rat.

Background: Skeletally mature rodents are frequently used in studies of bone health and bone healing, some of them requiring longitudinal observations that span a significant portion of the animals' adulthood. However, changes in whole bone mechanics associated with the natural aging of adult rats have not been extensively characterized.

Methods: Femurs from skeletally mature Wistar rats in three age groups of 24-week (young adult), 39-week (middle-age), and 54-week (late middle-age) were tested under three-point bending load in the anterior-posterior direction.

Biomechanical Comparison of Tension Band Fixation of Patella Transverse Fracture: Headless Screws Versus Headed Screws.

Objective: This study aimed to investigate the stability and strength of tension band wire fixation using headless compression screws versus headed screws for transverse patella fractures.

Methods: Six matched pairs of fresh-frozen cadaveric knees with transverse osteotomies created at the midpoint of the patella were surgically fixed, with one knee randomly receiving fixation with headless screws (Acumed Acutrak 4/5) and the other with headed screws (Synthes 4.0 partially threaded cannulated screws).

Assessment of Mechanical Characteristics of Ankle-Foot Orthoses.

Recent designs of ankle-foot orthoses (AFOs) have been influenced by the increasing demand for higher function from active individuals. The biomechanical function of the individual and device is dependent upon the underlying mechanical characteristics of the AFO. Prior mechanical testing of AFOs has primarily focused on rotational stiffness to provide insight into expected functional outcomes; mechanical characteristics pertaining to energy storage and release have not yet been investigated.

Training and fidelity monitoring of alcohol treatment interventions integrated into routine tuberculosis care in Tomsk, Russia: the IMPACT Effectiveness Trial.

IMPACT (Integrated Management of Physician-Delivered Alcohol Care for Tuberculosis patients) is a randomized, controlled effectiveness trial based in Tomsk, Russia, that assesses the effect of oral naltrexone and brief behavioral counseling on tuberculosis outcomes and alcohol use in 200 patients. Tuberculosis physicians without addiction experience delivered interventions as part of routine care over a 6-month period, focusing on alcohol intake reduction to support successful tuberculosis treatment. We describe design, training, and fidelity monitoring using a Russian and American team of physicians, bilingual coders, and supervisors.

Biomechanical comparison of supplemental posterior fixations for two-level anterior lumbar interbody fusion.

Posterior instrumentations have been used to supplement anterior lumbar interbody fusion with cages. Biomechanical studies on single-level anterior lumbar interbody fusion show that stand-alone cages supplemented with posterior translaminar facet or transfacet screw fixation exhibit comparable stability to those supplemented with pedicle screw/rod fixation, while stability of multilevel anterior lumbar interbody fusion remains mostly unknown. The objectives of this study are to compare the stabilization of three supplemental posterior fixations to two-level anterior lumbar interbody fusion, including translaminar facet fixation, transfacet screw fixation, and pedicle screw/rod fixation.

Evaluation of cast creep occurring during simulated clubfoot correction.

The Ponseti method is a widely accepted and highly successful conservative treatment of pediatric clubfoot involving weekly manipulations and cast applications. Qualitative assessments have indicated the potential success of the technique with cast materials other than standard plaster of Paris. However, guidelines for clubfoot correction based on the mechanical response of these materials have yet to be investigated.

The effect of dynamic femoroacetabular impingement on pubic symphysis motion: a cadaveric study.

Background: A link between femoroacetabular impingement and athletic pubalgia has been reported clinically. One proposed origin of athletic pubalgia is secondary to repetitive loading of the pubic symphysis, leading to instability and parasymphyseal tendon and ligament injury. Hypothesis/

Purpose: The purpose of this study was to investigate the effect of simulated femoral-based femoroacetabular impingement on rotational motion at the pubic symphysis.

Infant birth outcomes among substance using women: why quitting smoking during pregnancy is just as important as quitting illicit drug use.

Poor birth outcomes are associated with illicit drug use during pregnancy. While prenatal cigarette exposure has similar effects, cessation of illicit drug use during pregnancy is often prioritized over cessation of smoking. The study goal was to examine the impact of pregnancy tobacco use, relative to use of illicit drugs, on birth outcomes.

Biomechanical and radiographic evaluation of an ovine model for the human lumbar spine.

While various species of animal models have been used in preclinical investigations of spinal implant devices to assess their biological adaptation and biomechanical performance, few studies have made comprehensive comparisons to validate their suitability of modelling the human spine. The purpose of this study was to assess essential biomechanical behaviours and disc morphology of the ovine lumbar model. Flexibility testing was conducted on the spines (L3-L4 and L4-L5) of nine skeletally matured sheep.

Alteration of load sharing of anterior cervical implants with change in cervical sagittal alignment.

Anterior cervical discectomy and fusion (ACDF) is often supplemented with the application of an anterior plate to improve the stability of the fusion segment. While plate design has been shown to influence stress shielding of the graft, little is known about how the kyphotic alignment of a fused cervical segment affects the load sharing between the anterior plate and the osteoligamentous structures of the spine. The aim of this study was to characterize load sharing between an anterior plate and the osteoligamentous structures of the cervical motion segments in kyphotic versus normal lordotic alignment following single-level ACDF using fresh ovine cervical spines (C3-C6).

Changes in the lumbar foramen following anterior interbody fusion with tapered or cylindrical cages.

Background Context: Anterior lumbar interbody fusion (ALIF) using both cylindrical and tapered threaded interbody cages has been shown to restore disc height, reduce segmental motion, and relieve low back pain. The effectiveness of these stand-alone cage designs in restoration and maintenance of intervertebral foraminal dimensions has received little attention.

Purpose: To investigate the effects of anterior implantation of cylindrical and tapered interbody cages on morphologic changes of the lumbar neuroforamen and maintenance of foraminal dimensions under dynamic loading.

Biomechanical comparison of fixed-angle volar plate versus fixed-angle volar plate plus fragment-specific fixation in a cadaveric distal radius fracture model.

Purpose: To test the hypothesis that combining orthogonal fragment-specific fixation with volar fixed-angle fixation provides markedly higher interfragment stability and construct strength compared with volar fixed-angle fixation alone.

Methods: Eight matched pairs of fresh cadaveric hand and forearm specimens were potted upright in cement. Flexor and extensor tendons were isolated at insertion sites and sutured into a looped bundle for loading in flexion and extension, respectively (up to 61 N).

Does anterior plating of the cervical spine predispose to adjacent segment changes?

Study Design: In a human cadaveric model, the effects of plate supplementation on the mechanical behaviors of adjacent segments were investigated.

Objectives: The objective was to determine the effects of anterior cervical fusion and plating on the adjacent segments.

Summary Of Background Data: Increases in intradiscal pressure and intervertebral motion at adjacent segments have been reported in the lumbar spine following an instrumented fusion.

Behavioral medicine in Russian family medicine.

The Russian Federation's recently adopted family medicine as a specialty, but with little or no training in psychosocial and behavioral issues, unlike many training programs in other countries. The purpose of this qualitative study was to explore the perceptions and experiences of Russian primary care physicians regarding the practice of behavioral medicine and psychosocial methods. Semi-structured in-depth interviews were conducted with ten Russian family physicians.

Mechanical evaluation of posterior wiring as a supplement to anterior cervical plate fixation.

Study Design: An in vitro experimental study was performed to examine 3-dimensional biomechanical stability of cervical fixations.

Objectives: To determine whether posterior interspinous wiring contributes to the rigidity of a single-level motion segment that has been plated anteriorly, and to determine the effects of this combined fixation on intradiscal pressure and spinal motion at the adjacent segments.

Summary Of Background Data: Combined anterior and posterior column fixation is being increasingly used in a variety of clinical situations that do not involve complete disruption of the motion segment.

Biomechanical evaluation of contemporary posterior spinal internal fixation configurations in an unstable burst-fracture calf spine model: special references of hook configurations and pedicle screws.

Study Design: This study attempts to determine the most biomechanically rigid posterior spinal instrumentation configuration in a burst-fracture calf spine model.

Objectives: To compare the biomechanical stability of contemporary posterior spinal instrumentation in various hook and screw configurations in an unstable calf spine model.

Summary Of Background Data: Burst-fractures are relatively common injuries seen in the setting of spinal trauma.

Intradiscal pressure and kinematic behavior of lumbar spine after bilateral laminotomy and laminectomy.

Background Context: Bilateral laminotomy has been proposed as an alternative to laminectomy for decompression of lumbar spinal stenosis. Preservation of the posterior midline ligaments with laminotomy is presumed to maintain spinal segment stability. There have been no previous studies that directly compare the amount of destabilization and increase in disc pressures between the two procedures.

Effects of trunk position on back surface-contour measured by raster stereophotography.

A study of the contour of the surface of the back was conducted using the Quantec spinal image system (QSIS; raster stereophotography) and the Vicon 3-dimensional (3-D) motion analysis system with a plaster model of the scoliotic spine. With postural changes in 3 dimensions came alterations in the surface shape of the back. Most changes in QSIS parameters occurred in the coronal plane.

A noninvasive, three-dimensional spinal motion analysis method.

Study Design: A three-dimensional, noninvasive motion analysis method was developed by monitoring the orientation of the principal axes of each vertebra.

Objectives: To develop a method of performing three-dimensional, noninvasive motion analysis of the spine using computed tomography data.

Summary Of Background Data: The concept of using principal axes of the moment of inertia tensor to measure the orientation and position of a rigid body has been applied to the wrist and subtalar joints, but has not yet been applied to the spine.

In vitro evaluation of shoulder external rotation after a Bankart reconstruction.

The Bankart procedure is a commonly performed anterior shoulder reconstruction that may shorten the anterior capsule. In this study, biomechanical testing was performed to evaluate the effect of the classic Bankart reconstruction on external rotation of the shoulder. The procedure was performed on six fresh-frozen cadaveric specimens that were free of intraarticular pathologic changes.

Laparoscopic assisted fusion of the lumbosacral spine. A biomechanical and histologic analysis of the open versus laparoscopic technique in an animal model.

Study Design: An animal model for laparoscopic lumbosacral fusion.

Objectives: To compare the biomechanical and histologic results of open to laparoscopic lumbosacral discectomy and fusion in an animal model.

Background Data: Early clinical reports of laparoscopic lumbosacral fusions are encouraging, but animal experiments have not been reported.

Biomechanical evaluation of anterior and posterior fixations in an unstable calf spine model.

Study Design: Fresh calf lumbar spines were used to perform flexibility tests in multiple loading directions to compare the stabilizing effects of anterior and posterior rigid instrumentations.

Objective: To compare the biomechanical flexibility of anterior and posterior instrumentation constructs using an unstable calf spine model.

Summary Of Background Data: Unstable burst fractures of the thoracolumbar spine can be managed anteriorly or posteriorly.