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PubMed1999

Relationship between borderline personality disorder and Axis I diagnosis in severity of depression and anxiety.

BACKGROUND: This study tested the hypothesis that subjects with borderline personality disorder irrespective of the presence or absence of an Axis I mood or anxiety disorder would exhibit greater severity of depression and anxiety than subjects with either a personality disorder other than borderline personality disorder or no personality disorder. METHOD: Two hundred eighty-three subjects from an outpatient psychiatry clinic were administered the following assessments: the Structured Clinical Interview for DSM-III-R (SCID) for Axes I and II, the Hamilton Rating Scales for Depression and Anxiety, the Beck Depression Inventory, and the Spielberger State-Trait Anxiety Inventory. Subjects were categorized into borderline personality disorder, other personality disorder, and no personality disorder categories and into present versus absent categories on Axis I diagnosis of depression and of anxiety. A 2-factor multiple analysis of variance compared personality disorder status and Axis I diagnosis on severity of depression by observer rating and self-report. The analysis was repeated for anxiety. RESULTS: As hypothesized, significant main effects were found for borderline personality disorder and for both depression and anxiety. Subjects with borderline personality disorder showed greater severity on both depression and anxiety rating scales than did patients with another personality disorder, who showed greater severity than did patients with no personality disorder. Axis I diagnosis was also associated with greater severity on depression or anxiety rating scales. These differences were found for both observer ratings and self-report. An interaction was also found for depression: Subjects with borderline personality disorder but without an Axis I diagnosis of depression rated themselves as more severely depressed on the Beck Depression Inventory than did subjects with another or no personality disorder who also had an Axis I diagnosis of depression. CONCLUSION: Implications from the study are discussed including the need to assess for borderline personality disorder in research studies of depression and anxiety and to integrate treatments for borderline personality disorder into depression and anxiety treatment to maximize clinical outcomes.

Adult↗
PubMed2001

The Hypothalamic-Pituitary-Adrenal Axis in Major Depressive Disorder: A Brief Primer for Primary Care Physicians.

BACKGROUND: One of the most enduring and replicated findings in biological psychiatry is activation of the hypothalamic-pituitary-adrenal (HPA) axis in a subset of patients with major depressive disorder. This review will discuss some of these findings and their pertinence to the assessment and treatment of depressed patients. METHOD: MEDLINE, PsychINFO, and Current Contents databases were searched for pertinent articles on the HPA axis in patients with depression. In addition, hand searches were conducted of references from these sources and abstracts from meetings and books on this topic. Articles that would provide an overview of major or interesting studies in the field were selected for inclusion. RESULTS: The data support that HPA axis activation is common in depressed patients. Frequently reported findings include elevated cortisol and corticotropin-releasing hormone (CRH), nonsuppression on the dexamethasone suppression test, a blunted adrenocorticotropic hormone (ACTH) response to CRH, and hippocampal volume reduction. Evidence of HPA axis activation appears to have prognostic value and is associated with increased risk of depression relapse and even suicide. CONCLUSION: Future research in this area will focus on a better understanding of the etiology and long-term consequences of HPA axis activation in depressed patients. In addition, medications that act on the HPA axis are currently in development and may be part of the psychiatrist's and primary care physician's pharmacopoeia in the near future.

Journal Article↗
PubMed1992

Clinical determination of the linear equation for the subtalar joint axis.

The authors present a methodology to measure the frontal plane angular and linear displacement and the transverse plane angular displacement of subtalar joint movement. This method is combined with a modification of the Kirby method for determining the transverse plane projection of the subtalar joint axis onto the plantar foot. A mathematical model is then used to construct the subtalar joint axis into a three-dimensional linear equation. Data are obtained from an in vivo series of 62 feet that indicates that within acceptable clinical errors of measurement the subtalar joint is a ginglymus type of joint that moves around a single fixed axis. Results also indicate that the subtalar joint axis is more superior and lateral to the neutral foot than any previous studies on cadaver feet have shown. Finally, the authors show that once the subtalar joint axis can be accurately located, the torque on the joint axis produced by ground reactive forces and muscular forces can be computed.

Adolescent↗
PubMed2000

Cross axis VOR induced by pursuit training in monkeys: further properties of adaptive responses.

We have shown recently in alert monkeys that repeated interaction between the pursuit and vestibular systems in the orthogonal plane induces adaptive changes in the VOR. To examine further properties of adaptive cross axis VOR induced by pursuit training, sinusoidal whole body rotation was applied either in the pitch or yaw plane while presenting a target spot that moved orthogonally to the rotation plane with either 90 degrees phase-lead or 90 degrees phase-lag to the chair signal. After one hour of training at 0.5 Hz (+/- 10 degrees), considerable phase-shift was observed in orthogonal eye movement responses consistent with the training paradigms by identical chair rotation in complete darkness, with further lead at lower frequencies and lag at higher frequencies. However, gains (eye/chair) induced by phase- shift pursuit training was different during pitch and yaw rotation. Although frequency tuning was maintained during pitch in the phase-shift paradigms, it was not maintained during yaw, resulting in higher gains at lower stimulus frequencies compared to the gains during yaw. This difference may reflect otolith contribution during pitch rotation. To understand further the nature of signals that induce adaptive cross axis VOR, we examined interaction of pursuit, whole field-visual pattern and vestibular stimuli. Magnitudes of the cross axis VOR with a spot alone on one hand and with a spot and pattern moving together in the same plane on the other during chair rotation were similar, and when one of the two visual stimuli was stationary during chair rotation, our well trained monkeys did not induce the cross axis VOR. These results suggest that the cross axis VOR induced by pursuit training shares common mechanisms with the cross axis VOR induced by whole field-slip stimuli and that if conflicting information is given between the two visual stimuli, adaptive changes are inhibited. Horizontal GVPs were recorded in the cerebellar floccular lobe during pitch rotation coupled with horizontal pursuit stimuli. These GVPs did not respond to pitch in the dark before training, but responded after 60 min of pursuit training with eye velocity sensitivities similar to those before training. Adaptive change in the VOR was specific to smooth eye movements but not to saccades in our paradigms.

Adaptation, Physiological↗
PubMed1999

[Clinical significance of cardiac axis determination in prenatal echocardiographic diagnosis of fetal congenital heart disease].

OBJECTIVE: To investigate the clinical significance of cardiac axis determined by echocardiography in prenatal diagnosis of fetal congenital heart disease (CHD). METHODS: 518 high risk fetuses for CHD were and 90 normal fetuses were examined by echocardiography. Cardiac axis was measured on four-chamber view and fetal cardiac anatomical structure was examined in multiple views to determine CHD. RESULTS: The 35 fetuses with CHD diagnosed by prenatal echocardiography. There is significant difference of caidiac axis between CHD group (58.1 +/- 15.7 degree) and normal group (44.8 +/- 10.3 degree, P < 0.01). Sensitivity of CHD diagnosis using four-chamber view alone is 68.5%, it will be elevated to 91.4% by combination of four-chamber view and cardiac axis determination (P < 0.05). CONCLUSION: Cardiac axis play an important role in fetal echocardiographic screening for CHD and it should be measured routinely as part of the four-chamber view of the fetal heart. The normal range of fetal cardiac axis is 20 to 75 degree. If it was more than 75 degree, the CHD should be suspected.

Adult↗
PubMed2001

Experimentally challenged reactivity of the hypothalamic pituitary adrenal axis in patients with recently diagnosed rheumatoid arthritis.

OBJECTIVE: There is evidence that the hypothalamic pituitary adrenal (HPA) axis is subresponsive in patients with rheumatoid arthritis (RA). We assessed HPA axis responses to experimental stressors mimicking daily life challenges in patients with RA to determine whether HPA axis activity is associated with Th1 and Th2 activity. METHODS: ACTH and cortisol responses in reaction to the succession of a bicycle ergometer task, a cold pressor task, and a computerized Stroop Color-Word interference test, as well as basal Th1 and Th2 cell activity, were assessed in 29 patients (21 female, 8 male) with recently diagnosed RA (mean disease duration 29 wks, range 5-69), mean age 55.7 years, none receiving glucocorticoid treatment, and 30 (20 female, 10 male) healthy age and sex matched controls (mean age 54.1 yrs). RESULTS: Mean ACTH and cortisol levels did not differ between the groups (p > 0.10). Patients tended to have a less pronounced ACTH response (F2.50 = 2.7, p = 0.08) and had a significantly smaller cortisol response (P F2.50 = 6.1, p < 0.01) than healthy controls in reaction to the stressors. This difference in cortisol response was reduced, but remained significant when ACTH responsiveness was accounted for by entering it as a covariate (P F2.49 = 3.7, p = 0.03). ACTH and cortisol levels and responses were not associated (all p > 0.19) with basal interferon-gamma and interleukin 4 as reflections of Th1 and Th2 cell activity, respectively. HPA axis activity was not linked to current disease activity. CONCLUSION: Our findings show reduced HPA axis responsiveness in RA patients with recent diagnosis receiving longterm medication that is suggested to be located both at a hypothalamic/pituitary and at an adrenal level. It appears that common HPA axis activity accomplishes low amounts of cortisol release, which makes it difficult to determine an influence of endogenous cortisol changes on the Th1/Th2 balance.

Adrenocorticotropic Hormone↗
PubMed2001

Adaptive eye movements induced by cross-axis pursuit--vestibular interactions in trained monkeys.

We showed previously that smooth pursuit training combined with whole-body rotation in the orthogonal plane induces adaptive cross-axis vestibulo-ocular reflex (VOR). To gain an insight into the possible pathways and the nature of error signals for cross-axis VOR adaptation, we examined further properties of adaptive responses. In the first series, we trained monkeys for vertical pursuit during sinusoidal yaw rotation at 0.5 Hz (+/- 10 degrees) by presenting a target spot either in phase with, or with phase shifts (lead or lag) of 90 degrees to, the chair for 1 h. After training, sinusoidal or trapezoidal yaw rotation was tested in complete darkness without a target. Different training conditions resulted in different amounts of phase shift in cross-axis VOR. Trapezoidal yaw rotation (peak acceleration approximately 780 degrees/s2) revealed further differences in the direction, latency and time course of the adaptive responses depending on the conditions of the pursuit task. At least two (fast and slow) components with different latencies were induced in the cross-axis VOR by trapezoidal rotation after in-phase and phase-shift training. Adaptive responses were accurately simulated by the weighted sum of these two components. In the second series, we examined the effects of sequentially flashed (10 microseconds) targets in the horizontal plane during pitch rotation. The monkeys learned to track such targets by smooth pursuit, and cross-axis VOR was also induced after such apparent motion stimuli without retinal slip of the target image. These results indicate the importance of eye velocity for cross-axis VOR and suggest that this adaptation occurs most probably in the smooth pursuit pathways.

Adaptation, Physiological↗
PubMed2002

Left ventricular long-axis changes in early diastole and systole: impact of systolic function on diastole.

Impaired long-axis motion is a sensitive marker of systolic myocardial dysfunction, but no data are available that relate long-axis changes in systole with those in diastole, particularly in subjects with diastolic dysfunction and a 'normal' left ventricular (LV) ejection fraction. A total of 311 subjects (including 105 normal healthy volunteers) aged 20-89 years with variable degrees of systolic function (LV ejection fraction range 0.15-0.84) and diastolic function were studied using tissue Doppler echocardiography and M-mode echocardiography to determine mean mitral annular amplitude and peak velocity in systole and early and late diastole. The LV systolic mitral annular amplitude (S(LAX), where LAX is long-axis amplitude) and peak velocity (S(m)) correlated well with the respective early diastolic components (E(LAX) and E(m)) and late diastolic (atrial) components (A(LAX) and A(m)). A non-linear equation fitted better than a linear relationship (non-linear model: S(LAX) against E(LAX), r(2)=0.67; S(m) against E(m), r(2)=0.60; S(LAX) against A(LAX) and S(m) against A(m), r(2)=0.42). After adjusting for age, sex and heart rate, linear relationships of early diastolic (E(LAX), r(2)=0.70; E(m), r(2)=0.60) and late diastolic (A(LAX), r(2)=0.61; A(m), r(2)=0.64) long-axis amplitudes and velocities with the respective values for S(LAX) and S(m) were found, even in those subjects with apparently 'isolated' diastolic dysfunction. Long-axis changes in systole or diastole did not correlate with Doppler mitral velocities. We conclude that ventricular long-axis changes in early diastole are closely related to systolic function, even in subjects with diastolic dysfunction. 'Pure' or isolated diastolic dysfunction is uncommon.

Adult↗
PubMed2002

Reliability, validity, and clinical utility of the research diagnostic criteria for Temporomandibular Disorders Axis II Scales: depression, non-specific physical symptoms, and graded chronic pain.

AIMS: To analyze the reliability, validity, and clinical utility of the depression, non-specific physical symptoms, and graded chronic pain scales comprising the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis II. METHODS: Data resulting from independent longitudinal and cross-sectional epidemiological studies as well as randomized clinical trials conducted at the University of Washington and the University at Buffalo were submitted to descriptive, correlational, and inferential statistical analyses to evaluate selected psychometric properties of the RDC/TMD Axis II scales. RESULTS: Analyses of available data from both TMD clinical centers revealed good to excellent reliability, validity, and clinical utility for the Axis II measures of depression, somatization, and graded chronic pain. Specifically, data were presented comparing the RDC/TMD depression scale to the Beck Depression Inventory and the Center for Epidemiologic Studies Depression Scale; these data supported concurrent validity of the RDC/TMD measure and its use as a depression screening tool. Its clinical utility lies in its demonstrated usefulness for alerting TMD clinicians to potentially noteworthy depressive symptomatology in TMD patients. Others have shown that elevated somatization, the tendency to report non-specific physical symptoms as noxious or troublesome, is a predictor of poor TMD treatment outcome. The present analyses demonstrated that the RDC/TMD Axis II non-specific physical symptoms scale has acceptable reliability and that severe levels of somatization can potentially confound interpretation of the Axis I clinical examination. The graded chronic pain scale was demonstrated to have clinical utility for tailoring TMD treatment to levels of a patient's psychosocial adaptation. CONCLUSION: The major RDC/TMD Axis II measures demonstrate psychometric properties suitable for comprehensive assessment and management of TMD patients.

Activities of Daily Living↗
PubMed2002

Tissue Doppler imaging assessment of long axis left ventricular function in hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy is classically defined as a diastolic disease with normal systolic function. Long axis left ventricular function is an important and sensitive determinant of global ventricular function but its assessment is often difficult and complex. Tissue Doppler imaging of the mitral annulus allows the study of long axis left ventricular function. METHODS: 47 patients with non-obstructive hypertrophic cardiomyopathy and 45 healthy volunteers, matched by age and sex, were studied with pulsed tissue Doppler imaging of the 4 sides of the mitral annulus (septal, lateral, inferior, anterior) in 4 and 2 chamber views. In each wave (systolic-s, rapid filling-e, atrial contraction-a) we analyzed velocities, time intervals and velocity-time integrals, as well as heterogeneity and asynchrony. Data were compared among the different sides in each group, between groups and with conventional Doppler data. RESULTS: In contrast to normal subjects, hypertrophic cardiomyopathy patients showed: 1--Systolic function: lower velocities, longer systolic time intervals (isovolumic relaxation time, time to peak s, ejection time), higher systolic asynchrony (time to peak s, ejection time, systolic time) and lower s/shortening fraction ratio. These changes occurred despite normal indices of global systolic function. 2--Diastolic function: lower velocities (much lower rapid filling velocity, lower atrial contraction velocity, lower septal e/a), higher e/a heterogeneity index, longer protodiastolic times (isovolumic relaxation time and time to peak e), higher diastolic asynchrony (time to peak e) and lower e wave integral. Hypertrophic cardiomyopathy patients also showed higher average number of annular sides with e/a < 1 per patient and higher percentage of e/a < 1, mainly on the septal side. CONCLUSIONS: This study shows that: 1--Tissue Doppler imaging allows the detailed analysis of long axis left ventricular function in hypertrophic cardiomyopathy patients. 2--Long axis systolic function is abnormal in this disease, even in the presence of normal indices of global systolic function. 3--Long axis diastolic function is deeply disturbed in hypertrophic cardiomyopathy, at ventricular and atrial levels. 4--Long axis dysfunction occurs in annular sides contiguous to hypertrophied and non-hypertrophied walls, highlighting the role of other factors in its pathophysiology.

Adolescent↗
PubMed1990

Effects of axis placement on measurement of isokinetic flexion and extension torque in the lumbar spine.

We wanted to ascertain whether changing the machine axis placement relative to the anatomic landmarks of a tested subject in isokinetic flexion and extension trunk strength would influence the measurements obtained. Twenty healthy volunteers were tested with the machine axis intentionally displaced from a reference position at the lumbosacral junction. Displacing the axis 50 mm vertically produced on average 15% increase in the torque produced, and displacing it 10 mm horizontally produced approximately 5% reduction in torque, independent of the direction of displacement from the reference position. The angle at which maximum torque occurred and the ratio of extension to flexion torque were unaffected by axis placement. Intertester reliability in axis placement was found experimentally to produce variations of usually less than 10 mm. We conclude that isokinetic trunk strength measurement is affected by testing axis placement; this should be controlled, especially in repetitive testing of the same individual.

Adult↗
PubMed1989

Mean frontal QRS axis and pulmonary artery pressures in rheumatic mitral stenosis.

The relationship between the mean frontal QRS axis calculated from the scalar 12 lead ECG, and the pulmonary artery (PA) pressures obtained by cardiac catheterisation in 64 cases of isolated rheumatic mitral stenosis (MS), was analysed. An overall trend of rightward axis shift with increasing PA pressures was observed; the best correlation was seen with systolic PA pressures (r = 0.51). It was possible to recognise 3 categories of patients: (1) With an axis of 70 degrees and below, systolic PA pressures were below 70 mm Hg in 82.4% of cases and below 80 mm Hg in 94% of cases; diastolic pressures were below 40 mm Hg in 88.2%; mean PA pressures were below 50 mm Hg in 88.2% cases. (2) With an axis of 71 degrees to 100 degrees, systolic PA pressures ranged from 30 to 120 mm Hg, diastolic PA pressures from 12 to 60 mm Hg and mean PA pressures from 19 to 80 mm Hg. (3) With an axis of above 100 degrees, systolic PA pressures were over 70 mm Hg in 95.5% of cases, diastolic PA pressures more than 30 mm Hg in 90.9%, and mean PA pressures more than 45 mm Hg in 90.9% cases. It was therefore possible to predict, with reasonable accuracy, the range of PA pressures in patients with isolated MS, except in those cases with an axis between 71 and 100 degrees.

Adolescent↗
PubMed1989

Thresholds for the perception of whole body angular movement about a vertical axis.

Thresholds for the detection (at p = 0.75 correct) of the direction of discrete angular movements about a vertical Z axis, having a cosine bell velocity trajectory and a duration of 3.3 s, were determined using an adaptive psychophysical procedure. In 30 subjects the mean threshold for the detection of Z axis stimuli was 1.5 deg.s-1. X and Y axis thresholds of 20 subjects had mean values of 2.04 and 2.07 deg.5(-1), respectively, and were significantly higher than Z axis thresholds. The mean Z axis threshold of 6 subjects, who viewed a visual target fixed to the turntable, was reduced by 8.6 dB over that obtained in darkness. Z axis thresholds were found to increase at 5.9 dB/decade as a function of stimulus duration over the range 0.9 to 20 s. The possible implication of this finding in relation to the dynamics of the sensory system mediating the perception of whole-body angular movement is discussed.

Acceleration↗
PubMed1986

[Left axis deviation investigated by body surface mapping and phase image analysis].

Relationship between left axis deviation and left anterior fascicular block (LAFB) was investigated by estimating the ventricular excitation and contraction sequence using body surface potential mapping and phase image analysis by radionuclide ventriculography. This study included seven normal persons, eight patients with complete right bundle branch block (RBBB) without left axis deviation (LAD), twelve with RBBB and unblocked axis (determined by the first half of the QRS complex) of 0 degrees or farther deviated to the left (RBBB with LAD), and three with isolated LAD. The isochrone ventricular activation maps (VAT maps) were obtained by body surface mapping technique. Planar phase images in the left anterior oblique projection and short-axis ventricular tomographic phase images using a seven-pinhole collimator were constructed by ECG-gated equilibrium blood pool scintigrams. On the VAT maps of RBBB, there was a markedly delayed conduction to the right ventricle, however, in the left ventricle, the excitation was initiated in the anterior paraseptal region, and it proceeded rapidly toward the lateral and posterior walls, and in the same direction as normal. The VAT maps of RBBB with LAD were categorized in three types according to the activation sequence in the left ventricle. Type I, the same as maps of RBBB, consisted of three cases. Type II, four cases, showed excitation starting from the apex and ascending in the anterior wall. There were five cases of type III, which showed the earliest excitation in the basal posteroparaseptal region, proceeding toward the apex and ascending in the anterior wall. Type II was considered compatible with block of the left anterosuperior fascicle, and type III was that of left anterosuperior and midseptal fascicles. In types II and III, the phase delay in the left anterior wall was recognized in tomographic phase images, and the difference between right and left ventricular mean phase angles in planar phase images was significantly smaller than in cases of isolated RBBB, These were thought to support the existence of LAFB. The range of the unblocked axis of RBBB with LAD was -3 degrees approximately 13 degrees (-7.7 +/- 5.0 degrees) in type I, -8 degrees approximately -30 degrees (-19.8 +/- 9.1 degrees) in type II, and -33 degrees approximately -60 degrees (-51.0 +/- 10.9 degrees) in type III. All cases with left axis deviation beyond -30 degrees were of type III, and suspected to have extensive damage, including the midseptal fascicle.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1983

["Left anterior hemiblock" or "extreme left axis deviation" in the ECG of children].

A comprehensive study involving the use of ECG's from children at the Giessen University Children's Hospital was conducted with the specific intent of identifying all children with an extreme left-axis deviation. This study showed that, in a time period of five years, 212 out of 3618 children examined electrocardiographically had an extreme left-axis deviation according to very strict criteria, their ECG-types could be divided into three groups: 1. without heart defects, 2. with congenital heart anomalies, 3. after surgery for congenital heart problems. Measurement of the QRS-complex in eighty children without heart defect showed that fifty-nine of the children (73.8%) had a vector -QRS between -30 degrees to -90 degrees. Ih the 88 children with congenital heart defects, and in 20 with an extreme left-axis deviation previous to surgery, an angle of -60 degrees to -90 degrees was found, most often in children with complete A-V canals of Down's Syndrome (as well as in children with transposition of the great arteries, univentricular heart or other complicated malformations of the heart). And finally, an extreme left axis deviation was very often found after surgery to correct Tetralogy of Fallot, ventricular defect, or endocardial cushion defect. Since an extreme left-axis deviation often occurs in children without heart defects, we would like to suggest that the term "Left anterior Hemiblock" be reserved for cases where there is certainty that damage to the conduction system has occurred. In all other cases, we prefer the term "left-axis deviation" as a more appropriate because an anomaly in the conduction system is more likely than a "block" i.e. an interruption of the conduction of electrical impulses through the heart muscle.

Adolescent↗
PubMed1995

The anteroposterior axis for femoral rotational alignment in valgus total knee arthroplasty.

This study evaluated a technique using the anteroposterior axis of the distal femur, rather than the transepicondylar or posterior femoral condylar axis, to establish rotational alignment of the femoral component in valgus knees. The anteroposterior axis of the distal femur was defined by a line through the deepest part of the patellar groove anteriorly and the center of the intercondylar notch posteriorly. Total knee arthroplasty was done in 46 valgus knees between 1980 and 1986 using the posterior femoral condyles as landmarks for rotational alignment. From January 1986 through January 1992 total knee arthroplasty was done in 107 valgus knees using the anteroposterior axis for rotational alignment of the femoral component. In the group of knees using the posterior condylar axis, medial tibial tubercle transfer was needed intra-operatively in 8 knees to prevent lateral dislocation of the patella. In the first 2 postoperative years, 4 knees had recurrent patellar dislocation or subluxation that required surgical correction. In the group of knees using the anteroposterior axis, patellar tracking problems that required realignment were significantly reduced. One knee required medial tibial tubercle transfer to correct a Q angle > 20 degrees. In the remaining knees, the Q angle was < 10 degrees, and patellar tracking was acceptable. Two years after surgery, no knees had patellar instability.

Aged↗
PubMed1995

An articulated ankle external fixation system that can be aligned with the ankle axis.

Aligning an articulated ankle external fixator with the ankle axis located using a mechanical axis finder has been shown to preserve normal ankle joint kinematics while the fixed hinge device is attached. However, several problems exist preventing the clinical application of this finding for fractures of the tibial plafond. We initiated a series of studies to resolve these issues. First, the accuracy of the mechanical axis finder in biological systems was quantified by comparing it to that of a computationally derived helical axis. Second, a prototype fixator design was developed in the biomechanics lab to increase the versatility of intraoperative fixator placement. Finally, a radiographic method of locating the ankle axis was developed which is based on talar morphology independent of the fractured tibia. The prototype fixator has been accurately aligned along the ankle axis in cadaveric specimens using this method. Open reduction and internal fixation (ORIF) is the accepted method of treatment for tibial plafond fractures. It holds the advantage of sufficient fracture fixation to permit early joint motion. Good results have been reported using this method, but some authors have reported complication rates up to 50%. The wide surgical approaches required, in conjunction with preexisting soft tissue injury, are thought to significantly increase the risk of soft tissue complications. In response to these problems, many investigators are beginning to utilize external fixation as an alternate treatment modality. One external fixation system which has shown particularly good results is a monolateral cross-ankle articulated fixator (Orthofix SRL., Verona, Italy) which allows motion at the ankle joint as the plafond fracture is healing (Figure 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Ankle Joint↗
PubMedDate not supplied

Comparison of astigmatic axis in the seated and supine positions.

BACKGROUND: Refractive error is assessed in the seated position while keratorefractive procedures are performed in the supine position. Since position-induced ocular torsion could yield suboptimal results from improper axis alignment, this study was undertaken to ascertain whether ocular cyclotorsion occurs when a subject moves from a seated to supine position. METHODS: Fifty eyes of 29 subjects with refractive cylinder greater than 0.50 diopters were enrolled. Refraction was done with a phoropter and the correction was placed in a trial frame using plus cylinder. Astigmatic axis was determined in the seated and supine positions for 32 eyes by utilizing the "rocking the cylinder" technique and for 32 eyes using the Jackson cross cylinder. Both techniques were used for 14 eyes. RESULTS: No statistically-significant difference for cylinder axis measured in the seated versus supine position was observed using the rocking the cylinder (4.3 degrees standard deviation [SD], 3.5 degrees, range 0 degrees to 13 degrees, p = NS) or the Jackson cross cylinder methods (2.3 degrees, SD, 1.9 degrees, range 0 degrees to 7 degrees, p = NS). Approximately 25% of eyes had a change in axis of 7 degrees to 16 degrees. CONCLUSIONS: These data suggest that the cylinder axis does not change significantly or predictably when most subjects move from the seated to supine position. The Jackson cross cylinder method seems more accurate and reproducible than the rocking the cylinder technique in determination of astigmatic axis under these circumstances.

Adult↗