Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “LATERALITY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22Linked to original sources
PubMed2005

[Anatomic identification of the location of the pedicle of atlas with the lateral mass of C2 to C4 as the landmark].

OBJECTIVE: To study the relevant position of the pedicle of C1 to the lateral mass of C(2-4), set up an identification technique for the entry point decision of C1 pedicle screw by using the lateral mass of C(2-4) as anatomic landmarks. METHODS: Twenty cadaver specimens were used to measure the distance from the sagittal midline of spine to the medial border, the midpoint and the lateral border of C1 pedicle or the lateral mass of C2, C3 or C4. The anatomic relation between the measurements data of C1 pedicle and that of the lateral masses of the cervical vertebrae were analyzed, and the technique of C1 pedicle screw fixation was established. RESULTS: The average medial border of the lateral mass of C2, C3 and C4 was 0.37 mm, 0.27 mm and 0.24 mm lateral to that of C1 pedicle, the average midpoint of the lateral mass of C2, C3 and C4 was 1.18 mm, 1.41 mm and 1.74 mm lateral to that of C1 pedicle, and the average lateral border of the lateral mass of C2, C3 and C4 was 1.96 mm, 2.54 mm and 3.24 mm lateral to that of C1 pedicle, respectively. CONCLUSION: There is a steady anatomic location relation between C1 pedicle and the lateral mass of C2, C3 or C4. As well as the lateral mass of C2, the lateral mass of C3 or that of C4 could be convenient anatomic landmarks to determine the location of C1 pedicle and the position of C1 pedicle screw entry point.

Adult↗
PubMed2006

Lateral osteoarthritis of the knee. Etiology based on morphological, anatomical, kinematic and kinetic observations.

This thesis aimed to study osteoarthritis (OA) of the knee and its subgroup with lateral wear (valgus knees). Anatomy, kinematics and kinetics (movements and moments) of the hip and knee joint and the sensitivity and specificity of diagnostic procedures were evaluated. Our hypothesis was that there are biomechanical reasons for development of either lateral or medial OA. The wear pattern of the tibial plateau and the femoral condyles was delineated in 42 patients. The diagnostic accuracy of standing knee radiographs was validated in 34 and reproducibility and validity of the Ahlbäck classification was studied in 48 patients. The Influence of working conditions or gender on the prevalence of uni or bilateral knee OA was evaluated in 990 patients from 2 hospitals (Varberg and Halmstad) operated during 1985-1994 with knee arthroplasty or proximal tibial osteotomy. For each patient, 3 age- and gender-matched controls were found. Studies of the anatomy of the hip and pelvic regions and the motions and moments in the hip and knee in medial and lateral OA were performed. The detailed kinematics of the knee during active extension in lateral OA were recorded using dynamic radiostereometry (RSA). In both medial and lateral OA the central part of the tibial plateau showed the most pronounced wear (p<0.001), followed by the anterior part in medial OA (p=0.02) and the posterior part in lateral OA (p=0.001). In medial OA the observed difference between the 2 radiographic methods was small and acceptable (median; p=0.05; 0-0.5 mm). In lateral OA there was no consistent underestimation, but larger scatter (median; p=0.04; -0.1-1.2 mm) suggesting less precise determination. The repeatability of the Ahlbäck classification for one observer was fair (kappa: medial OA: 0.15-0.65; lateral OA: 0.59-0.76), but between observers it was poor (kappa: 0.1). The validity revealed an acceptable sensitivity in both medial (67-95%) and lateral (43--86%) OA but the specificity was low (medial: 11-67%; lateral: 25-75%). Farmers (RR: 1.7; p<0.0005) and building workers (RR: 1.4; p=0.047) run increased risk to undergo surgical treatment because of OA of the knee. Unilateral disease was 3.7 times more common among men. Patients with lateral knee OA had a 14 mm wider pelvis (p=0.001) and those with medial knee OA an 11 mm higher offset (p=0.005). In the gait analysis they showed more outward rotation of the hip (p=0.001) and more inward rotation of the tibia than did patients with medial OA (p=0.001). In lateral OA, the medial femoral condyle translated 7-8 mm forward with 450 flexion whereas controls translated 4 mm less (p=0.03), without any difference of the lateral femoral condyle. Conventional radiographs do not give sufficient information for correct grading, especially in lateral OA where the scatter is high. The joint space can often be seen on radiographs despite presence of bone attrition as observed on the preparations. Increased incidence of unilateral disease in men and building workers suggests that this joint disease more commonly originates from previous trauma. Our findings suggest that the occurrence of medial or lateral OA has a biomechanical background originating from pelvis and hip anatomy.

Adolescent↗
PubMed1987

Metamorphic changes within the lateral-line system of Anura.

The metamorphic loss of lateral-line organs, lateral-line nerves and second order lateral-line neurons was examined in two Anuran species. At the onset of metamorphic climax, terminals within the lateral-line neuropil showed accumulation of glycogen-like granules. Neither the lateral-line nerve nor the organs or the nerve terminals inside the organs displayed any sign of degeneration at this stage. A few second order neurons exhibited accumulations of chromatin into conspicuous masses. These cells were partially or completely engulfed by phagocytes. At mid-metamorphosis all lateral-line organs were lost. The proximal parts of the lateral-line nerve fibers entering the rhombencephalic alar plate showed signs of degeneration. Within the lateral-line neuropil, pre- and some postsynaptic elements exhibited the flocculent type of degeneration or, to a lesser extent, the dark type of degeneration. Second order lateral-line neurons underwent an electron-dense or electron-lucent type of degeneration and were taken up by phagocytes. At the end of metamorphic climax the distal parts of the lateral-line nerves showed numerous dark degenerating fibers inside an intact myelin sheath. Within the lateral-line neuropil, numerous dark degenerating presynaptic elements were found next to some elements showing flocculent degeneration. Fewer degenerating second order neurons were found in the alar plate. They showed predominantly the dark type of degeneration. In contrast to earlier reports, our data suggest that the degenerative metamorphic changes observed in the present study are initiated in all parts of the lateral-line system simultaneously, and lead to the complete loss of all lateral-line organs and nerves and presumably all second order lateral-line neurons as well.

Animals↗
PubMed1998

The lateral calcaneal artery.

An anatomic study of the lateral extraosseous and intraosseous arterial supply of the calcaneus and the lateral soft tissue was carried out on 10 fresh lower adult cadaver legs using different anatomic and radiologic procedures (plastination, modified Spalteholz clearing technique, digital subtraction and rotational angiography and computed tomographic angiography). Consistent patterns of extraosseous and intraosseous lateral calcaneal vascular anatomy were demonstrated. The lateral calcaneal artery is a branch of the anterior tibial artery which crosses over the calcaneal tuberosity and forms a large lateral arch with the lateral tarsal artery which is a branch of the dorsalis pedis artery. The intraosseous circulation is supplied laterally by the lateral calcanear artery, medially via the short branches of the lateral plantar artery. Comparing magnet resonance images after fresh calcaneal fractures the lateral calcanear artery may be interrupted by the impacted lateral bulge, by the conventional lateral surgical approach, or by applying a lateral osteosynthesis plate. This may cause avascular bone necrosis. Furthermore the lateral calcanear artery can clinically serve as a vascular pedicle for a local rotational skin flap to cover soft tissue defects of the heel.

Adult↗
PubMed1994

Structural and molecular heterogeneity of astrocytes and oligodendrocytes in the gerbil lateral superior olive.

The goal of this study was to determine the distribution and diversity of astrocytes and oligodendrocytes within the lateral superior olive of the gerbil. We used morphometric analyses and several immunocytochemical markers to assess differences in glial cell composition between the lateral (low-frequency projection) and the medial (high-frequency projection) limb of the lateral superior olive. Cell counts from Toluidine-stained semithin sections revealed a similar density of total astrocytes in both the lateral and the medial limbs. However, based on cytologic features, there was a prevalence of fibrous-like astrocytes in the lateral limb and protoplasmic-like astrocytes in the medial limb. In a similar manner, glial fibrillary acidic protein staining of astrocytes was intense in the lateral limb, but was largely restricted to the nucleus borders in the medial limb of the lateral superior olive. While glial fibrillary acidic protein was largely restricted to astrocytic processes, glutamine synthetase and S100 protein staining occurred, for the most part, in glial cell bodies. The density of glutamine synthetase positive cell bodies was homogeneous between the two limbs, while the density of S100-positive somata was significantly greater in the lateral limb. Cell counts obtained from semithin sections demonstrated a greater density of oligodendrocytes in the lateral limb than in the medial limb of the lateral superior olive. In a similar manner, there was a 40% greater density of carbonic anhydrase-positive somata in the lateral limb compared to the medial limb. Transferrin immunostaining was restricted to oligodendrocytes, but the density of labeled somata was identical in the lateral and medial limbs. 2',3'-Cyclic nucleotide 3'-phosphodiesterase and myelin-associated glycoprotein were also localized to the somata of oligodendrocytes, labeling both perisomatic and interfascicular cells. At the ultrastructural level, specialized contacts were found between pairs or clusters of oligodendrocytes. These results suggest that more than one type of astrocyte and oligodendrocyte is present within the gerbil lateral superior olive. Furthermore, glial cells were unevenly distributed, such that a greater density of oligodendrocytes and fibrous-like astrocytes were found in the low-frequency projection region. This heterogeneity is well correlated with known differences in the neuronal morphology within the lateral superior olive.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed2006

The ratio of medial to lateral tibial plateau bone mineral density and compartment-specific tibiofemoral osteoarthritis.

INTRODUCTION: Bone is thought to play an important role in osteoarthritis (OA) pathophysiology. Our aim was to look at specific features of OA and their relation to the ratio of medial:lateral tibial plateau bone mineral density (M:L BMD Ratio). METHODS: We examined our research question in the Framingham OA Study Cohort. All participants had BMDs and weight-bearing plain radiographs of the knees (2002-2005). M:L BMD Ratios were calculated using BMD from medial and lateral regions in the tibial plateau. Knee x-rays were read for osteophytes (OSTs), joint space narrowing (JSN), and sclerosis (Osteoarthritis Research Society International (OARSI) scoring system). Knees were classified as having medial and/or lateral JSN if they had JSN >or=1 in the medial and/or lateral tibiofemoral compartments, respectively. Medial and/or lateral OSTs were defined as medial and/or lateral tibial and/or femoral OSTs >or=2, respectively. Medial sclerosis and lateral sclerosis were defined as medial and lateral tibial sclerosis >or=1, respectively. We performed a logistic regression with medial JSN as the outcome and with M:L BMD Ratio groups as predictor variables, using the median group as the referent. Analyses were adjusted for age, sex, and body mass index (BMI). Generalized estimating equations were used to adjust for correlation between knees. Identical analyses were performed with medial OSTs, medial sclerosis, lateral JSN, lateral OSTs, and lateral sclerosis as the outcomes. RESULTS: Mean age of 1612 subjects (3048 knees) was 63.9 (Standard Deviation (SD)+/-8.9), 56% were women, and mean BMI was 28.5 (SD+/-5.5). M:L BMD Ratio was positively associated with medial JSN (P for linear trend <0.0001) and negatively associated with lateral JSN (P for linear trend <0.0001). The relations of the ratio with medial and lateral OSTs were j-shaped with P for quadratic trends <0.0001. There were also strong associations between M:L BMD Ratio and compartment-specific sclerosis (P for linear trends <0.0001) with most knees with medial and lateral sclerosis being in the highest and lowest M:L BMD Ratio groups, respectively. CONCLUSION: In summary, the extremes of the M:L BMD Ratio are strongly associated with individual radiographic features of OA. These findings add to existing evidence supporting the importance of understanding bone in OA pathophysiology.

Absorptiometry, Photon↗
PubMed1997

Vertical muscle transposition augmented with lateral fixation.

INTRODUCTION: Full vertical rectus muscle transpositions have been shown to be an effective treatment for lateral rectus palsies and type I Duane syndrome. This operation is usually accompanied by mechanical or botulinum toxin treatment of one or both medial rectus muscles. This series evaluates the effect of augmenting the transposed muscles with lateral fixation sutures. METHODS: Transposition of the vertical rectus muscles to the lateral rectus muscle was performed in 23 eyes of 21 patients; transposition to the medial rectus muscle was performed in one eye of one of these 21 patients. A lateral fixation suture of 5-0 Dacron polyester filament was placed in the sclera 16 mm posterior to the limbus and adjacent to the lateral rectus muscle, incorporating one fourth of the transposed vertical rectus muscle. Of the 21 patients, five had type I Duane syndrome with a face turn and esotropia in the primary position, seven had a unilateral lateral rectus palsy, two had bilateral lateral rectus palsy, four had an ipsilateral lateral rectus palsy combined with a contralateral lateral rectus paresis (a recess resect procedure was performed on the paretic eye along with the augmented transposition on the paralyzed eye), two had gaze palsies, and one had a unilateral lateral rectus palsy with recurrent esotropia after a transposition procedure performed 16 years previously. Lateral fixation sutures alone were used in the last case listed. Postoperative diplopia-free fields were measured when possible (10 cases). RESULTS: In most cases (19/23 eyes), alignment was achieved in the primary position with the use of the augmented transposition procedure alone. On average,20 degrees of binocular fusion into the abducted field was obtained. No postoperative limitation of adduction in the transposed eye was noted. Among the patients with Duane syndrome, 80% had elimination of the face turn; one patient had 5 degrees of residual face turn. The one patient with previous transposition surgery alone had an 80% (16 PD) reduction of the recurrent esotropia after placement of lateral fixation sutures. After augmented transpositions, induced vertical deviations in the primary position were uncommon (4/20 patients) and not greater than 2 PD. Significant lid fissure changes were not seen. CONCLUSIONS: The addition of lateral fixation sutures to full vertical rectus muscle transpositions improves the tonic abducting force of the procedure for patients with lateral rectus palsy and type I Duane syndrome without compromising adduction.

Adolescent↗
PubMed2006

Use of spinous processes to determine drill trajectory during placement of lateral mass screws: a cadaveric analysis.

OBJECTIVE: Prior cadaveric research showed that the lateral mass and facets are landmarks to determine the initial starting point for lateral mass screws and that the optimum screw trajectory was 30 degrees lateral and 15 degrees cephalad. The missing link was an intraoperative landmark to guide the trajectory for drilling according to these angles. The authors hypothesized that spinous processes can be used to guide the trajectory for lateral mass screw placement. METHODS: The authors analyzed 144 lateral masses of 72 cervical vertebrae in 18 cadavers (7 males and 11 females). The lateral and cephalocaudad angles were measured for each lateral mass from C3 to C6 while using the spinous processes of the adjacent three caudad vertebrae at each level to guide the starting trajectories for a total of 864 angles. The lateral and cephalad trajectory angles at each spinous process relative to the starting hole were compared with 30 degrees and 15 degrees . For each angle measured at a particular level, the same starting hole was used in the lateral mass, and the superolateral cortex of each spinous process was the most medial point. RESULTS: When drilling for the C3 and C4 lateral mass screws, the C4 and C5 spinous processes provided an accurate starting point, respectively, for the lateral angle but moderately overestimated the cephalocaudad angle. For C5 and C6 lateral mass screws, the C6 and C7 spinous processes provided an accurate starting point, respectively, for both the lateral and the cephalocaudad angles. CONCLUSION: The spinous processes can be an accurate local anatomic guide for lateral mass screw trajectory and will allow greater safety while drilling before performing laminectomies. These guides may change in patients with cervical spinal deformities.

Bone Screws↗
PubMed1982

Adsorption kinetics of laterally and polarly flagellated Vibrio.

The adsorption of laterally and polarly flagellated bacteria to chitin was measured, and from the data obtained, a modified Langmuir adsorption isotherm was derived. Results indicated that the adsorption of laterally flagellated Vibrio parahaemolyticus follows the Langmuir adsorption isotherm, a type of adsorption referred to as surface saturation kinetics, when conditions are favorable for the production of lateral flagella. When conditions were not favorable for the production of lateral flagella, bacterial adsorption did not follow the Langmuir adsorption isotherm; instead, proportional adsorption kinetics were observed. The adsorption of some polarly flagellated bacteria exhibited surface saturation kinetics. However, the binding index (the product of the number of binding sites and bacterial affinity to the surface) of polarly flagellated bacteria differed significantly from that of laterally flagellated bacteria, suggesting that polarly flagellated bacteria adsorb to chitin by a different mechanism from that used by the laterally flagellated bacteria. From the results of dual-label adsorption competition experiments, in which polarly flagellated V. cholerae competed with increasing concentrations of laterally flagellated V. parahaemolyticus, it was observed that laterally flagellated bacteria inhibited the adsorption of polarly flagellated bacteria. In contrast, polarly flagellated bacteria enhanced the adsorption of V. cholerae. In competition experiments, where V. parahaemolyticus competed against increasing concentrations of other bacteria, polarly flagellated bacteria enhanced V. parahaemolyticus adsorption significantly, whereas laterally flagellated bacteria only slightly enhanced the process. The direct correlation observed between surface saturation kinetics, the production of lateral flagella, and the ability of laterally flagellated bacteria to inhibit the adsorption of polarly flagellated bacteria suggests that lateral flagella represent a component of bacterial structure that is important in the adsorption of laterally flagellated bacteria to surfaces. A model for adsorption events of laterally flagellated bacteria is proposed, based on the evidence presented.

Adsorption↗
PubMed1991

Morphology, distribution and innervation of the lateral-line receptors of the Florida gar, Lepisosteus platyrhincus.

The lateral-line system of gars consists of superficial neuromasts, which are arranged in lines termed pit lines, canal neuromasts and spiracular organs, which are located within diverticula of the hyoid gill pouch. Both canal and superficial neuromasts possess polarized hair cells whose directional sensitivity parallels the long axis of their respective lines. However, the apical surfaces of canal neuromasts are larger and possess far more hair cells than do those of superficial neuromasts, but superficial neuromasts have longer kinocilia and, presumably, longer cupulae. The receptors of the lateral-line system are innervated by three pairs of cranial nerves: anterior, middle and posterior lateral-line nerves. The anterior lateral-line nerves innervate neuromasts of the supraorbital, infraorbital and preoperculo-mandibular canals as well as dorsally located anterior pit lines, cheek (horizontal, vertical and mandibular) and gular pit lines of superficial neuromasts and the spiracular organ. The middle lateral-line nerves innervate dorsally located middle pit lines and a single neuromast in each temporal canal. The posterior lateral-line nerves innervate dorsally located posterior pit lines, neuromasts of the supratemporal commissures and all remaining postotic and trunk neuromasts. The ganglion of the anterior lateral-line nerve is divided into dorsal and ventral subganglia; the single ganglion of the middle lateral line nerve has no recognizable subdivisions, and the ganglion of the posterior lateral-line nerve consists of rostral and caudal subganglia. Analysis of the roots of these nerves and review of the embryonic origin of their ganglia as well as comparisons with cranial nerves in other anamniotes suggest that the anterior and posterior lateral-line nerves of gars may represent the fusion of four to five separate lateral-line nerves at some stage in vertebrate phylogeny. Thus, with the addition of the middle lateral-line nerve, and the possible existence of a ventral lateral-line nerve of the trunk, it is possible that the earliest jawed vertebrates possessed six or even seven pairs of lateral-line nerves.

Afferent Pathways↗
PubMed1988

The lateral-line and inner-ear afferents in larval and adult urodeles.

The inner-ear and lateral-line afferents were studied in members of almost all urodele families and in two primitive representatives of anurans and gymnophionans by means of transganglionically transported horseradish peroxidase. The lateral-line projection patterns are, when present, identical in all urodeles and gymnophionans. This is in agreement with the presence of ampullary organs in all urodeles and gymnophionans which possess a lateral-line neuromast system. In contrast, even the most primitive anurans lack both ampullary organs and the dorsal projection of afferents from these organs. In urodeles the inner-ear afferents are found to enter the rhombencephalon via the octaval nerve and bifurcate in the neuropil lateral to the nucleus magnocellularis into a short ascending and a longer descending subpial fascicle. Fibers of the ascending fascicle reach the tip of the lateral recess and terminate in the eminentia granularis. Collaterals are confined to the ipsilateral lobulus lateralis and end presumably as mossy fibers. The descending fascicle ends at the obex level with only a few fibers reaching the second spinal segment. Besides extensive fiber supply to the cells of the ipsilateral ventral-zone column, collaterals are found to reach the reticular formation, nucleus cerebelli, nucleus fasciculus solitarius, intermediate nucleus and several motor nuclei. Differences in the octaval projection among urodele families are limited to variation in its size relative to that of the lateral-line projection. Only species that develop without free-living larvae differ markedly with respect to the absence of lateral-line projections and, presumably, the lateral-line nuclei of the alar plate that exists in larvae. Almost all urodeles that possess a lateral-line system as larvae retain a complete lateral-line system, including neuromasts and ampullary organs, after metamorphosis. Only Salamandra and Chioglossa lose most of their lateral-line afferents and presumably all lateral-line organs around metamorphosis. The octavolateralis projections in urodeles are found to be strikingly similar to those in lampreys, sharks, sturgeons, and, especially, gymnophionans. This points to a great conservatism of this pattern, at least among anamniotic vertebrates. However, even primitive anurans such as Ascaphus differ markedly from these patterns in that they show no ampullary organs or dorsal lateral-line projection but a dorsal projection of the inner ear. Outgroup comparison with other anamniotic vertebrates indicates that the pattern in anurans is derived from the more generalized lateral-line and inner-ear projection pattern as represented in many urodeles and gymno

Amphibians↗
PubMedDate not supplied

The lateral notch sign associated with acute anterior cruciate ligament disruption.

We prospectively studied all of the patients with anterior cruciate ligament disruptions who sought treatment at the senior author's office during a 36-month period. Plain radiographs identified depressions measuring 2 mm or more in the lateral femoral condyle (lateral notch sign) in 9 of 120 knees (7.5%) with acute anterior cruciate ligament disruption and in 2 of 44 knees (4.5%) with chronic pivot shift instability. The depression ranged from 2 to 6 mm deep and from 20 to 25 mm long. The mean age for acutely injured patients with lateral notch signs was 17.2 years, 6 years younger than the mean age of the group with acutely injured anterior cruciate ligaments as a whole. Ten of the 11 patients (91%) with lateral notch signs were men, and all 6 patients with depressions shallower than prior descriptions of the notch sign were men. In contrast, 67% (N = 110) of the entire group of patients who had anterior cruciate ligament disruption were men. Ten of the 11 patients (91%) with the lateral notch signs and 4 of the 6 patients (66%) with minimal depressions also had lateral meniscus tears, while 58 of 147 patients (39%) without lateral femoral condyle depression had lateral meniscus tears. Previous reports that the lateral notch is a sign of chronic anterior cruciate ligament deficiency with recurrent pivot shifts are not supported by the number of prospectively recognized acute lateral femoral notch signs in this series. We found the presence of radiographic changes in the lateral femoral condyle to have statistically significant correlations with young age, male sex, lateral meniscus tears in general and anterior-horn lateral meniscus tears specifically, and lateral femoral chondral lesions.

Adolescent↗
PubMed1994

A comparison of lateral versus anterior-posterior spine dual energy x-ray absorptiometry for the diagnosis of osteopenia.

Because bone mineral density (BMD) measurements at various sites differ in the relative amounts of cortical and trabecular bone that they assess, they also differ in their sensitivity for detecting osteopenia. Lateral spine dual energy x-ray absorptiometry (DXA) allows measurement of BMD of the vertebral bodies, which contain mainly trabecular bone, without contribution from the posterior vertebral elements, which are rich in cortical bone. Thus, we hypothesized that lateral spine DXA would detect osteopenia more frequently than anterior-posterior (AP) spine DXA. To assess the ability of DXA to estimate trabecular bone mass, we compared AP and lateral DXA spine measurements with trabecular bone measurements by quantitative computed tomography (QCT) in 58 patients. We then compared AP vs. lateral spine DXA measurements in 1) 300 women referred for routine bone densitometry, 2) 30 glucocorticoid-treated women, and 3) 44 women with vertebral compression fractures. To compare short term reproducibility, we performed repeat AP and lateral DXA scans in 50 women. The association between QCT and DXA measurements was stronger when DXA measurements were made in the lateral (r = 0.784) or midlateral (r = 0.823) projection than in the AP (r = 0.571) projection. The association of BMD with age was stronger when DXA measurements were made in the lateral (r = 0.536) or midlateral (r = 0.536) projection than in the AP (r = 0.382) projection. The declines in BMD with age for AP, lateral, and midlateral DXA measurements were 0.48%, 0.60%, and 0.88%/yr, respectively. In the women referred for routine densitometry, lateral DXA measurements were significantly (P < 0.05) more abnormal than AP measurements compared with those in young women. This was also true in the women treated with glucocorticoids and women with vertebral compression fractures. Lateral DXA often detected osteopenia in patients whose AP DXA was normal. The 95% confidence limits for changes in BMD attributable to measurement error for AP, lateral, and midlateral DXA were 0.027, 0.038, and 0.057 g/cm2, respectively. These results indicate that lateral DXA measurements identify patients with osteopenia more often than AP DXA measurements, probably because lateral DXA more accurately estimates trabecular bone mass. Short term reproducibility of lateral DXA is nearly as good as that for AP DXA.

Absorptiometry, Photon↗
PubMed2003

Mesh expansion release of the lateral patellar retinaculum during total knee arthroplasty.

BACKGROUND: Release of the lateral patellar retinaculum can be used to treat patellofemoral instability and to balance the extensor mechanism during knee replacement operations. However, conventional lateral release disrupts the integrity of the lateral knee capsule, may damage the blood supply to the patella, and is associated with several other potential complications. Mesh expansion release of the lateral patellar retinaculum was developed to achieve the goal of lateral release and to reduce the potential for postoperative morbidity. METHODS: Thirteen consecutive knees in eleven patients were treated with mesh expansion lateral release during a total knee arthroplasty and were evaluated after a minimum duration of follow-up of two years. The mesh release technique consisted of multiple, longitudinal, parallel 5 to 10-mm stab incisions to mesh and expand the lateral patellar retinaculum and thereby medialize the patella in the trochlear groove of the femoral implant. RESULTS: Mesh expansion lateral release balanced the extensor mechanism in each knee, maintained the mechanical integrity of the lateral capsule, and avoided disruption of the lateral genicular blood supply to the patella. After a minimum duration of follow-up of two years, no complications had been noted in association with mesh expansion lateral release. CONCLUSION: Mesh expansion release of the lateral patellar retinaculum effectively balanced the patellofemoral joint during total knee arthroplasty, maintained the integrity of the lateral capsule, and preserved the lateral genicular blood supply.

Aged↗
PubMed2004

Mesh expansion release of the lateral patellar retinaculum during total knee arthroplasty.

BACKGROUND: Release of the lateral patellar retinaculum can be used to treat patellofemoral instability and to balance the extensor mechanism during knee replacement operations. However, conventional lateral release disrupts the integrity of the lateral knee capsule, may damage the blood supply to the patella, and is associated with several other potential complications. Mesh expansion release of the lateral patellar retinaculum was developed to achieve the goal of lateral release and to reduce the potential for postoperative morbidity. METHODS: Thirteen consecutive knees in eleven patients were treated with mesh expansion lateral release during a total knee arthroplastyand were evaluated after a minimum duration of follow-up of two years. The mesh release technique consisted of multiple, longitudinal, parallel 5 to 10-mm stab incisions to mesh and expand the lateral patellar retinaculum and thereby medialize the patella in the trochlear groove of the femoral implant. RESULTS: Mesh expansion lateral release balanced the extensor mechanism in each knee, maintained the mechanical integrity of the lateral capsule, and avoided disruption of the lateral genicular blood supply to the patella. After a minimum duration of follow-up of two years, no complications had been noted in association with mesh expansion lateral release. CONCLUSIONS: Mesh expansion release of the lateral patellar retinaculum effectively balanced the patellofemoral joint during total knee arthroplasty, maintained the integrity of the lateral capsule, and preserved the lateral genicular blood supply.

Arthroplasty, Replacement, Knee↗
PubMed2006

[Adult lateral meniscus].

Meniscal lesion does not mean meniscectomy and this is particularly true for the lateral meniscus. The reputation of mildness of the meniscectomy is usurped. The rate of joint space narrowing after lateral meniscectomy is of 40% at a follow-up of 13 years compared to 28% for the medial meniscus (symposium SFA 1996). Several arguments explain those results: biomechanical: the lateral meniscus contributes to the congruence; particularly the lateral meniscus is the zone where antero-posterior translational during knee flexion is 12 mm. The pejorative effects of lateral meniscectomy have conducted, more though to the medial meniscus, to the concept of meniscal economy. Lateral meniscectomy must be as partial as possible. Particularly, a discoid meniscus presenting a complete tear should be treated by a meniscoplasty in order to shape the meniscus in a more anatomic form than a total meniscectomy. Lateral meniscectomy is indicated in complex or horizontal cleavage, symptomatic, on stable knees. A particular case is the cyst of the lateral meniscus. It is a cystic subcutaneous formation, usual consequence of a horizontal cleaved meniscus of which the particularity is that it opens besides the articulation. The strategy must not consist in the isolated treatment of the cyst. This pathology should be addressed by an arthroscopic meniscectomy reaching the meniscosynovial junction at the level of the cyst. Meniscal repair must be proposed every time if possible. Criteria of reparability are better studied on MRI. Preoperatively MRI is the first choice radiological exam. Two essential indications can be held back: the vertical peripheral longitudinal lesion is on the non-vascularized area, and the horizontal cleaving of the junior athlete (if the cleaving remains purely intra meniscal). Meniscal repair is highly performed when the meniscal tear is associated to a rupture of the ACL (simultaneous reconstruction of the LCA). Postoperative outcome is different of that of a "simple" arthroscopic meniscectomy. The healing process being slow, it suits to protect the suture by a splint in the first month, and with an exclusion of sports with knee torsion during 6 months. Functional results (absence of secondary meniscectomy) and anatomical results (reality of the cicatrisation) are good in 77% of cases (symposium of the French Society of Arthroscopy 2003) at a follow-up of 55 months. Survivorship analysis indicates that majority of the failures occur within two years: this testifies a default of primary cicatrisation. At the studied follow-up, meniscal repair was efficient to protect the cartilage. Lateral meniscus results are better that medial meniscus one. Those data support indications: All suspicion of meniscal lesion must have an MRI preoperatively to confirm the lesion, to localize her and to search criteria of reparability; All vertical longitudinal peripheral lesions can and must be repaired especially in young patients and children; All horizontal cleaving of the junior athletes should be treated by open repair; surgical abstention must be proposed when the lesion is non symptomatic, or when lesion is limited and associated to an ACL tear (in that case isolated ACL reconstruction is proposed), or when clinical symptoms are minimal; Meniscectomy, always arthroscopic, is proposed for a symptomatic lesion in the avascular zone or for a deep horizontal cleavage or a complex tear; Tear of the discoid meniscus should be treated by meniscoplasty. A painful knee after lateral meniscectomy might be due to a too limited initial meniscectomy: an iterative meniscectomy may be indicated or lateral femorotibial arthritis, especially after subtotal or total meniscectomy. In this last case and after failure of usual medical treatment such as viscosupplementation surgery may be indicated. Osteotomy in order to unload the lateral femorotibial compartment gives a partial response as the shearing forces remain. This osteotomy is indicated only if the lower limb axis is normal or in valgus. Meniscal allograft is an option in young patients in grade I or II arthritis. Results are promising. Rene Verdonk's series show a survivorship analysis of 75% at 7 years. Early diagnosis of a postmeniscectomy syndrome before cartilaginous lesions occur is essential for an adapted treatment. In conclusion, lateral meniscectomy are less frequent than those of the medial meniscus but their prognosis is less favorable. They should be early diagnosed (MRI). Treatment options are various: abstention, meniscectomy, and repair. Painful post lateral meniscectomy syndrome may be treated by a new surgical option: meniscal allograft.

Cysts↗
PubMed1989

[Experimental studies on adaptation of mandibular masticatory movements to given laterally shifted intercuspal position].

When, the intercuspal position is newly established during reconstruction of maxillomandibular relationship, understanding the process of adaptation for the laterally shifted eccentric intercuspal position is very significant for problems involving maxillo-mandibular registration and diagnosis of occlusion, which has very important meaning for clarifying the neuromuscular control system for mandibular movement. In this studies, changes in clinical symptoms and masticatory movements were observed longitudinally when the laterally shifted intercuspal positions were newly established. Conditions for selecting four subjects were that they wore suitable overlay maxillary dentures connected to abutment teeth and that their mandibular dentition were natural and included good fixed restoration. Experimentally prepared overlay dentures were identical to those worn by subjects except that they included a structure of lateral shift of artificial dentition positioning to given newly laterally shifted intercuspal position. The condition of lateral shift of the intercuspal positions are established by the protrusion of the condyle on one side, amounts of lateral shift of the intercuspal positions were 0, 0.5, 1 and 2mm. From immediately after until a week after insertion of the experimental denture, observations were made to determine clinical symptoms and alterations in the chewing strokes on the frontal plane and in the rhythm of chewing movements. At first, the experimental denture with no lateral shift was inserted into the subject's mouth. Next, this was replaced by the experimental denture with a lateral shift of 1mm, and then this was replaced with a denture with a lateral shift of 2mm. When clinical obstruction was encountered, during this process this was replaced by one with a lateral shift of 0.5mm. Analysis of data of mandibular movement obtained was performed by means of a personal computer system. Results 1. Individual difference was observed in the process of adapting to laterally shifted intercuspal positions. One subject adapted adequately to a shift of 2mm, another to a shift of 1mm; and still another to a shift of 0.5mm. One subject failed to adapt adequately to a shift of 0.5mm. 2. When the laterally shifted intercuspal position was newly established, subject complained of a slightly high feeling in occlusion on the direction opposite to the lateral shift, occlusal sounds, and glide from the initial contact positions to the intercuspal position. All subjects, however, found it difficult to indicate the amount or direction of lateral shift; and there was no obstruction to intentional mastication under these conditions.(ABSTRACT TRUNCATED AT 400 WORDS)

Dental Occlusion↗
PubMed1998

GABA receptor mediated suppression of defensive rage behavior elicited from the medial hypothalamus of the cat: role of the lateral hypothalamus.

Recently, our laboratory has demonstrated that predatory attack behavior in the cat, elicited by electrical stimulation of the lateral hypothalamus, is suppressed following activation of the region of the medial hypothalamus from which defensive rage behavior is elicited [Han, Y., Shaikh, M.B., Siegel, A., Medical amygdaloid suppression of predatory attack behavior in the cat: II. Role of a GABAergic pathway from the medial to the lateral hypothalamus, Brain Res., 716 (1996) 72-83.]. The mechanism for this suppression is a direct GABAergic projection from the medial to lateral hypothalamus. The present study tested the hypothesis that the inhibitory relationship between these two regions of hypothalamus is reciprocal, namely, that a GABAergic neuron, which also projects from the lateral to medial hypothalamus, serves to suppress defensive rage elicited from the medial hypothalamus. Monopolar stimulating electrodes were implanted into lateral hypothalamic sites from which predatory attack behavior was elicited. In addition, cannula-electrodes were implanted into the medial hypothalamus for elicitation of defensive rage behavior and for microinjections of GABA compounds. Initially, in the absence of drug administration, the effects of dual stimulation of the lateral and medial hypothalamus upon response latencies were compared with those following single stimulation of the medial hypothalamus alone. Dual stimulation significantly (p<0.01) suppressed defensive rage behavior elicited from the medial hypothalamus. Then, administration of the GABAA receptor antagonist, bicuculline (10-60 pmol), into medial hypothalamic sites from which defensive rage was elicited blocked the suppressive effects of lateral hypothalamic stimulation. The GABAA receptor agonist, muscimol (0.3-30 pmol), microinjected into the medial hypothalamus, suppressed defensive rage elicited by single stimulation of the medial hypothalamus in a dose dependent manner. These suppressive effects of muscimol upon defensive rage were blocked following pretreatment with bicuculline (60 pmol). Administration of muscimol into adjoining regions of the lateral hypothalamus had no effect upon defensive rage, indicating its site specificity. Bicuculline (60 pmol) delivery into the medial hypothalamus had no effect upon defensive rage, suggesting the, presence of a phasic rather than tonic mechanism. A combination of immunocytochemical and retro grade tracing procedures were then employed to determine the origin of the putative GABAergic pathway projecting to the medial hypothalamus. In this experiment, the retrograde tracer, Fluoro-Gold (8%, 0.5 microl), was microinjected through a cannula-electrode in the medial hypothalamus from which defensive rage had been elicited. Following survival periods of 5-6 days, cats were perfused with 4% paraformaldehyde and brain tissue was processed for immunocytochemical staining of GABA neurons. Retrogradely labeled, immunopositively labeled, as well as Fluoro-Gold and GABA labeled cells, were identified in the lateral hypothalamus. Each type of neuron was distributed over wide regions of the lateral hypothalamus, extending from the area immediately caudal to the optic chiasm to the level of the posterior hypothalamus. Together, the behavioral pharmacological and anatomical data provide evidence of a direct inhibitory projection from the lateral to medial hypothalamus whose functions are mediated by GABAA receptors. When coupled with our previous findings, these results reveal the presence of reciprocal GABAergic inhibitory pathways between the medial and lateral hypothalamus. The findings suggest that functions associated with either the lateral or medial hypothalamus, but not both, can be activated at a given time.

Aggression↗