PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Photogrammetry”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 1,351 records · Page 75Linked to original sources
PubMed1983

Biplane radiographic measurements of reversible displacement (including clinical loosening) and migration of total joint replacements.

UNLABELLED: We studied nineteen total knee replacements and thirty-three total hip replacements with simultaneous biplane radiography to measure in vivo micromotion at the cement-bone interface. Spherical cobalt-chromium markers were embedded in the cement and cortical bone. Relative motion of the cement-markers was measured with respect to the markers in the cortical bone. Reversible displacement (relative motion during a change from non-weight-bearing to weight-bearing) and migration (relative motion over time from one non-weight-bearing study to another) were calculated. The resolution of the measuring system was 0.2 millimeter. The range for symptomatic reversible displacement was 0.4 to 4.5 millimeters, while that for asymptomatic reversible displacement was 0.3 to 1.9 millimeters. All reversible displacement of less than 0.4 millimeter was asymptomatic. Migration of as much as 2.1 millimeters occurred without concomitant reversible displacement. All radiolucent lines correlated with measured reversible displacement. Half of the patients who were evaluated two weeks postoperatively had measurable reversible displacement. CLINICAL RELEVANCE: Our findings were based on a small series from a selected population. The incidence of measured reversible displacement (75 per cent) was based on in vivo techniques and included symptomatic and asymptomatic reversible displacement; therefore, it was higher than the incidence of clinical loosening (9.6 per cent in our series). Simultaneous biplane radiography may become an important adjunct in the postoperative management of patients with a total joint replacement.

Follow-Up Studies↗
PubMed1983

Evaluation of hyperpronation and pes planus in adults.

Pes planus and hyperpronation of the hindfoot and midfoot are differentiated, and the numerous methods available for the clinical evaluation of both (including their norms) in the adult are presented. Pedotopography, a moiré fringe technique, is currently used in the clinical evaluation, along with "eyeball" visualization, tape measurement, ink mats, and roentgenography. Static deformities of the lower limbs and their joints are frequently responsible for manifestations of hyperpronation in the feet. Trauma and disease to bone, joints, or tendons in the region of the hindfoot or ankle can result in spastic pes planus with hyperpronation. Hyperpronation (excessive medial rotation of the talus) may exist without pes planus, but pes planus rarely is present without some degree of hyperpronation.

Adult↗
PubMed1984

A new photogrammetric method for quantifying corneal topography.

Attempts to describe normal corneal shape and to represent corneal topography by an array of discrete points have limited usefulness. A quantitative photogrammetric method that produces indices to describe corneal shape was developed. Four indices depict the departure of keratographic rings from circularity, and two indices express the trends and consistencies of all the rings from one keratograph. This photogrammetric index method (PIM) was evaluated against established measurement techniques. Values for the six indices were computed for groups (10 corneas each) of symmetrical, regularly astigmatic, and keratoconic corneas that had been defined by keratometry and clinical criteria. Predictions of the differences among groups were formulated for each index based on group descriptions and anticipated manual tracing and/or digitization error. Parametric and nonparametric tests of significance supported most predictions. The asymmetry of irregularly astigmatic keratoconic corneas, the variability of their orthogonal principal meridians, and an increasing symmetry toward their peripheries were documented clearly. The circularity of symmetrical group rings and the ellipticity of regularly astigmatic group rings were also evident. Preliminary norms are offered to illustrate the usefulness of the PIM in defining groups of corneas with the same histories and in classifying individual corneas.

Adult↗
PubMedDate not supplied

[Testometric stereoroentgenographic method].

The use of special test-objects in the course of the stereoroentgenographic studies allows one, to a high accuracy, to determine the space coordinates of the required points inside the structures of the subject being examined. The roentgenotopometric process is substantially simplified.

Digestive System↗