Abstract
Objective The main purpose of this study was to evaluate the effect of varying elbow flexion
angle and elbow orientation on the radiological measurement of component position
for first (1G) and second-generation (2G) TATE elbow cartridges, and to test intra/inter-observer
variability of measurements.
Materials and Methods A cadaveric thoracic limb was implanted with a 1G then 2G cartridge, and mounted
in lateral recumbency on an acrylic platform. The platform was tilted by set increments
up to 10° in both planes, and radiographs were performed at each angle before repeating
with the limb in caudocranial positioning. A deterministic trigonometric model was
used to show how component angles should vary with changes in orientation, and these
were compared with those measured by two observers. Humeral component angle (HCA),
radioulnar component angle, varus/valgus cartridge alignment angle and the cartridge
height:isthmus width ratio (CIR) were evaluated. Angles within 5° of the zero degrees
inclination angle and ratios within 0.2 of the zero degrees inclination ratio were
defined as acceptable.
Results Observer component angles for both cartridges were accurate and precise for inclinations
up to 10° except for HCA during adduction/abduction. The CIR values were within the
acceptable limit for inclinations up to 7.5° in both planes.
Clinical Significance Acceptable limits of limb inclination during positioning for TATE elbow replacement
cartridge assessment were defined. All component measurements were sufficiently accurate
and precise to be considered for evaluation of component position in clinical cases.
Keywords
canine total elbow replacement - TATE - component positioning - evaluation - radiological
