Accuracy and precision of measurements performed on three-dimensional printed pelvises when compared to computed tomography measurements.

The preoperative contouring of plates decreases the duration of surgery and improves the quality of the reduction of pelvic fractures. Patient-tailored three-dimensionally printed pelvises might be an interesting tool for achieving that purpose. Currently, no study has evaluated the accuracy of measurements performed on three-dimensional printed models in comparison with computed tomography data for complex bones, such as the pelvis. This study examined whether the measurements obtained on pelvises printed using dual-material fused deposition modeling technology are not significantly different from those obtained on computed tomography images. The computed tomography images of the pelvic region from 10 dogs were used to produce three-dimensionally printed models with a dual-material fused deposition-modeling process. Four segments were measured on both three-dimensionally printed models and computed tomography images. The measurements were performed by three observers and repeated twice. Concordance correlation coefficients were used to assess the precision and accuracy of the measurements as well as evaluate the agreement between the methods. The accuracy of measurements between the methods was > 0.99 for all measurements. The precision was almost perfect for AE (0.996), substantial for BD and BC (0.963 and 0.958, respectively), and moderate for CD (0.912). These results indicate that, despite some minor variations, the measurements performed on printed models reproduced the computed tomography data reliably.

Comparison of Doppler ultrasonography and high-definition oscillometry for blood pressure measurements in healthy awake dogs.

OBJECTIVE: To determine the intra- and interobserver variability of systolic arterial pressure (SAP) and diastolic arterial pressure (DAP) measurements obtained with 2 indirect methods in awake dogs and percentage of successful measurements. ANIMALS: 6 healthy conscious adult dogs. PROCEDURES: 4 observers with different levels of training measured SAP and DAP on 4 days by use of Doppler ultrasonography (DU) and high-definition oscillometry (HDO). The examinations were randomized. Measurements for each technique were recorded 5 consecutive times, and mean values (total, 720 measurements) were used for statistical analysis. RESULTS: All within- and between-day coefficients of variation (CVs) for SAP were < 15% irrespective of the observer or method (HDO, 3.6% to 14.1%; DU, 4.1% to 12.4%). Conversely, half the CVs for DAP were > 15% with the highest within- and between-day CVs obtained by the least experienced observer by use of DU (19.5% and 25.9%, respectively). All attempts with HDO were successful, whereas DAP could not be measured by use of DU by the least experienced observer in 17% of attempts. CONCLUSIONS AND CLINICAL RELEVANCE: SAP may be assessed in healthy dogs by use of DU and HDO with good repeatability and reproducibility after a short period of training. Conversely, the variability of DAP is higher and longer training is required to assess DAP via DU than via HDO.