Reliability of 3 different methods for assessing amputees residdum volume

Aims and objectives: Objective methods of assessing amputee residuum volumeare required to inform treatment decisions with regard to timing and design ofprosthetic sockets. Computer Aided Design (CAD) methods (e.g. optical 3Dscanners) can capture surface geometry and colour without the need for reference targets. Data collected on residual limb models suggest these novel methods may have greater validity and reliability than methods currently used in clinical practice1.The aim of this study was to assess the reliability of a new 3D laser free scannercompared with two alternative methods previously adopted in clinical practice. We hypothesize that the CAD hand scanner will be more reliable than the other clinical measurement systems, for assessing amputee residuum limb volumes.Methods: Three different operators measured the residuum volume of ten chronic lower limb amputees (5 transtibial, 5 transfemoral), on three occasions for each operator, using an Artec Eva 3D scanner, an Omega Tracer and a geometrical formula based on anthropometric measures, using a Gulick measuring tape and a crotch stick. Models were manually aligned using anatomical reference points. Intra and inter-rater reliability coefficients were calculated according with Bland-Altman statistic, for measuring indices of residual limb model volume for each method1.Results: Participants were chronic (>1 year) lower limb amputees with a mean: body mass 79±13 kg; height 173±11.6 cm and; time post-amputation 25.8±14.6 years).Residual limb volumes ranged from 1077 to 2406 ml. Intra-rater and inter-raterreliability coefficients were respectively 45 ml and 65 ml for the Artec Scanner (2.5 to 3.7% volume)., 70 ml and 72 ml for the Omega Tracer (3.9 % volume) and 112ml and 256 ml (>10% volume) for the anthropometric measurements.Conclusions: Prerequisites for a clinical method to measure amputee residuumvolume are reliability, safety, and portability. Optical 3D scanners, based on laserfree technology, are a promising method for assessing residuum limb volumechanges in lower limb amputees. The Artec Eva scanner revealed the lowestreliability coefficients (2.5 to 3.7% volume) and could therefore be a useful method for quantifying short-term changes in the residuum volume of lower limb amputees, that might indicate recasting and refitting requirements.References:1. Seminati E, Canepa Talamas D, young M, Twiste M, Dhokia V, Bilzon J. Validityand reliability of a novel 3D scanner for assessment of the shape and volume ofamputees’ residual limb models. Plos One. 2017

Validity and reliability of a novel 3D scanner for assessment of the shape and volume of amputees’ residual limb models

Objective assessment methods to monitor residual limb volume following lower-limb amputation are required to enhance practitioner-led prosthetic fitting. Computer aided systems, including 3D scanners, present numerous advantages and the recent Artec Eva scanner, based on laser free technology, could potentially be an effective solution for monitoring residual limb volumes. The aim of this study was to assess the validity and reliability of the Artec Eva scanner (practical measurement) against a high precision laser 3D scanner (criterion measurement) for the determination of residual limb model shape and volume. Three observers completed three repeat assessments of ten residual limb models, using both the scanners. Validity of the Artec Eva scanner was assessed (mean percentage error <2%) and Bland-Altman statistics were adopted to assess the agreement between the two scanners. Intra and inter-rater reliability (repeatability coefficient <5%) of the Artec Eva scanner was calculated for measuring indices of residual limb model volume and shape (i.e. residual limb cross sectional areas and perimeters). Residual limb model volumes ranged from 885 to 4399 ml. Mean percentage error of the Artec Eva scanner (validity) was 1.4% of the criterion volumes. Correlation coefficients between the Artec Eva and the Romer determined variables were higher than 0.9. Volume intra-rater and inter-rater reliability coefficients were 0.5% and 0.7%, respectively. Shape percentage maximal error was 2% at the distal end of the residual limb, with intra-rater reliability coefficients presenting the lowest errors (0.2%), both for cross sectional areas and perimeters of the residual limb models. The Artec Eva scanner is a valid and reliable method for assessing residual limb model shapes and volumes. While the method needs to be tested on human residual limbs and the results compared with the current system used in clinical practice, it has the potential to quantify shape and volume fluctuations with greater resolution

Validity and reliability of a novel 3D scanner for assessment of the shape and volume of amputees’ residual limb models

Background: Objective assessment methods to monitor residual limb volume following lower-limb amputation are required to enhance practitioner-led prosthetic fitting. Computer aided systems, including 3D scanners, present numerous advantages and the recent Artec Eva scanner, based on laser free technology, could potentially be an effective solution for monitoring residual limb volumes.Purpose: The aim of this study was to assess the validity and reliability of the Artec Eva scanner (practical measurement) against a high precision laser 3D scanner (criterion measurement) for the determination of residual limb model shape and volume.Methods: Three observers completed three repeat assessments of ten residual limb models, using both the scanners. Validity of the Artec Eva scanner was assessed (mean percentage error &lt;2%) and Bland-Altman statistics were adopted to assess the agreement between the two scanners. Intra and inter-rater reliability (repeatability coefficient &lt;5%) of the Artec Eva scanner was calculated for measuring indices of residual limb model volume and shape (i.e. residual limb cross sectional areas and perimeters).Results: Residual limb model volumes ranged from 885 to 4399 ml. Mean percentage error of the Artec Eva scanner (validity) was 1.4% of the criterion volumes. Correlation coefficients between the Artec Eva and the Romer determined variables were higher than 0.9. Volume intra-rater and inter-rater reliability coefficients were 0.5% and 0.7%, respectively. Shape percentage maximal error was 2% at the distal end of the residual limb, with intra-rater reliability coefficients presenting the lowest errors (0.2%), both for cross sectional areas and perimeters of the residual limb models.Conclusion: The Artec Eva scanner is a valid and reliable method for assessing residual limb model shapes and volumes. While the method needs to be tested on human residual limbs and the results compared with the current system used in clinical practice, it has the potential to quantify shape and volume fluctuations with greater resolution