Julia Elrod1, Bettina Müller2, Christoph Mohr3, Martin Meuli4, Edoardo Mazza5, Clemens Schiestl6. 1. Pediatric Burn Center, Division of Plastic and Reconstructive Surgery, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland. Electronic address: julia.elrod@kispi.uzh.ch. 2. Institute for Mechanical Systems, Department of Mechanical and Process Engineering, ETH Zurich, Leonhardstrasse 21, 8092 Zurich, Switzerland. Electronic address: mueller@imes.mavt.ethz.ch. 3. Pediatric Burn Center, Division of Plastic and Reconstructive Surgery, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland. Electronic address: christoph.mohr@kispi.uzh.ch. 4. Pediatric Burn Center, Division of Plastic and Reconstructive Surgery, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland. Electronic address: martin.meuli@kispi.uzh.ch. 5. Institute for Mechanical Systems, Department of Mechanical and Process Engineering, ETH Zurich, Leonhardstrasse 21, 8092 Zurich, Switzerland; Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland. Electronic address: mazza@imes.mavt.ethz.ch. 6. Pediatric Burn Center, Division of Plastic and Reconstructive Surgery, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032 Zurich, Switzerland. Electronic address: clemens.schiestl@kispi.uzh.ch.
Abstract
BACKGROUND: The objective evaluation of scar quality plays a crucial role in improving burn surgery and scar rehabilitation. Suction-based skin measurements were proposed as a method to objectively determine the mechanical properties of scars, yet their use is limited, in particular for paediatric burn care. A new device was developed which provides essential advantages for scar assessment. The aim of this study was to assess its reliability, intra- and interobserver variability. METHODS: The new device, "Nimble", consists of a lightweight probe that measures the negative pressure needed to obtain a predefined tissue elevation, revealing information on the stiffness of the tissue. 29 former paediatric burn patients were included. Three observers measured the tissue stiffness of a predefined location on the scar and on healthy skin using the Nimble, and the established suction device, the Cutometer®. The reliability of both instruments in distinguishing between healthy skin and scar was assessed by means of the intraclass correlation coefficient. RESULTS: The Nimble successfully differentiated between scar tissue and healthy skin in 92%, the Cutometer in 80% of the patients (p<0.05). Inter- and intraobserver variability of the Nimble (ICCs) were excellent. For the majority of the calculated ICC values the Nimble exceeded the Cutometer®. CONCLUSION: The new device enables reliable and safe measurement of the stiffness of scars. Measurements are less susceptible to patient non-compliance and observer dependency. The Nimble might therefore constitute an easy to use tool for the systematic assessment of scars, thus supporting decision-making in paediatric burn care.
BACKGROUND: The objective evaluation of scar quality plays a crucial role in improving burn surgery and scar rehabilitation. Suction-based skin measurements were proposed as a method to objectively determine the mechanical properties of scars, yet their use is limited, in particular for paediatric burn care. A new device was developed which provides essential advantages for scar assessment. The aim of this study was to assess its reliability, intra- and interobserver variability. METHODS: The new device, "Nimble", consists of a lightweight probe that measures the negative pressure needed to obtain a predefined tissue elevation, revealing information on the stiffness of the tissue. 29 former paediatric burn patients were included. Three observers measured the tissue stiffness of a predefined location on the scar and on healthy skin using the Nimble, and the established suction device, the Cutometer®. The reliability of both instruments in distinguishing between healthy skin and scar was assessed by means of the intraclass correlation coefficient. RESULTS: The Nimble successfully differentiated between scar tissue and healthy skin in 92%, the Cutometer in 80% of the patients (p<0.05). Inter- and intraobserver variability of the Nimble (ICCs) were excellent. For the majority of the calculated ICC values the Nimble exceeded the Cutometer®. CONCLUSION: The new device enables reliable and safe measurement of the stiffness of scars. Measurements are less susceptible to patient non-compliance and observer dependency. The Nimble might therefore constitute an easy to use tool for the systematic assessment of scars, thus supporting decision-making in paediatric burn care.