Patients who require external fixation represent a major challenge for NPWT, particularly when external fixation pins and screws are inside the area of intended NPWT. A variety of methods have been developed to create a reliable seal [3,4,5,6,7,8,9,10,11,12]. Incorporate the bulk of the external fixation device within the large ioband drapes or a separate piece of foam could secure NPWT [6, 7] but sometimes interferes with the assessment of skin condition and blood supply of the tissue. This method also interferes with the movement and functional exercise of the affected limb. There is also a risk that the pins and wires puncture the drape after the application of the suction . Skin adhesives improve the adhesiveness of the plastic drape to the skin in maintaining the seal in difficult areas [8,9,10], but have not proven useful in sealing the gap between plastic drape and external fixation pins. Rubber strips have been reported to be tightly tied around the pins outside the adhesive plastic drape to obtain the vacuum , but the adhesive plastic drape remnants on the pins and screws are difficult to remove in subsequent debridement. Placing sterile bone wax at the junction between the screws and plastic drape is another method to create vacuum , but is prone to seal failure due to low viscosity and adhesiveness. Colostomy paste has also been reported to seal the junction between the screw and plastic drape . Colostomy paste has desirable properties, including high viscosity and plasticity, but is non-sterile, and thus could contaminate the wound if entering the wound along pressure gradient. In the “Filled Chocolates Technique”, sterile bone wax was applied to seal the gap between external fixation pins and drape to obtain the vacuum; the seal was then reinforced by applying colostomy paste over the bone wax. This method takes advantage of the desirable property of colostomy paste while avoiding direct contact between the colostomy paste and the dressing, or even the wound. Furthermore, bone wax and colostomy paste can be easily removed from the pins and screws with an iodopovidone-soaked gauze for subsequent debridements. The results of this trial demonstrated a dramatic reduction in seal failure.
A major limitation in the current study was the relatively short observation period. Second, we did not examine whether the decrease in seal failure improves the treatment outcomes.
Using bone wax followed by colostomy paste to seal NPWT around external fixation devices could reduce seal failure. Whether this method could decrease the rate of infection and produce clinically meaningful results requires further studies.
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.