X-ray microtomography-based measurements of meniscal allografts

BackgroundX-ray microcomputed tomography (XMT) is a technique widely used to image hard and soft tissues. Meniscal allografts as collagen structures can be imaged and analyzed using XMT. The aim of this study was to present an XMT scanning protocol that can be used to obtain the 3D geometry of menisci. It was further applied to compare two methods of meniscal allograft measurement: traditional (based on manual measurement) and novel (based on digital measurement of 3D models of menisci obtained with use of XMT scanner).HypothesisThe XMT-based menisci measurement is a reliable method for assessing the geometry of a meniscal allograft by measuring the basic meniscal dimensions known from traditional protocol.Materials and methodsThirteen dissected menisci were measured according the same principles traditionally applied in a tissue bank. Next, the same specimens were scanned by a laboratory scanner in the XMT Lab. The images were processed to obtain a 3D mesh. 3D models of allograft geometry were then measured using a novel protocol enhanced by computer software. Then, both measurements were compared using statistical tests.ResultsThe results showed significant differences (P < 0.05) between the lengths of the medial and lateral menisci measured in the tissue bank and the XMT Lab. Also, medial meniscal widths were significantly different (P < 0.05).DiscussionDifferences in meniscal lengths may result from difficulties in dissected meniscus measurements in tissue banks, and may be related to the elastic structure of the dissected meniscus. Errors may also be caused by the lack of highlighted landmarks on the meniscal surface in this study.ConclusionThe XMT may be a good technique for assessing meniscal dimensions without actually touching the specimen.Level of evidenceLevel IV.