Meniscus matching: Evaluation of direct anatomical, indirect radiographic, and photographic methods in 10 cadaver knees

SummaryIntroductionWhen performing meniscus transplantation, allograft size must be carefully matched to the host knee anatomy. The radiographic method devised by Pollard et al. is the current reference standard for meniscus size matching. The primary objective of this study was to compare the accuracy of radiographic measurement according to Pollard, direct anatomic measurement, and photographic measurement.HypothesisAnatomic and photographic allograft size measurement is as reliable as radiographic host-knee sizing according to Pollard et al.Materials and methodsThree methods for measuring meniscal width and length based on reliable landmarks were assessed in 10 cadaver knees: direct measurement of anatomic specimens, measurement of photographs, and the radiographic method described by Pollard et al.ResultsNo significant differences were found between the anatomic and radiographic methods, whereas the anatomic and photographic methods produced significantly different results. Compared to the anatomic method, mean overall measurement error was 7.9% for the radiographic method and 24.1% for the photographic method.DiscussionThe photographic method used in everyday practice during allograft harvesting is not reliable. Correcting for magnification bias might improve the performance of the photographic method. The radiographic method described by Pollard et al. is acceptable, with a margin of error of about 10%, which is considered tolerable. In practice, however, the radiographic method is burdensome to use.ConclusionThe best measurement method is direct measurement of the specimen during allograft harvesting.Level of evidenceLevel IV.