Which modality is most accurate in sizing meniscal allografts for transplant - A systematic review

Meniscal allograft transplantation (MAT) is a surgical intervention for patients which is indicated in patients with painful meniscus deficiency. Accurate sizing of the meniscal allograft is paramount for normalising compartmental pressures and reducing graft extrusion. In this systematic review we explore and compare the evidence for different imaging methods for meniscal sizing.

A systematic search of electronic databases identified 14 relevant studies and 1 report that matched the specified inclusion criteria. This search focused on comparisons of imaging methods, quantitative data on meniscal dimensions, and reports on accuracy rather than clinical outcomes.

When considered together, radiographic measurements show a wide range of concordance with true measurements due to differences in acquisition and positioning whereas MRI measurements are relatively uniform. The comparisons between Yoon and Pollard radiographic methods for lateral meniscal length support the Yoon method although data is scarce. Studies generally agree that the menisci are symmetrical within 10 % although when compounded with other measurement errors this may become significant.

The trend is that MRI demonstrates more uniform accuracy over radiographic methods although when acquired correctly, the modified Pollard and Yoon methods are able to attain comparable accuracy. In the future, ideally 3D modelling is potentially the most promising method of graft to recipient matching.