Pollard Method: Images are used to size potential patients for grafts using conversion factors. “Allograft and synthetic meniscal replacement have the potential to thwart the inevitable degenerative processes that occur in the menisctomized knee. Meniscal implants must, however, be size and side specific. This investigation demonstrated that meniscal size can reliably be determined from standard AP and lateral knee radiographs.The coronal width of the medial and lateral menisci roughly equaled the distance from the respective tibial eminence to the periphery of the tibial compartment on AP films. TheSagittal length of the medial meniscus is 80%, and the lateral meniscus 70% of the anterior-to-posterior tibial plateau dimension measured from lateral radiographs.Correcting for magnification with a calibrated measuring device, meniscal sizing by these parameters can be determined within 8.4%, or 3.8 mm of error."1
Yoon Method (Modified Pollard): “The measurements under strict radiographic protocol, as in our study, reproduced the relation between the anatomic and radiographic measurements of tibial plateau according to their protocol, which resulted in the following equation anatomic length = 0.523 plateau length (according to the Pollard method) 15.2—and not as they suggested (anatomic length = 0.73 plateau length). When based on the conventional Pollard method, the accuracy was 40%. In contrast, when the modifiedPollard method was used (anatomic length = 0.523 Pollard’s plateau length 15.2), the accuracy increased to 92%.”2
1. Matthew E. Pollard, Qian Kang, M.D., and Eugene E Berg, M.D. “Radiographic Sizing for Meniscal Transplantation”, Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 11, No 6 (December), 1995: pp. 684-687.
2. Yoon JR, Kim TS, Lim HC, Lim HT et al. “Is Radiographic Measurement of Bony Landmarks Reliable for Lateral Meniscus Sizing?” Am J Sports Med. 2011; 39(3):582-590.
Download a .pdf outlining the differences between the Pollard Method and the Yoon Method below: