Variations of the 'Grand Piano' Sign in Total Knee Arthroplasty

摘要

I have read with interest the recently published paper by Moyad and colleagues. I should note, however, that the "grand piano sign" was first described by John N. Insall. It would be fair to clarify this, not only for the sake of informing the readers of your Journal, but also as a tribute to this pioneer of knee replacement surgery.It is also worthwhile mentioning the previous elaborate study on the same topic by Cui and colleagues,3 who have employed computer tomography reconstructions and computer simulation in a larger sample size (n - 50). Their methodology was validated on 5 cadaver femora. Cui and colleagues3 found that the medial to lateral (M:L) ratio was very close to 0.66, or , when the anterior cut was performed parallel to the epicondylar axis. They, however, distinguished between what they termed the clinical and the surgical epicondylar axes, referencing them off of the most prominent point of the medial epicondyle and the deepest point of the sulcus of the medial epicondyle, respectively.