LAUSR

Author response to letter to the editor re: “Non-treatment of stable ramp lesions does not degrade clinical outcomes in the setting of primary ACL reconstruction.” We appreciate the detailed comments by Cerciello et al. regarding our recent article, “Non-treatment of stable ramp lesions does not degrade clinical outcomes in the setting of primary ACL reconstruction” [2]. They express great concern regarding both our method of diagnosis of ramp lesions, as well as our conclusion that stable ramp lesions (lesions which do not displace with probing from the anterior portal) can be safely ignored without worsening clinical results of primary ACL reconstruction. With regards to our method of diagnosis, we agree with Cerciello et al. that MRI has been reported as having highly variable sensitivity and specificity in the literature. They especially emphasize the work of Bollen et al. who found an overall incidence of 9.3% among 183 knees undergoing ACL reconstruction, none of which were visible on MRI [3]. It is worth noting that this paper, published in 2010, provided no information on the MRI sequences and magnet strength employed. The more appropriate comparison is likely the work of Arner et al. published in 2017, which found moderate-to-high (54–99%) sensitivity and high (92–99%) specificity of MRI when compared to intraoperative examination using a posteromedial portal [1]. These examinations were performed with a 1.5 T MRI, whereas we utilized a 3.0 T MRI with high in plane and through plane resolution. Imaging technology advances rapidly, and one should be cautious of drawing particularly strong conclusions from imagingbased studies published over a decade ago. Additionally, the prevalence of ramp lesions using our 3.0 T MRI-based methodology was 41%, which is comparable to the prevalence from series using posteromedial examination [4, 9]. If, as is commonly claimed, up to 48% ramp lesions are missed using conventional techniques [4], then the “true” prevalence in our series was 58%. That would far exceed the published rates from most other major centers. It seems more likely to us that our use of high resolution protocols with higher magnetic field strength improves the sensitivity and specificity for detecting these lesions. However, in the absence of correlating data from posterior knee arthroscopy at the time of surgery, we cannot prove this statement. At this time, our treatment algorithm is to selectively use a posteromedial portal for direct evaluation only if MRI scan and/or initial anterior probing elicit concern requiring further direct evaluation. More importantly however, the central thesis of Cerciello et al.’s argument is that every ramp lesion needs to be identified and repaired. They argue that there is a “dramatic impact on knee biomechanics and risk of ACL re-rupture” with these lesions, even when apparently stable on anterior probing. This presumption of importance, however, is largely based on cadaveric biomechanical studies in which ramp lesions are simulated by transection of the meniscocapsular and/or meniscotibial attachments with subsequent repair [6, 11]. In vitro biomechanical studies are limited by the testing of cadaveric specimens that are typically from Investigation performed at Hospital for Special Surgery, New York, NY.