CORR Insights 1 : Anterolateral Ligament of the Knee Shows Variable Anatomy in Pediatric Specimens

S hea and colleagues are not the first to recently investigate the appearance of the anterior lateral ligament (ALL) [5, 7] on MRI, but they do expand our knowledge on the frequency of its existence in the pediatric population. Although we have known about the ALL for more than a century, its very existence has yet to be universally accepted, and its functional role and mechanical involvement in the Segond fracture has yet to be determined. The existence of a ‘‘pearly white band’’ was described by Segond more than a century ago as a lateral capsular structure associated with a tibial fracture fragment [9]. As a young surgeon, I learned that the fragment only appeared in a small percentage of ACL injuries [10] on special oblique radiographs. Its presence was a strong indicator of a corresponding ACL injury. This was the same era when my own surgical approach was an open ACL reconstruction combined with nonanatomic extracapsular reconstruction [2, 4]. Around that time, Terry and colleagues [11] examined the role of the lateral structures relative to ACL deficient knees, focusing on concomitant lateral femoral tenderness and pathology in the deep layers of the lateral capsular-osseous connection of the iliotibial band to the femur. But rapidly developing expertise with the arthroscope, as well as questions about the value of techniques for extraarticular reconstruction, led us into an era of confining and refining our techniques for intraarticular ACL reconstructions. Consequently, interest regarding the ALL or any extraarticular tissue damage faded. The current CT-based study gets us back to the business of filling in one of the many gaps in our knowledge regarding extraarticular structures. Shea and colleagues found that nine out of 14 specimens studied had ALL. The ALL not only exists by CT, but one can completely identify its course distally on the tibia and proximally on the femur. Van Dyck and colleagues [12] found that 46% of patients with ACL ruptures had ALL pathology demonstrated on MRI and a considerably higher incidence of lateral meniscus tears, collateral ligament, and osseous injuries in the group where the ALL was injured. This adds This CORR Insights is a commentary on the article ‘‘Anterolateral Ligament of the Knee Shows Variable Anatomy in Pediatric Specimens’’ by Shea and colleagues available at: DOI: 10.1007/s11999-0165123-6. The author certifies that neither he, nor any members of his immediate family, have any commercial associations (such as consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research editors and board members are on file with the publication and can be viewed on request. The opinions expressed are those of the writers, and do not reflect the opinion or policy of CORR or The Association of Bone and Joint Surgeons. This CORR Insights comment refers to the article available at DOI: 10.1007/s11999016-5123-6. J. P. Albright MD (&) University of Iowa Sports Medicine, 2701 Prairie Meadow Drive, Iowa City, IA 52242, USA e-mail: John-albright@uiowa.edu CORR Insights Published online: 28 February 2017 The Association of Bone and Joint Surgeons1 2017