Stener-Like Lesions of the Superficial Medial Collateral Ligament of the Knee: MRI Features.

To listen to the podcast associated with this article, please select one of the following: iTunes or Google Play. The purpose of this article is to describe Stener-like lesions of the superficial medial collateral ligament (sMCL) of the knee, which, to our knowledge, have not yet been reported in the radiologic literature. This lesion, defined as a distal tear with interposition of osseous or soft-tissue structures between the ligament and its tibial attachment, often requires surgical intervention. Knee MRI examinations of grade 3 sMCL tears were identified via a search of department imaging and orthopedic case files of medial collateral ligament (MCL) tears for the period of January 2010-April 2017 using the keywords "complete MCL tear" or "near complete MCL tear." Two musculoskeletal radiologists reviewed the MRI examinations. The location of the sMCL tear, presence of a Stener-like lesion, associated ligamentous injuries, and surgical findings were recorded. Review of 65 knee MRI examinations identified 20 cases of distal tibial grade 3 sMCL tear. Of the distal tears, 12 (60%) were Stener-like lesions and six (30%) were borderline lesions. Of these 18 cases, 14 (78%) were associated with multiligament knee injury and nine (50%) underwent MCL repair or reconstruction. Ten of the 12 (83%) Stener-like lesions were displaced superficial to the pes anserinus and two (17%) were entrapped, one in a reverse Segond fracture and one in the femorotibial compartment. Stener-like lesions represent a high percentage of tibia-sided sMCL avulsions, are found most often with pes anserinus interposition, and are frequently associated with multiligamentous injury, suggesting high-energy trauma. MRI diagnosis is important because interposition preventing anatomic healing and potential secondary valgus instability often prompt surgical intervention.