The Glenoid Track and How It Can Guide Management

Abstract

The classification and treatment of bone loss in anterior shoulder instability remain as significant challenges to the shoulder surgeon, particularly when bipolar lesions are present. The concept of the glenoid track was developed in order to be able to predict whether engagement of a humeral Hill-Sachs lesion (HSL) would occur in the anterior apprehension position of the shoulder. A rational classification system for HSL as “on-track” (nonengaging) or “off-track” (engaging) flowed out of the biomechanical knowledge of the glenoid track. An “on-track, off-track” treatment paradigm has subsequently been described whereby “off-track” HSL are recommended to be treated by arthroscopic remplissage and Bankart repair to restore shoulder stability and prevent engagement. This article contains a discussion of the history, the biomechanics, and the treatment considerations of Hill-Sachs lesions with a focus on bipolar bone loss as informed by the glenoid track.