There are many ways to describe and classify rotator cuff tears (RCTs). In most cases, the surgeon first determines if the tear is a partial or full-thickness tear. They look to see which side the tear occurs on (bursal or articular).
In other words, is it right next to the bursa or on the side where the tendon attaches to the joint? The bursa is a small fluid-filled sac located at the point where a muscle or tendon slides across bone. The bursa reduces friction between the two moving surfaces.
Using an arthroscopic exam, the surgeon identifies the size, shape, and depth of the tear. A commonly used method to describe location of RCTs is the Patte classification. Tears are classified as stage one (I), two (II), or three (III). In stage I, the tendon is torn close to the place where it inserts into the bone.
Stage II describes a tendon tear close to the level of the humeral head. The humeral head is the round knob at the top of the humerus (upper arm bone) that fits into the shoulder socket.
Stage III is a RCT much closer to the shoulder socket called the glenoid cavity. The glenoid is part of the shoulder blade.
You may have to ask your surgeon to explain a grade two tear based on whatever system he or she is using.