What Is the Sulcus Sign?

The sulcus sign is a finding on an orthopedic examination indicating the shoulder joint is unstable. It consists of a depression around the glenohumeral joint, the site where the arm bone joins with the shoulder blade, when the patient’s arm is gently pulled downwards. A care provider may identify this sign during a routine shoulder examination, or could specifically test for it if a patient reports symptoms associated with instability in the shoulder joint. This finding may indicate the need for further diagnostic evaluation and testing to determine which treatments, if any, should be provided.

To check for the sulcus sign, the care provider asks the patient to sit or stand upright, leaving the arm relaxed at the side. Next, gentle downward traction is applied at the elbow while the observer carefully watches the patient’s shoulder. If the joint is unstable, a depression will develop at the shoulder joint, looking like a small divot in the skin. The test can be repeated on the opposite shoulder, which can provide additional information, as both shoulders shouldn’t have the sign.

This joint is one of the most flexible in the body, allowing for a very broad range of motion during a variety of dynamic activities. When the shoulder joint is unstable, it can put patients at risk of injuries and discomfort. Instability may develop as a result of strain or injury. Medical imaging studies and an in-depth physical examination can provide more information about what is happening inside the joint. These evaluations can help a care provider determine which treatments the patient might need.

Patients demonstrating the sulcus sign might need physical therapy and rest to allow the shoulder to rebuild after injury. In some cases, it is an indicator that surgery is necessary to stabilize the joint. Sometimes the care provider may recommend an exploratory surgery to look inside the joint with arthroscopic techniques. This can determine the need for additional treatment and may provide guidance about how to proceed.

A review of radiographs of the knee can reveal another phenomenon also known as the sulcus sign. It refers to a deep notch in the femur that may be apparent when films are taken from the correct angle. Another medical sign known as the deep sulcus sign shares a similar name, but is very different. The deep sulcus sign is a radiological finding in the chest suggestive of pneumothorax, air around the lungs that makes it difficult to breathe.