An Overview of Glenoid Fractures

The glenoid is the socket part of the ball-and-socket shoulder joint. It's part of the scapula (shoulder blade), which is a thin, broad bone that sits behind the rib cage. The scapula itself is mobile (its orientation shifts on your back with movement), and normal scapular motion is important for normal shoulder function. 

The glenoid is covered by articular cartilage (the smooth lining of joints) and sticks out toward your arm from the outer edge of the scapula. The glenoid socket is almost flat, which makes it quite shallow when compared to the hip joint's socket. 

To make it a little deeper, another type of cartilage called the shoulder labrum surrounds the glenoid. When there's a problem with the labrum, the shoulder is prone to episodes of shoulder instability, such as dislocation. This often occurs when people tear the shoulder labrum.

Types

Fractures of the glenoid are a relatively uncommon type of shoulder fracture, only accounting for about 10%. Glenoid fractures most often occur when there is significant trauma to the shoulder, or as a result of high-energy sports injuries.

The two most common fracture patterns are:

• Glenoid Lip Fractures: Glenoid lip fractures occur when there is a shoulder dislocation or shoulder subluxation, and the ball comes out of the socket. As the ball dislocates, it can push against the rim of the glenoid socket, causing a fragment of the bone to fracture. Treatment of a glenoid rim fracture is focused on restoring the normal contour of the shoulder socket to prevent recurrent instability (repeat dislocations) of the shoulder joint. Surgical treatment is often considered for these injuries, especially when the fracture is out of position or if there is a large fragment of the glenoid bone.
• Glenoid Fossa Fractures: The glenoid fossa is the center portion of the socket. Glenoid fossa fractures are much less common injuries, and often associated with severe trauma. There is little data on the ideal treatment of these injuries because they are so uncommon. However, most surgeons agree that fracture management decisions must take into account both the fracture type and the patient's need. More active patients with fractures that are not in the proper position will most likely benefit from surgery to realign these injuries.

Treatment

Treatment of glenoid fractures can be controversial as there have been very few studies to compare different treatment methods. Because these are uncommon injuries, it is difficult to perform comparison studies as even specialized surgeons may only treat these types of injuries infrequently.

In general, it is agreed that unstable fractures are best treated with surgery whereas stable fractures can be treated conservatively. The goal of surgical treatment is to restore the alignment of the normal joint surface. It is typical to repair the bone with small plates and/or screws to ensure that the bones heal in the proper position.

Rehabilitation after surgery to repair a glenoid fracture is focused on restoring normal mobility and strength to the shoulder joint. Your surgeon may recommend a brief time of immobilization to allow the bones to begin to heal, but as soon as possible will begin range-of-motion exercises. As the healing becomes stronger, you will progress to strengthening exercises of the shoulder.

Risks of surgical treatment include infection, shoulder stiffness, nerve injury, and shoulder arthritis. The reason people may develop arthritis of the joint is because of the trauma to the cartilage surface of the socket. Even if surgery is performed to realign the damaged bone, the injury to the cartilage increases the chance of the development of arthritis, which in turn increases the risk of shoulder replacement surgery later in life.

A Word From Verywell

Glenoid fractures are uncommon shoulder injuries. Most glenoid are smaller injuries associated with more significant traumatic conditions, but there are some circumstances where a glenoid fracture can occur in isolation. Proper treatment is important for avoiding shoulder problems later in life.