What is Glenoid Fractures?
The glenohumeral joint, commonly known as the shoulder joint, is rather complex and naturally unstable. The part of the upper arm bone (the humeral head) heavily depends on ligaments and muscles (the rotator cuff) to stay stable. This humeral head fits into the glenoid fossa, a shallow dish-like section on the outward-facing part of the shoulder blade (or scapula). This makes up the socket part of the shoulder joint where it connects with the humeral head.
If the glenoid gets fractured, it is often in conjunction with shoulder instability. However, this fracture can also occur less commonly from direct force to the glenoid. Glenoid fractures are typically related to other injuries and usually happen due to blunt trauma or high-impact sports injuries when the humeral head forcefully hits against the glenoid.
There are many ways to categorize glenoid fractures, which can be based on how the fracture happened, where it’s located, and the specific fracture pattern after the injury. Injuries to the glenoid can vary significantly in their severity. The outcomes for patients also vary; milder injuries can often heal well and lead to full recovery without surgery, while more complex injuries can lead to difficulties even with the best available treatment.
What Causes Glenoid Fractures?
Scapular fractures, which include breaks in the glenoid fossa (a part of the shoulder blade), usually happen due to high-impact, blunt force trauma, and are often accompanied by other injuries. A common way the glenoid fossa can get fractured is if a strong blunt force causes the top of the upper arm bone (humerus) to strike the glenoid cavity (a socket in the shoulder blade). These fractures usually go across in the direction the force came from.
Other injuries, such as those to the glenoid rim (edge) or where the glenoid gets ripped off (avulsion), often happen along with a shoulder popping out of joint (anterior shoulder dislocation). These injuries don’t always come from super high-impact instances; they can also happen in sports injuries, minor trauma instances, or from falls, especially in older people who might also injure their rotator cuff (a group of muscles and tendons in the shoulder) at the same time.
Rim fractures and avulsion regions can also occur due to a lot of pressure put onto the capsulo-labral-ligament complex (a group of tissues in the shoulder joint) from indirect force or from being forcefully pulled apart and twisted.
Risk Factors and Frequency for Glenoid Fractures
A scapular fracture, or a break in the shoulder blade, is uncommon. It represents less than 1% of all fractures and only about 3 to 5% of injuries to the shoulder area. These fractures often happen due to severe accidents or falls, mostly affect men, and the average age of people who get them is 35.
- Glenoid fractures, which are specific injuries to a part of the shoulder blade, make up 10 to 20% of scapular fractures.
- These fractures have a wider range of occurrence but most often affect people aged between 40 and 50.
- Glenoid fractures commonly include anterior avulsion fractures and rim fractures.
- These types of fractures are often seen in sports-related injuries, mainly affecting younger men.
- Only around 1% of scapular fractures are intraarticular, meaning they occur within the joint itself, and are also primarily linked with high impact trauma.
Signs and Symptoms of Glenoid Fractures
To determine the type of shoulder injury a person has, it is crucial to know how the injury occurred. This information can help to figure out if the injury is to the glenoid fossa or involves glenoid rim and avulsion fractures. During a physical exam, the healthcare provider will check the arm bone, collarbone, shoulder blade, and shoulder joint. The doctor will evaluate whether the patient can move their arm on their own and if they can move it when someone else applies force. Additionally, the provider will test the patient’s strength and verify that blood is circulating properly to the area and that nerves are functioning as they should be.
Patients with an injury to the scapula, or shoulder blade, often have bruises and feel pain when the shoulder is touched. They might also have limited movement in the shoulder, particularly when trying to rotate the arm or lift it out to the side, and may experience tenderness in the collarbone. Bruising has been found to have a strong link to fractures of the glenoid, which is the part of the shoulder blade that forms the socket for the arm.
Testing for Glenoid Fractures
Doctors can diagnose scapular fractures, or broken shoulder blades, using simple X-rays. The best view of the shoulder socket, known as the glenoid fossa, can be seen in an anteroposterior (scapular plane) and axillary view. Regular chest X-rays are usually taken to check for chest injuries. However, studies have indicated that doctors might sometimes miss shoulder blade fractures on these images.
Other types of injuries, like broken ribs, collarbones, lung bruising or a collapsed lung, can make the fracture hard to spot and distract from the actual injury. That is why the use of Computerized Tomography (CT) scans is often required. Even when an X-ray shows the fracture, a CT scan can give a more detailed view of the size and exact impact on the shoulder socket.
Treatment Options for Glenoid Fractures
There is some debate about the best way to manage a glenoid fracture, which is a break in the part of the shoulder blade that forms the socket for the shoulder joint. The treatment will depend on whether the shoulder is stable or unstable, how much the bone has shifted out of place, how big the break is and how big the gap between the broken bones is.
Most of these fractures are small and don’t shift much, so they can be treated without surgery. In the past, it was thought that all glenoid fractures needed to be treated surgically, but now surgery is only suggested for about 10% of cases. Specifically, fractures towards the front of the socket might need surgery.
If the fracture is an avulsion type, where a small piece of bone has been pulled away, and the break is less than 5mm and the shoulder is still stable, then conservative treatment with immobilization can be used. Similarly, rim fractures, involving the edge of the glenoid, with a shift less than 5mm and where less than 21% of the front or less than 33% of the back of the rim is affected, can also be treated with immobilization.
However, if the depression in the glenoid where the top of the arm bone fits (the fossa) is involved in the fracture and the arm bone doesn’t sit properly in the socket, surgery may be needed. Advances in arthroscopic surgery, which uses small instruments and a camera inserted through tiny incisions, have improved the treatment of anterior glenoid rim fractures, reducing complications and the need for subsequent surgeries. Surgeons often combine this technique with inserting screws through the skin to fix the fracture. This method has now replaced another surgical approach, called the Judet method, for fractures in the front part of the rim.
However, open surgery, where larger incisions are made, is still needed for some fractures. For fractures at the back and lower part of the glenoid, which make up about 80% of those requiring open surgery, the back approach is chosen. For fractures in the superior fossa, at the top of the glenoid, the front or deltopectoral approach is used.
What else can Glenoid Fractures be?
When a doctor is trying to identify an injury in the shoulder area, they might consider a few different conditions. These include:
- Broken collarbone (clavicular fracture)
- Broken rib (rib fracture)
- Broken shoulder blade (scapular body fracture)
- Broken process of the shoulder blade (scapular process fracture)
- Dislocated shoulder (dislocation)
- Sprained or torn ligaments in the shoulder (shoulder separation)
- Damage to the muscles in the shoulder (rotator cuff injury)
It’s crucial for the doctor to consider all these possibilities and conduct the necessary tests to make a correct diagnosis.
What to expect with Glenoid Fractures
The results are often satisfactory with both conservative (non-surgical) and surgical treatment. However, the presence of other medical conditions or injuries can have an impact on the results. There isn’t a lot of research about the long-term function and progress of these patients, and some evidence suggests that not all patients recover completely.
Some research indicates that patients who receive non-surgical treatment may continue to experience pain and movement difficulties. It’s also been found that habits such as smoking or alcohol misuse can directly affect and slow down the healing process in patients who’ve suffered a fracture of the scapula (shoulder blade).
Possible Complications When Diagnosed with Glenoid Fractures
Fractures at the front part of the glenoid rim (the socket part of the shoulder joint) can cause problems like recurrent dislocations, improper healing, continuous pain, and early start of osteoarthritis. If you don’t get treatment, these fractures can shift and result in chronic pain and disability, including early start of a different kind of osteoarthritis in the shoulder joint and continuous shoulder dislocation.
Other health conditions, concurrent injuries, as well as tobacco and alcohol use can often worsen the situation, leading to less favorable outcomes.
Recovery from Glenoid Fractures
People with either firmly fixed or slightly displaced bone fractures usually start doing gentle movement exercises a few days post surgery. It’s suggested to regularly check the healing of their fractures through X-rays for several weeks to make sure there’s no displacement and that everything is healing correctly. Surgery involving a scope and rigid fixation generally limits movement the least, whereas surgeries involving the front and back of the joint limit movement in abduction (moving the arm away from the body’s midline) and rotation more. In these cases, a brace is often recommended to restrict extreme or harmful movements and manage joint instability. Returning to normal functioning after such a procedure can sometimes take up to a whole year.
Preventing Glenoid Fractures
People should be aware that if they’ve experienced a traumatic shoulder dislocation accompanied by loss of bone in the glenoid (the part of the shoulder blade that forms the socket of the shoulder joint), they might have ongoing, repeated instability in the shoulder. Generally speaking, young individuals who participate in competitive sports activities such as football are at the greatest risk of experiencing repeated shoulder dislocations.
Moreover, loss of bone in the glenoid, when paired with an unstable shoulder, reduces the likelihood of fully recovering and being able to return to sports, even after suitable surgery and subsequent rehabilitation. Therefore, it’s crucial to have a realistic understanding and setting appropriate expectations for these medical situations, for both the patient and their families.
