What is Anterior Elbow Dislocation?
The elbow is a joint that often gets dislocated, especially in children. But a specific type of dislocation called ‘anterior elbow dislocation’ is quite rare in both children and adults. In simple terms, the elbow is a joint that connects the lower part of the upper arm bone with the upper parts of the two bones in the forearm. When we talk about elbow dislocations, we usually refer to the position of the upper bone of the forearm compared to the arm bone. So, an anterior dislocation means that the top of the forearm bone has been pushed in front of the lower part of the upper arm bone. This could also occur with the other bone in the forearm. It typically happens when someone falls on a bent elbow, pushing the upper forearm bone forward.
Dislocations of the elbow can be grouped into two main categories: simple and complex. A simple dislocation is when only the tissues around the joint or its capsule are injured. A complex dislocation, on the other hand, also involves a bone breakage around the elbow. Anterior elbow dislocations are often complex because they are usually associated with bone fractures. The initial treatment for elbow dislocations involves repositioning and stabilizing the dislocated joint. If the condition keeps happening, or if there is a bone fracture, or a problem with the nerves or blood vessels, then surgery is generally required to fix it.
What Causes Anterior Elbow Dislocation?
If you fall onto an outstretched arm, pushing the upper part of your forearm bone (ulna) from the front, this can result in a dislocated elbow, where the joint pops out of position.
To understand this injury, it helps to know a little about the elbow itself. This joint involves three bones: humerus (upper arm), ulna and radius (lower arm). The lower part of the humerus, which looks a bit like a flare on either side, connects with the top of the ulna and the top of the radius.
The elbow has a bony bump at the back called the olecranon, located at the upper end of the ulna. This links with the lower end of the humerus. The front part of the upper ulna, where the muscle and a ligament attach, is called the coronoid process. The ulna also connects with the radius at a notch.
Surrounding the elbow are soft tissues that help to keep the joint stable. There’s a circular ligament that goes around the top of the radius and links to the joint’s protective covering (capsule). This capsule also attaches to the front of the coronoid and the back of the olecranon, helping to keep the elbow stable when it’s straightened. Other ligaments help reinforce the elbow’s stability from side to side.
The nerve and blood vessels that cross the elbow can be damaged when the elbow dislocates. The main artery (brachial) crosses the elbow joint at the front before splitting into two (radial and ulnar) further down the arm. The nerves for feeling and movement (median, radial and ulnar) also cross the elbow joint in specific locations and could be prone to injury.
Most often, the elbow dislocates as a result of forceful pushing to the back of the bent elbow, causing it to stretch beyond its normal limit. This might fracture the olecranon, as the force applied to the bent elbow pushes it forward, leaving the broken olecranon piece behind.
Risk Factors and Frequency for Anterior Elbow Dislocation
Anterior elbow dislocation is an uncommon type of injury and only accounts for around 0-2.6% of all elbow dislocations. It takes a high amount of force and a certain elbow position to cause this injury, making it quite rare.
Signs and Symptoms of Anterior Elbow Dislocation
Anterior elbow dislocations, like all types of elbow dislocations, are caused by a traumatic event. Most commonly, this occurs when someone falls onto an outstretched arm or experiences a severe injury to the arm, such as in a car accident. This usually results in intense pain and inability to move the affected elbow. Depending on the individual’s body and the specifics of the dislocation, there may be a visible deformity in the affected elbow.
When discussing the injury with the patient, it’s essential to establish whether they have previously dislocated the elbow or suffered any injury to it. It’s important to inquire about any new symptoms such as numbness, tingling, or weakness, as these could indicate damage to nerves or blood vessels. This kind of damage can influence the urgency of treatment required. Similarly, it’s crucial to evaluate whether the patient experienced any head trauma, loss of consciousness, or pain in other areas, as these factors can determine the subsequent medical investigations required. Finally, getting complete information about the patient’s medical history, any congenital deformities, and current medications is necessary to understand their diagnosis and the best course of treatment.
Testing for Anterior Elbow Dislocation
The first thing doctors should do when evaluating a patient is visually inspect the patient and conduct a physical exam. They should look and feel for other injuries on bones and joints. When they examine the injured area, they should check for signs like open fractures, swelling, changes in skin, and any changes in blood circulation or nerves. They should feel along the injured part to check if all compartments (areas) are soft enough to be pressed. If a compartment is too tightly filled and can’t be pressed, it might indicate a serious condition called compartment syndrome, which requires immediate surgery. In cases of compartment syndrome, the nerves and blood supply of the patient are usually affected. The blood circulation can be assessed by looking at the color of the part, feeling its temperature, checking if the wrist pulses can be felt, and seeing how quickly the blood returns to the fingers after being pressed. The nerves can be checked by testing the sensation along the entire length of the part and asking patients to perform certain actions to check their movement ability. Conditions like compartment syndrome, open fractures or problems in nerves or blood circulation call for urgent evaluation by a bone specialist.
The elbow dislocation usually affects the median and ulnar nerves most commonly. The sensation of the median nerve can be checked by lightly touching the thumb and index finger’s inner side. The movement function of this nerve is checked by examining the strength of thumb pressing against the other fingers. The sensation in the ulnar nerve is checked by lightly touching the inner side of the fourth and fifth fingers. The ulnar nerve’s ability to move can be checked by testing the strength of fingers spreading out and closing in.
After the physical examination, doctors should take pictures of the inside of the affected area using X-rays. The injured part should be x-rayed from the front-back, side, and a slanted angle. It is also important to get a front-back and side x-ray of the forearm, wrist, and shoulder to check for any other injuries.
Treatment Options for Anterior Elbow Dislocation
The first step in managing a dislocated elbow is called closed reduction. This is designed to bring the dislodged bones back into place, ease pain and swelling, and take pressure off soft tissues and blood vessels. The procedure for reducing an anterior (forward-facing) elbow dislocation differs a bit from regular elbow reductions.
Usually, the patient will need an intravenous sedative to relax the muscles, allowing proper adjustment for the reduction. Once settled, gentle pulling should be applied to the arm. Ideally, two healthcare providers will do this – one pulling the forearm, and the other pulling on the upper arm bone (humerus). For a forward-facing dislocation, they’ll bend the elbow while pulling and applying a downward force on the top part of the forearm.
After the procedure, they’ll check the elbow’s stability by moving it around and applying pressure from side to side. An unstable elbow after reduction may need surgery more than a stable one. The healthcare professional will also recheck the blood flow and nerve responses in the arm after the procedure. They will then put a splint on the back of your arm, with your elbow bent at a right angle, and take another x-ray to check that everything is back in alignment.
The patient will keep the splint on and have a check-up 5-10 days after the procedure. At this appointment, the doctor will check the elbow’s stability and nerve function. If the elbow is unstable or the x-ray reveals a fracture, the patient will need surgery. But if the elbow is stable, the doctor will likely recommend starting gentle movements to prevent stiffness. Elbows can stiffen up if they’re kept still for over three weeks. After about three weeks of immobilization, it can become tricky for the patient to regain full movement in their elbow.
What else can Anterior Elbow Dislocation be?
If someone comes to a doctor with a painful elbow, especially after an accident or injury, it could be a forward dislocation of the elbow. This kind of dislocation can be seen and confirmed through X-rays. But elbow pain could also be a sign of other injuries. These might include breaks or fractures in the bones of the upper arm or forearm, or damage to the ligaments around the elbow. So, when examining a patient, doctors need to consider a variety of possible explanations for the pain. They will use the patient’s medical history, a physical examination, and imaging tests like X-rays to make the correct diagnosis.
What to expect with Anterior Elbow Dislocation
The most usual long-term issue after an elbow dislocation at the front (anterior) is the inability to fully extend the elbow. Patients with a straightforward front elbow dislocation usually regain full movement after recovering. However, those with more serious injuries needing more than three weeks of inactivity, like complex front elbow dislocations or those involving nerve or blood vessel damage, often have trouble fully extending their elbow. It’s not rare for patients to lose up to 10 to 15 degrees of elbow extension after such a dislocation.
Possible Complications When Diagnosed with Anterior Elbow Dislocation
The complications that might happen with anterior elbow dislocations are the same as those with general elbow dislocations. The most common problem after an elbow dislocation is stiffness and a limited range of movement, especially the inability to completely straighten the elbow. This typically happens if the elbow was immobilized for a long time, typically more than three weeks. Physical therapy that focuses on improving the range of motion can help this issue.
After an elbow dislocation, another issue that might happen is a persistent instability of the elbow. Varus instability is the most common type, and it happens when the lateral collateral ligament isn’t working properly. This issue can often be treated by holding the elbow in a certain position using a splint, but sometimes it might need surgical repair.
Injury to the nerves and blood vessels can also be a complication of anterior elbow dislocation. The three parts of the elbow most commonly injured are the ulnar nerve, median nerve, and the brachial artery. The most common nerve injury is to the ulnar nerve, because it gets stretched during the dislocation, with the median nerve being the second most common. These nerve injuries are usually observed and typically get better over time. If the median nerve gets entrapped because of a fracture, surgery might be needed. Lastly, injury to the brachial artery is rare but can happen with severe, open fracture-dislocations. If the pulse doesn’t return after the elbow is put back in place, more tests and possibly surgery might be needed.
Common complications include:
- Stiffness and limited range of movement
- Persistent elbow instability
- Injury to the ulnar and median nerves
- Injury to the brachial artery
Preventing Anterior Elbow Dislocation
It’s important for patients to understand that stiffness in the elbow is a common occurrence after experiencing an elbow dislocation. They are encouraged to start working towards regaining their full elbow movement as soon as possible. The elbow’s normal range of motion spans from zero to one hundred fifty degrees, while a functional range that allows for daily activities covers thirty to one hundred thirty degrees. If a patient experiences stiffness after an injury, they should aim to recover at least the functional range of motion. This way, they can continue doing their day-to-day tasks independently.
