What is supracondylar humerus fracture?
A supracondylar humerus fracture is defined as a fracture of the lower end (distal part) of the humerus just above the elbow joint. This fracture pattern is comparatively less common in adults but is the most frequent sort of elbow fracture in children. A supracondylar humerus fracture is generally more common in children between 5 to 8 years of age by a fall on an outstretched hand.
A Non-dominant side(left) is most commonly affected as compared to the Dominant side (Right side).
Supracondylar humerus fractures are classified in several ways –
- Undisplaced or displaced fracture
- Uncomplicated (without neurological involvement) or Complicated fractures (with neurological involvement)
- Open (The bone is visible because it pokes through the skin). And Closed (The bone is broken but it is not visible and the skin remain intact)
- Supracondylar fractures are divided into two types, depending on the direction of displacement of the distal fragment –
- Extension type Most common (More than 95%) – Distal fragment is displaced posteriorly (proximal fragment is displaced anteriorly).
- Flexion type Less common (Less than 5%) – Distal fragment is displaced anteriorly (proximal fragment is displaced posteriorly).
Generally, Gartland’s classification is widely used for further classification of the Extension type supracondylar fracture.
What is the Gartland Classification of supracondylar humerus fracture?
The Gartland classification of the supracondylar humerus fracture is based on the direction and degree of displacement, and also the existence of the intact cortex. It generally applies to extension type supracondylar fractures rather than (given more importance to one thing when two things are compared) rare flexion supracondylar fractures.
This is because extension type supracondylar fractures are very common (95%) in comparison to the flexion type supracondylar fractures (less than 5%). It predicts the probability of related neurovascular injury, for example, anterior interosseous nerve neurapraxia or brachial artery disturbance.
Displaced having an angulation, but maintain an intact posterior cortex
|The distal fragment is displaced posteriorly, and there is no cortical contact. But they have a periosteal hinge intact either medial periosteal hinge intact or lateral periosteal hinge intact
An intact periosteal hinge allows the orthopedic surgeon to reduce the fracture by reversing the rotational injury.
There are generally two types of Type III supracondylar fractures
III A fractures – Distal fragment is displaced posteromedially but has a medial periosteal hinge intact
III B fractures – Distal fragment is displaced posterolaterally but has a lateral periosteal hinge intact.
Type IV fractures – Have no periosteal hinge intact (complete periosteal disruption). And also they are very unstable both in flexion type as well as in extension type i.e., they’ve multidirectional instability.
Mechanism of injury
The most common mechanism of injury is an Extension type and it occurs due to falling on an outstretched hand. And as the hand strikes the ground, the elbow is forced into hyperextension. The olecranon functions as a fulcrum which focuses the strain on the distal humerus (supracondylar region), predisposing the distal humerus to break.
The supracondylar area undergoes remodeling in age 6 to 7, which makes this region thin and susceptible to fractures. Many important nerves and artery like (Median nerve, Radial nerve, Ulnar nerve, Brachial artery) lie in the supracondylar region. And if in case any of them got injured it can give rise to major complications.
Meanwhile, the flexion-type of supracondylar humerus fracture is not much common. It happens by falling over the tip of the elbow or falling with the arm twisted behind the trunk.
It becomes very crucial to do a neurovascular exam before performing any reduction maneuver. Because by performing a neurovascular exam you will get to know that whether the artery(brachial artery) or nerves(Radial, Ulnar, and Median nerves) got stuck into the fracture site.
Clinical trials like the temperature of the limb extremities (cold or warm), oxygen saturation on the pulse oximeter of the affected limb, capillary refilling time, the presence of the radial and ulnar pulses, and also some other wounds that would signal open fracture.
Doppler ultrasonography should be performed in case of vascular injury if distal or radial pulses are not palpable.
Injury to nerves –
When a neurological involvement is mentioned, it warrants a very careful examination and documentation for example when it first became evident, the degree of involvement and desirable progression/regression of symptoms.
As in the diagram, you can see that the Radial and Median nerve passes anteriorly ie upper to the supracondylar region. While Ulnar nerve passes posteriorly to the medial epicondyle of the humerus.
The radial nerve
is most commonly injured when the distal humerus is displaced posteromedially. This happens because the proximal fracture fragment is displaced anterio-laterally. As you can see in the upper diagram the radial nerve lies anteriorly and laterally to the supracondylar region. So when the proximal fragment is displaced anterio-laterally the radial nerve gets affected.
The ulnar nerve
is most commonly injured in the flexion type of supracondylar fractures because in flexion type supracondylar fractures the proximal fragment is displaced posteriorly. As you can see in the upper diagram the ulnar nerve crosses the elbow posteriorly to the medial epicondyle of the humerus. So when the proximal fragment is displaced posteriorly the ulnar nerve gets affected.
The Anterior Interosseous Nerve Branch (AION) of the median nerve
is most commonly injured from the postero-lateral displacement of the distal humerus since the proximal fragment is displaced anterio-medially. As you can see in the upper diagram that the median nerve passes anteriorly and medially to the supracondylar region. So when the proximal fragment is displaced anterio-medially the median nerve is most commonly get affected.
This can be evidenced by weakness in the hands with a weak “OK” sign on physical examination (unable to perform an “OK” sign; instead the patient may perform a pincer grip).
Injury to the Brachial Artery –
The brachial artery along with the median nerve crosses (anteriorly) to the elbow joint. At first brachial artery lies medial to the humerus, but as it runs down it gradually gets in front of the humerus and then crosses anteriorly to the supracondylar region and the elbow joint and finally bifurcates into the radial and ulnar artery.
It is generally seen that 6 to 20 percent of the supracondylar fractures reported the absence of a radial pulse. This is because the brachial artery is frequently injured in Type II and Type III Gartland fractures especially when the distal fragment is displaced postero-laterally (proximal fragment displaced antero-medially).
A puckered, dimple, or ecchymosis of skin only anterior to the distal humerus is an indication of difficult reduction. Because the proximal fragment may have penetrated the brachialis muscle and maybe the subcutaneous layer too.
The diagnosis is confirmed by x-ray imaging. Generally, Anterior-posterior(AP) and lateral view of the distal humerus (not elbow) are obtained. If there is any pain, injury, deformity, or tenderness in the forearm or wrist. Then separate films of these areas should be ordered.
Radiographs should be obtained just after proper analgesia and splinting of their extremity. Ideally, splintage should be used to immobilize the elbow at 20 to 30 degrees flexion to prevent any neurovascular injury (injury of the blood vessels and nerves) while still performing X-rays.
Splinting of the fracture site with full flexion or extension of the elbow Isn’t recommended as it may stretch the blood vessels and nerves over the fracture site or may lead to the impingement of these structures between fractured fragments.
This view helps us to check out the direction of displacement, the presence of valgus and varus alignment. In this view, you can also assess the Baumann’s angle.
Baumann’s angle –
Baumann’s angle is an angle between a line drawn parallel to the longitudinal axis of the humeral shaft and a line drawn along the lateral epicondyle of the humerus. The normal angle should lie between 70-75 degrees.
However, because of the significant difference between people, Baumann’s angle is
much better evaluated compared to the contralateral side. And also a difference of more than over 5° between both sides is deemed abnormal.
On the lateral view, five radiological parameters should be looked for: Anterior humeral Line, teardrop sign, Fish-tail Sign, Coronoid Line, Fat pad Sign/Sail sign.
Anterior humeral Line –
In a normal elbow, a line is drawn down along the front of the humerus in the lateral view and it should pass through the middle third of the capitulum of the humerus. If it passes through the anterior third of the capitulum or misses the capitulum completely, then it indicates that the supracondylar humerus fracture is displaced posteriorly.
Fat pad Sign/Sail sign-
A non-displaced fracture can be hard to recognize and also a fracture line may not be observable on the X-rays. On the other hand, the existence of a joint effusion is beneficial in identifying a non-displaced fracture. Bleeding from the fracture expands the joint capsule and can be visualized on the lateral view as a darker place anteriorly and posteriorly, and is referred to as the fat pad sign.
Gartland type I (Non-Displaced Fractures)
Undisplaced or minimally displaced fractures are generally treated by immobilization in an above-elbow plaster slab, with the elbow in 90 degrees flexion for 3 weeks. Orthopedic casting and extremes of flexion should be avoided to prevent vascular compromise and compartment syndrome. The plaster slab (backslab) should extend as high above the elbow (close to the axilla) and down to the MCP joints.
Although it becomes very easy to visualize displacement or angulation on the lateral radiograph. But varus mal-alignment is best represented by Baumann’s angle on the AP radiograph. In the case of varus mal-alignment, if the varus mal-alignment at the fracture site is more than 10 degrees when compared to the normal elbow (contralateral side). Then closed reduction and percutaneous pinning should be strongly recommended.
In the case of Displaced fractures –
Before going for the management of Gartland type II, III, and IV fractures first take a look at the basic knowledge about open reduction closed reduction? And what is percutaneous pinning? Does percutaneous pinning used in both open and closed reduction? And In what conditions percutaneous pinning is performed?
It is necessary to get basic knowledge and answers to all the questions because type II, III, IV fractures come in a category of displaced fractures and are generally reduced by closed and open reduction along with percutaneous K wire fixation.
In all the displaced fractures, the patient should be immediately admitted to the hospital within 24 hours after the injury because serious complications can occur within the first 48 hours. The following methods of treatment are used in the case of displaced fractures.
What are closed reduction and percutaneous K-wire fixation-
The close reduction is a process to set (reduce) a broken bone without opening the fracture site surgically. The broken bone is set back into its normal position, allowing it to grow back together. It functions best when it’s performed as soon as possible following the bone fractures.
Mostly displaced fractures are easily reduced by close reduction, but sometimes they often slip. Suppose closed reduction has been performed after performing the reduction, an X-ray has been performed. As seen in the X-ray the reduction got accepted. Now here comes 2 cases –
Case A – After 7 days when the X-ray is performed again, the reduction was maintained.
Case B – After 7 days when the X-ray is performed again, The reduction got slipped. So to fix it your surgeon will go for the open reduction along with percutaneous pinning.
So to avoid slipping, and neurovascular complications, the best way to fix these kinds of fractures is by inserting one or two K-wires (percutaneous pinning) over the medial or lateral side of the elbow under X-ray image intensifier guidance.
There is approximately 1.8 times greater chance of getting nerve damage when inserting both medial and lateral pins when compared to lateral pin insertion alone. But, medial and lateral pins insertions can stabilize the fractures more correctly than inserting the lateral pin alone. Consequently, medial and lateral pins insertion should be done with caution to prevent nerve injuries around the elbow region.
When percutaneous pinning is performed?
Percutaneous pinning is used in both types of reduction either open or closed. Now Let’s discuss in what cases percutaneous pinning is performed –
- To avoid slipping as explained above.
- For providing better stability to the displaced fracture.
- Neurological deficits occur after or during close reduction.
- All Form of type II and III fractures if requiring elbow flexion of more than 90 degrees to maintain the reduction needs to be fixed by percutaneous pinning.
- Generally, all Type IV fractures of the supracondylar humerus are unstable. Therefore either they are reduced by open or closed reduction requires percutaneous pinning.
- In any case, any polytrauma with numerous fractures of the same side requiring surgical intervention is just another sign for percutaneous pinning.
When open reduction and K-wire fixation(percutaneous pinning) is performed?
In some cases like –
- If the displaced fracture gets reduced by close reduction and after performing the reduction, an X-ray is performed. As seen in the X-ray the reduction is unacceptable (closed reduction not able to achieve a good position). Then open reduction along with K wire fixation is performed.
- In case when the reduction is done by close reduction without percutaneous pinning and after performing the close reduction, an X-ray is performed. As seen in the X-ray the reduction got accepted but after 7 days when the X-ray is performed again, Then the reduced fracture got slipped.
- In the cases of open fractures (The bone is visible because it pokes through the skin).
- Significant swelling over the elbow.
- Some vascular deficits.
In such cases, open reduction and K-wire fixation are necessary. This is also used as the first line of treatment in some open fractures and those requiring exploration of the brachial artery for the suspected injury.
Gartland type II
Gartland Type II fractures require closed reduction. Further, they may become stable following closed reduction and casting at 90° of flexion. But when greater than 90° of flexion is needed to maintain the reduction. Then to minimize risks of complications, percutaneous pinning should be performed for the stabilization of the reduction. Reports claim that extremely low levels of complication after closed reduction and percutaneous pinning.
Performing a closed reduction requires experience and it is performed by applying traction along the long axis of the humerus with the elbow in slight flexion.
Gartland type III
Gartland type III fractures are more prone to neurovascular injury. As explained above the closed reduction and percutaneous pinning is the most favored/preferred treatment for the gartland type III displaced fractures. Therefore, management with closed or open reduction with percutaneous pinning within 24 hours has low complication rates when compared to management with closed reduction and casting as they have a higher incidence of residual deformity.
Gartland type IV
Gartland type IV fractures come in the category of highly displaced fractures. They are either stabilized by open or closed reduction with percutaneous pinning.
There are generally 3 types of serious complications that occur after supracondylar fracture of the humerus.
- Immediate – occurring at the time of the supracondylar fractures
- Late – Complications will occur generally after weeks or months after the supracondylar fracture.
1. Injury to brachial artery –
The brachial artery most commonly injured when the distal fragment is displaced postero-laterally (proximal fragment displaced antero-medially). Closed reduction with percutaneous pinning is the first line of treatment. After performing closed reduction here comes two cases.
- Case 1 – If pulse return within 1 hour then there is no need for the surgical exploration of the brachial artery. Then treat it normally by applying a plaster slab.
- Case 2 (a) – if the pulse does not return as well as capillary circulation is poor, then go for the surgical exploration of the vessel (brachial artery) and fix the fracture internally.
- Case 2 (b) – if the pulse does not return but the capillary circulation is good enough, then the patient will be observed and kept under close supervision. If the circulation improves then treat it normally. But if the circulation deteriorates/worsen then go for the surgical exploration of the vessel (brachial artery) and fix the fracture internally.
2. Injury to nerves –
Isolated neurological deficits can reach up to 49% in type III Gartland fractures. Nerve injuries can occur either primarily immediately after trauma or secondarily after treatment. Here let me explain you this by taking 3 cases.
Nerve injuries occuring after trauma – It is recommended to immediately perform CMR (close manipulative reduction) in any case of supracondylar humeral fractures before transferring the patient to the operation room. As by performing CMR, it releases tension on the nerves.
Case 1 – Neuropraxia (temporary neurological deficits due to blockage of the nerves)- In case after performing close reduction along with percutaneous pinning. The fracture got reduced back into there postions as well as the nerves also. Now in case of neurapraxic nerve injuries most of the surgeons chooses ‘wait and see’ method for the nerve recovery. They wait for next 3 to 5 months. And if there comes no sign of recovery then the surgeons will plan for the second surgery (surgical exploration the nerve).
Case 2 – And in case if the fracture got failed to reduce by close manipulative reduction and open reduction is performed. Then it will be a good opportunity for the surgeons to open and explore the fracture as well as the nerve and also to correct both of them.
It is very important to remember that if in case the supracondylar fractures are reduced by open or close reduction along with percutaneous pinning. The surgeons should insert the K wires (percutaneous pinning) very carefully. As it is seen in many cases if the K wires either medial or lateral or both are not inserted properly then they can cause impingement on the nerves.
Case 3 – Nerve injuries occuring after the treatment –
As in many cases it is seen that due to improper insertion of the K wires (percutaneous pinning) can cause impingement on the nerves. In these cases, the patient will complain of pain and neurological deficits after the treatment done with K wire. Then doctors will perform the surgical exploration of the nerve and remove the K wire that was impinging on the nerve. And insert a new wire at a safe distance from the nerve.
1 – Malunion
This is the most common complication in the Supracondylar humerus fracture which is known as Malunion. Because post-fracture the distal humerus grows slowly, therefore there is a very high rate of malunion. Malunion may occur either due to
- Displacement of the fracture within the plaster or
- Failure to achieve a good reduction.
Such malunion can result in a cubitus varus deformity. The cubitus varus is often referred to as Gunstock deformity.
2 – Volkmann’s ischaemic contracture –
Swelling and vascular injury (injury to the brachail artery) following supracondylar fracture can lead to the development of comartment syndrome. So continued serial examination should be done which includes evaluation of the patients pain level, Pain, Distress/agitation response to the medication and splinting.
All these finding should be noted beacause they can be due to the muscle ischemia (descreased blood supply to the nerves and the muscle). As indication to all the findings can lead to the development of compartment syndrome.
In case if the compartment syndrome is not identified or got missed. Then it can lead to the development of Volkmann’s ischaemic contracture.
In this what happens is that the ischemic muscles ie (muscles that are getting diminished blood supply) are gradually replaced by fibrous tissue. Which in turn contracts and draws the wrist and fingers into flexion, fixed flexion of the elbow, pronation of the forearm. Therefore, early surgical reduction is indicated for the prevention of these types of complications. Distress/agitation response to the medication and splinting.
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