. Distal humeral fractures. Musculoskeletal Medicine for Medical Students. In: OrthopaedicsOne - The Orthopaedic Knowledge Network. Created Jan 15, 2012 09:36. Last modified Feb 21, 2012 04:26 ver.43. Retrieved 2019-05-20, from https://www.orthopaedicsone.com/x/RoGTB.
Distal humeral fractures can generate complicated clinical scenarios and definitive treatment remains controversial. The complexity of these fractures is due to the close relationship of anatomic structures within the elbow joint. Distal humeral fractures are classified anatomically into the following seven subtypes: supracondylar, transcondylar, intercondylar, condylar, epicondylar, capitellum, and trochlear. Intercondylar fractures being the most common in adults, whereas, supracondylar fractures are the most common in children.
Structure and function
The elbow is a hinge joint comprised of three bones: the humerus, radius, and ulna. Providing stability for the joint are ligaments, muscles, tendons, and the articulatory surface of the bones.
The distal humerus is often discussed anatomically in terms of medial and lateral columns that are connected distally by a “tie arch”. The lateral column includes the lateral condyle, lateral epicondyle, and capitellum. The medial column includes the medial condyle and medial epicondyle. They are both joined together distally by the “tie arch” which is composed of the trochlea and capitellum, as seen in the image below.
A figure like the one in 17.1
The majority of the blood supply to the elbow is supplied via the brachial artery which descends along the anterior aspect of the humerus before reaching the elbow. Proximal to the elbow, smaller arteries branch off the brachial artery and anastomose with either the radial artery or ulnar artery distal to the elbow. This is clinically significant in the situation that blood flow through the brachial artery is interrupted, as collateral circulation is often sufficient enough to avoid serious complications due to ischemia.
The median nerve descends anteriorly alongside the brachial artery before reaching the elbow. Distal to the elbow, the median nerve gives off the anterior interosseous nerve which can become compressed following a distal humeral fracture leading to weakness of the pronator quadratus, flexor pollicis longus, and the lateral half of the flexor digitorum profundus. The radial nerve descends within the posterior compartment of the arm and wraps around the humerus to enter the elbow at the anterolateral aspect. The ulnar nerve runs along the posteromedial aspect of the elbow and is most often injured due to surgical approaches from the medial side of the elbow.
Distal humeral fractures occur in a bimodal distribution with the majority occurring in young males between the ages of 5 and 10. The second most prevalent population are the elderly with osteoporosis. Distal humeral fractures comprise approximately 2% of all fractures in the adult population and roughly 17% in the pediatric population.
Most fractures of the distal humerus are due to a fall (low-energy), direct blow to the posterior aspect of the elbow (high-energy), or a motor vehicle accident (high-energy). Low-energy injuries are more common in the elderly with osteoporosis following a fall onto an outstretched hand. These patients classically present with considerable pain and swelling which can make it difficult to appreciate notable landmarks.
The pediatric population are more likely to sustain a high-energy injury resulting from trauma. High-energy fractures are likely to present with gross deformity along with pain and swelling. A careful neurovascular exam is important, making sure to pay special attention to the median nerve, radial nerve, ulnar nerve, and capillary refill.
Must exclude open fractures when blood is present on the skin
Volkmann’s ischemia. A rare complication that most often occurs following extension-type supracondylar humeral fractures. Signs of pain, compartment tightness, paleness of skin, and a progressive decrease in motor function are preemptive symptoms of Volkmann’s ischemia. A prolonged decrease in blood flow results in a contracture deformity of the joints distal to the elbow due to stiffening and shortening of the forearm muscles.
Elbow dislocations are frequently due to falling onto an outstretched hand and patients generally present with obvious deformity, guarding, or instability surrounding the joint. A high level of suspicion must be present to make the diagnosis as conclusive evidence is often unavailable.
An olecranon fracture should be suspected in all patients who have sustained a direct high-energy force to the posterior aspect of the elbow or those who cannot actively extend the elbow against gravity.
Radial head fractures most often occur following a fall onto an outstretched hand causing the radial head to collide with the capitellum. Ligamentous injury is more common than capitellum fracture.
Anterior, lateral, and oblique radiographs of the entire humerus, including the glenohumeral joint and elbow, should be obtained. Depending on the clinical symptoms, imaging of the forearm, wrist, and/or hand may be needed to rule out additional fractures along the extremity.
The anteroposterior (A/P) view should be carefully examined for evidence of a vertical fracture line between the medial and lateral columns. The lateral view is important to assess for the presence of a "fat pad sign" (Fig. 1). An anterior or posterior fat pad sign is indicative of intra-articular hemarthrosis or effusion which is highly suggestive of an occult elbow fracture.
If comminution is present at the articular surface, a CT scan (Fig. 2) should be performed utilizing 3D reconstruction to ensure proper treatment decision-making.
Figure 1. Lateral x-ray of fat pad sign
A figure like this one
Figure 2. 3D CT scan of a distal humerus fracture
Risk factors and prevention
Individuals with an increased risk of falling such as the elderly and persons with alcohol intoxication, neuromuscular disease, and/or vision problems. Sports and motor vehicle accidents are a common cause among children.
The goal of treatment is to restore anatomic joint alignment and congruence of articular surface.
Although current research clearly indicates that operative treatment is preferred in most cases, nonoperative management is recommended for patients with nondisplaced fractures, advanced dementia, elderly with limited functional mobility, or those unable to undergo anesthesia. Nonoperative treatment should begin once initial swelling decreases and includes a posterior long arm splint for approximately 6 weeks. Range of motion exercises should begin two weeks after the splint is applied to avoid stiffness.
Operative treatment is reserved for the majority of distal humeral fractures including displaced fracture, vascular injury, and open fractures. Open reduction and internal plate fixation is most often the procedure of choice because it gives the patient the opportunity to begin active and passive ROM exercises as soon as tolerated. The procedure involves plating the medial and lateral columns while utilizing screws for fixation.
External fixation can be used in open fractures with significant soft tissue damage.
Recent studies have suggested good to excellent outcomes along with mild to moderate long term impairment. A study consisting of twenty-five patients with an average follow-up of thirty-seven months found that flexion strength was reduced by 26% and extension strength was reduced by 24% compared to the uninjured arm. Twenty-five percent of patients report exertional pain on long-term follow-up.
Stiffness: the most common complication. Early active ROM and physical therapy have been shown to reduce the incidence of stiffness.
Nonunion: arises when stable fixation has not been achieved and occur in 2-7% of patients treated surgically.
Heterotopic ossification: defined by the presence of bone in the surrounding soft tissue. It has been reported in 3% of distal humerus fractures. Indomethacin prophylaxis is indicated in patients with accompanying central nervous system injury.
Cubitus varus deformity: occurs in the pediatric population due to malreduction or loss of reduction following supracondylar fractures of the humerus.
Posttraumatic arthritis: presents following intraarticular trauma or inadequate reduction of the articular surface.
Anterior Interosseous Syndrome: can occur following hemorrhaging into the deep compartment of the forearm, resulting in nerve compression due to compartment syndrome
Ulnar nerve damage: occurs from iatrogenic causes, especially in children during insertion of a Kirschner wire through the medial column.
Exercise along with adequate intake of vitamin D and calcium can reduce the risk of developing osteoporosis and subsequently, broken bones.
The majority of research regarding treatment of distal humeral fractures is level III or IV studies. As a result, there remains uncertainty regarding the best approach to managing complex and complicated cases. More level I and II research is needed in the future to help guide decision-making.
humerus fracture; elbow fracture; supracondylar fracture; intercondylar fracture; volkmann’s contracture; compartment syndrome
Accurately assess radiographs and describe fracture patterns and classification; recognize early signs of compartment syndrome and Volkmann’s ischemia; apply a posterior long arm splint; assess and accurately distinguish between median, ulnar, and radial neuropathies