History and Physical Examination
Medial condyle fracture
The patient usually presents with a recent history of a significant fall on an outstretched hand or directly on the apex of the flexed elbow. The elbow may be severely painful after this injury. Swelling, [26] deformity, and loss of function of the elbow may be present. Palpable crepitus may be present over the medial condyle. Elbow motion may be decreased as a consequence of swelling and pain. The patient often holds the elbow fixed at approximately 90° of flexion. The patient may present with medial dislocation of the forearm, referred to as a fracture dislocation.
Distal neurovascular changes may occur, especially in the ulnar nerve distribution. Other injuries may be present that are easier to detect, such as elbow dislocation or fracture of the radial head or olecranon, which may distract the physician from making the diagnosis of medial condyle fracture. A high index of suspicion for this type of injury concurrent with other elbow injuries can ensure timely diagnosis and treatment. [2, 3, 4, 6, 7, 8, 9, 10, 12, 19]
Medial epicondyle fracture
The presentation of a patient with a medial epicondyle fracture does not differ significantly from that of a patient with a medial condyle fracture, as described above. A through physical examination should include a valgus stress test to assess for instability of the anterior oblique band of the ulnar collateral ligament (UCL; see the image below). The test is performed with the patient supine and the arm abducted 90º. The shoulder and arm are externally rotated 90º, with the elbow flexed at least 15º to unlock the olecranon. Valgus stress is then placed through the elbow to assess for ligamentous instability. [20, 21]
Classification
Medial condyle fracture
Fracture of the medial condyle of the humerus is a rare injury. Isolated case reports appear in the literature. Although the medial condyle fracture has been described in the literature since the early 1800s, some controversy exists as to whether these were descriptions of true medial condyle fractures or whether they were really descriptions of the more common medial epicondyle fractures. Studies have reported greater numbers of medial condyle fractures in the literature; however, the overall incidence of these fractures remains quite low. Of all elbow fractures in children, medial condyle fractures are reported to account for fewer than 1%. [2, 3, 4, 5, 6, 7, 8, 9, 10, 19, 27]
In 1964, Milch proposed the first classification system for unicondylar humerus fractures. [28] The Milch system is based on the location of the fracture line in the distal humeral epiphysis. Milch first described an avulsion fracture due to a transverse valgus force. He then described a classification system for two types of fracture caused by longitudinal forces (see the image below).
A Milch type I fracture splits the trochlear groove, leaving the lateral trochlear ridge intact. A Milch type II fracture splits the capitotrochlear sulcus in such a way that the lateral trochlear ridge is part of the fracture fragment (see image below for a depiction of the two types). A type II fracture is inherently unstable and is called a fracture dislocation. [5] The avulsion and type I fractures can be treated open or closed; however, more complex type II fractures should be treated only with open reduction and internal fixation (ORIF). [8]
In 1965, Kilfoyle combined his own experience with that of five colleagues to collect a total of 11 examples of medial condyle fracture and separated them into three types of injury (see the image below). [29]
A Kilfoyle type I injury involves a greenstick fracture or crush of the medial condyle metaphysis down to, but not including, the physis; Kilfoyle also stated that these may actually be incomplete supracondyle or intracondyle fractures. A type II injury involves a fracture through the physeal plate and epiphysis without displacement or rotation. Type III is similar to type II but with moderate-to-severe displacement and rotation of the fracture fragment.
Medial epicondyle fracture
In 1818, Granger reported the first unequivocal description of a medial epicondyle fracture. Granger described a fracture that resolved rapidly and left little functional deficit. In the early 1900s, several authors recognized that the fracture was often associated with elbow dislocation and that the avulsed fragment could become entrapped within the joint.
In 1950, Smith dispelled many of the complications previously attributed to medial epicondyle fractures. Smith refuted the view that medial epicondyle fractures were associated with growth disturbance, pain and disability, weak elbow flexion, or ulnar nerve dysfunction and went on to prove his theories in his classic study. He concluded that fractures involving the medial epicondyle were relatively benign and were not associated with significant functional deficit.
Farsetti et al confirmed Smith's conclusions. [30] Even in 42 patients with isolated fractures of the medial epicondyle with displacement of 5-15 mm, no significant difference was found between those treated with ORIF and those treated nonsurgically. No universally accepted system exists for classification of medial epicondyle fractures.
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Schematic of two types of medial condyle fractures, as described by Milch.
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Medial epicondyle fracture.
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Displacement patterns as described by Kilfoyle.
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Valgus levering force creating fracture.
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Olecranon acting as a wedge and creating medial condyle fracture.
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Medial condyle fracture caused by traction through flexor pronator origin.
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Epicondyle fractures can be caused by traction forces.
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Positioning for valgus stress radiograph.
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Anteroposterior view of displaced medial epicondyle fracture.
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Anteroposterior view of displaced medial epicondyle fracture after reduction.
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Elbow dislocation associated with medial epicondyle fracture. In this lateral view, fragment is marked with circle.
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Elbow dislocation associated with medial epicondyle fracture. Lateral view after reduction. Reduced fragment is marked. Note normal location somewhat posteriorly on distal humerus.
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Elbow dislocation associated with medial epicondyle fracture. Anteroposterior view after fixation.
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Attachment of medial collateral ligament components is pictured.
