History and Physical Examination
The clinical presentation of a supracondylar humerus fracture (SCHF) is that of a painful swollen elbow that the patient is hesitant to move. The elbow may appear angulated and the upper extremity shortened. Some series report that open wounds are present in as many as 30% of these fractures. Patient history includes a high-energy trauma or significant fall. Evaluate adjacent joints for associated injuries.
Neurovascular status must be carefully evaluated and monitored. Owing to the close proximity of the neurovascular structures, injury is not uncommon. If a deficiency is noted, carefully evaluate and document when it first became apparent, the degree of involvement, and possible progression. If it first appeared following manipulation or splint placement, consider remanipulation; if the deficiency does not resolve, urgently explore to evaluate possible nerve entrapment. Neurapraxias are not uncommon and generally resolve with restoration of normal alignment and lengths. In the author's experience, resolution has occurred up to 18 months after injury.
Radiographic evaluations (see Workup) should include standard anteroposterior (AP) and lateral films. With comminuted bicolumn fractures (type C3 in the Arbeitsgemeinschaft für Osteosynthesefragen–Association for the Study of Internal Fixation [AO-ASIF] classification; see Classification), repeat films following initial reduction or with longitudinal traction maintained often prove helpful in further defining articular fracture fragments. For complicated fractures, computed tomography (CT) also can be helpful with regard to surgical planning.
If vascular compromise is evident, obtain emergency arteriograms. If arterial disruption is present, obtain a vascular surgery consultation followed by immediate open reduction and internal fixation (ORIF) to provide skeletal stability and support of vascular reconstruction.
Classification
AO-ASIF classification
AO-ASIF type A fractures are extra-articular fractures and are further subclassified as follows:
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A1 - Epicondylar avulsions
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A2 - Supracondylar fractures
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A3 - Supracondylar fractures with comminution
AO-ASIF type B fractures are unicondylar fractures and are further subclassified as follows:
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B1 - Fracture of the lateral condyle
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B2 - Fracture of the medial condyle
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B3 - Tangential fracture of the condyle
AO-ASIF type C fractures are bicondylar fractures and are further subclassified as follows:
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C1 - T-shaped or Y-shaped fractures
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C2 - T-shaped or Y-shaped fractures with comminution of one or two pillars
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C3 - Extensive comminution of the condyles and pillars
This classification remains somewhat deficient in describing the mechanically important concept of the medial and lateral columns and their fracture involvement. It also is somewhat deficient in describing the level through which the fracture occurs in each column and related important surgical considerations.
Mehne-Matta classification
In view of the aforementioned limitations of the AO-ASIF classification, the author believes that the classification of bicolumn fractures of the distal humerus introduced by Mehne and Matta proves useful in planning bicolumn surgical fixation.
The classification of Mehne and Matta describes the specific characteristics of bicolumn fractures and allows for better preoperative planning. [9] The classification is as follows:
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High T fracture
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Low T fracture
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Y fracture
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H fracture
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Medial lambda fracture
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Lateral lambda fracture
Although the medial and lateral lambda fractures are not technically bicolumn fractures, they are included in this classification because they require similar operative fixation techniques.
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Supracondylar humerus fractures: anatomy. Trochlea rests in 6-8º valgus in relation to humeral shaft.
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Supracondylar humerus fractures: anatomy. When viewed on end, trochlea resembles spool.
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Supracondylar humerus fractures: anatomy. Note medial and lateral columns, connected by trochlea, thus forming triangle of distal humerus. Also note location of sulcus for ulnar nerve in relation to placement of medial plate, as well as location of radial nerve sulcus in relation to proximal placement of plates.
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Incision is made along proximal 5 cm of medial ulnar border, curving to medial side of olecranon and returning to midline posteriorly to approximately 15-20 cm above elbow joint.
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Nerve is traced distally and released from cubital tunnel and into flexor muscle mass; care is taken to avoid motor branch to flexor carpi ulnaris. Articular branches need to be sacrificed for later anterior transposition. Nerve then is carefully retracted and protected with vascular tape.
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Cut is made with oscillating saw and completed with sharp osteotome to prevent damage to articular surfaces. Gauze sponge can be inserted into joint prior to osteotomy completion to further protect articular cartilage. Olecranon, with intact triceps insertion, is reflected posteriorly and covered with moist sponge, allowing easy access to entire supracondylar and to joint surfaces.
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Between postoperative days 10 and 14, sutures are removed. If wound is stable, patient is placed in hinged elbow orthoses, and protected active range of motion is allowed. Passive assisted range of motion is allowed to point of discomfort, not pain. Importance of early range of motion to final outcome is well documented. Orthosis is worn until evidence (both clinical and radiographic) of fracture union is present, and then orthosis use is discontinued. This usually occurs 6-12 weeks postoperatively.
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Radiographs of type 3C distal humerus fracture 5 months after injury and fixation using olecranon osteotomy approach and medial and posterolateral plates. Range of motion, 10-140º without pain.