Imaging Studies
Radiography
Adequate radiographs must be obtained to evaluate the fracture anatomy and to plan for surgical treatment. Radiography should include routine anteroposterior (AP) and lateral films, and possibly additional studies (eg, oblique views) as well. With comminuted bicolumn fractures (Arbeitsgemeinschaft für Osteosynthesefragen–Association for the Study of Internal Fixation [AO-ASIF] type C3), repeat films following initial reduction or with longitudinal traction maintained often prove helpful in further defining articular fracture fragments.
Silva et al studied the interobserver reliability (IEOR) and intraobserver reliability (IAOR) of the Baumann angle of the humerus (a simple, repeatable measurement that can determine outcome of supracondylar humerus fractures [SCHFs] in children). [10] This angle was measured by five observers on AP radiographs of 35 elbows that had sustained a nondisplaced supracondylar humerus fracture.
Ranges of differences in the measurement of the Baumann angles were established, and the percentage of agreement between observers was then calculated. [10] When the difference between observers in reported measurements of the Baumann angle was calculated to be within 7º of each other, at least four of the five observers agreed 100% of the time.
Heal et al evaluated the IEOR and IAOR of the Gartland radiographic classification for SCHFs in children. [11] AP and lateral radiographs of 50 SCHFs were graded on two occasions by four orthopedic surgeons according to the Wilkins modification of the Gartland classification, with the following results:
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Type I fractures - Poor agreement
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Type II fractures - Fair to moderate agreement
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Type III fractures and the flexion group - Good to very good agreement
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Good to very good intraobserver agreement
The authors concluded that surgeons should treat pediatric SCHFs on the basis of degree of displacement rather than the Gartland classification. [11]
Computed tomography
Computed tomography (CT) can also be helpful in surgical planning for complicated fractures. When concern exists about vascular injury, arteriography can be beneficial.
Other Tests
In cases of neurologic injury, electromyography (EMG) generally is not helpful until approximately 3 months after injury, at which point it may serve as a helpful baseline for assessing progress.
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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.
