Although the vagaries of the secondary centers of ossification can provide a diagnostic dilemma at times, radiographic assessment of most injuries around the pediatric elbow are relatively straightforward for the experienced pediatric orthopaedic surgeon. There are, however, a small subset injuries that can be missed and as a result, have dire consequences in the long term. Kasser has defined these injuries as “TRASH lesions” (Table 1): the radiographic appearance seemed harmless. These lesions are predominantly osteochondral injuries in children less than age 10 years of age,1–5 often associated with unrecognized, spontaneously reduced elbow dislocations. Small, anterior radial head compression fractures with initially subtle, then progressive, posterior radiocapitellar subluxation, are a classic example of this subgroup of serious injuries (Fig. 1). A high index of suspicion, early additional imaging [ultrasound, arthrogram, magnetic resonance imaging (MRI) scan],6 and aggressive surgical care are usually necessary for prompt diagnosis and successful treatment of these injuries before complications arise.
HISTORY, EXAMINATION, AND RADIOGRAPHIC EVALUATION
The history is usually indicative of high-energy trauma. For example, a fall from a significant height in a small-sized child (Fig. 2).7 The examination generally reveals more swelling than expected by the misinterpreted benign radiographs. Flexion extension of the elbow and/or rotation of the forearm is often restricted. If inspected closely, the radiographs usually reveal a bony fragment or a joint malalignment. However, in a busy emergency room or office setting, without close, careful inspection, qualified physicians and surgeons have missed the findings. Due diligence is required to make the diagnosis acutely. Special imaging is usually necessary to define the extent of the injury and plan appropriate care. Ultrasound in a skilled pediatric center may be diagnostic with cartilaginous injuries and does not require sedation even in the young child (Fig. 2).7 MRI scans in the ambulatory setting will be diagnostic6 but may require conscious sedation (Figs. 3, 5) Intraoperative arthrograms can also be definitive (Fig. 4) but fracture dislocations may have leakage of dye into the surrounding soft tissues that can be confusing. In any given patient, some or all of this work-up may be necessary to reach clarity on diagnosis and care.
Specific injuries include (1) epiphyseal separations (Fig. 5); (2) displaced intra-articular medial condylar fractures before ossification of the secondary center (age 7 to 8 y) (Fig. 4); (3) capitellar shear fractures; (4) radial head fractures with radiocapitellar subluxation (Fig. 1); and (5) osteochondral fractures of the olecranon, radial head or distal humerus with joint incongruity (Fig. 6). With regard to the last 3, any elbow dislocation in a child less than 10 years old should raise concerns about a displaced, intra-articular osteochondral fracture. In retrospect, the diagnosis appears obvious. The challenge is in prospective, prompt diagnosis.
Displaced injuries require anatomic articular reduction. Most are unstable and require operative fixation. In cases with multiple fractures, preoperative planning, often with special imaging, is mandatory to determine the best surgical approach. Instrumentation of the fracture(s) has to be appropriate for fracture fragment size. The options include permanent 1.5 to 3.5 mm plates and/or screws, osseous screws or anchors,8 suture fixation of osteochondral flaps, and/or removable smooth, small wires. Rigid internal fixation is preferred to allow for early, protected motion. Soft tissue reconstruction may be necessary if there is still instability after operative fixation of the fracture(s). Repair of disrupted ligaments to the periosteum or with osseous suture anchors is performed in markedly unstable situations. With stable constructs, hinged elbow braces are used to gradually regain flexion—extension while avoiding varus—valgus stress. However, it may be necessary to immobilize in a long arm until sufficient bony healing if the fixation or vascularity of the fragments is precarious.
The most common complication with these rare injuries is failure to make an accurate diagnosis in a timely manner. Acute care is usually in a splint or cast for an inaccurate, simplified diagnosis of a contusion, sprain, or nondisplaced fracture. Referral for further consultation is often late when pain and limitations in motion and function persist. This may be after a trial of therapy. Unfortunately, anatomic reconstruction may not then be possible. Consequently, permanent malalignment, limited motion, and function may be the end result.
Unfortunately, even when the diagnosis is made acutely and surgical intervention is prompt, there can be a poor end result. Incomplete or unstable reduction of the fracture fragment(s) or joint has occurred. In cases with multiple fractures, one or more of the injuries has been missed and consequently, not treated surgically. Avascular necrosis, heterotopic ossification, periarticular contractures, and late joint subluxation all have developed with these injuries. Simply, care of these injuries is not for the uninitiated.
To reiterate, a high index of suspicion, early additional imaging (ultrasound, arthrogram, MRI scan), and aggressive surgical care are usually necessary for prompt diagnosis and successful treatment of these “TRASH” lesions before complications arise. These injuries are not to be simplified either in diagnosis or treatment.
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