Pediatric Terrible Triad Injury of the Elbow: A Rare and Easily Missed Injury: A Case Report

Terrible Triad Injury in a Skeletally Immature Patient: A Case Report

CASE

A 7-year-old girl presented with an elbow terrible triad injury (coronoid fracture, Salter-Harris IV radial head fracture, and lateral collateral ligament avulsion) diagnosed after magnetic resonance imaging was obtained to evaluate subtle subluxation on radiographs. The patient underwent physeal-sparing fixation using the anconeus-extensor carpi ulnaris interval. One year postoperatively, she had full, stable symmetric range of motion compared with the contralateral side without complication.

CONCLUSION

Pediatric terrible triad injuries are rare, are easily missed, and have poor results after late reconstruction. Subtle radiographic abnormalities may benefit from evaluation with advanced imaging since early diagnosis and treatment can lead to excellent results as demonstrated in this case.

"Unhappy triad" of the trauma elbow in children: Diagnosis, classification, and mid-term outcomes

Background

The aim of this study was to describe the epidemiology, physiopathology, and outcomes of elbow "unhappy triad" trauma in children, combining a posterior dislocation, a proximal radius fracture, and a third lesion (i.e. bony or capsuloligamentous injury).

Methods

A retrospective bicentric study was conducted between 1999 and 2020. All skeletally immature children who presented to the emergency department and underwent surgery for a proximal radius injury were selected. Among this selection, only patients with two associated ipsilateral elbow injuries (i.e. posterior elbow dislocation and a bony and/or capsuloligamentous injury) were included. Active elbow ranges of motion, Mayo Elbow Performance Score and Quick-Disabilities Of The Arm, Shoulder And Hand scores and standard radiographs were recorded at last follow-up.

Results

Twenty-one patients met the inclusion criteria (mean age at surgery = 11.4 years) among 737 selected. The "unhappy triad" diagnosis was made preoperatively in nine cases (bone lesion only), intraoperatively in nine cases, and postoperatively in one case. The third lesions were surgically treated when the lesion was a bony fracture or if the elbow remains unstable between 60° and 90° of flexion (i.e. capsuloligamentous injury). Twenty patients were reviewed (mean follow-up = 5.8 years). The complications and re-operations rates were of 10%.

Conclusion

The "unhappy" triad of the child's elbow is a rare injury, where the preoperative diagnosis is frequently missed and lead to 10% of complications and re-operations.

Level of evidence

level III.

Terrible triad of the elbow and associated variants: a systematic review

Background

The terrible triad of the elbow (TTE) is a complex injury consisting of simultaneous elbow dislocation or subluxation, radial head fracture, and coronoid fracture. During the initial assessment of a TTE, the typical severity of presenting pain, swelling, and limited range of motion may limit the ability to perform a thorough physical examination and thus divert a clinician's attention away from additional injuries to the ipsilateral upper extremity. Therefore, the purpose of this study was to review the literature for reported cases of concomitant ipsilateral upper extremity injuries associated with a TTE and discuss various strategies to increase clinician awareness to avoid underdiagnosis and missed diagnoses.

Methods

A systematic review of five databases in four languages (English, Spanish, French, and Portuguese), from inception to May 2021, was conducted. Articles describing a TTE with a concomitant osseous, chondral, ligamentous, or musculotendinous injury occurring on the ipsilateral upper extremity were included. The patients were divided into two groups, those presenting with a classic TTE and concomitant ipsilateral upper extremity injury (group 1) and those in whom a TTE variant was described (group 2). A TTE variant was defined as a combination of osseous and/or chondral injuries to the elbow other than the classic description of TTE, in which at least two of the three classical elements of a TTE (elbow dislocation, coronoid fracture, and radial head fracture) were present in addition to other unique elbow osteoarticular injury.

Results

Nineteen articles met inclusion criteria and were further analyzed. A total of 27 patients were analyzed, 23 from group 1 and 4 from group 2. Overall, 33 concomitant injuries were documented in group 1, the most common being an olecranon fracture (27.3%), followed by Essex-Lopresti injury, triceps tendon avulsion, and carpal fracture-dislocation with 4 (12.1%) cases each. Group 2 had four patients, all of whom presented with a unique variant of the classically described TTE.

Conclusion

Despite a characteristic radiographic appearance of the classic TTE, additional injuries of the ipsilateral extremity or variants of the classic TTE may be easily missed, especially in cases resulting from high-energy mechanisms of injury. By analyzing the available data on associated injuries and variants that may occur with a TTE, we hope to increase awareness so that clinicians may recognize these less common but more complex injury patterns.

Complex Fracture-Dislocations of the Elbow in the Pediatric Population

BACKGROUND

Complex fracture-dislocations of the elbow, including terrible triad of the elbow, are serious injuries with guarded outcomes in adults. Although described extensively in adults, little is known about similar complex fracture-dislocations of the elbow in the pediatric population. The purpose of this study was to describe patterns of elbow dislocations with associated fractures in children and report the outcomes of these injuries.

METHODS

This was a retrospective review of patients who presented to a level I trauma center from 2007 to 2019 with an elbow dislocation and at least 2 associated fractures. Demographic data, fracture locations, and treatment modality were recorded. Operative reports and radiographs were reviewed to determine clinical outcomes and complications.

RESULTS

A total of 26 patients (mean age, 9.8 y) were identified. The majority of patients sustained an elbow dislocation and a medial epicondyle fracture (n=16). The most common third fractures involved the lateral condyle (n=8) or radial neck (n=7). At mean 6.03±3.11 months follow-up, 3 patients lacked ≥10 degrees of extension, and 2 patients lacked ≥15 degrees of flexion. Most patients had a Flynn score of "excellent" (n=20, 76.9%) or "good" (n=2, 7.7%). One patient with significant residual stiffness (>30 degrees flexion contracture) eventually underwent open contracture release.

CONCLUSIONS

The most common complex elbow fracture-dislocation pattern in this series was an elbow dislocation with fracture of the medial epicondyle and lateral condyle or radial neck. In contrast to adult terrible triad injuries, most patients had a favorable clinical outcome, with nearly 80% excellent results and a low rate of complications.

LEVEL OF EVIDENCE

Therapeutic Level IV-case series.