Continuing Education Activity
This activity reviews the injury mechanism, presentation, evaluation, management, and post-operative care of pediatric lateral humeral condyle fractures. It highlights the common associated injuries, assessment pitfalls, and related complications of both operative and non-operative care to improve care for patients with this condition.
- Identify the etiology of lateral humeral condyle fractures in the pediatric population.
- Summarize the commonly associated history and physical findings seen in the evaluation of pediatric lateral humeral condyle fractures.
- Outline the treatment options for lateral humeral condyle fractures.
- Explain the importance of a close collaboration between the interprofessional team (surgical, radiological, nursing and physiotherapeutic) in order to achieve and maximize the functional recovery following lateral humeral condyle fractures.
Lateral humeral condyle fractures are the second most commonly encountered elbow fracture after supracondylar fractures.
Several classification systems have been developed to aid on treatment recommendation, with a 2 mm displacement being considered the general cut-off for fixation. Displaced fractures are at a higher risk of non-union. Malunion, cubitus varus, avascular necrosis, and post-operative infection are recognized complications following surgery.
Trauma is invariably associated with lateral humeral condyle fractures. Falls during outdoor/indoor activities and sports account for the majority of the presentations.
This injury is the second most common pediatric elbow fracture. It has a peak incidence at six years, with 67.4% being males. Interestingly a left-sided injury is more frequent.
Common associated injuries include ipsilateral elbow dislocations 11.4% (posterolateral) and ipsilateral upper limb fractures (olecranon 2.8%, forearm 1.5%, medial epicondyle 1.2%).
Several theories have tried to describe the mechanism of injury behind this fracture. Milch first suggested a push-off theory. According to it, an upward and outward force applied through the radius is responsible for the fracture. Jakob defends a pull-off mechanism, where the extensor carpi radialis along with the brachioradialis avulse the lateral condyle during the adduction of the supinated forearm. The mechanism of injury is, therefore, accepted as a combination of these two theories.
Common associated injuries include ipsilateral elbow dislocations 11.4% (posterolateral) and ipsilateral upper limb fractures (olecranon 2.8%, forearm 1.5%, medial epicondyle 1.2%)
History and Physical
History of a fall onto an outstretched hand is very common. Elbow swelling and ecchymosis may be present. Tenderness to the lateral aspect of the elbow is usually present. However, all these signs can also be present in the more frequent supracondylar fracture type. The latter is commonly associated with a higher degree of elbow deformity. Unlike supracondylar fractures, lateral condyle fractures have fewer associated neurovascular deficits.
It has also been proposed by Jakob et al. that a violent varus force to an extended elbow can cause the lateral condyle to be avulsed by the extensor muscles and attached ligament. The integrity of this cartilage dictates if displacement is present or not.
Due to the nature of this injury, a full neurovascular assessment is crucial during the initial presentation. This evaluation should include documentation of radial and ulnar pulses, with nerve function (radial, ulnar, median, and anterior interosseous).
Plain radiographs should be obtained in AP, lateral, and internal oblique views of the affected elbow. Because the fractured fragment will frequently lie posterolaterally, an internal oblique view is often useful in detecting minimally displaced fractures (<2 mm).
Computerized axial tomography has proved helpful in characterizing fracture patterns and comminution. It provides, however, limited evaluation of the articular cartilage.
Magnetic resonance imaging is, therefore, useful in assessing the integrity of the articular cartilage. When this is intact, the risk of late displacement is low and indicates fracture stability.
Multiple classifications have been suggested. Two have seen extensive discussion. An earlier by Milch et al. distinguishes between a type I and a type II pattern. Type I is characterized by a fracture line lateral to the trochlear groove. Because it does not extend to the trochlear groove, this is considered a stable fracture. Type II extends medially into the trochlear groove, thus creating a potentially unstable elbow.
Although the Milch classification tried to predict elbow displacement, it did not correlate with intraoperative findings and presented limited recommendations on treatment.
A second classification by Jakob and then Weiss divides fracture patterns into three types according to displacement. Type I has less than 2mm displacement. Type II has ≥2mm displacement but intact articular cartilage. In type III, there is also ≥2mm displacement but associated disruption of the articular surface.
Treatment / Management
Conservative treatment will generally be indicated in less displaced fractures in an above-elbow cast. Immobilization is advised for a minimum period of 4 weeks. Depending on fracture healing at this stage, further immobilization for another two weeks may be indicated.
Generally, fractures with <2mm displacement can have conservative treatment. Repeat radiographs are recommended at one week to rule out fracture displacement. There is a reported union rate of 98% when meeting this criterion.
When fracture displacement exceeds 2mm, operative management is necessary. Closed reduction and percutaneous fixation are options where possible. Using two Kirschner wires instead of three is recommended when stability is achieved.; this can improve the range of movement and reduce the resulting bone spur. Wire removal can occur when there is clinical and radiological evidence of fracture healing. Removal typically occurs around 4 to 6 weeks. Cannulated screws can be an option with similar outcomes. This approach can prevent skin infection commonly associated with Kirschner wires, although they will require further surgery for their removal. Failing this, open reduction and internal fixation is required. Lag screw osteosynthesis is recommended when performing open reduction due to its lower rates of mal reduction and subsequent complications. Kirschner wire fixation remains a valid alternative in these situations.
Ipsilateral upper limb fractures must be ruled out, including elbow dislocations, as often, ipsilateral limb injuries carry different management options and poorer outcomes when present.
When promptly diagnosed and managed, the prognosis is favorable. Overall reported union rates for pediatric lateral humeral condyle fractures are at 91%. Delayed presentation is associated with a future range of motion limitation and avascular necrosis.
Fracture displacement is also a significant factor in clinical outcomes. A displacement of 2 mm appears to be a cut off for conservative management and is associated with fewer complications.
Delayed union can occur in 1% of cases and is commonly managed conservatively. Prominent lateral condyles are the most frequent complication found in 27% of cases, but they don’t seem to influence clinical outcomes.
Weiss et al. report that according to their classification, type II fractures, when surgically managed, seem to have half the rate of complications associated with type III injuries, described at 34% and 11%, respectively.
Lateral condyle fractures are generally intra-articular (Salter-Harris IV). Growth arrest can occur when the ossific nucleus is involved.
Fishtail deformities and avascular necrosis can develop in 14% and 1.7% of cases, respectively. This deformity is commonly attributed to medial instability between epiphyseal plates. A fishtail deformity will be a characteristic deformity of the distal humerus, which is caused by a failure of the lateral trochlear ossification centers to undergo normal development. It is relevant to mention that lag screw osteosynthesis seems to be associated with less risk of fishtail deformities or avascular necrosis. This outcome appears to favor this technique when open reduction is required.
Non-union seems to be more common on lateral condyle fractures compared to other elbow fractures. Prior studies have placed the risk between 1 to 5% depending on the definition used. A study that included 530 children by Pace et al. between 2001 and 2014 showed a risk of non-union of 1.4%. It defined non-union as the absence of callus at 8weeks after definitive treatment with fracture migration. All cases which underwent non-union surgery went into union. Complications with non-union included one case of avascular necrosis and 2 cases of cubitus varus. Type III (Weiss) fractures were the only significant risk factor for non-union (3%).
Cubitus varus/cubitus valgus – Healing of a lateral condyle fracture can often lead to a wider distal humerus. Cubitus varus develops in more than 20% of patients, while a valgus deformity can occur in more than 10%. These deformities alter the normal physiological carrying angle (5 to 15 degrees). Healing in a slightly displaced fashion compared to the initial position seems to be responsible for a varus deformity. A bony prominence can sometimes be felt clinically or seen radiologically, with little significance.
Tardy Ulnar nerve palsy is usually a consequence of non-union of a prior lateral condyle fracture. As there is skeleton development, a cubitus valgus deformity develops, which leads to ulnar nerve stretching and classic neuropathic symptoms. Paraesthesia is usually of late-onset, and examination reveals atrophy of the intrinsic hand muscles.
Postoperative and Rehabilitation Care
Immobilization in a long-arm cast (above elbow) is indicated until there is clinical and radiographic evidence of healing; this usually occurs between 4 and 6 weeks. Range of movement exercises are recommendations following cast removal. Avoidance of contact activities should be for a period of 1 to 2 months after the removal of the cast.
The mean arc of motion at the time of cast removal was 64 degrees in a study by Bernthal et al. Recovery was significantly faster in the first six weeks and up to week 48. Patients treated surgically had slower recoveries but no significant difference beyond week 18. Older age, a longer period of immobilization, and more severe injuries will also have slower recoveries.
Deterrence and Patient Education
Following injury, clear communication with patients and their guardians is crucial to education on this injury. While less severe patterns are associated with few complications, more severe fractures are at significant risk of complications even when treated surgically.
Rehabilitation following this injury and recovery of elbow arc of motion can take up to a year.
Pearls and Other Issues
Lateral humeral condyle fractures are a common injury in the pediatric population. Due to its traumatic etiology, thorough assessment and imaging are crucial to deciding on management. The Weiss classification is one of many used to categorize these fractures. In summary, a cutoff of 2 mm displacement can be an option when determining conservative or surgical management. Closed reduction and internal pinning with two Kirschner wires is the recommendation when performing surgery, and closed reduction is possible. Non-union, avascular necrosis, and several other complications can occur. Immobilization will generally be for a period of 4 to 6 weeks. Recovery of the elbow arc of motion will occur up to a year post-injury.
Enhancing Healthcare Team Outcomes
Pediatric lateral humeral condyle fractures are a complex elbow injury that requires a multidisciplinary approach. Initial assessment by a clinician with neurovascular documentation is the first crucial step. Radiographers should be aware of the importance of obtaining AP, lateral, and internal oblique views of the affected elbow. This imaging will aid in better visualization and management decision by the referring clinician. When further investigation is required, a radiologist should be consulted to discuss magnetic resonance imaging to evaluate the articular cartilage.
Nurses play a crucial role in managing these patients. Either during the initial assessment or in the postoperative period, they will be paramount in spotting neurovascular compromise. Rehabilitation is also key to ensuring good outcomes following this injury. Physiotherapists will be able to orient and counsel these patients to restore elbow function as much as possible.