Fractures of the lateral condylar physis rarely are associated with injuries outside the elbow region and unlike supracondylar humeral fractures, fractures of the lateral condyle rarely are associated with neurovascular injuries. Within the elbow region, the associated injuries that uncommonly occur with this fracture include dislocation of the elbow (which may be a result of the injury to the lateral condylar physis rather than a separate injury), radial head fractures, and fractures of the olecranon, which are often greenstick fractures. Acute fractures involving only the articular capitellum are rare in skeletally immature patients but are serious injuries that need to be recognized and treated appropriately.

Two mechanisms have been suggested: “push-off” and “pull-off.” The pull-off or avulsion theory has more advocates than the push-off mechanism.

The mechanism of injury includes either avulsion forces from the lateral ligaments with the elbow extended, or impaction of the radius on the capitellum after a fall on an outstretched arm 4.

Compared with the marked distortion of the elbow that occurs with displaced supracondylar fractures, little distortion of the elbow, other than that produced by the fracture hematoma, may be present with lateral condylar fractures. The key to the clinical evaluation of this fracture is the location of soft-tissue swelling and pain concentrated over the lateral aspect of the distal humerus.

Diagnosis is made based on radiographs and it may be difficult in children 5. The radiographic appearance varies according to the fracture line’s anatomic location and the displacement stage.

The degree of displacement may be seen on the true lateral view. In determining whether the articular hinge is intact (i.e., stage I vs. stage II), the relationship of the proximal ulna to the distal humerus is evaluated for the presence of lateral translocation. Oblique views are especially helpful in patients in whom a stage I displacement is suspected but not evident on AP and lateral views. Figure 1 and Figure 2.

Arthrography or MRI evaluation has been suggested to identify unstable fractures in the acute

setting and to aid in preoperative planning for those with late displacement, delayed union, or malunion. MRI can be a very useful diagnostic aid to guiding treatment, especially with delayed unions.

Non-displaced and stable fractures may be treated by cast immobilization with close follow-up, but fractures displaced >2 to 3 mm may indicate surgical fixation 78. Surgical treatment can be done either by closed reduction and percutaneous osteosynthesis or open reduction and osteosynthesis. Figure 3.

Surgical fixation is either by screw, smooth K-wires or both. The K-wires can be buried under the skin or not.

The idea behind burying K-wires is to reduce infection rates because it is felt that the wires have to stay in for a minimum of six weeks to prevent non-union. Some studies show no cases of non-union in either the buried or unburied wires group and infection rates that were comparable. In addition some of the cases with buried wires became effectively unburied. So that is why some authors concluded there is no justification in burying wires, which requires an additional general anaesthesia for removal 9.

Regarding pin orientation, most authors favor a divergent construct for greater stability.

For 2-pin constructs, maximizing pin divergence at the fracture site provided greater stability in torsional loading and valgus loading. The addition of a third pin in a divergent orientation increases stability compared with 2-pin constructs in valgus, internal, and external rotation loading. The pins must be placed in a bicortical manner, with maximum divergence and spread at the fracture site 10.

Many complications are known to be associated with childhood lateral condylar humeral fractures, with poor outcomes often related to delayed or inadequate initial treatment 511.

Lateral humeral condylar fractures are the most common injuries that involve the growth line around the elbow region 12. There are also intra-articular fractures, which may affect bone healing and the joint surface 13. These fractures more commonly result in decreased range of movement more than any other elbow fractures 14. Up to 20% of patients with lateral condylar fractures show a cubitus varus deformity and >10% show a cubitus valgus deformity 151617.

Fractures involving the medial condyle have two components. The intra-articular component involves, in some manner, the trochlear articular surface. The extra-articular portion includes the medial metaphysis and medial epicondyle.

As this fracture is rare, studies describing associated injuries are rare. Medial condylar physeal fractures have been reported in association with greenstick fractures of the olecranon and with true posterolateral elbow dislocations

Three possible mechanisms for medial condyle fracture are described; axial compression with concomitant valgus stress (fall on an outstretched arm), direct impaction of olecranon to medial condyle (direct fall on olecranon when the arm is flexed) and avulsion of the medial condyle due to violent contraction of the common flexor muscles of the forearm 2122.

A dislocation of the elbow ist most often associated with a fracture of the medial epicondyle.

Clinical Presentation

A fracture of the medial condylar physis is most often confused with a fracture of the medial epicondyle. In both types of intra- and extra-articular fractures, swelling is concentrated medially, and there may be valgus instability of the elbow joint. Ulnar nerve paresthesia may be present with both types of fractures.

In older children with a large metaphyseal fragment, involvement of the entire condyle is usually obvious on radiographs. In younger children, in whom only the epicondyle is ossified, fracture of the medial condylar physis may be erroneously diagnosed as an isolated fracture of the medial epicondyle. In differentiating these two fractures, it is helpful to remember that medial epicondylar fractures are often associated with elbow dislocations, usually posterolateral, and that elbow dislocations are rare before ossification of the medial condylar epiphysis begins. With medial condylar physeal fractures, the elbow tends to subluxate posteromedially because of the loss of trochlear stability.

As the trochlea ossifies by the age of 9, the difficulty of making diagnosis by plain radiographs in younger children is not a major problem in adolescents. Nevertheless, some other problems may complicate the injury. These intraarticular fractures are prone to nonunion 2324. In addition, these fractures are Salter–Harris type IV physeal injuries, and even with adequate reduction, partial physeal arrest can develop and lead to consequent problems.

Undisplaced fractures are simply immobilized in a cast or posterior splint. As with fractures of the lateral condylar physis union may be slow. In fractures treated promptly, results have been satisfactory. Because there is usually more displacement in older children, the results in this age group are not as satisfactory as those in younger children, who tend to have relatively nondisplaced fractures. For displaced fractures, open reduction with internal fixation is the most often used treatment method.

The fracture fragment can be approached by a posteromedial incision that allows good exposure of both the fracture site and the ulnar nerve. Fixation is easily achieved with smooth K-wires or with screws in older adolescents. Two wires are necessary because of the sagittal rotation forces exerted on the fracture fragment by the common flexor muscles. Figure 4 and Figure 5.

Although nondisplaced or minimally displaced fractures can be treated nonoperatively in a cast, careful monitoring is required to identify further displacement and delayed union.

When displaced, open treatment with identification of the ulnar nerve and direct visualization of the joint surface is needed. The rate of complications is relatively high and may include osteonecrosis, elbow stiffness, malunion, or delayed union.

Leet et al.20 reported complications after 33% of 21 medial condylar fractures, including osteonecrosis of the trochlea, nonunion, and loss of reduction. Untreated displaced fractures usually result in nonunion with cubitus varus deformity. Both cubitus varus and valgus deformities have been reported in patients whose fractures united uneventfully. The valgus deformity appears to be caused by secondary stimulation or overgrowth of the medial condylar fragment. Some simple stimulation of the medial epicondyle’s prominence may also produce the false appearance of a cubitus valgus deformity. Cubitus varus appears to result from decreased growth of the trochlea, possibly caused by a vascular insult. Principles for treating nonunion of lateral condylar fractures are generally applicable to nonunions of the medial condyle.