Condylar Fractures in Children

Chapter 10 Condylar Fractures in Children




Introduction


These fractures include:







Lateral condylar, medial condylar and T-condylar fractures of the elbow in children are intra-articular fractures and require precision in assessment and management. Clinical and radiological assessment is often difficult and the propensity for these seemingly innocuous fractures to later displace makes them a challenge to manage. Radiological assessment is difficult owing to the presence of a largely cartilaginous distal humerus and different ossification centres. In contrast to metaphyseal and diaphyseal fractures, the long-term consequences of inaccurate management may be dire, in particular non-union with the later development of deformities, tardy ulnar nerve palsy and a degenerate elbow. Salvage procedures such as osteotomies do not have the same satisfactory results as those done for deformities following metaphyseal or diaphyseal fractures. Surgery for non-union may result in avascular necrosis.


The age of occurrence depends on the anatomical location. The average age for lateral condylar injuries is around 6 years.1,2 The less common medial condylar injuries occur in the age range 8–12 years.2,3 T-condylar fractures are more common in adolescents but occur in children in the age range 5–12 years (average 8.8 years).4 Fractures involving the entire distal humeral physis may be misdiagnosed as lateral condylar fractures. They should be suspected in a child below 1 year of age but can occur from birth to 6 years.57 They have an association with child abuse.


Epicondylar fractures are often associated with dislocations of the elbow and have a peak incidence in the 6- to 12-years age group.811


In essence, fractures involving the joint surface (lateral condylar, medial condylar and T-condylar) require anatomical reduction and early mobilization at 3 weeks. EDHP injuries are treated like supracondylar fractures, but are more stable and less likely to require percutaneous pinning. Epicondylar injuries can be treated conservatively. If associated with a dislocation and incarcerated within the joint, however, they must be extracted (closed or open method) and moved at 1 week to prevent stiffness.



Lateral condylar fractures




Background/aetiology


Fractures of the lateral condyle in children represent 15% of all paediatric elbow fractures and are the second most common childhood elbow injury after supracondylar fractures (70%).12


These fractures constitute 75% of distal humeral physeal fractures.12 It is noted that fractures that exit in the trochlear notch will lead to an element of elbow instability with subluxation of the radius and ulna with the lateral condylar fragment.


Dislocation in association with a lateral condylar fracture has been reported by Rasool.13 He described 14 cases with a posteromedial dislocation and lateral condylar fracture, five of which also had a fracture of the medial epicondyle. He stressed the importance of looking for a lateral condylar fracture in children with a dislocation of the elbow.



Classification





Staging


Jakob et al16 described three stages of displacement (Fig. 10.2):






Badelon et al17 modified this classification into four stages. In stage I the fracture line is seen on only one X-ray view and displaced less than 2 mm. In stage II the fracture line is seen on both the anteroposterior (AP) and lateral views but remains displaced less than 2 mm. Stages III and IV are the equivalent of Jakob stage II and stage III, respectively. The addition of the extra stage was to distinguish which fractures were unstable and more likely to displace and thus identify which should be fixed. They determined that stage I could be treated conservatively by plaster immobilization but stages II, III and IV required open reduction and internal fixation.


We use the thee-stage classification of Jakob et al in this text.




Presentation, investigation and treatment options




Investigations



Radiographs


Adequate views may be difficult to obtain because the child is distressed and in pain. Even when these are achieved the presence of a largely cartilaginous distal humerus with different ossification centres may make interpretation difficult. Radiographs of the normal side may be helpful for comparison.


The metaphyseal fragment is often small and minimally displaced, with displacement best appreciated on the lateral view. Badelon et al17 found that if the fracture could only be appreciated on one view then it was stable, but if seen on both views there was more likelihood that the articular hinge was disrupted, making the fracture unstable. The relationship of the proximal ulna and radius to the humerus must be studied since lateral subluxation of the distal radius and ulna imply a Milch II fracture with disruption of the articular hinge.


Finnbogason et al20 reviewed 112 undisplaced and minimally displaced fractures and classified them as stable fractures, fractures with an undefinable risk and high-risk fractures. Stable fractures had no gap or a minimal gap that did not extend all the way to the epiphyseal cartilage (65 cases, none of which had lateral displacement). Fractures with an undefinable risk showed the fracture line extending all the way to the epiphyseal cartilage (displacement occurred in 6 (17%) of 35 fractures). High-risk fractures had a fracture gap that was almost as equally separated laterally and medially. Five (42%) of 12 of these fractures displaced.


Oblique radiographs may improve the diagnosis and Song et al21 found that the internal oblique view was significantly more accurate in demonstrating the fracture gap and fracture pattern than the AP and lateral views. They concluded that classifications should be based on the greatest displacement seen on at least three views, namely AP, lateral and internal oblique.




CT scan


Chapman et al23 showed that multi-detector computed tomography, which can be done in children without using sedation, was highly reproducible in characterizing lateral condylar fractures and frequently demonstrated disruption of the articular surface. It may lead to a change in treatment for children with fracture displacement near the threshold of 2 mm.



MRI


Kamegaya et al24 performed MRI on 12 patients with fractures of less than 2 mm displacement as seen on plain radiographs. Fractures that passed through the articular surface into the joint were deemed unstable. One of five fractures that had 1 mm displacement was found to be unstable and four of seven with 2 mm displacement were found to be unstable. This study suggests that MRI is a useful and accurate method of assessing fracture stability and enables the identification of fractures that would be better treated by pin fixation rather than cast immobilization.





Treatment


Treatment is determined by the type of fracture and comprises plaster immobilization, closed reduction and pinning, and open reduction and internal fixation.



Plaster immobilization


For stage I fractures simple immobilization in an above-elbow backslab is recommended. Careful follow-up, however, is required to check for late displacement.


Immobilization is appropriate for 30–40% of lateral condylar fractures.17,26 Badelon et al17 stated that in cases where the fracture is seen in only one view and displaced less than 2 mm (i.e. stable fracture) immobilization is adequate. Speed and Macey27 showed uniformly good results using this method and had no abnormalities of growth or premature fusion. Some authors have recommended placing the forearm in supination to decrease the muscle pull of the extensors and reduce the risk of displacement on the distal fragment.


Late displacement is the concern with simple immobilization. Beaty and Kassar28 had two cases of late displacement out of 24 stage I fractures. Their criteria for plaster immobilization was displacement of less than 2 mm on three X-ray views (AP, lateral and internal oblique).



Closed reduction and pinning for stage II


Mintzer et al29 reported good results after percutaneous pin fixation in 12 fractures with displacement of less than 2 mm. Joint congruity was checked with an arthrogram.






Outcome


Badelon et al17 and Speed and Macey27 reported excellent results in patients with undisplaced fractures.


Bast et al33 reported union rates of 98% following non-operative treatment for undisplaced or minimally displaced fractures.


Ippolito et al34 evaluated 49 individuals at a follow-up of 18–45 years. Twenty fractures with displacement of 2–10 mm without tilting had been treated non-operatively and 36 with displacement and tilting had been treated surgically. All patients had a good result.





Complications


Complications of lateral condylar fractures include lateral spur formation/lateral condylar overgrowth with cubitus varus, delayed union, non-union, avascular necrosis and nerve injury.



Lateral spur formation/lateral condylar overgrowth with cubitus varus


This is seen in 40–50% of patients with loss of carrying angle.27,36,37 De Jager and Hoffman26 reviewed 60 patients following lateral condylar fractures and found an average of 4 mm of lateral condylar overgrowth and an average of 3° loss of the carrying angle. It occurs in those treated operatively or non-operatively and can lead to clinical cubitus varus depending on the pre-morbid carrying angle. It is rarely of cosmetic or functional significance. It is important, however, to warn parents that this deformity may occur.




Non-union


Non-union is defined as no union by 12 weeks.38 It occurs with stage II or III fractures that are untreated, present late or are inadequately reduced.


Non-unions with displacement lead to cubitus valgus. In stage III the articular surface of the fragment comes into contact with the metaphyseal bone and thus non-union is inevitable. Progressive cubitus valgus is common in Milch II fractures with lateral translation of the proximal ulna and radius. As the valgus progresses there is the potential for ulnar nerve dysfunction with the development of a classical tardy ulnar nerve palsy.


The management of non-unions is controversial. Jakob et al16 and Dhillon et al39 reported that patients who were treated after 3 weeks had the same results as patients who had no treatment at all. Complications included loss of motion, delayed union and non-union, deformity and avascular necrosis.


Other authors have reported success with operative treatment prior to closure of the growth plate.1,38,40 Shimada et al41 reported good results at an average of 11 years follow-up. The average time between injury and surgery was 5 years (5 months to 10 years). One poor result was due to avascular necrosis.


The main concern with late surgery is the risk of avascular necrosis. Speed and Macey27 reported a high incidence of ‘epiphyseal changes’ in patients treated with late surgery. Yang et al,42 however, reported low rates of avascular necrosis and good results by approaching the non-union through an olecranon osteotomy, thus not disrupting the soft tissue attachment to the fragment.


Some patients who are seen years after their fracture (Fig. 10.5) may never have sought treatment at the time of the injury. They present with cubitus valgus. In addition, tardy ulnar nerve palsy may be noted, although this does not normally occur until an average of 22 years after the injury.43 When present, motor loss is usually followed by sensory changes. Papandrea and Waters44 recommended that late presentations were treated by a two-stage procedure. The first stage involved fixation and bone grafting of the non-union with anterior transposition of the ulnar nerve. At a later stage an osteotomy was advised. Milch15 described a transverse osteotomy and, more recently, Tien et al45 has advocated a dome osteotomy with fixation of the non-union through a posterior approach. This is thought to be associated with a reduced rate of complication.






Personal view





Medial condylar fractures



Introduction


These fractures are rare and account for less than 1% of fractures of the distal humerus.12 However, as they are intra-articular fractures they require accurate reduction to avoid later complications.



Background/aetiology


Infants may sustain this injury but more commonly they occur in the age range of 8–14 years.50 The fracture line extends from the metaphysis of the medial condyle and exits between the ossification centres of the lateral and medial condyle (apex of the trochlea) or through the lateral condylar epiphysis (capitulotrochlear groove). The fragment includes the medial epicondyle and the attached flexor muscles. These muscles cause the fragment to rotate so that the articular surface of the fragment faces posteriorly and laterally.


In younger children there is an association with child abuse,51,52 but the fracture also occurs with greenstick fractures of the olecranon and true posterolateral dislocations of the elbow.51,53



Classification





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Sep 8, 2016 | Posted by in MUSCULOSKELETAL MEDICINE | Comments Off on Condylar Fractures in Children

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