Humeral condylar fracture is a common elbow injury, reaching 16.9% among distal humeral fractures in children ages 2 to 8 years old, with an average of 6 years old. In lateral condylar fractures with no shift or a displacement of less than 2 mm, long arm cast immobilization is effective . However, due to the need to restore the integrity of the articular surface of the distal humerus, internal fixation is considered the optimal choice for most displaced lateral condylar fractures [1-9]. Due to epiphysis, standard x-ray examination of the lateral elbow does not provide a full, clear view of metaphyseal fractures. Therefore, clinicians are unable to properly assess the degree of fracture displacement, leading to possible neglect and misdiagnosis of fractures [2-4]. If a fracture is missed, the treatment becomes difficult and bony abnormalities can occur. Because the fracture surface slopes from the outside to the inside, elbow oblique plain films can show the greatest degree of displacement. Accordingly, a standard x-ray of humeral condylar fractures should include front, side, and oblique views [1-2].
Flynn believes that a fracture of the humeral condylar is considered non-union if the patient has not recovered after 12 weeks of treatment. 2 Non-union occurs when persistent synovial fluid soaks the fracture site, resulting in inhibition of fibrin formation. This leads to secondary barrier callus formation. In addition, other factors contributing to non-union include the continuity stretches of the forearm extensors and the fragile blood supply for the lateral condylar [7-8]. Humeral condylar fracture non-union in children can cause progressive elbow valgus deformity and skeletal dysplasia and is often accompanied by gradual emergence of chronic ulnar neuritis . Moreover, the fracture lines of lateral condylar fractures often extend to the trochlea, non-union of the fragment or bone absorption may shift the normal position of elbow joint, causing subluxation and instability of the elbow joint . In the case of a non-union, the lateral condylar in the elbow may still allow controlled motion and elbow function may not be impaired. However, in children, ulnar nerve palsy symptoms gradually appear as primary symptoms with lateral condylar fracture non-union .
According to reports, the surgery for humeral condylar fracture non-union combined with elbow valgus deformity has a high rate of complications due to the need for ORIF and autologous bone graft. Since the surgery requires the entire complex epicondyle of the humerus bone, an extensor cut is necessary in order to enhance the stability of the lateral condylar, increasing the risk of osteonecrosis of the external humeral condylar [5, 7, 9, 13, 15-16]. In addition, if an abnormal lateral condylar is rigidly stabilized, loss of elbow function is likely to occur. A lateral condylar fracture results in an incomplete elbow pulley surface. Overgrowth of the condylar causes the pulley surface to slope to the radial articular surface, leading to elbow dislocation and lateral elbow instability . Surgical treatment to restore the stability of the elbow without loss of elbow function is difficult. Toh et al. believes that long-term lateral condylar fracture non-union only requires humeral osteotomy line and/or ulnar nerve release pre-surgery and does not immediately require directly addressing the non-union . However, Jakob et al. reported that simple elbow valgus deformity correction cannot completely solve ulnar nerve symptoms . Meanwhile, Dellon recommended initial ulnar nerve release surgery for traumatic ulnar neuritis . According to Dellon’s literature review of over 50 articles reporting more than 2,000 patients, there was no statistical difference in the effect of various treatments for ulnar nerve compression . Abed et al treated nonunion of the lateral humeral condyle using a triple management (fixation of the nonunion site, dome corrective osteotomy, and anterior transposition of ulnar nerve) through a modified para-triceptal approach, the results showed that all patients gained union, all gained excellent or good elbow function according to the Mayo elbow performance score . However, there is still controversy about whether to treat the non-union or not because of complications like stiffness of elbow and avascular necrosis of the fragment .
In the past, the main treatment for lateral condylar fractures with non-union was osteotomy surgery to correct elbow valgus deformity . However, osteotomy surgery alone does not address instability of the elbow, and may result in detrimental impact on the patient quality of life. Conversely, the two staged surgery initially manages the stability of the elbow and then focuses on the deformity correction. As such, this approach addresses the deficiencies of conventional treatment modalities. Among our group of patients, the results were satisfactory and largely dependent on the success of the first stage of surgery. The following are key issues in the staged surgical approach:
1) The goal of surgical treatment is to restore the stability of the elbow without losing function. Our experience is that when reducing the distal fragment, shifting the fragment slightly forward will decrease the obstruction of the lateral condylar fragment to the radial head, thus providing the greatest degree of elbow function correction.
2) Hardened scars on the bone surface should be completely removed.
3) The blood supply of the lateral condyle of the humerus should be protected. Studies have shown that lateral condylar epiphyseal vascular supply goes through the posterior part of the articular surface of the condyle to reach the lateral condyle, while protection of the blood supply of the nonunited fragment is the key to successful management [5, 8, 18]. Therefore, the integrity of the soft tissue and vascular supply should be protected.
4) In completing the secondary surgery to correct the valgus deformity in children, the posterior elbow approach should be avoided. The posterior approach requires splitting of the triceps fibers and may impact the function of the elbow. We used the original lateral approach and on-line supracondylar osteotomies to safely manage the cubitus valgus and aesthetic needs.