Transphyseal distal humeral separation in neonates: A case series

Birth trauma is a rare condition. Typically, injury in neonates occurs as a result of obstetrical manipulation to allow delivery or from trauma sustained during a difficult passage through the birth canal. Transphyseal separation of the humerus is particularly rare. Diagnosis is not always straightforward and is prone to mistakes. There is a general consensus that the outcome is usually favorable. It is generally agreed that the fracture needs to be realigned, while the suggested methods in contention vary from a simple plaster cast to closed and even open reduction and percutaneous Kirschner wire fixation. The purpose of this study was to review our experience in treating transphyseal distal humeral separation in neonates to better define the diagnostic and therapeutic pathway.

Ten consecutive cases of transphyseal distal humeral separation in neonates were treated at our institution between September 2008 and June 2021. All cases were reviewed and clinical data collected on birth injury risk factors, diagnostic workup, age at diagnosis and treatment, and type of treatment. Results of treatment and outcome were analyzed for time to fracture union, complications and clinical alignment, range of motion and residual pain at the latest follow-up.

Mean age at diagnosis was 4.2 days (range 0 to 9 days) and time between diagnosis and treatment varied from three to 26 h (average 15 h). Risk factors for birth injury were present in six patients. Four patients were initially treated with closed reduction and cast immobilization, all the other cases were treated with closed reduction and percutaneous pinning. Arthrography was performed at the time of treatment in six cases. Average follow-up was 37 months (range 12 to 120 months). At the latest follow-up, all fractures had healed with full range of motion. No clinical or radiographic deformity requiring repeated surgery or physeal damage was observed.

This rare lesion may occur both in the presence and in the absence of risk factors. Due to the rarity of the injury, misdiagnosis and delayed diagnosis are not uncommon. Treatment with closed reduction and percutaneous pin fixation is advisable and safe.