Trochlear deformity occurring after distal humeral fractures: magnetic resonance imaging and its natural progression

Area of Science:

• Pediatric Orthopedics
• Pediatric Traumatology
• Pediatric Radiology

Background:

• Distal humeral fractures are common in children.
• These fractures can lead to secondary trochlear deformities and altered carrying angles.
• Long-term outcomes regarding bony healing and functional recovery are not fully elucidated.

Purpose of the Study:

• To evaluate the natural history of trochlear deformities following distal humeral fractures in children.
• To assess the radiographic and clinical outcomes, including range of motion and carrying angle, after fracture treatment.
• To investigate the potential for cartilage necrosis and its long-term implications.

Main Methods:

• Serial radiographic evaluation of 18 children with post-traumatic trochlear deformities.
• Measurement of carrying angle and range of motion throughout follow-up (up to 13 years).
• Magnetic resonance imaging (MRI) in eight patients to assess cartilage viability.

Main Results:

• Bony defects of the trochlea were observed in most patients, persisting for several years before eventual reossification by skeletal maturity.
• Cubitus varus deformity developed in nearly all patients but became nonprogressive after 3-4 years.
• MRI revealed cartilage necrosis (low T2 signal) with an intact articular surface; no limitation of motion or late neuropathy was observed.

Conclusions:

• Trochlear deformities and cubitus varus following pediatric distal humeral fractures typically resolve with skeletal maturity.
• Despite initial bony defects and cartilage necrosis, functional outcomes are generally favorable with no significant long-term morbidity.
• Serial radiographs and MRI are valuable tools for monitoring these injuries and their sequelae.