Epiphyseal involvement in unicameral bone cysts

Area of Science:

• Orthopedics
• Pediatric Orthopedics
• Skeletal Dysplasias

Background:

• Unicameral bone cysts (UBCs) are benign bone lesions that commonly affect long bones in children and adolescents.
• Involvement of the epiphysis or apophysis across an open growth plate presents unique challenges in management and potential for growth disturbance.
• Pathologic fractures are a known complication of UBCs, but their incidence in epiphyseal/apophyseal involvement requires further characterization.

Purpose of the Study:

• To investigate the clinical presentation and outcomes of unicameral bone cysts involving the epiphysis or apophysis across an open growth plate.
• To determine the frequency of associated complications such as pathologic fractures and growth disturbances.
• To evaluate the long-term functional impact and angulation in patients with epiphyseal/apophyseal UBCs.

Main Methods:

• Retrospective case series analysis of twelve pediatric patients diagnosed with unicameral bone cysts.
• Inclusion criteria: UBC involving the epiphysis or apophysis across an open growth plate.
• Data collection included fracture history, presence of growth disturbance, angular deformity (varus/valgus), and functional outcomes.

Main Results:

• Twelve patients with epiphyseal/apophyseal UBCs were identified.
• Nine out of twelve patients (75%) experienced a pathologic fracture.
• Four patients (33%) exhibited a growth disturbance, and most cases presented with some degree of varus angulation.
• No patients reported functional impairment related to the cyst or its complications.

Conclusions:

• Unicameral bone cysts extending into the epiphysis or apophysis of an open growth plate are associated with a high rate of pathologic fractures and potential for growth disturbances.
• While angular deformities like varus angulation are common, functional impairment appears to be minimal in the long term.
• Early recognition and management are crucial to mitigate complications and preserve limb function in pediatric patients with these specific UBC presentations.