Acute Interpositional Fat Autograft Does Not Protect Against Bar Formation in Physeal Fractures.

Area of Science:

• Orthopedics
• Pediatric Orthopedics
• Skeletal Biology

Background:

• Pediatric long-bone fractures risk premature physeal bar formation and growth disturbance.
• Limited data exists on prophylactic tissue interposition for physeal fractures.
• This study evaluates acute fat autograft placement in an animal model.

Purpose of the Study:

• To assess the efficacy of acute fat autograft interposition in preventing radiographic bar formation and growth disturbance in pediatric physeal fractures.
• To compare outcomes between fat autograft interposition, fracture only, and control groups.

Main Methods:

• Proximal tibial physeal fractures were created in 30 rabbits.
• Twenty fractures received fat autograft interposition (fat group), 10 did not (fracture group).
• Contralateral limbs served as controls. Radiographs, micro-CT, and histology analyzed bar formation and growth.

Main Results:

• No significant difference in radiographic bar formation between fat and fracture groups (p = 0.702).
• Both fat and fracture groups showed increased valgus growth compared to controls (p = 0.002, p = 0.04).
• Tibial length was reduced in the fat group versus controls (p = 0.02); fat was converted to bone, not preserving cartilage.

Conclusions:

• Acute fat autograft interposition did not reliably prevent radiographic bar formation or angular deformity in physeal fractures.
• The fat graft converted to bone, similar to the fracture-only group, without significant reduction in bone bar formation.
• Current findings do not support acute prophylactic fat interposition for preventing bars in pediatric physeal fractures.