[Intramedullary Elastic Transphyseal Tibial Osteosynthesis and Its Effect on Segmental Growth]

Area of Science:

• Pediatric Orthopedics
• Biomaterials Engineering
• Skeletal Biology

Background:

• Intramedullary transphyseal elastic osteosynthesis is utilized for pediatric conditions with weakened bone tissue, such as osteogenesis imperfecta.
• This technique involves inserting elastic rods across growth plates to stabilize bones.

Purpose of the Study:

• To evaluate the impact of transphyseal elastic rod insertion on tibial growth in a pediatric model.
• To investigate the effects of combining transphyseal reinforcement with transverse fracture modeling and subperiosteal titanium mesh placement.

Main Methods:

• A non-randomized controlled study was conducted on 18 puppies, divided into three experimental series.
• Series I: Counter-directed transphyseal tibial reinforcement.
• Series II: Transphyseal reinforcement with transverse osteotomy.
• Series III: Transphyseal elastic osteosynthesis combined with subperiosteal titanium mesh and elastic rods during transverse osteotomy.

Main Results:

• Transphyseal reinforcement led to significant growth retardation in the operated tibia across all series (3.8-7.8 mm loss).
• Eccentric rod placement resulted in angular deformities of the distal tibial epiphysis (mean 7°).
• Periosteal and endosteal reactions caused diaphyseal diameter enlargement in Series II and III, but not in Series I.

Conclusions:

• Intramedullary transphyseal reinforcement retards longitudinal bone growth.
• Precise placement of elastic rods near the center of growth plates is essential to avoid angular deformities.
• Subperiosteal reinforcement does not impede fragment consolidation and can be integrated with transphyseal osteosynthesis.