Eight-plate epiphysiodesis: are we creating an intra-articular deformity?

Area of Science:

• Orthopedic surgery
• Pediatric orthopedics
• Skeletal growth modulation

Background:

• Eight-plates are used for angular limb deformities and limb-length discrepancy (LLD) in children.
• The technique involves peripheral physeal tethering to guide bone growth.
• Potential for iatrogenic epiphyseal deformity has been a concern but not previously quantified.

Purpose of the Study:

• To detect and quantify epiphyseal deformities in the proximal tibia after eight-plate treatment.
• To evaluate changes in tibial plateau morphology following guided growth procedures.

Main Methods:

• Retrospective study of 42 children (mean age 10.8 years) treated with 64 eight-plates.
• Proximal tibial eight-plate insertion for angular deformities or LLD (2007-2015).
• Radiographic analysis of interscrew angle, plateau slope angles, and tibial plateau roof angle, comparing pre- and post-operative measurements.

Main Results:

• Increased slope angle in 49.2% of operated epiphyses (mean 5° increase).
• Decreased roof angle in 46.0% of operated tibias (mean 5° decrease).
• Roof angle changes correlated with interscrew angle changes, particularly in LLD cases.

Conclusions:

• Eight-plate use in the proximal tibia alters tibial plateau bony morphology.
• These morphological changes are observed in a significant number of patients.
• The effect on tibial plateau morphology is more pronounced when correcting limb-length discrepancy.