Does the Location of the Distal Tibial Epiphyseal Fixation Affect Rod Failure in Children With Osteogenesis Imperfecta?

BACKGROUND

Fassier-Duval (FD) rods are commonly used for tibial stabilization in children with osteogenesis imperfecta (OI). However, failure to telescope remains frequent, and the impact of rod positioning and patient age on outcomes remains poorly defined.

METHODS

A retrospective review of 452 tibial FD rod placements in 102 pediatric OI patients was performed. Rod position on the anteroposterior (AP) and mediolateral (ML) axes was determined using postoperative radiographs. Failure to telescope was assessed as the primary outcome. Secondary outcome was time to failure. Statistical analysis included chi-squared, linear regression, and multivariable logistic regression.

RESULTS

The failure to telescope rate was 39.6%. Lateral placement significantly increased the odds of failure (OR: 2.71; 95% CI: 1.48-5.05; P=0.001), whereas medial placement showed a nonsignificant trend (OR: 1.94; P=0.088). Central positioning was associated with the lowest failure rate, although AP positioning was not a significant predictor on multivariate analysis. Younger age was significantly associated with failure (OR: 0.90; 95% CI: 0.85-0.95; P<0.001).

CONCLUSIONS

Intermediate rod placement on the AP view significantly reduces the risk of telescoping failure in FD-stabilized tibiae in children with OI. Younger age is a strong predictor of failure, likely due to anatomic challenges. Emphasis on optimal rod placement is warranted to improve outcomes and reduce revision rates.

LEVEL OF EVIDENCE: Level III, retrospective cohort study.