The Fassier technique for correction of proximal femoral deformity in children with osteogenesis imperfecta
Keywords:osteogenesis imperfecta, coxa vara, Fassier–Duval, neck-shaft angle
Background: Children with osteogenesis imperfecta frequently present with coxa vara. Skeletal fragility, severe deformity and limited fixation options make this a challenging condition to correct surgically. Our study aimed to determine the efficacy of the Fassier technique to correct coxa vara and determine the complication rate.
Methods: We retrospectively reviewed the records of a cohort of eight children (four females, 12 hips) with osteogenesis imperfecta (6/8 Sillence type III, 2/8 type IV) who had surgical treatment with the Fassier technique for proximal femoral deformity between 2014 and 2020.
Results: The mean age at operation was 5.8 years (range 2–10). The mean neck-shaft angle (NSA) was corrected from 96.8° preoperatively to 137º postoperatively. At a mean follow-up of 38.6 months, the mean NSA was maintained at 133°, and 83 (10/12) of hips had an NSA that remained greater than 120°. There was a 42% (5/12) complication rate: three Fassier–Duval rods failed to expand after distal epiphyseal fixation was lost during growth; one Rush rod migrated through the lateral proximal femur cortex with recurrent coxa vara; and one Rush rod migrated proximally and required rod revision.
Conclusion: The Fassier technique effectively corrected coxa vara in children with moderate and progressively deforming osteogenesis imperfecta. The deformity correction was maintained in the short term. The complication rate was high, but mainly related to the failed expansion of the Fassier–Duval rods. Further studies are required to determine the long-term outcome of this technique.
Level of evidence: Level 4