178
· DOS Abstracts
Skeletal Healing after Periacetabular Osteotomy
Measured by RSA - Preliminary Results
Peter Buxbom, Stig Sonne-Holm, Christian Wong
Orthopedic Department, Hvidovre Hospital
Background:
Approximately 25-28% of children with cerebral palsy (CP) de-
velop subluxation or dislocation of the hip that needs surgical intervention.
When this problem is discovered in early childhood the preferred treatment is a
combination of periacetabular and varizating femoral osteotomy. However, 16-
22 % of these children require another similar surgery due to re-luxation during
adolescence.
Purpose / Aim of Study:
To descriptively assess migration and rotation around
periacetabular osteotomies in children with CP measured by radiostereometric
analysis (RSA).
Materials and Methods:
A protocol of perioperative insertion of 4-8 tantalum
markers on each side of the femoral and periacetabular osteotomy was per-
formed and RSA radiographs were recorded and subsequently analysed longi-
tudinally postoperatively (in cast) and at time 5, 12 weeks, 6 and 12 months
after surgery.
Findings / Results:
The cohort consisted of 6 girls and 9 boys, 8 left and 7
right hips. The median age was 7.3 years. 12 underwent Dega, 2 Salter and 1
Chiari osteotomy. All had 3 months follow- up period, and 9 had been followed
1 year. The average Maximum Total Point Motion (MTPM) is 1.57, 1.52, 1.88
and 2.17 at respectively 5, 12 weeks, 6 and 12 months.
Conclusions:
Results show initial movement across the osteotomy in spite
of being casted for 5 weeks. However, this pattern ceases from 5 weeks to 3
months, where the ΔMTPM decrease the remaining follow-up period. Salter
and Chiari osteotomies demonstrate largest MTPM values, though there is not
enough data to perform statistical analysis.
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