Telescoping versus non-telescoping rods in the treatment of osteogenesis imperfecta.

A retrospective study was undertaken to evaluate and compare the results of telescoping (group I) versus non telescoping rods (group II) in the treatment of osteogenesis imperfecta. Thirty-three lower limb segments in ten patients were studied (14 segments in group I and 19 segments in group II). The surgical techniques of Sofield and Miller (1959) and Lang-Stevenson and Sharrard (1984) for rod insertion were used. All cases were assessed clinically regarding mobility status, growth and limb-length, refracture, and infection. They were also assessed radiologically regarding rod migration, bone outgrowing the rod, incorrect T-piece placement, breakage and bending of rods. The average duration of follow-up was 86.2 months (range: 6 to 8 years). Mobility status and bone growth were better in group I than in group II patients. The overall implant related complication rate was 28.6% in group I in comparison to 68.4% in group II. Rod migration was twice more common in group II than in group I. Bone outgrowing the rod and breakage of rods with fracture was seen in group II only. The three-year survival rate for telescoping rods was 92.9% in contrast to 68.4% for non telescoping rods. The reoperation rate was 7.2% in group I and 31.6% in group II. From this comparative study it was clear that the results were significantly better after Sheffield rods with regard to mobility status, longevity of the rod, and the frequency of complications requiring reoperations. Also most of the complications were related to the technique of rod insertion and the type of rod.