Long-term Outcomes of Intramedullary Nails in Osteogenesis Imperfecta: Fewer Surgeries and Longer Survival Times With Telescoping Rods in Patients With Over Ten Years Follow-up.

Abstract

Objective: Intramedullary rodding of lower extremity long bones in patients with osteogenesis imperfecta (OI) is a widely accepted technique for fracture treatment and prevention. Previous small studies with short to medium-term follow-up have shown that telescoping rods have longer survival times compared with static rods. However, there are no long-term studies (10 or more years) longitudinally evaluating the results of these procedures. The purpose of this study was to compare the rod survival duration and number of procedures in patients treated with static versus telescoping rods with 10 years minimum follow-up.

Methods: This was a multicenter retrospective comparative study of patients with a diagnosis of OI who had intramedullary nailing of the femur and/or tibia. Each bone included in the study had a 10-year minimum follow-up, only one type of rod utilized over the follow-up period, and no rod replacement surgeries outside of the primary hospital system. Patient demographics, clinical data, and details of each procedure were obtained. Groups were compared using univariate analysis with a 2-independent samples t test for continuous variables, χ2 for categorical variables, and the Kaplan-Meier method for survival analysis.

Results: A total of 119 bones in 52 patients met inclusion criteria. Average follow up was 13.1 (range: 10.2 to 18.4) years. There were no differences between groups in follow-up length, Sillence type, bisphosphonate use, or age at first-rod placement. There were significantly more tibias treated in the static rod group compared with the telescopic rod group. The average survival length was significantly longer for telescopic rods, 5.8 ± 3.9 years versus 4.0±3.6 years for static rods. On average, bones treated with telescopic rods had significantly fewer surgeries compared with static rods (2.2 ± 0.8 vs 3.3 ± 1.6).

Conclusion: At long term follow up, bone segments in patients with OI treated with telescopic rods required fewer surgeries and had longer implant survival times compared with those treated with static rods. When available, surgeons should consider telescopic rods as the initial implant choice in this patient population.