Which is the best femoral implant in children with osteogenesis imperfecta? a retrospective cohort study of 783 procedures.

backgroundOsteogenesis imperfecta (OI) is a hereditary genetic disorder characterized by bone fragility and extremity deformities. The surgical management for long-bone fractures and deformities in OI remains a challenge. We aimed to compare clinical outcomes after femoral surgery splinted with the telescopic rod, the plate and screws, the elastic nail and the non-elongating rod in setting of OI.

methodsA retrospective cohort study included 783 femoral procedures (mean age 6.00 (interquartile range (IQR) 5.00) years, 335 (42.8%) females) was conducted, and individuals were categorized into four groups according to implants. After verifying comparability among the groups, revision rate and implant survival period were compared among the Sillence types and the same comparison were made among four groups within each Sillence type. The incidence of refractures, deformities, and implant-related complications were also compared among the four groups.

resultsThere were no significant differences in demographic information among the four groups in terms of sex (p = 0.101), laterality (p = 0.587), Sillence type (p = 0.122), and postoperative follow-up period (p = 0.214). In total, children with Sillence type III had the highest revision rate and the shortest implant survival period; children with Sillence type I had the lowest revision rate and the longest implant survival period; and children with Sillence type IV had the revision rate and the implant survival period between those observed in Sillence types I and III. In Sillence types III and IV, the telescopic rod had lower revision rate (III 24.8%; IV 20.9%) compared to the plate (III 97.2%, p<0.001; IV 80.3%, p<0.001), the elastic nail (III 100.0%, p=0.019; IV 73.9%, p<0.001) and the non-elongating rod (III 65.0%, p<0.001; IV46.9%, p<0.001); the median implant survival period of the telescopic rod (III 48.00 (IQR 28.50) months; IV 43.00 (33.00) months) is longer than the plate (III 11.00 (9.00) months, p<0.001; IV 19.00 (20.00) months, p<0.001), the elastic nail (III 45.00 (37.75) months, p=1.000; IV 19.00 (35.00) months, p=0.028) and the non-elongating rod (III 39.00 (31.75) months, p=0.473; IV 38.50 (29.75) months, p=1.000).A similar trend was observed in Sillence type I (p = 0.063, p = 0.003; respectively). In addition, the incidence of refracture (15.5%), deformity (2.8%) and implant-related complications (23.1%) were also statistically lower in the telescopic rod group.

conclusionIn our cohort, lower revision rate and longer implant survival period were observed in telescopic rod group. This was mainly due to the significant lower incidence of refracture, deformity and implant-related complications with the use of telescopic rod.