Implant-related fractures in children with proximal femoral osteotomy: Blade plate versus screw-side plate constructs

Background: Implant design may affect risk of fracture, especially in the proximal femur, which has been shown to have the highest risk of implant-related fracture (IRF). Blade plate (BPL) and screw-side plate (SSP) implants are used to stabilize proximal femoral osteotomies (PFOs). Our goal was to compare BPL and SSP constructs with regard to the rate, location, and timing of IRF in children undergoing PFOs. Methods: We retrospectively reviewed clinical and radiographic records from 1 pediatric orthopaedic practice from 1995 through 2010. We identified 734 children 18 years or younger who underwent PFO with a BPL (480 patients) or an SSP (254 patients). Manufacture and style of implants were consistent throughout this period. There were no significant differences between the 2 groups in terms of mean age, sex, race, or diagnosis. The 2 groups were compared with respect to the rate, location, and timing of IRF. The t, Z, w2, and Fisher exact tests were used to analyze the data (statistical significance, P<0.05 for all analyses). Results: The IRF rates were 2.9% and 1.6% in the BPL and SSP groups, respectively (P=0.27). The overall rate of IRF in all patients was 2.5%. Fractures distal to the implant occurred in 7 of 14 patients in the BPL group and 3 of 4 patients in the SSP group. There was no significant difference between the 2 groups in location of fracture with respect to the implant (P=0.78). The mean times to fracture were 3.8±2.9 and 2.4±2.3 years (P=0.39) in the BPL and SSP groups, respectively. Conclusions: The risk of IRF in children after PFO is substantial. Despite differences in design, there was no significant difference between BPL and SSP implants with respect to IRF risk. Level of Evidence: Level III.