ABSTRACT
Objective To discuss the biomechanical factors in the nonunion of femoral fractures and raise corresponding measures. Methods Sixty eight cases with nonunion of femoral shaft fractures were treated with interlocking intramedullary nailing and 13 with nonunion of distal femoral fractures fixated with dynamic condylar screw (DCS). Inner and outer intramedullary bone graft was performed simultaneously. Results The follow up time was 8 24 months with an average of 14 months in all cases. Sixty eight cases got bone healing except for five cases with breakage of nail or lock nail, which were all cured with again interlocking intramedullary nailing combined with bone graft. Thirteen cases with nonunion of distal femoral fractures were healed after DCS internal fixation treatment. The healing time averaged 6.5 months in 81 cases. According to synthetic standards including bone healing and function recovery, 54 cases won excellent bone healing, 21 good and 6 poor, with an excellence rate of 92.6%. Conclusions The failed femoral fracture operation is mainly due to the failed internal fixation caused by the biomechanical factor of the abductor muscles. Therefore, intramedullary nailing system should be the first choice for internal fixation of femoral shaft fractures and nonunion; and DCS should be used for condylar fractures and nonunion.