Case ReportSubtrochanteric Fracture after Internal Fixation of Femoral Neck Fracture Using the Hansson Pinloc System: A Case Report

INTRODUCTION: Hansson Pinloc system consists of three pins locking into a plate. In biomechanical trials, the novel plate design with its pin configuration enhanced torsional stability. Hansson Pinloc has been used for femoral neck fracture in some countries including Sweden and Japan. Recently, the outcome of a randomized clinical study comparing Hansson Pinloc and conventional Hansson pins was published. However, subtrochanteric fracture after internal fixation using Hansson Pinloc has not been reported in the English literature including the above report. Only several Japanese literatures reported some cases with this post-operative complication. We present a case with subtrochanteric fracture after internal fixation using Hansson Pinloc. CASE REPORT: Subtrochanteric fractures after internal fixation of femoral neck fractures are rare but severe complications. We present our experience of this complication after internal fixation using Hansson Pinloc system which is a new design implant for femoral neck fracture. A 67-year-old woman was diagnosed with a femoral neck fracture of Garden stage I after a fall. She underwent closed reduction and internal fixation using Hansson Pinloc system. At 4 weeks after surgery, she suffered subtrochanteric fracture without any episode of trauma. The patient underwent removal of the instrumentation and internal fixation with a long femoral nail. We get in trouble with removing Hansson Pinloc system due to secondary fracture, and of bone defect. 9 weeks after the second surgery, the patient could get bone union and walk using double T-canes. CONCLUSION: Surgeons should be cognizant of this post-operative complication before using this system. In osteosynthesis of the femoral neck fracture using Hansson Pinloc, we should keep in mind that subtrochanteric fracture is a possible post-operative complication.