Indirect reduction of distal femur by Less Invasive Stabilization System-Distal Femur plate

Abstract

Objective To introduce a type of anatomical locking plate (Synthes(R) LISS DF) in the less invasive stabilization system (LISS) which can have an effect of indirect reduction and fixation on comminuted fractures of the femur.Methods From December 2002 through December 2006,13 male patients with complicated fresh fracture of the distal femur were treated with Synthes LISS DF.Their ages ranged from 18 through 58 years,with an average of 37.1 years.First,a specially shaped LISS DF was placedat the femoral external condyle to fixate the distal femur.The distal locking screws at the holes D and F of the LISS DF plate were paralleled to the knee joint surface in the anteriorposterior view and the line between the screw holes D and F was kept as long as the axis of the femoral lateral condyle in the lateral view.Next the proximal end of the LISS DF was placed at the lateral femur to fixate the femur shaft after traction to restore the length of the femur.After the fixation like this,the femoral fractures were reduced automatically in a functional reduction.The femoral axis orientation and the Blumensaat line were used for evaluation of the reduc-tion.Results All the patients were followed up for an average of 18 months (from 13 to 36 months).The fracture united in 61.5％ (8/13) of the patients at 3 months postoperation and in all at 12 months postoperation.The average distal femoral axis orientation was 81.7°±3.5° and the average angle between the Blumensaat line and the long axis of the femoral shaft was 38.7° + 6.0°.The last follow-up found no secondarydisplacement of the fracture or no implant failure.By the evaluation system of The Hospital for Special Surgery (HSS),the patients scored 76 on average (from 42 to 96).Three cases were rated as excellent,6 as fine,3 as fair and one as poor,with a good to excellent rate of 69.2％.Conclusions LISS DF can be used as a template to fix and reduce simultaneously the comminuted fractures of the distal femur,especially in cases who have lost the reduction marks on X-ray.In this way,the surgical procedures can be simplified to achieve a functional reduction of the femur in a minimally invasive plate osteosynthesis. Key words: Femoral fractures; Bone plates; Fracture fixation, internal; Reduction