Biomechanical analysis of distal femoral fracture fixation: dynamic condylar screw versus locked compression plate

AbstractBackground This human cadaveric study i ntroduces a laboratory model to establish and compare the fixation stability of the distal femoral locking plate (DFLP) and dynamic condylar screw (DCS) in distal femoral fracture fixation.Materials and methodsThe study was conducted on 16 fresh cadaveric femoral specimens, 8 implanted with the DCS and the other 8 with the DFLP. The construct was made unstable by removing a standard-sized medial wedge with a 1-cm base (gap osteotomy) beginning 6 cm proximal to the lateral joint line in the distal metaphyseal region with loss of the medial buttress. Each specimen underwent axial and torsional stiffness testing along with cyclic axial loading to failure. The mean DEXA value for the DFLP group was 0.82 g/cm2 and in the DCS group was 0.79 g/cm2.ResultsAxial stiffness in the DFLP group was significantly higher than in the DCS group, but no significant difference was found in torsional stiffness between the groups. A significant difference was found in the load-to-failure results between the groups. Plastic and total deformation was significantly higher in constructs in the DCS group than in those in the DFLP group. Total energy absorbed before construct failure was also significantly higher in the DFLP group than in the DCS group. ConclusionsThe DFLP construct proved stronger than the DCS in both axial stiffness and cyclic loading, but similar in torsional stiffness in biomechanical testing in a simulated A3 distal femoral fracture.

[1]  Erik N. Kubiak,et al.  The evolution of locked plates. , 2006, The Journal of bone and joint surgery. American volume.

[2]  F. Kummer,et al.  Comparison of the LISS and a retrograde-inserted supracondylar intramedullary nail for fixation of a periprosthetic distal femur fracture proximal to a total knee arthroplasty. , 2002, The Journal of arthroplasty.

[3]  D. Seligson,et al.  Intramedullary supracondylar nailing of femoral fractures. A preliminary report of the GSH supracondylar nail. , 1993, Clinical orthopaedics and related research.

[4]  A. Busuttil,et al.  Fatal falls down stairs. , 1999, Injury.

[5]  K. Ito,et al.  Internal fixation of supracondylar femoral fractures: comparative biomechanical performance of the 95-degree blade plate and two retrograde nails. , 1998, Journal of orthopaedic trauma.

[6]  B. Romanus,et al.  An experimental study of devices for internal fixation of distal femoral fractures. , 1982, Clinical Orthopaedics and Related Research.

[7]  F. Kummer,et al.  Distal femoral fixation: a biomechanical comparison of the standard condylar buttress plate, a locked buttress plate, and the 95-degree blade plate. , 1997, Journal of orthopaedic trauma.

[8]  S. Gilbert,et al.  The development of the distal femur Less Invasive Stabilization System (LISS). , 2001, Injury.

[9]  K. Firoozbakhsh,et al.  Mechanics of Retrograde Nail Versus Plate Fixation for Supracondylar Femur Fractures , 1995, Journal of orthopaedic trauma.

[10]  J. Vroemen,et al.  Biomechanical analysis of the Gamma nail and sliding hip screw. , 1994, Clinical orthopaedics and related research.

[11]  Ulrich Dieter,et al.  Biomechanical testing of the LCP--how can stability in locked internal fixators be controlled? , 2003, Injury.

[12]  M. Zlowodzki,et al.  Biomechanical Evaluation of the Less Invasive Stabilization System, Angled Blade Plate, and Retrograde Intramedullary Nail for the Internal Fixation of Distal Femur Fractures , 2004, Journal of orthopaedic trauma.

[13]  J Cordey,et al.  Biomechanical Evaluation of the Less Invasive Stabilization System for the Internal Fixation of Distal Femur Fractures , 2001, Journal of orthopaedic trauma.

[14]  K. Wulff,et al.  Epidemiology and treatment of distal femoral fractures in adults. , 1982, Acta orthopaedica Scandinavica.

[15]  C Krettek,et al.  Evolution of minimally invasive plate osteosynthesis (MIPO) in the femur. , 2001, Injury.

[16]  Kent N Bachus,et al.  Biomechanical Analysis of Distal Femur Fracture Fixation: Fixed-Angle Screw-Plate Construct Versus Condylar Blade Plate , 2007, Journal of orthopaedic trauma.

[17]  D. Lorich,et al.  Retrograde intramedullary nailing of supracondylar femoral fractures. , 1998, Clinical orthopaedics and related research.

[18]  Michael D. Barnett,et al.  Distal femoral fixation: a biomechanical comparison of trigen retrograde intramedullary (i.m.) nail, dynamic condylar screw (DCS), and locking compression plate (LCP) condylar plate. , 2009, The Journal of trauma.

[19]  Maurice E. Muller,et al.  The Comprehensive Classification of Fractures of Long Bones , 1990 .

[20]  J. Delee,et al.  Supracondylar-intercondylar fractures of the femur treated with a supracondylar plate and lag screw. , 1982, The Journal of bone and joint surgery. American volume.

[21]  M. Swiontkowski,et al.  Double-plating of comminuted, unstable fractures of the distal part of the femur. , 1991, The Journal of bone and joint surgery. American volume.

[22]  W. Hutton,et al.  Supracondylar femur fracture fixation: Mechanical comparison of the 95° condylar side plate and screw versus 95° angled blade plate , 2002 .

[23]  J. Cordey,et al.  The mechanics of internal fixation of fractures of the distal femur: a comparison of the condylar screw (DCS) with the condylar plate (CP). , 1999, Injury.

[24]  J Cordey,et al.  The epidemiology of fractures of the distal femur. , 2000, Injury.

[25]  M. Kuster,et al.  Biomechanical Considerations in Plate Osteosynthesis: The Effect of Plate-to-Bone Compression With and Without Angular Screw Stability , 2007, Journal of orthopaedic trauma.