ankle fracture orif - american podiatric medical association power point for apma updated.pdfankle...

Ankle Fracture ORIFGetting Back to the Principles

Dr. Javan S. Bass, FACFAS

Metro Foot & Ankle Centers, PC

Georgia Podiatric Association Board of Directors

No Disclosures

Why Bother?

Questions

- How many locked screws are needed to improve fixation

- Where should locked screws be placed for biomechanical adv.

- What is the effect of each additional locked screw

- How locked screws affect hybrid plate fatigue properties

-Appropriate plate length and screw density

Hybrid Plating

- Locked plating (single beam construct)

secondary bone healing

- Rigidity up to 4 x’s greater than intact bone

- Non-Lock plating relies on friction (plate/bone)

primary bone healing

- 3-5 Nm of torque needed unobtainable in

osteoporotic bone

Gautier et al, INJURY March 2000

Hybrid Plating

Freeman et al, J Orthop Trauma March 2010

- Stiffness

-33% increase from 3 to 4

screws (row 3)

- addt. 34% increase when

increasing to 3 locked screw (row 7)

-addt. Screws allowed for

smaller % reductions in stiffness

over the cycle loading period

Freeman et al, J Orthop Trauma March 2010

Removal Torque

- same for locked screws

- Non-lock screw removal

torque increased by 274%

when farthest from fracture

line and immediately distal to

locking screw

Freeman et al, J Orthop Trauma March 2010

Plate Ratio and Screw Density

Plate ratio is ratio

btw plate length and

fracture length

-(2/3:1) - complex frx’s

-(8/10-1) - simple frx’s

Increase working length

Decrease screw load

Gautier et al, Injury, Int J. Care Injured 2003

Plate Ratio and Screw Density

Screw density refers to

number of screws

occupying holes within

the plate

- 0.5 when possible

Decreased screw density

allows for decreased bending

moments

Gautier et al, Injury, Int J. Care Injured 2003

Increased Bending Moments

MVA

Why Bother?

Metro Foot and Ankle Centers, P.C

Metrofootanklepc.com

Info@metrofootanklepc.com

Javanbass@yahoo.com

770-484-9599