Original Author: Dan Horwitz, MD; March 2004
Revision Author: Michael Archdeacon, MD, MSE; January 2006
New Author: Brett D. Crist, MD; October 2009

• Union
– Bone’s mechanical stability restored to withstand normal loads
• Clinically: no pain at fracture site
• Radiographically: 3 out of 4 cortices with bridging callus
• Delayed Union
– Fx not consolidated at 3 months, but progressive callus
• Non Union
– No improvement clinically or radiographically over 3 consecutive months
– A fibrocartilaginous interface
From: OTA Resident Course – Russel, T

• “High Energy"
– Direct axial load or bending force
– Fall from height/Motor vehicle crash
– Soft tissue envelope significantly damaged
– Comminuted fracture patterns
– Open fractures
• “Low Energy“
– Twisting mechanism or direct load on weak bone
– Fall from standing
– Less soft tissue injury
– Simple fracture pattern
“Low
Energy"
“High
Energy"

• Fracture patterns occur based on mode, magnitude and rate of force application to bone
– Bending Load → transverse fx with wedge segment
• 3-point Bend →Wedge fragment
• 4-point Bend → Segmental fragment
– Torsional Load → oblique or spiral fx
– Axial Load → Articular impaction (Plateau, Pilon, etc.)

• Understanding these patterns and the inherent stability of each type is important in choosing the most appropriate method of fixation and surgical approach

THE SIMPLE VERSION...
Absolute Stability =
1 0 Bone Healing
Relative Stability =
2 0 Bone Healing
Haversian
Remodeling
High Rate of Healing
Fibrous Matrix >
Cartilage > Calcified
Cartilage > Woven
Bone > Lamellar Bone
Minimal
Callus
Spectrum of Healing
Callus

• Direct/Primary bone healing
– Requires rigid internal fixation and intimate cortical contact – absolute stability
– Minimal callus formation
– Cannot tolerate fracture gap
– Interfragmental compression will minimize fracture motion
– Relies on Haversian remodeling with bridging of small gaps by osteocytes (cutting cones)
Figure from: OTA Resident Course - Russel

• Indirect/Secondary Bone
Healing = CALLUS
– Divided into stages
• Inflammatory Stage
• Repair Stage
– Soft Callus Stage
– Hard Callus Stage
• Remodeling Stage
3-24 mo
– Relative stability
Figures from: OTA Resident Course - Russel

Primary/Direct Bone
Healing
• Simple fracture patterns
• See the fx during surgery and directly reduce and fix with:
– Lag screws
– Plates and screws
Secondary/Indirect Bone
Healing
• Complex fracture patterns
• Don’t directly see the fracture during surgery
(use fluoro)
• Indirectly reduce the fx and fix with:
– IM Rods
– Bridge plate fixation
– External fixation
– Cast

•
Relative Stability
– IM nailing
– Ex fix
– Bridge plating
–Cast
•
Absolute Stability
– Lag screw/ plate
– Compression plate

Cast
Relative
(Flexible)
IM Nail
Ex Fix
Bridge Plating
Compression
Plating/ Lag screw
Absolute
(Rigid)

• Most fixation probably involves components of both types of healing. Even in situations of excellent rigid internal fixation one often sees a small degree of callus formation...

Absolute
(Flexible)
Reality
Callus
No callus
Relative
(Rigid)

• Interfragmentary
Compression
– Lag Screw
• Plate Functions
– Neutralization
– Buttress
– Bridge
– Tension Band
– Compression
– Locking
• Intramedullary Nails
– Internal splint
• Bridge plate fixation
– Internal splint
• External fixation
– External splint
• Cast
– External splint
*Not internal fixation

• Displaced intra-articular fracture
• Axial, angular, or rotational instability that cannot be controlled by closed methods
• Open fracture
• Polytrauma
• Associated neurovascular injury
MULTIPLE REASONS EXIST
BEYOND THESE ...

• Earlier functional recovery
• More predictable fracture alignment
• Potentially faster time to healing

• Cortical screws:
–Greater number of threads
–Threads spaced closer together (pitch is
(smaller pitch)
–Outer thread diameter to core diameter ratio is less
–Better hold in cortical bone
• Cancellous screws:
–
Larger thread to core diameter ratio
–Threads are spaced farther apart (pitch is greater)
– Lag effect with partially-threaded screws
– Theoretically allows better fixation in cancellous bone
Figure from: Rockwood and Green’s, 5 th ed.

• Screw compresses both sides of fx together
– Best form of compression
– Poor shear, bending, and rotational force resistance
• Partially-threaded screw
(lag by design)
• Fully-threaded screw (lag by technique)

• “Lag by technique”
• Using fully-threaded screw
• Step One: Gliding hole = drill outer thread diameter of screw & perpendicular to fx
• Step Two: Pilot hole= Guide sleeve in gliding hole & drill far cortex = to the core diameter of the screw
2
1
Figure from: Schatzker J, Tile M: The Rationale of
Operative Fracture Care. Springer-Verlag, 1987.

• Step Three: counter sink near cortex so screw head will sit flush
• Step Four: screw inserted and glides through the near cortex
& engages the far cortex which compresses the fx when the
Figure from: Schatzker J, Tile M: The
Rationale of Operative Fracture Care.
Springer-Verlag, 1987.
screw head engages the near cortex

• Functional Lag Screw
- note the near cortex has been drilled to the outer diameter = compression
• Position Screw - note the near cortex has not been drilled to the outer diameter = lack of compression & fx gap maintained

• Malposition of screw, or neglecting to countersink can lead to a loss of reduction
• Ideally lag screw should pass perpendicular to fx
Figure from: OTA Resident Course - Olsen

• Neutralizes/protects lag screws from shear, bending, and torsional forces across fx
• “Protection Plate"
Figure from: Schatzker J, Tile M: The Rationale of
Operative Fracture Care. Springer-Verlag, 1987.

• “Hold” the bone up
• Resist shear forces during axial loading
– Used in metaphyseal areas to support intraarticular fragments
• Plate must match contour of bone to truly provide buttress effect

• Order of fixation:
• Articular surface compressed with bone forceps and provisionally fixed with k-wires
1. Bottom 3 cortical screws placed
•
Provide buttress effect
2. Top 2 partially-threaded cancellous screws placed
•
Lag articular surface together
3. Third screw placed either in lag or normal fashion since articular surface already compressed
Figure from: Schatzker J, Tile M: The Rationale of
Operative Fracture Care. Springer-Verlag, 1987.

• Plate is secured by three black screws distal to the red fracture line
• Axial loading causes proximal fragment to move distal and to the left along fracture line
• Plate buttresses the proximal fragment
• Prevents it from “sliding”
• Buttress Plate
– When applied to an intra-articular fractures
• Antiglide Plate
– When applied to diaphyseal fractures

• “Bridge”/bypass comminution
• Proximal & distal fixation
• Goal:
– Maintain length, rotation, & axial alignment
• Avoids soft tissue disruption at fx = maintain fx blood supply

• Plate counteracts natural bending moment seen w/ physiologic loading of bone
– Applied to tension side to prevent “gapping”
– Plate converts bending force to compression
– Examples: Proximal Femur &
Olecranon

• The fixation on the opposite side from the articular surface provides reduction and compressive forces at the joint by converting bending forces into compression
• The fracture has tension forces applied by the muscles or load bearing
JOINT SURFACE
Tension band
Load applied to bone

• The tension band prevents distraction and the force is converted to compression at the joint
• The tension band functions like a door hinge, converting displacing forces into beneficial compressive forces at the joint
JOINT SURFACE
Tension band
Load applied to bone

• Wires can be used for tension band as well
• Ex: Olecranon and patella
• 2 K-wires from tip of olecranon across fx site into anterior cortex to maintain initial reduction and anchor for the tension wire
• Tension wire brought through a drill hole in the ulna
• Both sides of the tension wire tightened to ensure even compression
• Bend down and impact wires
Figure from: Rockwood and Green’s, 4 th ed.

• Reduce & Compress transverse or oblique fx’s
– Unable to use lag screw
– Exert compression across fracture
• Pre-bending plate
• External compression devices (tensioner)
• Dynamic compression w/ oval holes & eccentric screw placement in plate

• LC-Dynamic
Compression Plate :
– stronger and stiffer
– more difficult to contour.
– usually used in the treatment radius and ulna fractures
• Semitubular plates:
– very pliable
– limited strength
– most often used in the treatment of fibula fractures
Figure from: Rockwood and Green’s, 5 th ed.
Figure from: Rockwood and Green’s, 5 th ed.

• Fundamental concept critical for primary bone healing
• Compressing bone fragments decreases the gap and maintains the bone position even when physiologic loads are applied to the bone. Thus, the narrow gap and the stability assist in bone healing.
• Achieved through lag screw or plating techniques.

• Prebent plate
– A small angle is bent into the plate centered at the fracture
– The plate is applied
– As the prebent plate compresses to the bone, the plate wants to straighten and forces opposite cortex into compression
– Near cortex is compressed via standard methods
• External devices as shown
• Plate hole design

• Requires a separate drill/screw hole beyond the plate
• Concept of anatomic reduction with added stability by compression to promote primary bone healing has not changed
• Currently, more commonly used with indirect fracture reduction techniques
Figure from: Schatzker J, Tile M: The Rationale of
Operative Fracture Care. Springer-Verlag, 1987.

• Note the screw holes in the plate have a slope built into one side.
• The drill hole can be purposely placed eccentrically so that when the head of the screw engages the plate, the screw and the bone beneath are driven or compressed towards the fracture site one millimeter.
Figure from: Schatzker J, Tile M: The Rationale of
Operative Fracture Care. Springer-Verlag, 1987.
This maneuver can be performed twice before compression is maximized .

• Compression applied via oval holes and eccentric drilling
– Plate forces bone to move as screw tightened = compression

• Compression can be achieved and rigidity obtained all with one construct
• Compression plate first
• Then lag screw placed through plate if fx allows Figure from: Rockwood and Green’s, 5 th ed.

• Screw head has threads that lock into threaded hole in the plate
• Creates a “fixed angle” at each hole
• Theoretically eliminates individual screw failure
• Plate-bone contact not critical
Courtesy AO Archives

• Must have reduction and compression done prior to using locking screws
– CANNOT PUT CORTICAL SCREW OR LAG
SCREW AFTER LOCKING SCREW

• Increased axial stability
• It is much less likely that an individual screw will fail
– But, plates can still break

• Indications:
– Osteopenic bone
– Metaphyseal fractures with short articular block
– Bridge plating

• Relative stability
• Intramedullary splint
• Less likely to break with repetitive loading than plate
• More likely to be load sharing (i.e. allow axial loading of fracture with weight bearing).
• Secondary bone healing
• Diaphyseal and some metaphyseal fractures

• Generally utilizes closed/indirect or minimally open reduction techniques
• Greater preservation of soft tissues as compared to ORIF
• IM reaming has been shown to stimulate fracture healing
• Expanded indications i.e. Reamed IM nail is acceptable in many open fractures

• Rotational and axial stability provided by interlocking bolts
• Reduction can be technically difficult in segmental and comminuted fractures
• Maintaining reduction of fractures in close proximity to metaphyseal flare may be difficult

• Open segmental tibia fracture treated with a reamed, locked IM Nail.
• Note the use of multiple proximal interlocks where angular control is more difficult to maintain due to the metaphyseal flare.

• Intertrochanteric/
Subtrochanteric fracture treated with closed IM
Nail
• The goal:
• Restore length, alignment, and rotation
• NOT anatomic reduction
• Without extensive exposure this fracture formed abundant callus by 6 weeks
Valgus is restored...

Indirect Methods
• Traction-assistant, fx table, intraop skeletal traction
• Direct external force i.e. push on it
• Percutaneous clamps
• Percutaneous K wires/Schantz pins—
”Joysticks”
• External fixator or distractor
Direct Methods
• Incision with direct fracture exposure and reduction with reduction forceps

• Over the last 25 years the biggest change regarding ORIF of fractures has probably been the increased respect for soft tissues.
• Whatever reduction or fixation technique is chosen, the surgeon must minimize periosteal stripping and soft tissue damage.
– EXAMPLE
: supraperiosteal plating techniques

• Pointed reduction clamps used to reduce a complex distal femur fracture
• Open surgical approach
• Excellent access to the fracture to place lag screws with the clamp in place
• Remember, displaced articular fractures require direct exposure and reduction because anatomic reduction is essential

• Place clamp over bone and the plate
• Maintain fracture reduction
• Ensure appropriate plate position proximally and distally with respect to the bone, adjacent joints, and neurovascular structures
• Ensure that the clamp does not scratch the plate , otherwise the created stress riser will weaken the plate
Figure from: Rockwood and Green’s, 5 th ed.

• Plating through modified incisions
– Indirect reduction techniques
– Limited incision for:
• Passing and positioning the plate
• Individual screw placement
– Soft tissue “friendly”

• Classic example of inadequate fixation & stability
• Narrow, weak plate that is too short
• Insufficient cortices engaged with screws through plate
• Gaps left at the fx site
Unavoidable result =
Nonunion Figure from: Schatzker J, Tile M: The Rationale of
Operative Fracture Care. Springer-Verlag, 1987.

• Respect soft tissues
• Choose appropriate fixation method
• Achieve length, alignment, and rotational control to permit motion as soon as possible
• Understand the requirements and limitations of each method of internal fixation
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