Intramedullary nailing seminar by dr ashwani panchal

DR ASHWANI PANCHAL

JSS MEDICAL COLLEGE

MYSORE

The intramedullary nail is commonly used for long-bone

fracture fixation and has become the standard treatment

of most long-bone diaphyseal and selected metaphyseal

fractures1

To understand the intramedullary nail, knowledge of

evolution and biomechanics are helpful 2

In 16 th Century In Mexico Aztec physicians have placed

wooden sticks into the medullary canals of patients with long

bone non-union.

In Mid 1800’s Ivory pegs were inserted into the medullary

canal for non-union. In1917 ‘s Hoglund of United States

reported the use of autogenous bone as a intramedulary

implant.

1930’s In the United States, Rush and Rush described the

use of Steinman pins placed in the medullary canal to treat

fractures of the proximal ulna and proximal femur.

1940 ‘s : The Evolution of Kűntscher Nailing

Gerhard Kűntscher was born in Germany in 1900

1931 : Smith-Petersen reported the success of stainless

steel nails for the treatment of NOF #s

1940’s:

Gerard

Küntscher developed ‘V’

nail, Cloverleaf shaped and

the ‘Y’ nail.

His methods were based on

two principles: stable fixation

and closed nailing. .

.

Harvey C. Hansen and Dana

M. Street developed a diamond

shaped nail which is relied on

the holding power of cancellous

bone at both ends. He termed

the word ‘Bolt

Lottes designed three flanged

femur and tibial nails. Both nails

employed a screw-on driver-

extractor

1950’s:

Stryker designed a broach in

a cloverleaf and diamond

shaped pattern. It provided

maximum holding power to

resist torque and avoided

reaming the entire canal

circumference.

.

.

Schneider designed his nail

which incorporated a double-

ended stud, self broaching and

fluted with a square cross

section

1950’s Interlocking Screws :

Modny and Bambara introduced

the transfixion intramedullary

nail in 1953

Nailing of tibia is introduced by

herzog in 1950.

Livingston bar,introduced a

short I-beam pattern pointed

nail at both ends,which had

short slots for cross-pinning with

screws

Today any fracture is stabilized by one of the two

systems of fracture fixation .

1. compression system

2. splinting system

Intramedullary fixation belongs to internal splinting

system.

Splintage may be defined as a construct in which

micromotion can occur between bone & implant,

providing only relative stability without interfragmentary

compression.

Depending on the anatomy the insertion can be ante

grade and retrograde.

The entry point depends on the anatomy of the bone but

is distant from the fracture site.

Intramedullary fixation techniques offer the advantages of

closed reduction and closed fixation.

A.CENTROMEDULLARY- K NAIL,FIRST GENERATION

IM NAIL

B.CEPHALOMEDULLARY- GAMMA NAIL, RUSSELL

TAYLOR NAIL,UNIFLEX, PFN

C.CONDYLOCEPHALIC NAIL-ENDER NAIL,LOTTES

ETC

•Also known as elastic stable intramedullary nailing

(ESIN), is a primary definitvie fracture care (PDFC) in

paediatric orthopaedic practice.

•This method works by 3 – point fixation or bundle

nailing.

•The elasticity of the construct allows for ideal

cirumstances of micro-motion for rapid fracture healing.

• Nonreamed nails are actually not nails but pins. Their mechanical characteristics and use are different from IM nails. They are of smaller diameter and are more elastic.

• Their flexibility allows insertion through a cortical window. There are many different types of flexible nails, the best known are:-

Lottes nails - Tibia Rush pins – for all the long bones of the body Ender nailsMorote nails Nancy nails Prevot nails Bundle nails

Intramedullary nails to be

used as single without

reaming.

A. Schneider nail [ solid,

four flutedcross section

and self broaching ends.

B. Harris condylocephalic

nail [curved in two

planes, and designed for

percutaneous, retrograde

fixation of extra capsular

hip fractures.

C. Lottes tibial nail

specially curved to fit the

tibia, and has triflanged

cross section.

RUSH NAILS

SOLID, CIRCULAR IN

CROSS SECTION,

STRAIGHT,WITH A

SHARP BEVELLED TIPS

AND A HOOK AT THE

DRIVING END.

Ender Nails, which are

solid pins with an

oblique tip and an eye in

flange at the other end,

were originally designed

for percutaneous, closed

treatment of extra

capsular hip fractures

•Each nail is precurved to achieve 3-point fixation where the

required precurve should be approximately 3 times the

diameter of a long bone at its narrowest point.

•Part of the biomechanical

stability is provided by the intact

muscle envelope surrounding

the long bone.

•All currently available nails

have beaked or hooked ends to

allow satisfactory sliding down

on insertion along inner surface

of the diaphysis without

impacting the opposite cortex.

•Insertion points that do not lie

opposite to one another produce

differing internal tension and

imbalance of the fracture stability

and fixation.

•The apex of the curvature should

be at the level of the fracture site.

•The nail diameter should be 40%

of the narrowest medullary space

diameter.

•.

•Two nails of the same diameter

and similarly prebent to be

used.

•Commonest biomechanical

error is lack of internal support.

There are two basic methods of IM pinning, they are: 1. Three point compression.2. Bundle nailing.

Most pins stabilize fracture by three point compression.

These pins are C- or S – Shaped, they act like a spring. The equilibrium between the tensioned pin and the bone with its attached soft tissues will hold the alignment.

The principle of bundle nailing was introduced by Hackethal. He inserted many pins into the bone until they jammed within the medullary cavity to provide compression between the nails and the bone.

Both techniques should be seen more as IM splinting than rigid fixation.

Bending movements are neutralized, but telescoping and rotational torsion are not prevented with this technique

Flexible nail are usually simpler to use and can be inserted more quickly.

If infection intervenes, the complication of likely less severe. So can be used in tibia open fracture because of its less blood supply and its subcutaneous location.

Because of small size of forearm bones reaming is technically difficult, so unreamed nail have generally been used.

•They are usually reamed nails in which interlocking is

its newer modification.

•The classic reamed nail is the hollow, open – section

nail of Küntscher.

•Most other reamed nails are variations of the

Küntscher nail such as the AO nail, and the various

interlocking nails, such as the Grosse – kempf, Klemm

Alta, Russell – Taylor, Uniflex, AO Universal and

others.

Consecutive advancements of nails over years Can be

grouped under three generations

1 st generation:

primarily act as splints ,rotational stability is minimal , primarly

relies on close fit

Eg –K nail , V nail

2 nd generation :

Improved rotational stability due to locking screw

Eg-Russel taylor nail

3 rd generation:

Nails with various designs to fit anatomocally as much as

possible ,to aid the insertion and stability

Eg -Nails with multiple curves ,multiple fixation systems

Tibial nail with malleolar fixation

A. Kuntscher nail, designed for open

nailing.

B. Kuntscher nail designed for closed

nailing which has a curved, tapered

tip, and is slotted throughout.

C.Grosse – Kempf nail

D.Alta intramedullary locking nail for

the femur. This is solid section,

cannulated nail with a hexagonal

cross section with smooth flutes to

enhance revascularization.

.

Russell – Taylor nail:

This is a second generation nail.

Proximal locking into the

femoral head enhances its

stability in hip fractures

Brooker – Wills nail fixing a

fracture of the femur, an AP

roentgenogram. This nail has

flanges deployed through

slots in the tip of the nail for

distal stability.

Except for the Brooker – Wills nail with its flanges and the expandable tip of the Seidel nail, which is used exclusively for the humerus, all current designs use two distal transverse cross – locking screws, as in the Alta intramedullary rod

Proximal fixation includes inclined screws as in the Grosse Kempf nail, two transverse screws, as in the Alta, and specialized screws though the nail designed to secure fixation in the femoral head, as in the Russell –Taylor

Gamma nail: This intramedullary

device is designed for proximal

intramedullary fixation of

intertrochanteric and some

subtrochanterc fractues.

When placed in a fractured long

bone, IM nails act as internal

splints with load-sharing

characteristics.

Various types of load act on an IM

nail: torsion, compression, tension

and bending

Physiologic loading is a

combination of all these forces

Bending moment = F x DF = Force

D

F = Force

D

The bending moment for the plate

is greater due to the force being

applied over a larger distance.

IM Nail Plate

D = distance from force

to implant.

• Nail cross section

is round resisting

loads equally in all

directions.

• Plate cross-section

is rectangular

resisting greater

loads in one plane

versus the other.

The amount of load borne by the nail depends on the

stability of the fracture/implant construct.

This stability is determined by

1.Nail Characteristics

2.Number and orientation of locking screws

3.Distance of the locking screw from the fracture site

4.Reaming or non reaming

5.Quality of the bone

IM nails are assumed to bear most of the load initially, then

gradually transfer it to the bone as the fracture heals.

Several factors contribute to the overall biomechanical profile

and resulting structural stiffness of an IM nail.

Chief among them are

a)Material properties

b)Cross-sectional shape

c)Diameter Curves

d)Length and working length

e)Extreme ends of the nail

f) Supplementary fixation devices

•Metallurgy less importantthan other parameters forstiffness of an IM Nail.

Most of them arefabricated from stainlesssteel, with a small numberfrom titanium.

050

Cobalt

316L Stainlesssteel

Titanium

Bone cortex

PMMA

* 10 ⁸ psi

Titanium alloy has a modulus of elasticity closely

approximates that of cortical bone ( Modulus is ability to

resist deformation in tension

The material must be stiff . Titanium are 1.6 times stiffer and

elastic modulus is 50% lower than steel nail

The cross-sectional shape of the nail ,Diameter

determines its bending and torsional strengths( Resistance

of a structure to torsion or twisting force is called polar

movement of inertia )

Circular nail has polar movement of inertia proportional to

its diameter, in square nail its proportional to the edge

length

Nails with Sharp corners or fluted edges has more polar

movement inertia

Cloverleaf design resist bending most effectively .Presence

of slot reduces the torsional strength . It is more rigid when

slot is placed in tensile side

A-Schneider

B-Diamond

C-Sampson fluted

D- Kuntscher

E-Rush

F-Ender

G- Mondy

H-Halloran

I- Huckstep

J-AO/ASIF

K-Grosse – Kempf

L-Russell-Taylor

Diameter :

Nail diameter affects bending rigidity of nail.

For a solid circular nail, the bending rigidity is proportional to

the third power of nail diameter

Torsional rigidity is proportional to the fourth power of

diameter .

Large diameter with same cross-section are both stiffer and

stronger than smaller ones.

•Some nails are designed in a such a way that stiffness

doesn’t vary with diameter.

•The diameter of a nail should always

be measured with a circular guage.

•In reamed nailing, the width of nail is

better determined by the feel of the

reamers than by radiographic

measurements, although the

approximate size to be used can be

determined from preoperative

radiographs.

Nail

Diamete

r (mm)

Stainles

s Steel

(X 106 )

Titaniu

m

(X 106 )

10 40.0 20.0

11 52.0 26.0

12 69.0 34.5

13 88.8 44.4

14 112.1 56.4

15 139.1 69.6

16 170.1 75.1

17 241.4 120.7

Flexural rigidity (EI) of slotted cloverleaf

IM Nails (1mm wall thickness) (Nmm2)

Obtain preoperative radiographs of the

fractured long bone, including the proximal

and distal joints.

If there is any question, obtain an

anteroposterior radiograph of the opposite

normal limb at a tube distance of 1meter. A

nail of the appropriate size should be taped to

the side of the limb for reference, or a

radiographic ruler can be used, alternatively a

Kuntscher measuring device – the ossimeter

may be used to measure length and width.

The ossimeter has two scales, one of which

takes into account the magnification caused

by the X-ray at a 1 – m tube distance.

-In most cases, a nail reaching to within 1 to 2

cm of the subchondral bone distally is

indicated.

Size – length

CURVES

Longitudinal (Anterior) bow

•Governs how easily a nail can be inserted as well as bone/

nail mismatch, in turn influences the stability of fixation of the

nail in the bone.

•Complete congruency minimizes normal forces and hence

little frictional component to nail’s fixation.

•Conversely, gross mismatch increases frictional component of

fixation and inadequate fracture reduction.

Femoral nail designs have considerably less curve, with

radius ranging from 186 to 300 cm

Herzog bend

Tibial nail also has a smooth 11

bend in the anterioposterior

direction at junction of upper one

third and lower two third .

Mismatch in the radius of

curvature between the nail and

the femur can lead to distal

anterior cortical perforation

When inserting nail , axial force is necessary as the nail

must bend to fit the curvature of the medularly canal .

The insertion force generates hoop stress in the bone (

Circumferential expansion stress )

Greater the insertion force higher the hoop stress. Larger

hoop stress can split the bone

Over reaming the entry hole by 0.5-

1mm ,selecting entry point

posterior to the central axis reduce

the hoop stress

Example :The ideal starting

point for insertion of an

antegrade femoral nail is in the

posterior portion of the piriformis

fossa . It reduces the hoop

stress

Length and working length

A-Total nail length- total anatomical length

B-Working length-

-Length of a nail spanning the fracture site

from its distal point of fixation in the proximal

fragment to proximal point of fixation in the

distal fragment

-Length between proximal and distal point of

firm fixation to the bone

-Un supported portion of the nail between

two major fragments

Working length is affected by various factors

Type of force (Bending ,Torsion )

Type of fracture

Interlocking

Reaming

The bending stiffness of anail is inversely proportinal to

the square of its working

Length

The torsional stiffness is inversely proportional to its

working length.

Shorter the working length stronger the fixation

Medullary reaming prepares a uniform canal and improves

nail- bone fixation

Towards the fracture,thus reducing the working length.

Interlocking screws are recommended for most cases of IM

nailing.

The number of interlocks used is based on fracture location,

amount of fracture comminution , and the fit of the nail

within the canal.

Placing screws in multiple planes may lead to a reduction

of minor movement

The principle of interlocking nailing is different. The nail is

locked to the bone by inserting screws through the bone and

the screw holes. The resistance to axial and torsional forces

is mainly dependent on the screw – bone interface, and the

length of the bone is maintained even if there is a bone

defect.

when screws placed proximal and

distal to the fracture site. This restrict

translation and rotation at the fracture

site.

Indications – communited ,

spiral,pathologicalfractures Fractures

with bone loss lengthning or shortening

osteotomies , Atropic non union

•It achieves BRIDGING FIXATION

through which fracture is often held in

distraction , a favourable environment for

periosteal callus formation exists and

healing rather than nonunion is rule.

It achieves additional rotational

control of a fragment with large

medullary canal or short epi-

metaphyseal fragment.

It is effective only when the contact

area between the major fragments is

atleast 50% of the cortical

circumference.

With axial loading, working length in

bending and torsion is reduced as

nail bends and abuts against the

cortex near the fracture, improving

the nail-bone contact

•No longer std. practice to dynamize an interlocked

nail by removing the locked screws .

•It is indicated when there is a risk of development of

nonunion or established pseudoarthrosis.

•The screws are then removed from the longer

fragments, maintaining adequate control of shorter

fragment. Premature removal may cause shortening,

instability and nonunion.

•when malalignment develops during

nailinsertion,placement of blocking

screw, and nail reinsertion improves

alignment.

•Most reliable in proximal and distal

shaft fractures of tibia.

•A posteriorly placed screw prevents

anterior angulation and laterally placed

screw prevents valgus angulation.

Poller screw

•Characterised by an outer

diameter, root diameter and

pitch.

•Shape of the threads at their

base determines stress

concentration (sharp v/s

rounded).

•Pullout strength is dependent on

the outer diameter.

•The largest diameter of the screw

which can be used is limited by the

diameter of the nail.

•Increasing the diameter of the

screws reduces the cross section

of the nail at its hole and their by

predisposes to failure.

Stability depends on the locking screw diameter for a given

nail diameter. In general, 4 to 5 mm for humeral nails and 5

to 6 mm for tibial and femoral nails.

Nail hole size should not exceed 50% of the nail diameter.

Interlocking screws undergo four-point bending loads, with

higher screw stresses seen at the most distal locking sites

The number of locking screws is determined based on

fracture location and stability.

In general, one proximal one distal screw is sufficient for

stable fractures.

The location of the distal locking screws

affects the biomechanics of the fracture .

The closer the fracture to the distal locking

screws, the nail has less cortical contact ,

which leads to increased stress on the

locking screws.

More distal the locking screw is from

fracture site, the fracture becomes more

rotationally stable

.

-

Orientation of the proximal femur locking screws has little

effect on fixation stability, with both oblique and transverse

proximal locking screws showing equal axial load to failure.

.

-

Oblique ( angled to nail axis, not 90°) proximal locking

screws appear to increase the stability of proximal tibia

fractures compared with transverse ( 90° to nail axis)

locking screws.

However, oblique or transverse orientation of the distal

screws in distal-third tibia fractures has minimal effect on

stability

K-nail has slot/eye in the either ends for attachment of

extraction hook .one end is tapered to facilitate the insertion .

Present version of cannulated locking screw contains

cylinderical proximal end with internally threaded core to

allow firm attachment of driver and extracter.

Holes for interlocking screws present either ends .

Some nails have slots near the distal end for placement of

anti rotation screw

Slot

- Anterior slot - improved

flexibility

- Posterior slot - increased

bending strength

Non-slotted - increased

torsional stiffness, increased

strength in smaller sizes.

Unknown if its of any clinical

advantage.

Closed nailing :

- Fluoroscopy is used to achieve fracture reduction .

- Medullary cavity is entered through one end of the bone “

antegrade .

eg-Piriformis fossa in femur .

Closed antegrade nailing is the method of choice .

Open nailing :

- Performed in lessthan ideal operation room conditions

- Antegrade nailing is prefered .

- In retrograde method nail is inserted in to the proximal

fragment through fracture site and brought out at one end of

the bone ,after reduction nail is driven in to the distal

fragment

- Infection and non union is six and ten times greater in open

nailing

F R A C T U R E R E D U C T I O N

The earlier a fracture is nailed,

easier is the reduction. Shortly

after injury, the hydraulic effects

of edematous fluid can cause

shortening and rigidity of the

limb segment, which may make

fracture reduction extremely

difficult. If nailing is not done

before this degree of edema,

gentle traction may be required

to regain length and alignment

gradually.

In femur, the reduction is most easily achieved by placing

the distal fragment in neutral position, avoiding tightness of

the iliotibial band, which could otherwise result in shortening

and a fixed valgus deformity.

As the tibia is subcutaneous, directmanipulation results in reduction inmost cases.

- In upper extremity, reduction is

achieved by a combination of

manipulation of the proximal fragment

with the nail and direct manipulation

of the distal fragment and fracture site

.

- In open nailing, the key to reduction

is to angle the fracture. - The corners

of the cortices of the proximal and

distal fragments are approximated at

an acute angle, and the fracture is

then straightened into appropriate

alignment.

With reamed rods, which are generally fairly rigid, the entry site must be directly above the intramedullarycanal. Eccentric entry sites, particularly in the femur and tibia, can result in incarceration of the nail or comminution.

For nonreamed, flexible nails, an eccentric entry site is usually used to take advantage of three – point fixation of the curved nail within the medullary canal. Generally these nails are inserted distally through the supracondylar flares of the long bones

ENTRY SITES

The entry site for reamed

nails is in the thin cortex at

the base of the greater

trochanter at the site of its

junction with the superior

aspect of the femoral neck.

ANTEGRADE NAILING FOR FEMUR:

RETROGRADE IM

NAILING

3 cm longitudinal incision

approximately 1 cm from

the medial border of

patella, beginning about 2

cm proximal to distal pole

of the patella

IM reaming can act to increase the contact area between the

nail and cortical bone by smoothing internal surfaces.

When the nail is the same size as the reamer, 1 mm of

reaming can increase the contact area by 38% .

Reaming reduces the working length and increase the

stability.

More reaming allows insertion of a larger-diameter nail,

which provides more rigidity in bending and torsion.

Biomechanically, reamed nails provide better fixation stability

than do unreamed nails

Medullary canal is more or less like an hour-glass than

a perfect cylinder. Reaming is an attempt to make the

canal of uniform size to adapt the bone to the nail. The

size of the canal limits the size of the nail.

Reamers must be sharp, and the surgeon must consider the

relationship between the size of the reamers and the nail.

A 12mm reamer is not necessary equal in diameter to a 12mm nail. Because flexible reamers follow a

curvilinear pathway, overreaming is usually necessary for most nails.

Most nail require overreaming from 0.5 to 2mm over the size of the

nail, depending on the type of nail, the configuration of the fracture,

and the canal of the bone.

Insert a ball-tipped reaming guide pin across the fracture

to the subchondral bone in the distal fragment begin with

an end – cutting reamer, generally 8.5 to 9.0 mm in

diameter.

On the first pass of the reamer past the fracture site,

visualize it on the fluoroscope to ensure that reaming is

progressing appropriately.

It is safest to ream progressively in 0.5 – 1mm

increments.

Both reamed and unreamed nails cause damage to the endosteal blood supply.

Experimental data suggest that reamed nailing deleteriously affects nutrient artery blood flow, but cortical blood supply is significantly reduced after reamed nailing compared with unreamed nailing.

Reaming is also associated with the potential risk of fat necrosis

Blunt reamers and the use of reamers larger in diameter than the medullary canal Lead to increased temperature , therefore it suggested that long bones with very narrow canals should first be reamed manually or an alternative treatment method should be used.

Some surgeons believe that unreamed nailing is advantageous in the treatment of Gustilo III B open fractures, citing higher infection rates.

Clinical studies of both tibial and femoral fractures show that reamed nailing of fractures with low – grade soft tissue injuries significantly reduces the rates of nonunion and implant failure in comparison with unreamed nailing. In fractures with an intact soft tissue envelope, reaming of the medullary cavity increases significantly the circulation within the surrounding muscles. This increased circulation may improve fracture healing

Reaming does not increase the risk of compartment syndrome.

Fat embolism due to IM reaming was described by Kuntscher. Fat embolism due to passage of IM contents into the bloodstream can occur only in the IM pressure associated with instrumentation exceeds the physiologic IM pressure and out weighs the effects of the normal blood flow.

The incidence of fat embolism is more with femoral reaming,. Reaming of the tibia does not lead to a significant increase of IM pressure, and intraoperative echocardiography does not show significant fat embolism in reamed tibial fractures.

The use of a venting hole to reduce the IM pressure increase during reaming is controversial.

Advantages

• Allows insertion of larger-sized implants which helps in weight

bearing and joint function during the healing process.

- Improves nail-bone cortical contact across the working length of

the implant and directs fracture fragments into a more anatomical

position.

- From a biologic standpoint, provides systemic factors to promote

mitosis of osteogenic stem cells and to stimulate osteogenesis.

Disadvantages

Eccentric reaming may lead to malreduction of the fracture.

- Destroys all medullary vessels, resulting in a initial decrease in

endosteal blood flow and in turn decreased immune response and

delay in early healing of the involved cortices.

- In open fractures, avascular and nonviable fragments causes

increased susceptibility to infections.

Side effects

- Heat: a rise in temperature upto 44.6⁰ C had

a negative effect on fracture healing.

•Cell enzymes get damaged and cannot fullfill

their function.

•The threshold value of heat induced

osteonecrosis is 47⁰C.

- Pressure: hydraulic pressure builds up in the

cavity which far exceeds that of blood

pressure and is independent of the size of the

reamer.

•It acts as a piston in sleeve which is filled

with a mixture of medullary fat, blood, blood

clots and bone debris.

•High intramedullary pressure forces contents

into the cortical bone and systemic circulation.

A long, very sharp awl, mounted on a T – handle, must be used to pinpoint the area of penetration of the bone to avoid exposing the surgeon’s hands to the direct beam of the fluoroscope.

Bring the awl into the fluoroscope image, placing it directly over the screw hole image. Mark the location for the skin incisions.

Make a 1 cm longitudinal incision directly over the screw hole. Insert the awl percutaneously to the cortex of the bone.

Again, bring the tip of the awl into the fluoroscopic image at an angle to the fluoroscope beam and locate the tip of the awl directly in the middle of the screw hole, make a hole in cortex.

Once this hole is made, insert the appropriately sized drill point and, while maintaining alignment with fluoroscope head, drill the hole through the rod and medial cortex.

Verify its position on the anteroposterior view, and then insert the appropriately sized screw.

Lateral fluoroscopic

view of the distal

screws in Grosse –

Kempf nail:

The hole, which is to

be cross – locked is

in the center of the

screen and is

perfectly

superimposed

Segmentally comminuted diaphyseal fracture without bony

contact and nails with a 12-mm diameter and two distal

locking bolts could with stand the typical biomechanical

forces of weight bearing.

In patients who retain diaphyseal bony contact after fracture

fixation, nails with a diameter <12 mm or nails with a single

distal interlock may provide adequate stability for weight

bearing because the bony contact reduces the load

encountered by the distal interlocking screws.

Weight bearing through a locked IM nail could be allowed in

fractures in which 50% cortical contact is present

It is not necessary to remove a nail in a weight bearing limb

unlike a plate.

If needed can be removed after 18 months.

Indications for removal-

- Patient request, pain swelling secondary to backing out of

the implant.

- Nail removal should not be undertaken lightly ,specialized

extraction equipment fitting the nail must be available.

- Full weight bearing can commence immediately after the

removal of nail

Z-Effect is an unfortunate by-product of most intramedually

nails that utilize two screws placed up into the femoral neck

and head. Typically, the superior screw is of smaller diameter

than the inferior and bears a disproportionate amount of load

during weight bearing. Excessive varus forces placed on the

smaller screw at the lateral cortex cause it to toggle and either

back out or migrate through the femoral head into the

acetabulum. The larger inferior screw is neither keyed in

rotation nor locked in place, and it too will either back out or

migrate medially. The resultant Z-Effect where the two screws

move in opposite directions is one mode of failure for the

conventional two screw reconstruction device.

With all metallic implants, there is a relative race between

bone healing and implant failure.

Occasionally, an implant will break when fracture healing is

delayed or when nonunion occurs.

IM nails usually fail in predictable patterns. Unlocked nails

typically fail either at the fracture site or through a screw hole

or slot.

Locked nails fail by screw breakage or fracturing of the nail at

locking hole sites, most commonly at the proximal hole of the

distal interlocks

applications of im nail ingAnatomic alignment, early weight bearing, early unrestricted joint &

muscle rehabilitation are of advantage to the patient.

ARDS can be prevented in multiple injuries by stabilizing and mobilizing

the patient immediately.

Floating hip, floating knee, floating elbow.

To protect the vascular repair following injuries by a fracture.

Aseptic and septic non-union.

Pathological fractures.

Malunions.

High proximal and low distal fractures of long bones

Open tibial and femoral grade I and II fractures

40gms of bone cement is

taken and mixed with 2 to 4

gms of powder when dough

is semi solid.

It is wrapped around K nail

of size 6 to 7 mm and rolled

between two palms.The rod

is then passed through the

holes of the nail major

usually 8 to 9mm diameter

to maintain uniformity of

diameter.

1.CAMPBELL OPERATIVE ORTHOPAEDICS

11TH EDITION

2.The science and practice of Intramedullary

Nailing – Bruce D. Brown

3.ROCKWOOD AND GREENS

4.INTERLOCKING NAILING-DD.TANNA

5. The elements of fracture fixation – Anand J

Thakur6.Prospective study of distal end radius fracture by an

intramedullary nailing JBJS aug3 2011

7.Textbook of orthopaedics and trauma –GS

THANK YOU