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Re: Fixion nails
Erden Kilic 11 Март 2006, 20:19
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Mr. Chelnokov and group members,
I have graduated three months ago as an orthopedic
surgeon from Gülhane Military Medical Academy in
Turkey and my thesis was about the fixion nail in long bone fractures. So I would like to share my opinions about the fixion nail.
Fixion nails biomechanically behave as classic Küntscher nails because its stability depends on friction force between the bone and the nail surface.
Fixion nails have a contact surface much more than the classic Küntscher nail where its contact is just around the isthmus. Therefore it has better axial loading capabilities. Also inflation under pressure somewhat improves the axial stability. Rotational stability is achieved by for longitudinal bars.
Inflation of the nail forces and collapses the cancellous bone and embeds the bars in to the cancellous bone, preventing rotation.
Its main indication is long bone diaphyseal fractures, mainly AO type 1 and 2 fractures; it may not provide enough stability in type 3 fractures and fractures distal to the isthmus. Proximal fractures can be treated with proximal interlocking fixion nails and distal fractures with retrograde locking supracondylar nails.
I may list the advantages chronically as follows:
Deflated nail when inserting, optional reaming, bullet shaped tip, manipulation with its insertion handle favors closed nailing. Humeral and tibial closed nailing can be possible even without fluoroscopy.
Minimal incision can be used in femur fractures.
Operation time is really shortened because distal
locking is not required and reaming is optional. Full endosteal contact increases its stability, therefore early rehabilitation is possible. Its biomechanics allowing axial loading favors callus maturation.
Special considerations when using these nails can be expressed as follows. It is important to examine preoperative radiographs carefully because a missed fissure can turn out to be a spiral fracture when nail is inflated. Axially unstable fractures are not suitable for fixion nails because it cannot provide enough stability, it can separate fracture fragments when inflated, may result in limb shortening. So locking nails or ECF are still possible solutions for these fractures. When treating proximal and distal fractures fixion nails should be used cautiously because its stability decreases as fracture line comes closer to joints.
It is really an expensive implant which renders its use. Its expense and advantages for the patient and the surgeon should be weighed to decide the treatment. But it is not a candidate to replace locking nails.
Rather it has expanded the indications of Künstcher nails.
Those were my personal opinions which are mostly in theory because we do not yet have evidence based trials of these nails. Studies are mostly case series as our study, and it formed our basic experience about the fixion nail.
I would welcome any specific question about the nail.
Erden KILIC
Konya Military Hospital,
Konya, Turkey
(City of Mevlana, great philosophier of Anatolia, UN has accepted 2007 as "Mevlana" year.)
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Re: Fixion nails
Alexander Chelnokov 12 Март 2006, 18:31
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EK> mainly AO type 1 and 2 fractures; it may not provide
EK> enough stability in type 3 fractures and fractures
EK> distal to the isthmus.
Looks very reasonable.
EK> I may list the advantages chronically as follows:
EK> Minimal incision can be used in femur fractures.
What specific is in this for Fixion nails? Skin incision in interlocking nailing can be limited to nail diameter - it depends on the insertion handle design not a nail itself.
EK> preoperative radiographs carefully because
EK> a missed fissure can turn out to be a spiral fracture when nail is
EK> inflated. Axially unstable fractures are not suitable for fixion
EK> nails because it cannot provide enough stability, it can separate
EK> fracture fragments when inflated, may result in limb shortening.
THX, it is what i mainly was interested to confirm.
EK> theory because we do not yet have evidence based
EK> trials of these nails.
Many of your statements about the nails looks self-evident so RCT hardly ever are necessary to confirm that the missed fissure can expand
with inflating or that subisthmal fractures are less sable for this sort of nails.
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Re: Fixion nails
Отправитель: Erden Kilic 12 Март 2006, 18:35
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You are right. Diameter of unreamed locking nails is less than diameter of the isthmus. But these nails have a high incidence of delayed union, non-union and secondary procedures for union.
I meant that fixion's deflated diameter which is at least 2-3 mm less than the diameter of the bone, helps its insertion. In classic Kьnstcher or reamed locking nails, nail is inserted by force through the medullary canal and with some resistance. With fixion nails you can easily insert without reaming; actually it is the
same in unreamed nails.
I emphasized to use minimal incision through the fracture site in femoral fractures to help reduction and insertion of nail when surgeon does not have fluoroscopy. In fact the inventory you need to achieve operation is reasonably reduced, three nails, one you need, one longer and one shorter to be used in case, and the small insertion set.
Fractures proximal and distal to isthmus can be
managed by these nails, as it increases the contact area. Fractures very close to joints can be fixed with locking types of fixion nails.
I believe that important issues about these nails are: reduced operation time by easy insertion, optional reaming and no distal locking, reduced inventory, no floroscopy so no radiation to patient and to us.
I also want to add that biomechanics of these nails allow axial compression like Kьntscher nails. It resolves the stability problems of Kьnstcher nails and expands its indications. But indications of these fixion nails stand still between Kьntscher and locking nails.
Best regards.
Erden KILIC, MD
Konya Military Hospital
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