Limb Lengthening Surgery Devices

Limb Lengthening Devices

Mar 29, 2020

Since it was determined that bones could be surgically broken and lengthened to get taller several devices have been designed over the years to improve on the procedure.

You have 2 categories of lengthening methods…

A) External fixator techniques:

1. Ilizarov Ring Fixator (IRF)/Taylor Spatial Frame (TSF)

2. Lengthening Over Nails (LON)

3. Lengthening And Then Nailing (LATN)

4. Uni/Monolateral Fixator

B) Internal nails:

1. Albizzia/Guichet/Betzbone

2. Intramedullary Skeletal Kinetic Distractor (ISKD)

3. FitBone

4. PRECICE & STRYDE (PS)

Of these methods there are several pros and cons to each from… Price to Scars to Convenience to Effectiveness to Removal process that you should consider when making your decision.

Below is a more in depth blog I researched and wrote up with more details…

What is leg lengthening?

Limb lengthening is when an orthopedic surgeon will break the bone (osteotomy) to be lengthened and use an internal or external device to gradually pull the bone apart along with the skin, muscle, nerves and blood vessels in the process known as (distraction) phase. The rate is usually 1mm per day to avoid complications such as non-union if done too fast or early healing of the bone if done too slow. The (consolidation) phase is when the bone healing occurs and your new height gain is solidified. Usually a year after healing the lengthening device is taken out.

When it comes to limb lengthening there are many different methods you can choose from to gain additional length. Below I’ve compiled a list of the most common external and internal methods with the pros and cons of each…

External Lengthening Methods

Ilizarov:

Let’s start off with the original external technique of LL…the ilizarov Ring Fixator (IRF). First used in 1951 by it’s inventor, Dr. Gavriil Ilizarov of the Soviet Union, to correct various leg deformities such as non-unions and leg length discrepancies in athletes etc. Even though it’s still used today, it’s evolved form, the Taylor Spatial Frame (TSF) developed by Charles Taylor, is more efficient and common.

Pros & Cons:

Price: Now that there are newer methods, the IRF & TSF are pretty cheap in fact some of the cheapest external lengthening methods.
Scarring: The scarring is pretty bad due to the multiple pin and wire insertion sites which could also get infected if not regularly cleaned and taken care of.
Mobility/Convenience: Very bulky, decreased ROM, lack of desire to do physical therapy
Effectiveness: Well if it ain’t broke don’t fix it…just improve on it which is what was done via TSF and other external methods.
Removal: Easy, usually a quick outpatient procedure with rapid recovery with no additional surgery required.

LON (Lengthening on Nails):

Lengthening on nails is basically a combination of an external fixator and an intramedullary nail first introduced by Bost & Larsen in 1956. The way it works is the external fixator is put on as well as having the internal nail in place in the bone to stabilize the lengthening process. The actual distraction lengthening is done by the external fixator and once the length is gained, the internal nail is fully screwed in to further stabilize bone healing.

Pros & Cons:

Price: More involved and thus more expensive than external fixator alone.
Scarring: Same as ring fixator or monorail fixator since it’s also used here.
Mobility/Convenience: Same as ring or monorail fixator since it’s also used here. BUT much more time efficient as you’ll usually only have the external fixator in place for ⅓ of the time vs. external alone because LON also uses an internal nail to stabilize the healing process.
Effectiveness: Same as external fixator but less time.
Complications: Deep internal infections could occur.
Removal: External fixator is the same BUT they must be careful to not re-fracture when removing nails.

LATN (Lengthening & then Nailing):

This is basically the same as LON in #2, but the only difference is the internal nail is not put in until AFTER lengthening is done via the external ring fixator.

Pros & Cons:

Price: More than IRF/TSF alone and possibly more than LON due to additional surgery.
Scarring: Same as LON and ring fixator since it’s also used here.
Mobility/Convenience: Same as LON
Effectiveness: Same as LON.
Complications: Less chance of internal infection than LON, BUT still have to be careful when putting in after distraction although less chance of refracture than LON.
Removal: Same as LON

Monorail (Unilateral External Fixator)

This is a single bar external fixator rather than multiple cylindrical rings like IRF/TSF. It is placed laterally on the limb and held in place via thick pins. The distraction is similar to ring fixator but less stable and possibly more painful due to thicker pins but this is an arbitrary observation.

NX part: Knee-Spanning-TibFemLengthen

Pros & Cons:

Price: Can be less due to less device material or about the same as ring fixator. Overall affordable.
Scarring: fewer scars than ring fixator but holes could be larger due to thicker pins
Mobility/Convenience: Much better than ring fixator as clothes can be worn over it. Also easier to maneuver as it’s less bulky.
Effectiveness: Depends on the patient’s bone density but usually simpler than ring fixator yet just as effector.
Complications: Same as ring fixator the pin sites could get infected if not cleaned well.
Removal: Simple outpatient removal and rapid recovery.

Internal Methods

Albizzia, Guichet & Betzbone Internal Nails

The original Albizzia internal nail has since been replaced by newer methods aka: The Guichet Nail by Dr. Guichet and Betzbone by Dr. Betz. The nail is inserted in the medullary (middle) canal of the bone. The lengthening of the nail requires a ratcheting or clicking mechanism where the patient quarter turns their limb hearing a click to know lengthening occured.

Pros & Cons:

Price: Expensive! Much more than a typical external fixator
Scarring: minimal scarring via insertion of nail and screws through small incisions.
Mobility/Convenience: Much more comfortable, more ROM, less soft tissue stiffness. Much more convenient as nail is internal thus does not interfere with clothes or appearance.
Effectiveness: highly effective although the lengthening method is a bit tedious
Complications: Low. Occasional non-union or premature consolidation due to ineffective distraction by patient.
Removal: Simple outpatient removal rod and screws with moderate recovery due to hollow bone and screw sites need to fill in.

ISKD (Intramedullary Skeletal Kinetic Distractor)

The first FDA-approved intramedullary lengthening nail, developed by Dr. Jean Cole of Orthofix, the ISKD uses a kinetic clutch mechanism of a rod that is screwed onto another rod and basically has a monitor to see how much length is gained. The patient doesn’t have to do ratcheting as in the Albizzia nail but rather small rotational movements. Due to small movements to distract bone, it can be hard to control too much or too little.

Pros & Cons:

Price: More advanced than previous internal nails in #1.
Scarring: same benefits as other internal nails…minimal scarring.
Mobility/Convenience: same benefits as other internal nails…max convenience.
Effectiveness: highly effective although the lengthening method is a bit unpredictable and the construction is not the most sturdy.
Complications: same as other internals…low. Also dynamization where they remove screws so you can weight-bear post-consolidation can cause some height loss of 2-7mm.
Removal: Simple outpatient removal rod and screws with moderate recovery due to hollow bone and screw sites need to fill in.

FitBone

Developed by Dr. Betz & Baumgart, this method is done via an electric motor & antenna where the signal to the nail lengthens it. A telescopic nail has a small electric motor located at the end of it. Distraction happens from the motor that transmits to the internal nail and forces it to lengthen. The motor is powered from an external transmitter controlled by the patient to the receiver under the skin.

Pros & Cons:

Price: It is internal so very pricey but even more so than other internal methods.
Scarring: same benefits as other internal nails…minimal scarring.
Mobility/Convenience: same benefits as other internal nails…max convenience.
Effectiveness: poor weight bearing until bone is healed.
Complications: Dynamization where they remove the screws post consolidation to allow weight bearing risks height loss.
Removal: Simple outpatient removal rod and screws with moderate recovery due to hollow bone and screw sites need to fill in.

PRECICE & STRYDE Nails

The PRECICE nail developed by Ellipse technologies & made famous several surgeons including Dr. Paley & Herzenberg I personally got the PRECICE nail done myself. The magnetic titanium rod is lengthened via an ERC magnetic lengthener that is placed on top of the leg to be lengthened. The PRECICE 1, 2 and 2.2 have been observed and evolved upon via the newest version…the Precice-STRYDE nail. Stryde is a stainless steel (rather than titanium-thus stronger) and full weight bearing is allowed much sooner.

Pros & Cons:

Price: cream of the crop so it is very expensive!
Scarring: same benefits as other internal nails…minimal scarring.
Mobility/Convenience: same benefits as other internal nails…max convenience.
Effectiveness: PRECIE is poor weight bearing until bone is healed. STYRDE max weight bearing.
Complications: Low complications for both.
Removal: Simple outpatient removal rod and screws with moderate recovery due to hollow bone and screw sites need to fill in.

Alright, so there you have it! The most common external and internal limb lengthening methods. Be sure to leave a comment on what your favorite method is or any questions you may have. Until next time…

Victor

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