Limb Length Discrepancy And Treatment Options

Limb Length Discrepancy And Treatment Options 2017-06-22T19:54:30+00:00

“Now that I’ve had the surgery it’s just so much better. It’s changed my life.” – Lauryn Kapiloff

Treatment Options

Limb length discrepancy (LLD) does not cause a problem for everyone who has it. When limb length discrepancy does cause limping or pain, or keeps you from participating in the activities you like, you have options.
Use the information on this page to start learning about treatment options and inform your conversation with a health care professional who specializes in limb length discrepancy.

Your Guide to LLD Treatment Options

Determining the right treatment for limb length discrepancy can feel overwhelming. The information on this page is designed to help inform you about the treatment options available. Not all the information will apply to your individual treatment, and it is not meant to replace any personal conversations that you might wish to have with your physician or other member of your healthcare team.

A surgeon experienced in limb lengthening techniques can explain the treatment options, risks, and benefits in more detail – so it’s important to find a health care professional who specializes in limb length discrepancy to discuss whether surgical or non-surgical treatment is best for you.

Nonsurgical Treatment – Shoe Lift

Athletic shoes with a 1” lift on the right shoe. Proper lifts cover the entire sole of the shoe, not just the heel.

Often, a leg length discrepancy (LLD) of 2cm or less is not a functional problem. But, when this difference becomes uncomfortable or causes pain, surgeons often recommend a shoe lift as an alternative to a surgical approach.

Shoe lifts can help equalize leg lengths, and they are the most common nonsurgical treatment for a leg length discrepancy. In many cases, the lift can bring the discrepancy down to a comfortable level. Use of a lift can often improve a patient’s ability to walk or run, and it can alleviate back pain associated with a smaller leg length discrepancy.

While there are no medical risks associated with a shoe lift, it can be an expensive treatment option. Every pair of shoes worn must have the lift. If the lift is 1cm (1/2in.) or less, it can be placed inside the shoe. This type of lift can be switched from one shoe to another and is not visible to anyone else. For lifts that are greater than 1cm in size, they are added underneath the shoe. These lifts are permanently attached to a particular shoe. Sometimes custom-made shoes are required.

Lifts can be used indefinitely as a means of managing a leg length discrepancy. Some patients, however, find it to be bothersome to continually have to worry about having a shoe lift with their shoes. The shoe lift treatment method also does not correct the discrepancy, if you are not wearing shoes.

For a leg length discrepancy of more than 2cm, the shoe lift is not an ideal option. It limits the type of shoes you can wear, looks unsightly, and often causes instability. Ankle sprains and broken ankles are common with lifts.

Sometimes, a foot-in-foot prosthesis can be used as a temporary measure for young children with significant leg length discrepancies. But the prosthesis is bulky, and it can cause balance issues.

Surgical Treatment – Bone Shortening

In some cases, leg length discrepancy can be corrected by shortening the longer leg. Generally, bone shortening is limited to children or adults who have finished growing and reached their full height potential.

Leg shortening or restricting is considered for smaller differences in leg length (usually less than 5cm or 2in.). The longer bone is cut, and a section is removed. Then the ends of the cut bone are joined together.

During healing, fixation is necessary to hold the bone in place. Either a metal rod is inserted down the center of the bone, or a metal plate with screws is placed on the bone. This metal rod is usually removed after one year.

Bone shortening can pose significant risks and, in the case of a leg length discrepancy, it will make your full potential height shorter than if leg lengthening surgery was used to achieve limb equality. If too much length is removed from a bone, muscle weakness can be a permanent side effect. Additionally, there is a risk of nonunion, when a bone fails to heal properly, causing pain that may last months or even years.

After bone shortening surgery, it is common to spend two to three weeks in the hospital, and sometimes a cast may be placed on the leg for three to four weeks. Muscle weakness is common, but it often can be resolved with physical therapy. Crutches are generally necessary for six to eight weeks, and it may take six to 12 weeks to regain normal knee control and function.

Surgical Treatment – Epiphysiodesis (Growth Arrest)

Screws and plates are placed into the bone at the top and bottom of the growth plate, which prevent it from growing.
Surgeons can also “scoop” out cartilage to permanently stop growth.

One method to correct a leg length discrepancy is to slow down the growth of the longer leg, providing the shorter leg an opportunity to catch up in growth to the longer leg.

In children, whose bones are still growing, correcting limb length discrepancy can be accomplished with surgery that slows down or stops the growth of the longer limb. For adults, this procedure is not an option.

Each of the long bones in your lower limb (femur, tibia, fibula) has a growth center at the top and bottom of the bone. Your surgeon can selectively slow the growth of a bone by targeting one or more of the growth centers in the bones of the longer leg.

Epiphysiodesis is a pediatric procedure that fuses the epiphyseal (growth) plate – either temporarily or permanently – to cause growth arrest in the good leg. This will not instantly fix the leg length discrepancy. Instead, the leg length discrepancy slowly lessens as the shorter limb catches up.

There are several common methods of epiphysiodesis surgery. Surgeons can drill the growth center, place screws across the growth center, or tether each side of the growth center with a small plate to prevent the bone from growing. They can also remove the remaining cartilage to permanently stop growth.
Growth arrest may be used in conjunction with limb lengthening surgery for a large limb length discrepancy to avoid additional lengthening procedures. For example, if you have a 10cm inequality and have already gained 7cm by lengthening, growth arrest could result in limb length equality for the final 3cm without additional surgery.

Timing is key for this procedure. A surgeon must accurately predict the full potential height and determine at what time in adolescence the procedure should be performed so that limbs are near-equal length by the end of skeletal growth.

Growth arrest may be used in conjunction with limb lengthening surgery for a large limb length discrepancy to avoid additional lengthening procedures. For example, if you have a 10cm inequality and have already gained 7cm by lengthening, growth arrest could result in limb length equality for the final 3cm without additional surgery.

Despite all of medicine’s technological advances, determining the exact time to perform an epiphysiodesis is still just an educated guess. The surgeon needs to evaluate the remaining growth potential and decide when it is the right time to stop growth to obtain the desired correction. The surgeon also needs to choose which growth center (or centers) need to stop to obtain the correction.

This evaluation process is still an inexact science. In most cases, your surgeon should be able to estimate the timing fairly accurately, but it is possible to under-correct or over-correct the leg lengths with epiphysiodesis.

Often, children and their parents find this option unappealing, as it effectively shortens the longer leg and involves surgery on the healthy leg.

Also, the idea of this surgery is to slow down the growth of the longer limb to let the shorter limb catch up in growth – which, in the case of a leg length discrepancy, would mean the patient will lose some height. The amount of height lost will be equal to the amount of the desired leg length discrepancy correction.

For example, if the patient has a 2cm leg length discrepancy, the patient would potentially lose 2cm of height to obtain equal leg lengths. If the difference is small, this may not be a concern to the patient. However, for patients that are not expected to be very tall at the end of growth, losing height may not be acceptable.

Note: If an epiphysiodesis was performed but there is still a leg length discrepancy at the end of growth, any of the other treatments for leg length discrepancy can still be used. For example, a shoe lift could be placed under the short leg if the leg length discrepancy is small. For larger remaining discrepancies, the shorter limb could be lengthened or the longer limb could have a segment of bone removed to shorten it.

Surgical Treatment – External Fixation

An external fixator can be thought of as a cage or frame that is attached to the bone with special bone screws or wires. The fixator remains on the outside of the limb while the screws or wires pass through the skin into the bone. By anchoring this cage-like device to the leg and using the pull-apart method, bone lengthening is achieved.

Limb lengthening surgery works on the principle of bone regeneration (osteogenesis) as bones are pulled apart. With external fixation, a customized apparatus that encircles the leg is surgically attached to the limb.

To perform a lengthening, the surgeon cuts the bone into two segments. Each of the two segments of the bone is then attached to the fixator with special bone screws or wires. For a circular fixator, each segment is attached to a separate ring. For rail fixators, each bone segment is attached to an individual pin clamp. Adjustments are then made to the fixator to perform the limb lengthening.

Circular fixators can have special rods, called struts, placed in between the rings. These struts allow the bone to be lengthened, rotated, and/or angulated in any direction. The advantage of this type of external fixator is that it is very versatile. It can be used to correct both limb length and bone deformity simultaneously. The disadvantage of this frame is that it is bulky, which makes it more bothersome to wear. Rail-type fixators are less bulky but have less versatility in terms of combining gradual correction of deformity and leg length. Either type of fixator, however, can be used to perform limb lengthening.

The bone is surgically separated, and the frame extends when the device’s struts are lengthened, which is done several times a day. Bone lengthening usually begins about five to seven days after surgery, and the process can take up to a year or more. Until lengthening is complete and the bone is given a chance to harden, the fixator remains attached. After the external fixator is removed, a cast or brace may be required for some time.

Fixation pins are continuously connected to the bone, meaning pin tract infections and possible pin breakages are common. Nerve or vascular damage following insertion of the pins and soft tissue tethering around the wires or pins is also possible. Some patients suffer from bone weakening while in the fixator. Additionally, there may be permanent loss of range of motion in the nearby joints. Patients can greatly reduce the risk of permanent joint damage by following the physical therapy prescribed post-surgery.

While the incisions used to apply an external fixator are very small, there are often six or eight of them spread out over the limb. This may be less cosmetically appealing to some patients compared to the incisions used in placing an intramedullary lengthening device.

Additionally, having a frame attached to the outside of your limb can be bothersome. Your clothing may need to be altered to accommodate for the increased size of the limb. The fixator can bump into or scratch the other limb. Sitting and lying down with the external device attached to your limb may also require an adjustment period.

After the surgery attaching the device, patients generally spend a week or longer in the hospital. Frequent surgeon visits to adjust the pins are critical, and physical therapy is required to maintain a normal range of motion. Special care is necessary to clean and protect the pins or screws to prevent infection.

Surgical Treatment – PRECICE® Internal Lengthening Device

The PRECICE internal lengthening process, like external fixation, works on the principle of bone regeneration. However, new technology makes bone lengthening with a telescopic device inside the bone’s marrow cavity possible, eliminating the need for an external fixation apparatus.

The PRECICE Intramedullary Limb Lengthening System is a novel adjustable state-of-the-art device
The key to the NuVasive® platform technology is the magnetic interaction between the PRECICE intramedullary (IM) device and remote control.

The proprietary technology includes a complex internal gear system remotely activated and controlled by permanent magnets. This advancement in limb lengthening allows for a precision controlled distraction phase with the ability to non-invasively customize treatment.

The External Remote Control (ERC) is a portable, handheld unit that precisely lengthens or shortens the IM device through the touch of a button. The ERC is fully customizable to each patient based on their distraction needs. The ERC is designed to be used in a clinic setting or the comfort of the patient’s home.

Reach Your Height with PRECICE

  • 7 minutes a day
  • 1 inch a month
  • Improved accuracy1
  • Fewer complications1
  • Faster healing1
  • Less pain2
  • Earlier ability to bear full weight without aids1
  • No pin-site infections1
  • Improved patient satisfaction2

What are the Risks of Limb Lengthening Surgery?

As with any surgery, there are some risks associated with limb lengthening, and it’s important to discuss these risks with your surgeon to determine whether limb lengthening is right for you. Possible complications include:

  • Blood Clots – Patients are at risk for developing blood clots after orthopedic surgery, but there are measures in place at the hospital to help avoid this.
  • Nerve and Blood Vessel Injury – In some instances, nerves and blood vessels can become damaged, either at the time of surgery or during the subsequent lengthening of the bone.
  • Infection – As with any surgery, there is a risk of infection. Since the PRECICE device is inserted inside your bone, the risk of infection is very low, approximately < 1%. If you have had a previous lengthening with an external fixator, the infection risk is slightly higher. Your surgeon can discuss this with you.
  • Joint Stiffness and Soft Tissue Tightness – As your bone is lengthened, your soft tissues also get stretched. Muscles become very tight, and it is recommended you maintain movement in your hips, knees, and ankles. Physical therapists can teach you exercises to help prevent stiffness.
  • Joint Instability – Following long lengthening procedures, there is a small risk of dislocation of a nearby joint.
  • Delayed Union – This may occur if the bone does not form during lengthening or takes a long time to consolidate. Other reasons for failure to gain length relate to problems with stretching the nerves, blood vessels, muscles, and tendons.
  • Refracture – Following removal of the device, there is a small risk of fractures in the lengthened bone. If this occurs, the limb might require another surgery or time in a cast or brace; therefore, it is important to follow your surgeon’s recommendations about physical activities.


While a small limb length discrepancy may not cause problems, a significant difference can cause a noticeable limp and may require treatment. Non-surgical treatment options include the “wait-and-see” approach for children who are still growing and the shoe lift for those with a difference of less than 5cm.

Surgical treatment options are generally used for greater limb length discrepancy (more than 5cm).

  • Bone growth restriction (epiphysiodesis, or growth arrest) is often successful when performed at the right time in adolescence, but it may cause short stature.
  • Bone shortening is more predictable than epiphysiodesis, but it has a much longer recovery period.
  • Leg lengthening surgery allows patients to achieve their full height potential, but external fixators require continual maintenance. Internal fixators produce comparable results with fewer risks.

Some limb length discrepancies may require special treatment, but you and your surgeon can decide what treatment, if any, is best for you.
Find a surgeon >


How Do You Lengthen a Bone?
Bone is living tissue. It can regenerate itself. This is best illustrated by thinking about a broken bone. Many times, when a patient presents to the surgeon with a broken bone, a cast is placed on the injured arm or leg. Over the next few weeks, the bone repairs itself and heals. The cast is removed and the patient can resume his/her daily activities.

This same healing response can be used to lengthen a bone. The surgeon can make a precise surgical break in the bone and then allow it to start to heal. Instead of having the bone heal in its original position, however, the bone is slowly pulled apart (approximately 1mm per day).

As the two bone ends gradually separate, the body fills in the gap with new bone. The new bone slowly heals over a few months and creates the additional length in the previously shorter bone.

Does Limb Lengthening Hurt?
Stretching a bone seems like something that should be painful. However, the daily adjustments with the PRECICE internal lengthening device are so small that most patients don’t even feel them.

Everyone has a different experience with limb lengthening. In general, the first inch is the easiest, and then it gets a little more difficult. Once the initial discomfort from surgery has passed, many patients don’t require any pain medication during the lengthening process.

Per a patient satisfaction case study, the pain score with the PRECICE internal lengthening device was four points less than that of external fixation (3/10 as opposed to 7/10), and the length of time patients required prescription pain medication was significantly shorter (5.2 weeks as opposed to 11.4 weeks) – making the PRECICE internal lengthening device a less painful way to achieve leg lengthening.

How Much Discrepancy Can Leg Lengthening Surgery Correct?
The limitations of leg lengthening surgery mostly depend on the underlying reason for why the bone is to be lengthened in the first place. A good rule of thumb is that one can lengthen 20% of the current length of the bone relatively safely with the PRECICE internal lengthening device.

For example, if a bone measured 10in., it could safely be lengthened by 2in. (5cm). In general, the longer the lengthening, the more risks are involved, so it’s important to consult with your surgeon to determine how much lengthening is realistic for your specific circumstances.

Am I a Candidate for the PRECICE Internal Lengthening Device?

Contact your surgeon to learn more about the risks of leg lengthening and find out if PRECICE might be right for you.
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1. Laubscher M, Mitchell C, Timms A, et al. Outcomes following femoral lengthening: An initial comparison of the PRECICE intramedullary lengthening nail and the LRS external fixator monorail system. Bone Joint J 2016;98-B:1382–8.

2. Landge V, Shabtai L, Gesheff M, et al. Patient satisfaction after limb lengthening with internal and external devices. J Surg Orthop Adv 2015;24(2):174-9.

The PRECICE Intramedullary Limb Lengthening (IMLL) System is composed of an implantable intramedullary nail, locking screws, reusable instruments, and a hand-held External Remote Controller (ERC). The PRECICE nail is a sterile single use device that is surgically implanted using the instruments and locking screws. The ERC is used daily after implantation to non-invasively lengthen or shorten the implant to a prescribed length. The PRECICE System is intended for limb lengthening of the femur and tibia. Contraindications include infection or pathologic conditions of bone such as osteopenia which would impair the ability to securely fix the device, metal allergies and sensitivities, patients whose distance from the surface of the treated limb to the intramedullary canal is greater than 51 mm for the 10.7 and 12.5 mm diameter implants or greater than 38 mm for the 8.5 mm diameter implant, patients with an irregular bone diameter that would prevent insertion of the PRECICE nail, patients in which the PRECICE nail would cross joint spaces or open epiphyseal growth plates, patients in which there is an obliterated medullary canal or other conditions that tend to retard healing such as blood supply limitations, peripheral vascular disease or evidence of inadequate vascularity, patients unwilling or incapable of following postoperative care instructions, patients weighing in excess of 114 Kg for the 10.7 and 12.5 mm diameter implants (models A-G, H, J, K, and U) or weighing in excess of 57 Kg for the 8.5 and 10.7 mm diameter implants models (A-G, H, J, K, U, N, M ,P, and Q). The implantable device is only to be used by a trained licensed physician. Please refer to the PRECICE IMLL System instructions for use for complete Important Safety Information. Caution: Federal law restricts this device to sale by or on the order of a physician.