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How much growth would you expect the fused portion of my spine to have grown had it been left unfused

Dr. W. Christopher Urban

Glen Burnie, MD

A normal spine grows at a rate of approximately 0.7mm/year per vertebral segment. A large portion of spinal growth takes place in the first ten years and is almost finished by 14 years of age for girls and 16 years of age for boys. A scoliotic spine is different in that it does not grow straight. As the curve progresses, more growth causes the deformity to worsen rather than an increase in height. A patient may actually become shorter as the curve worsens and the patient becomes more imbalanced. Some patients notice that they get a little taller as a result of surgery, as their curve is straightened. Scoliosis surgery only involves fusing a portion of the spine. Therefore, in addition to long bone growth (legs), there are other vertebral levels that are left unfused that can continue to grow until skeletal maturity.

Dr. John T. Smith

University of Utah Department of Orthopaedic Surgery

Typically, patients gain some height during the correction of a curve. This is roughly equal to the amount of growth they lose when a fusion is done, unless they are very young. For most adolescents, however, what one loses in growth is gained during the correction of a curve.

Dr. Dennis G. Crandall

Mesa, AZ

For adolescent idiopathic scoliosis, most of the spine’s growth is already completed by the time the curve requires fusion. Patients are actually taller after their curves are surgically straightened than they would have been had their spines been allowed to continue growing.

Dr. Baron S. Lonner

New York, NY

The amount of growth that would have occurred if the spine were not fused would have been negligible as that growth would have resulted in further curvature of the spine. Therefore, the spine would grow more crooked and the patient would not gain significant height. One can calculate the amount of growth in a normal spine as being approximately 0.07 cm per segment per year in a growing child.

Dr. Michael F. O'Brien

Denver Orthopaedics

Occasionally in very young individuals requiring surgical intervention who are less than 10 years of age, the spine may continue to grow in spite of being fused in a particular section. However, in most adolescents, scoliosis surgery is done between the ages of 12 and 16 when growth is nearly finished. In this case, little growth potential is lost as a result of a thoracic spinal fusion.

Dr. Robert S. Pashman

Los Angeles, CA

Lost growth potential of fused vertebrae after scoliosis surgery is dependent on the age of the patient at the time of surgery. If a patient is extremely young (e.g., less than seven years old), significant loss of height can occur after spinal fusion. To the greatest extent possible, surgeons will delay operations in young patients in an attempt to maintain their maximum growth potential. Sometimes braces are used to hold the curve until this maximum growth potential is achieved.

Dr. Jean-Pierre C. Farcy

New York, NY
M.M.C. Spine Center

Usually very little because spine growth has almost always been completed when the surgery takes place, with the exception when surgery must be performed before the end of growth which is only indicated for specific serious case of non-idiopathic scoliosis.

Dr. James Mooney, III

Detroit, MI

If the fused portion of the spine had been left unfused, there is usually very little longitudinal growth that happens. The growth that occurs is converted into curvature type growth and does not contribute significantly to the patient's overall height.

Dr. Thomas G. Lowe

Woodridge Orthopaedics & Spine Center, P.C.

Generally, scoliosis fusions are not performed until growth is almost complete, unless it has advanced very rapidly in young patients. In this situation, I usually try to use a brace to postpone surgery until approximately 12 or 13 in females, or age 15-16 in males. By using these guidelines, there is really no more than ˝ to 1" of growth and no more than ˝" of height would be lost in the fusion. However, there is a significant increase in height immediately following the surgery from correction of the scoliosis.

Dr. Patrick Bosch

Albuquerque, NM

That depends on how many levels are fused, as well as the patient’s age and remaining potential growth. In most cases, about 2-4 cm of longitudinal growth is “lost” by spinal fusion. It is important to remember, however, that this estimate is relative to “normal” straight growth, which is unlikely to have been the case if fusion was needed.

Dr. Christopher L. Hamill

Buffalo, NY
Buffalo General Hospital

The growth potential depends on the age at the time of fusion.

Dr. Robert W. Molinari

Rochester, NY

Left unfused, this portion of your spine would undergo very little upward growth, as in height.

Dr. Scott J. Luhmann

St. Louis, MO

The amount of growth lost because of a spine fusion is typically 0.07 cm per level per years of growth remaining. Females typically complete growth by 14 years of age and males by 16 years of age. For example, an average 12 year old female with a spine fusion from T3-L1 would lose approximately 1.8 cm (2/3 of an inch) of overall height.

Dr. John P. Lubicky

Chicago, IL
Shriner's Hospital for Children

The amount of growth of the spine has been calculated, and it appears that if you average out the amount of growth of each vertebra, it grows about 0.7 mm. per year. So what you would do is multiply the number of vertebrae fused times 0.7 mm. times the number of years left to grow, and that will give you the length of the spine that has been lost by fusing it. The years of growth remaining are a child's current age minus 15 for girls and 17 for boys. Obviously, for adults the question of growth is not applicable.

Dr. Charles E. Johnston, II

Texas Scottish Rite Hospital Orthopedic Group

That depends on your physiologic age at the time of surgery and the number of vertebrae in your curve. Remember that once the curve becomes big enough to need surgical correction, further growth of the spine only makes the curve larger, rather than making you taller.

Dr. Stephen Ondra

Chicago, IL

How much the spine would grow if left unfused is entirely dependent on how old you are at the time of your surgery. In general, surgery is delayed until the patient has very nearly completed their skeletal growth. In this way, significant spine growth is not altered. When a scoliotic curve is progressing very rapidly and needs to be surgically addressed before the patient has completed spine growth, the spine will have very little to no growth in the fused area. In fact, we actively try to stop growth in the area of the fusion. If growth continues, it can result in a deformity within the fusion called Crankshaft phenomena. If a child needs a fusion before skeletal growth is near completion, the rods may require lengthening. If you are at or near the end of your growth, which can be judged by x-rays of the pelvis, as well as your age and the date of onset of puberty, you should not have any problem with this. In fact, you may gain height with the correction.

Dr. David W. Polly, Jr.

Minneapolis, MN

For a teenager, the loss of height, even for a long fusion, is about an inch. But if your curve is straightened, you usually feel taller after the surgery.

Dr. Frank J. Schwab

New York, NY

In most cases of idiopathic scoliosis the spine has nearly completed its growth at the time of surgery. For severe curvatures that require surgical correction, any remaining growth of the spine will tend to worsen the scoliosis rather than leading to gain in overall height.

In very young patients with scoliosis a corrective procedure may limit growth at the treated levels. There are techniques of correction that do not involve immediate fusion of the spine (but later on when more growth has occurred). Careful planning is essential for long-term success and cosmetic satisfaction.

The commentary above recounts the experiences of these physicians. Medtronic invited them to share their stories candidly. Keep in mind that results vary; not every patient's response is the same. Talk with your doctor to learn more about any products that are mentioned above.

It is important that you discuss the potential risks, complications and benefits of spinal surgery with your doctor prior to receiving treatment, and that you rely on your doctor's judgment. Only your doctor can determine whether you are a suitable candidate for this treatment.

  • Published: June 20, 2002
  • Updated: April 19, 2010