Traumatic Kyphosis

Cause

Post traumatic kyphosis occurs most commonly in the thoracolumbar and lumbar regions. Kyphosis of this kind is most common in patients with severe neurologic deficits such as quadriplegia or paraplegia. (figure 1A)

traumatic kyphosis 1Figure 1A-D: Post traumatic kyphosis can occur due to the failure of the initial management of the injury or unrecognized injury. It may also result from inadequate surgical treatment as shown in the figures to the right.

Symptoms

Kyphosis can result in chronic disabling pain. The sources of pain include:

  • spinal muscle fatigue
  • chronic inflammation and progressive degeneration
  • anterior cord or root impingement
  • Physical Findings

Progressive kyphosis develops when there is major disruption of the anterior column and all posterior ligaments. In paraplegic patients problems with sitting balance and skin alterations may be due to excessive kyphosis.
Treatment Options .The treatment of kyphosis is designed to correct the deformity, stabilize the area, decrease pain and improve neurologic function. Flexible deformities can be treated with posterior fusion and instrumentation. Fixed deformities often require more complex surgery.

Developmental Kyphosis

Hyper-kyphosis [forward bend of the thoracic (ribbed) vertebrae beyond normal limits] is classified as either postural or structural in origin. Postural kyphosis will correct when the patient is asked to stand up straight. Patients with postural kyphosis have no abnormalities in the shape of the vertebrae. Scheuremann’s kyphosis is defined as rigid (structural) kyphosis because the front sections of the vertebrae grow slower than the back sections. This results in wedge-shaped vertebrae rather than rectangular shaped vertebrae that line up well (Figure 1 and 2). This process occurs during a period of rapid bone growth, usually between the ages of 12 and 15 years of age in males, or a few years earlier in females. The abnormal kyphosis is best viewed from the side in the forward-bending position where a sharp, angular abnormal kyphosis is clearly visible.

developmental kyphosis 1

Figure 1: The right image shows a close-up of the wedged vertebrae inScheuremann’s

Patients with Scheuermann’s disease often present with poor posture and complaints of back pain. Back pain is most common during the early teenage years and in most instances will decrease as they approach adulthood. The pain rarely interferes with daily activity or professional careers. The kyphosis is more likely to be symptomatic if the apex (most angular section) is in the mid-to-low back instead of upper back. In severe cases, adolescents may not be able to lie on their back without several pillows under their head. The kyphotic deformity that develops with growth frequently remains mild and requires only periodic X-rays.

developmental kyphosis 2

Figure 2:

  1. A) Lateral x-ray of a patient with Scheuremann’s disease.
  1. B) Close-up x-ray demonstrating wedge-shaped vertebrae

characteristic of Scheuremann’s disease.

Nonsurgical Management

Observation

Observation is typically recommended in the following situations:

  1. Postural hyperkyphosis (their round back straightens with proper posture),
  2. Curves that are less than 60° in patients that are growing, or
  3. Curves 60°-80° in patients that are done growing.

Standing, long-cassette (scoliosis) X-rays are taken every 6 months as the child grows. If the child has pain, an exercise program is usually recommended.

developmental kyphosis 3

Figure 1. On the left is a side-view of a patient with

Scheuremann’s kyphosis. On the right is the same X-ray

after he was placed in a hyperextension brace.

Bracing
 When the deformity is moderately severe (60°-80°) and the patient remains skeletally immature, brace treatment in conjunction with an exercise program is the recommended treatment. Full time use of a brace (20 hours/day) is usually required initially until maximum correction has been achieved. The brace fit must be regularly evaluated and adjusted to ensure optimal correction. During the last year of treatment prior to skeletal maturity, part time brace wear (12-14 hours/day) may be proposed. Brace wear must be continued for a minimum of 18 months in order to maintain a significant, permanent correction of the deformity (Figure 1).

Surgical Treatment

Spinal Fusion

When the kyphotic deformity has become severe (greater than 80o) and the patient is often experiencing increased back pain, surgical treatment may be recommended. Surgical intervention allows significant correction to be achieved typically without the need for postoperative bracing. Pedicle screws are placed (2 per level) and connected with two rods. This process allows gentle straightening of the spine. Most surgeries are performed from the back. However, some physicians recommend additional surgery on the front of the spine. Patients are usually able to return to normal daily activities within 4-6 months following surgery. The correction achieved from surgical intervention is remarkable (Figure 1).

developmental kyphosis 4Smith-Peterson (Posterior) Osteotomy
Moderately flexible curves often straighten just from lying prone (face down) on the operating room table. However, rigid curves require additional steps. The Smith-Peterson osteotomy is often performed at multiple levels to allow safe application of additional corrective forces. Every spinal segment is limited in extension (backward bend) by two sliding facet joints. If these joints are removed, and the disc in front is mobile, approximately 5-10°/level of additional extension is possible to obtain (Figure 2)

developmental kyphosis 5

Kyphosis

Introduction

The normal spine, when viewed from behind, appears straight throughout its entire length. However, when one looks at the spine from the side, there are two visible curvatures. There is a gentle rounding of the upper back from the shoulders to the bottom of the ribcage known as thoracic kyphosis and an opposite curve in the lower back known as lumbar lordosis. These two opposite curvatures of the spine are necessary in the normal spine to balance the trunk and head over the pelvis. A normal thoracic spine extends from the 1st to the 12th vertebra and should have a slight kyphosis ranging from 20o to 45o. When the “roundness” of the upper spine increases past 45o it is called “hyperkyphosis”. Scheuermann’s kyphosis is the most classic form of hyperkyphosis and is the result of wedged vertebrae that develop during adolescence. The cause is not currently known and the condition appears to be multi-factorial and is seen more frequently in males than females.

Congenital Kyphosis

Definition and Classification

In the first six to eight weeks of embryonic life, a genetic mistake occurs that results in the failure of formation or failure of segmentation on the front part of one or more vertebral bodies and disc. This defect causes the spine to develop a sharp forward angle as it grows. The forward bend of the spine is called kyphosis and is considered to be congenital as it occurred prior to birth. Congenital kyphosis is not passed through families but rather something that happened for no known reason. The spine may appear straight when viewed from the front, or there may be congenital scoliosis as well. There are two basic types of congenital kyphosis: failure of formation and failure of segmentation. The failure of formation (Type I deformity) of a portion of one or more vertebral bodies results in kyphosis that usually worsens with growth (Figure 1). The deformity is usually visible at birth as a lump or bump on the infant’s spine. The failure of segmentation deformity (Type II deformity) occurs as two or more vertebrae fail to separate and to form normal discs and rectangular bones. This type of congenital kyphosis is often more likely to be diagnosed later, after the child is walking.

kyphosis 1
Congenital Kyphosis

Evaluation

On X-Ray, normal vertebrae are close to rectangular in size when viewed from the side. Thoracic vertebrae are somewhat smaller in the front than the back (to create kyphosis), while lumbar vertebrae are the opposite to create lordosis. Congenital kyphosis creates more kyphosis than expected for the particular region of the spine. As with congenital scoliosis, there is potential for defects in other organ systems. After X-rays confirm the diagnosis, the physician may order additional tests to determine if occult abnormalities are present in the spinal cord, kidneys, cardiac or gastrointestinal system. The MRI provides additional information regarding the abnormal growth potential and may assist in predicting progression of the spinal deformity (see Figure 1). From a clinical perspective, it is important to monitor the child’s leg strength and ability to walk. More severe kyphosis can place significant pressure on the spinal cord causing myelopathy (spinal cord compression). Young children may be perceived as being late walkers when they actually have spinal cord compression. In most instances, however, there is not significant pressure on the nerves.

kyphosis 2

Congenital Kyphosis

Prognosis

Failure of formation deformity can present with 30o – 60o degree deformities. With the rapid growth of the skeleton in the first year of life, progression is highly likely. Failure of separation (segmentation) deformity has a slower rate of worsening and may not become a surgical curve until adolescence.

Congenital Kyphosis

Non-Operative Treatments

Observation

Observation is usually the first method of treatment for a young child with a spinal deformity. The visits to the physician will be spaced according to the likelihood of measuring a significant change in the X-ray between each visit. Type I deformities are more likely to have several visits per year. Severe or progressive congenital kyphosis deformities greater than 45o or kyphosis associated with neurologic weakness are usually treated surgically. Early surgical intervention generally produces the best results and can halt progression of the curve. The type of surgical procedure will depend on the nature of the abnormality.

Bracing Unfortunately, bracing is not recommended when treating congenital scoliosis. Clinical studies fail to demonstrate improved patient outcomes with this method of treatment.

Surgical Treatments

In Situ Fusion

The surgical choice for a progressive kyphotic deformity is a solid fusion or arthrodesis of the deformed vertebrae. The fusion may also include one normal vertebra above and one normal vertebra below this area. Bone graft from the patient or tissue bank is placed posteriorly, on the back of the spine, along the area of the abnormality. In severely angulated curves, additional bone graft may be placed anteriorly, on the front of the spine, as well as from behind. The fusion may be performed with or without the use of instrumentation. In situ fusion is a non-instrumented fusion without correction of the angulation. The bone graft will require 4-6 months to mature into a solid fusion mass. During the postoperative period the fusion must be protected with a cast or brace until X-rays demonstrate a solid fusion.

kyphosis 3Surgical Treatments

Instrumented Fusion and Osteotomy

With progressive kyphotic curves in older children, surgery may include instrumentation (rods, hooks, and screws) that helps to correct the deformity. If the spinal cord is unable to tolerate the manipulative techniques that “straighten” the spine, the surgeon may consider the removal of the mis-shapened vertebrae to realign the spine. The postoperative course remains the same until the fusion mass is determined by X-ray to be solid. Your surgeon may recommend an osteotomy (bone-cutting procedure) to re-align the spine. Pedicle subtraction osteotomies work by removing the bone in the back of the vertebra so the bone can be collapsed backwards. Vertebral column resections allow resection of the front and the back of the spine from a posterior procedure. The surgeon may also recommend separate approaches from the front and the back of the spine.

kyphosis 4