Kyphosis KyphosisKyphosisKyphosisKyphosis.pptx

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1. Kyphosis

2. Introduction Kyphosis is defined as a deformity of the spine in the sagittal plane. Pure kyphotic deformities are not complicated by rotation as opposed to kyphoscoliosis . Historically, many idiopathic scoliosis curves were described as kyphoscoliotic because the rib hump gave the patients a kyphotic appearance ; however, the true deformity in scoliosis is actually lordotic in most instances and kyphoscoliosis is an uncommon deformity. This chapter will cover what are essentially pure kyphotic deformities that include postural and structural kyphosis . The normal kyphosis of the thoracic spine ranges from 20 to 50° and when the kyphosis exceeds this range it may be considered as being pathological.

3. Postural kyphosis (synonym : postural round back) Children with this deformity stand with a slouch; they are not unwell and pain is not an issue. Their parents have usually been telling them to ‘stand up straight’ for some time with little success. - The children are usually in their second decade. - Postural kyphosis is essentially a cosmetic problem. - If neglected, some deformities may become fixed or structural . -This deformity is not uncommon in girls attempting to disguise breast development. Sensitivity is required by the physician when dealing with these children.

4. Aims of treatment • Improve posture in the growing child An effort must be made to provide the patient with an insight into the relationship between habitual posture and fixed deformity. • Avoid a fixed or structural deformity before the end of growth Treatment should be instituted before the deformity becomes structural.

5. Treatment options Education Education regarding appearance and development will suffice for a large proportion of children who have what is, essentially, a normal variation or physiological deformity. Physiotherapy with extension exercises Moderately severe deformities detected in the growing child can be addressed by extension exercises . Most children will respond to treatment with extension exercises although compliance may be an issue. Milwaukee brace Deformities which are becoming stiffer with time can be improved with the use of a Milwaukee brace. Fixed deformities treated by the use of a Milwaukee brace usually resolve quickly if compliance is reasonable. The problem of brace treatment is that it is profoundly noncosmetic and the underlying issue is largely a cosmetic problem.

6. Factors to be taken into consideration while planning treatment ● The degree of deformity ● The age of the child ● The flexibility of the deformity.

7. Structural kyphosis Structural kyphosis is defined as a kyphotic deformity of the spine associated with deformity of the vertebrae that may be either developmental or congenital in origin . Introduction Structural deformities may be due to congenital vertebral anomalies or developmental disorders of the spinal column such as Scheuermann’s disease , deformities secondary to bone dysplasias or deformity arising from soft tissue laxity . Sepsis in the growing child may damage the vertebral growth plates leading to a progressive deformity that has some similarities to congenital kyphosis .

8. Scheuermann’s disease This disorder is usually seen in children over the age of ten years. Both pain and deformity usually accompany the thoracic kyphosis, which is the site of deformity of true Scheuermann’s disease, although the lumbar spine may also be affected. This disease may be more appropriately described as an osteochondritis . In the early stages of the disease mild wedging of the vertebrae or loss of signal in the anterior portion of the growing vertebrae and intervertebral discs may be evident on magnetic resonance imaging. There is often associated end plate irregularity and loss of disc height. Progressive notching of the anterior margins of the vertebrae and further wedging of the vertebral bodies occur. In the lumbar spine , pain rather than deformity is usually the presenting complaint although a modest kyphosis at the thoracolumbar junction can occur. The disease itself is self-limiting and resolves by the end of spinal growth, but the deformity may be permanent.

9. -Management can be controversial because the longterm disability is mild in most instances and the treatment unattractive to teenage children . -Treatment needs to begin before major structural changes in the vertebrae have developed . - Often the deformity is thought to be postural and thus presentation may be late, particularly if pain is not an issue.

10. -Frank neurological impairment is rare but can occur. Spinal cord irritation as evidenced by hamstring tightness and or clonus is not uncommon. -Pain is a common feature in this condition.

11. Aims of treatment • Early correction of deformity. The deformity must be corrected early in the course of the disease while there is significant growth left to allow for remodelling of the vertebrae. • Prevent neurological impairment. If signs of irritation are evident early intervention is mandatory. • Relieve pain.

12. Treatment options Extension exercises Children with a mild thoracic kyphosis ( < 60 °) can be managed with extension exercises and close observation and serial radiographs. Brace treatment A moderate thoracic kyphosis ( > 60°) can be managed by a Milwaukee brace . In osteochondritis of the thoracolumbar spine where the apex of the deformity is below T10 a TLSO or Boston brace is effective. Instrumentation and fusion of the spine More severe deformities ( > 75°) may require surgical intervention, particularly if there is evidence of cord involvement . In severe and rigid deformities towards the end of growth an anterior discectomy and posterior spinal fusion is necessary. If there is a more diffuse pattern of deformity, particularly if there is growth remaining, then a pure posterior approach will gain good correction. Pedicle screws may be more effective than hooks in these patients.

13. Factors to be taken into consideration while planning treatment ● The skeletal maturity of the child ● The degree of deformity of the spine ● The level of vertebral deformity and the extent of the disease throughout the spine ● The presence of neurological involvement.

14. Rationale of treatment suggested While in most cases the deformity is a cosmetic issue, a worsening thoracic and thoracolumbar kyphosis is associated with an increased lumbar lordosis and back pain in later life. Correction of the deformity can effectively treat the pain and neurological impairment and produce a pleasing improvement in the cosmetic appearance.

15. Kyphosis due to bone dysplasias A progressive kyphotic deformity of the thoracolumbar junction spine is commonly seen in achondroplasia . An outwardly similar deformity is also seen in storage disorders such as Morquio or Hurler’s disease . In achondroplasia the deformity is often associated with significant spinal stenosis whereas the latter group often has proximal cervical spine instability and cerebral impairment from the underlying disease process. In both groups there is deformity of the vertebrae with a kyphotic deformity that is often present early in life. The common feature of these groups of children is that the kyphosis is usually localized to a couple of vertebral segments despite generalized disease and widespread changes elsewhere in the spine .The spinal problems may be aggravated by weakness of the trunk extensors, ligamentous laxity and the weight from a relatively large head. Impaired cerebral function can make history-taking difficult and hence regular reviews involving careful neurological examination and radiological studies are essential.

16. -Worsening kyphosis in the thoracolumbar region can cause neurological compromise and it also results in an increase in lumbar lordosis which may, in turn, worsen any pre-existing spinal stenosis . -Brace management may be compromised by the short stature and mental impairment or behavioural issues . - Laminectomy may be necessary in order to deal with neurological compromise. However, laminectomy in the growing child, particularly in an area of kyphosis, can of itself lead to an increase in that deformity . Stabilization of the spine prior to laminectomy or in conjunction with the laminectomy should be considered for this reason. Surgical intervention may sometimes become necessary in early childhood but, in general, it is not a good option during the first five years. Furthermore, at this time, the family is still coming to grips with the complexities of the conditions.

17. Aims of treatment It is important to emphasize that a cure of the disease is not possible and the aims of treatment are: • Control of deformity and prevention of neurological impairment. The aim of treatment early in life is to control the deformity and prevent neurological deterioration at an age when surgical intervention is not a good option. • Correct deformity. Correction of the deformity may be indicated as a measure to prevent neurological damage from occurring or it may be as an adjunct to decompression of the cord once neurological deficit has developed . • Prevent deterioration of neurological status once neurological signs are evident Once there is evidence of neurological impairment it is imperative that further progression of the neurological damage is prevented.

18. Treatment options ● TLSO or similar underarm brace ● Posterior spinal fusion with continued anterior growth ● Combined anterior and posterior spinal fusion ● Posterior vertebrectomy and spinal fusion with instrumentation.

19. Factors to be taken into consideration while planning treatment ● The age of the patient ● The site and localization of the deformity within a widespread disease ● The presence of neurological impairment ● The associated clinical features and disabilities of the underlying condition.

20. Recommended treatment and rationale of treatment Under two years of age the management is by observation and education of the families as to the natural history of the particular condition. Beyond two years of age an underarm brace may be employed if the associated clinical issues permit . After five years of age a posterior-only fusion may gain stability and allow for the anterior vertebrae to grow out the deformity. This is more useful where the secondary changes from growth are greater than the deformity of the vertebra due to the disease. By the end of the first decade the vertebrae may be of a size to permit a definitive fusion , which may be a combined anterior discectomy and posterior instrumentation. If the deformity is due to focal disease a posterior-only approach with vertebrectomy and posterior instrumentation and fusion is employed.

21. Congenital kyphosis Kyphosis of congenital origin can arise because of failure of formation of vertebrae, failure of segmentation or due to congenital dislocation of the spine. The deformity in congenital kyphosis is often far more dramatic than congenital scoliosis. The major issue is the high risk of neurological involvement , particularly for deformities at or above the thoracolumbar junction.

22. Dubousset has described three types of failure of formation leading to kyphosis: ● Partial failure of formation with a well-aligned canal: Symmetrical deficiency is typically seen with a butterfly hemivertebra . An asymmetrical deficiency will lead to a kyphoscoliotic deformity. ● Partial failure of formation with a dislocated canal: This was described in 1973 as a ‘ congenital dislocation of the spine’. The risk to the cord, which is frequently dysraphic , is great and progression of the deformity can be rapid. ● Total failure of formation of vertebral bodies: Total failure of formation of one or more vertebrae is usually associated with congenital paralysis. This syndrome blends in with sacral agenesis.

23. Failure of segmentation of the anterior elements and continued growth posteriorly results in a smooth kyphosis. The fusion anteriorly may not be apparent early in life and the appearance may be similar to Scheuermann’s disease. There may be multiple vertebrae involved and severe deformity may develop.

24. Problems in management Growth imbalance Growth imbalance, on account of failure of growth of the anterior part of the vertebral column with growth of the posterior elements, will lead to progressive deformity. Once progression is documented surgical treatment should follow. Mechanical factors If the posterior elements are intact the spine may be stable but progression of the deformity will be rapid. If there are deficiencies in the posterior elements as well the resultant instability may lead to sudden neurological injury. Neurological factors Cord compromise may be antenatal in origin, secondary to malformation of the cord itself or develop in childhood secondary to the progressive deformity of the spine. Only cord compromise due to the latter can be expected to recover. Lesions of gradual onset, incomplete cord lesions and young age are better prognostic factors. The more long-standing and more severe the neuroogical deficit, the less likely are the chances of recovery.

25. Aims of treatment • Prevent neurological impairment This may entail correction of deformity, preventing the progression of existing deformity or stabilizing an inherently unstable spine. • Correct deformity Ideally, the deformity needs to be corrected before it becomes severe enough to put the cord in jeopardy . • Prevent deterioration of neurological status once neurological signs of recent onset are evident The same measures considered for prevention of neurological deficit may need to be applied. • Improve function If there is no likelihood of neurological improvement as in children with established long-standing neural damage, attention needs to be directed towards improving other functions. If spinal surgery can facilitate improvement of function (e.g. improving sitting balance in a child with spina bifida) it should be considered.

26. Treatment options for kyphosis without neurological deficit Traction or distraction casting If the kyphosis is flexible, traction or distraction casting can be utilized to lessen the deformity. Dubousset recommends a period in a distraction cast. However, the author is more familiar with traction . Excision of hemivertebra , posterior fusion and posterior instrumentation (posterior approach) In the young child with a posterolateral hemivertebra , resection of the hemivertebra via a posterior approach and a short segment fusion with internal fixation is the treatment of choice.

27. Anterior disc excision and posterior fusion and instrumentation (anterior and posterior approach) In the older child coming to the end of growth with an established or worsening deformity, the flexibility of the apex may dictate treatment. Anterior excision of discs and soft tissue followed by posterior fusion with internal fixation will be necessary if the deformity is becoming rigid. Anterior disc excision, anterior strut grafting, anterior instrumentation and fusion (anterior approach) If the deformity is moderate and the patient is symptom free without neurological compromise, an anterior approach with excision of discs and anterior instrumentation around a strut may be the less risky approach in regard to the spinal cord. Anterior strut grafting and fusion in situ without correcting the deformity (anterior approach) In severe deformities anterior struts may be used. If the apex is rigid then it may be preferable to accept the deformity and fuse in situ rather than risk neurological injury by exploration of the cord.

28. Treatment options for kyphosis associated with neurological deficit Indirect decompression by traction Traction may be used as a method of indirect decompression of the spinal cord in children with early recent onset neurological impairment. If the cord recovers by this indirect decompression then stabilization by fusion is necessary but can be performed in the position gained by the traction . Careful neurological monitoring is required while the child is in traction to ensure that there is no deterioration of the neurological deficit . Indirect decompression by distraction casting Distraction casting works in much the same way as traction and the same precautions need to betaken while this is being attempted.

29. Direct spinal decompression Cord or nerve compression of recent duration that does not resolve by conservative means will require direct decompression. This is usually accomplished via a posterior approach as it is the posterior aspect of the vertebral body that must be resected. Care must be taken to get above and below the apex of the offending lesion and surgical plans must incorporate stabilization as resection of anterior and posterior elements will render the spine more unstable. The decompression may then be followed by an anterior strut graft or posterior instrumentation. Posterior osteotomies or bone resection should be preceded by implant insertion and stabilization of the vertebral column to control any instability induced. Spinal stabilization without spinal decompression If there is a long-standing deficit or an incomplete lesion from birth then the surgical plan should be directed to stabilization rather than decompression. Congenital kyphosis with spina bifida is virtually always associated with a complete high lumbar or thoracic cord lesion which is permanent. In these children the indications for surgery include recurrent skin breakdown, sitting imbalance and the need to use hands for support instead of for activities of daily living. The treatment of choice is vertebral column resection and internal fixation . Intramedullary fixation of the lumbar spine with thoracic sublaminar wires is simple, cost-effective and readily available.

30. Factors to be taken into consideration while planning treatment ● Age of the child ● Flexibility of the deformity ● Severity of the deformity ● Duration of neurological deficit, if present.

31. Rarer causes of kyphosis Kyphosis at the lumbosacral junction Kyphosis at the sacroiliac level Iatrogenic kyphosis following laminectomy

32. Summary Kyphotic deformities of the spine are a common feature of many disease processes. While the deformity may be viewed as purely cosmetic in neurologically intact patients, the possibility of developing neurological impairment is real. Patients presenting with a recent neurological loss may require early stabilization and fusion, and possibly spinal cord decompression. Patients with long-standing paraplegia may warrant stabilization but the spinal cord cannot be expected to recover , and thus decompressive procedures are not indicated.

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