Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

Featured on Channel NewsAsia

Kyphosis

Basics
Description
  • Kyphosis, a spine curve in the sagittal plane with an anterior concavity, is normally present in the thoracic and sacral spine.
    • Normal thoracic kyphosis values: 20-40°.
    • Values >40° in the thoracic spine may be associated with postural kyphosis, congenital kyphosis, Scheuermann kyphosis, osteoporosis, AS, paralytic disorders, myelomeningocele, trauma, infection, surgery, and malignancy.
  • Kyphotic deformity (curvature >40°) may lead to increased incidences of back pain, lumbar spondylolysis and, in the case of congenital and infectious kyphosis, neurologic compromise.
General Prevention
  • Postural kyphosis (round back) can be influenced by attention to proper posture.
  • Prevention of osteoporosis
Epidemiology
Kyphotic deformity development is associated with NF, mucopolysaccharidosis, achondroplasia, myelomeningocele, AS, benign and malignant tumors.
 
Incidence
  • Kyphotic deformity secondary to osteoporotic fractures occur in 15% of Caucasian females.
  • Spinal tuberculosis complicates 3-5% of the 8 million new cases of tuberculosis reported worldwide per year.
  • In those with HIV, spine involvement may be as high as 60%.
Prevalence
  • Postural kyphosis is seen in young girls self-conscious of their breast development and in young patients who are taller than their peers.
  • Congenital kyphosis is rare.
  • Scheuermann kyphosis has been reported in 0.4-8.3% of the general population, and males are affected slightly more often than females.
  • Osteoporosis is more common in patients who are female, elderly, of Caucasian or Asian descent, or taking steroids chronically.
Risk Factors
  • Osteoporosis
  • Positive family history of kyphosis
  • History of spine fracture
  • Heavy loading of the spine during adolescence
  • Exposure to tuberculosis
  • Malignancy
Genetics
Some causes of kyphosis may be inherited, including AS, osteoporosis, and Scheuermann disease.
 
Etiology
  • Postural kyphosis results from ligament stretching; the vertebrae are formed normally.
  • Scheuermann kyphosis is caused by wedging of the vertebrae, which usually develops during early adolescence.
  • Congenital kyphosis is present at birth and is characterized by hemivertebrae or by fusion of the vertebrae anteriorly.
  • Kyphosis develops in patients with osteoporosis through the anterior wedge vertebral fractures produced by insufficiency fractures of the thoracic or lumbar spine.
  • Kyphosis develops in patients with tuberculosis as a result of destruction of the vertebral body.
Associated Conditions
  • Congenital kyphosis:
    • Kyphosis progresses rapidly over a short segment, and the resultant stretch of the spinal cord leads to neurologic decline.
    • Cardiac, renal, pulmonary, and auditory abnormalities
  • Congenital scoliosis or kyphosis presents intraspinal abnormalities in 30%
  • Scheuermann kyphosis:
    • Increased lumbar lordosis is associated with a 50% incidence of spondylolysis
    • 1/3 of patients have mild to moderate scoliotic curves (10-20°).
  • Osteoporosis:
    • Insufficiency fractures of the hip, pelvis, and wrist
Diagnosis
Signs and Symptoms
  • Congenital kyphosis may be detected on prenatal ultrasound but usually is diagnosed by a pediatrician or parent noticing the initial or increasing deformity.
  • Poor posture noted by parents, a sharp apex to the curve, and pain at the apex are indicative of Scheuermann kyphosis.
  • A loss of height, increasing curvature to the spine, and back pain are associated with kyphosis from osteoporosis.
  • Night sweats, weight loss, new deformity, and new neurologic deficit suggest tuberculosis or malignancy as a cause of kyphosis.
  • Postsurgical kyphotic deformity may be noted by comparison of the patient’s previous examinations, radiographs, and history.
History
  • Other congenital abnormalities
  • Family history of kyphosis
  • Progression of deformity
  • Neurologic deficit (onset and progression)
  • Constitutional signs (weight loss, fevers, etc.)
  • History of steroid use or insufficiency fractures
  • History of trauma
Physical Exam
  • Examine the patient when he or she is in the neutral standing position and bending forward.
  • Flexibility of the curve should be assessed by prone hyperextension.
  • Complete neurologic examination
Tests
Lab
  • If infection is suspected, it should be evaluated by obtaining a complete blood count, ESR, and possibly blood cultures.
  • Skin testing if tuberculosis is suspected
  • Biopsy may be indicated if the organism is not known.
  • Results of routine laboratory studies are normal in most cases of kyphosis, even if osteoporosis is present.
  • In AS, patients may have antibodies to HLA-B27, although the diagnosis remains largely clinical.
Imaging
  • Conventional radiographs:
    • For all types of kyphosis, conventional standing AP and lateral views of the entire spine on 1 cassette are required.
    • Additional plain films include focused views of the deformity to assess for bony abnormality and hyperextension views over a bolster to assess curve flexibility.
    • Risser sign usually can be assessed on the AP film.
  • MRI is indicated for patients with congenital kyphosis, neurologic deficit, and/or suspicion of malignancy.
  • Renal ultrasound to evaluate congenital abnormalities should be performed in children with congenital kyphosis.
  • DEXA scan to ascertain baseline values of osteoporosis should be considered for patients with osteoporotic kyphosis.
Pathological Findings
  • Scheuermann kyphosis (2 types):
    • Typical: Wedging of 3 or more consecutive vertebrae by >5° and an apex between T7-T9
    • Atypical: Vertebral endplate changes, Schomorl nodes, and disc space narrowing, but may lack 3 consecutive vertebrae with 5° of wedging
  • Anterior wedging of the superior end plate and loss of bone mass are seen in patients with osteoporosis.
  • In patients with AS, the vertebral bodies are wedged into a triangular shape at several levels, the spine is stiff, and eventually the involved vertebrae become fused.
  • In patients with kyphosis from infection or tumor, a soft-tissue mass that narrows the spinal cord may be present posterior to the vertebrae.
Differential Diagnosis
  • Scoliosis may resemble kyphosis because of the rib deformity on the convex side but, in fact, most patients with thoracic scoliosis have less than normal kyphosis.
  • The causes of kyphosis must be differentiated because the corresponding treatments differ.
  • Neuromuscular disorders may cause kyphosis because of low muscle tone.
  • Surgical laminectomy of the spine in a growing child may cause subsequent kyphosis to develop.
Treatment
General Measures
  • Observation: it is acceptable to use serial radiographs to monitor progression in patients with mild deformity.
  • Exercise:
    • For those complaining of pain, exercises and analgesics are the mainstays of treatment
    • Postural exercises for postural kyphosis
  • Bracing:
    • Not indicated for congenital kyphosis
    • Indicated for growing adolescents with Scheuermann kyphosis with an apex below the 8th thoracic vertebrae and curves ranging 40-70°.
    • Indicated for acute osteoporotic fractures
  • For patients with congenital kyphosis, surgery should be performed if the patient is still growing because a substantial chance exists for neurologic compromise if the curve worsens.
Special Therapy
Radiotherapy
Postirradiation kyphosis can be minimized with careful pretreatment planning to minimize exposure to the growth centers of the spine.
 
Physical Therapy
  • Exercises provide benefit for pain from many types of kyphosis.
  • Stretch the hamstrings, the tight structures on the anterior aspect of the kyphosis, and the tight muscles in the lumbar lordosis.
  • Strengthening should include abdominal muscles and the back extensors.
Medication
First Line
  • Analgesics, usually NSAIDs or acetaminophen, may be used if back pain recurs.
  • Physical therapy is the mainstay of treatment for Scheuermann kyphosis, but bracing treatment should be considered for curves >60°.
  • Calcium with vitamin D supplementation for patients at risk of developing osteoporosis
  • Diphosphonate or estrogens may be considered as part of a program to prevent or treat osteoporosis in appropriate patients.
  • Multidrug therapy is the mainstay of tuberculosis treatment.
Surgery
  • Surgery is indicated for various types of kyphosis if deformity or pain is unacceptable and unresponsive to nonoperative measures.
    • Congenital kyphosis:
      • Requires surgery in all but rare instances
      • In situ fusion or corrective osteotomy with posterior or anterior/posterior instrumentation are current treatments.
    • Scheuermann kyphosis:
      • Requires surgery for pain refractory to nonoperative measures, progression, neurologic compromise, cardiovascular compromise, or deformity
      • Posterior or anterior/posterior fusion after corrective osteotomy are current treatments.
  • Osteoporotic fractures can be treated with kyphoplasty to restore height and relieve pain or with vertebroplasty for pain relief alone.
  • Decompression, correction of deformity, and stabilization are indicated for infectious or malignant lesions with neurologic compromise.
Follow-up
Prognosis
  • Kyphosis tends to progress with age.
    • The back and neck pain it causes may range from minor to persistent.
  • Patients usually are able to carry out full-time jobs, although physical work may be limited.
Complications
  • Patients with severe, sharp kyphosis may have neurologic compromise from the apex of the curve.
    • May be triggered by a fall or fracture
  • Surgical correction carries an increased risk of neurologic compromise when compared with curves of the same magnitude in scoliotic deformity.
  • Pseudarthrosis
  • Curve progression
Patient Monitoring
  • In growing patients, the curve should be monitored every 4-6 months.
  • Adults may be seen as needed.
Miscellaneous
Codes
ICD9-CM
  • 732.0 Scheuermann kyphosis
  • 733.0 Congenital kyphosis
  • 737.10 Postural kyphosis
  • 737.41 Tuberculosis
Patient Teaching
Stress adequate daily calcium intake because, although osteoporosis may not play a role in the causes of most types of kyphosis, it may affect patients later and may worsen the kyphosis.
 
FAQ
Q: At what point should bracing be considered for Scheuermann kyphosis?
A: Approximately >60° of curvature.
Q: What is the most common cause of kyphosis in elderly Caucasian females?
A: Osteoporotic vertebral compression fractures.

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