Scoliosis, Low back pain, Ankylosing Spondylitis

Question 1

Intrinisic muscles of the back

Answer 1

• Covered by deep fascia, involved in movement of head and vertebral column. Divided into 3 groups:
  
  1. Superificial Intrinsic - Spinotransversales muscles (Splenius capitus and splenius cervicus) - movement of head and neck. Loacted on posterolateral aspect of neck.
  2. Intermediate intrinsic - Erector spine (iliocostalis, longissimus, and spinalis) - found posterolaterally to spinal column, between vertebral spinous processes and costal angle of the ribs.
  3. Deep intrinsic - (Semispinalis, multifidus, and rotatores). Located under erector spine. Short muscles associated with transverse and spinous processes of vertebral column. Act to stabilize vertevral column and provide proprioceptive function. Semispinalis is also capable of extension and contralateral rotation of head

Question 2

Extrinsic Muscles of the back

Answer 2

• Muscles that are superifical and responsible for movements at shoulder and upper limb. Extrinsic muscles of the back include:
  
  • Trapezius - elevates and rotates scapula during abduction of the arm
  • Latissimus dorsi - adducts, extends, and internally rotates the arm
  • Rhomboid major and minor - keep scapula in place and retract scapula when trapezius is contracted
  • Levator scapulae

Question 3

Adolescent Idiopathic Scoliosis

Answer 3

A lateral curvature of the spine typically accompanied by variable degree of rotation of the spinal column.

• ≥10⁰ curvature, as measured by the cobb angle, is considered scoliosis
• Direction of scoliotic curve is determined by curves convexity
• 3 subgroups:
  
  • Infantile: 0-3 years (early onset)
  • Juvenile: 4-9 years (early onset)
  • Adolescent: ≥ 10 years (Late onset)

Question 4

Etiology of Adolescent Idiopathic Scoliosis

Answer 4

• Cause in unknown, however, genetics seems to play a role
• Other proposed factors include abnormalities in GH secretion, connective tissue structure, paraspinal musculature, vestibular function, and melatonion secretion

Question 5

Clinical Presentation Adolescent Idiopathic Scoliosis

Answer 5

• Tends to come to medial attention via trunca asymmetry
• Patients with severe thoracic curves (cobbs ≥ 70⁰) may have restrictive pulmonary disease
• May have obstructive lung disease

Question 6

Investigations Adolescent Idiopathic Scoliosis

Answer 6

Inspection:

• Curvature of the spine
• Differences in height of shoulders or scapulae
• Asymmetry of waitline
• Asymmetry in distance that arms hand from the trunk
• Head not centered over sacrum
• Adams forward bend - get patient to bend forward and check if scapula remains level
• Scoliometer - deviced used for scoliosis screening and quatification of trunk rotation. Scoliometer is placed horizontally on patients back while they are bent over.

Examination to look for non-idiopathic causes.

• Cafe-au-lait and axillary freckling - neurofibromatosis
• Vascular lesions, hypopigmented lesions, hyperpigmented lesions, dimpling, hair patch over spine - spinal dysraptism.
• Excessive skin or joint laxity - Ehlers-Danlos, Marfan, or osteogenesis imperfecta

Leg length measurement (true) - if positive, scoliosis may be compensatory

Full neurological assessment should be conducted

Question 7

Imaging of Adolescent Idiopathic Scoliosis

Answer 7

• Imaging
  
  • Radiographs - used to confirm scoliosis diagnosis, evaluate for potential etiology, determine curve pattern and measure angle, evaluate skeletal maturity
    
    • Full-length posteroanterior and lateral views of spine from C7 to sacrum. Should be taken upright as supine can underestimate magnitude of curve.
  • MRI - May be indicated in patients with scoliosis and clinical or Xray findings suggestive of intraspinal pathology - i.e., neurologic symptoms, significant pain, progression of cobb angle of ≥ 10⁰ per year, abnormalities on plain Xray suggestive of congential scoliosis.

Question 8

Diagnosis of Adolescent Idiopathic Scoliosis

Answer 8

• Diagnosis is made by clinial and radiographic evaluation:
  
  • Age ≥ 10 years
  • Curvature of the spine in coronal plain with cobb angle ≥10⁰
  • Absence of other etiologies for scoliosis

Question 9

Differential Diagnosis of Adolescent Idiopathic Scoliosis

Answer 9

• Neuromuscular scoliosis - occurs in patients with neurologic or MSK problems like cerebral palsy or muscular dystrophy. Due to muscle imbalance and lack of trunk control
• Congential scoliosis - results from asymmetry in vertebrae secondary to congetial abnormalities (vertebrae fail to for or segment). Usually manifest before 10 years and if often associated with abnormalities of other organ systems. These congential vertebral abnormalities are evident on radiography.
• Syndrome scoliosis - occurs as part of certain genetic disorders, including connective tissue disorders - Marfan, osteogenesis imperfecta. Have additional features that help establish diagnosis.
• Postural -leg length discrepancy, muscle spasm

Question 10

Treatment of Adolescent Idiopathic Scoliosis

Answer 10

Treatment is based on the cobb angle

• <25⁰: Observe for changes with serial radiographs
• >25⁰ or progressive: Bracing that halt/slow curve progression but do NOT reverse deformity
• >45⁰, Cosmetrically unacceptable or respiratory problems: Surgical correction (spinal fusion).

Types of braces:

• Most curves can be managed with underarm brace (TLSO - thoraco-lumbar-sacral orthosis)
• Some curves need a brace with under-chin extension (CTLSO - cervico-thoraco-lumbar-sacral orthosis). Indications for this include thoracic curve with apex at or above T8 and doub;e thoracic curves.
• * Bracing is not effective in children with Risser grade > 2
• Patients are told to wear the brace 18 hours per day
• Brace should be used until the end of growth. Suggested that patients weam brace use over 6 months.

Surgery

• Goal is to prevent curve progression through spinal fusion. Secondary goals include curve correction and improved quality of life.
• Posterior spinal fusion and instrumentation and bone grafting - most common surgical procedure
• Anterior spinal fusion and instrumentation - may be performed from thoracolumbar and lumbar scoliosis

Question 11

Outcomes of Adolescent Idiopathic Scoliosis

Answer 11

• Curves measuring ≤ 30⁰ at end of growth tend to not progress
• Curves >50⁰ generally progess 1⁰ per year after skeletal maturity
• Increase risk of mild-moderate back pain or degerative disc changes in adulthood
• Increase of concerns related to body development and peer interactions

Question 12

Low Back Pain - Classification

Answer 12

• ≤ 4 weeks = acute
• 4-12 weeks = subacute
• ≥ 12 weeks = chronic

Question 13

Etiology of Back Pain

Serious systemic etiologies

Answer 13

Most causes of back pain are nonspecific and have MSK pain that will improve over a few weeks

Serious systemic etiologies - less than 1% of patients

• Spinal cord or cauda equina compression - most common cause of cauda equina syndrome is herniation of intervertebral disc with other causing being ankylosing spondylitis, lumbar puncture, trauma, and infection. Pain is usually the first symptoms, but motor weakness and sensory findings tend to be present. Bladder or bowel dysfunction tend to be a late finding.
• Metastatic Cancer - Bone is one of the most common sites of metastatic caner. A history of cancer is one of the strongest risk factors for back pain from metastasis (skeletal mets - breast, prostate, lung, thyroid, and kidney; Multiple Myeloma - 60% present with skeletal lytic lesions at diagnosis.
• Spinal Epidural Abscess - Starts with fevers and malaise. Over time, back pain may be followed by radicular pain and neurologic deficits. Risk factor include spinal injections or epidural catherter placement, IV drug use, and other infections. Urgent antibiotic treatment and surgical therapy for those with neurological symptoms is required.
• Vertebral osteomyelitis - incidece increases with age. Men>women. Many cases are thought to be due to hematgenous spread of bacteremia. Typially presents with gradual onset of symtpoms over several days. Most will present with back pain, but may not have fevers or other system features. Antiobotic treatment improves outcomes.

Question 14

Etiology of back pain

Less serious specific causes

Answer 14

Most causes of back pain are nonspecific and have MSK pain that will improve over a few weeks

Less serious specific etiologies of back pain:

• Vertebral compression fracture - some vertebral compression fractures produce no symptoms, others will have acutre onset localized back pain.
• Radiculopathy - symptoms/impairtments related to spinal nerve root damage. Damage may be due to degenerative chages in vertebrae, disc protrusion, and other causes. Clinical presentations vary based on nerve root involved, but 90% are L5 and S1, which tend to present with pain, sensory loss, weakness, and/or reflex changes consistent with nerve root involved.
• Spinal Stenosis - Tends to be multifactorial in nature. Most common causes are spondylosis, spondylolistheses and thickening of ligamentum falvum. Tends to affects patients >60 years. Ambulation induced pain localized to calf and distal lower extremity resolving with sitting or leaning forward is a hallmark feature. Other symptoms include back pain, sensory loss, and weakness in the legs.

Question 15

Imaging Back Pain

Answer 15

• Early use of imaging for low back pain without associated symptoms is not associated with improved outcomes, but increases use of invasive procedure. Often find features on imaging that do not correlate with pain.
• Indications for imaging:
  
  • Most patients with pain ≤4 weeks do not require imaging
  • Patients with red flags should undergo appropriate imaging modality.

Question 16

Red Flags for Acute Back Pain

Answer 16

These are indications for imaging

• Signs and symptoms of cauda syndrome - new urinary retention, fecal incontinence, or saddle anestheia
• Significant neurologic deficits - progressive motor weakness or significant motor deficit not localized to single unilateral nerve root
• Current or recent cancer history other than nonmelanoma skin cancer
• Moderate-high risk for cancer
• Signs, symptoms, risk factors for spinal infection (epidural abscess or osteomyelitis) - fever, history of IV drug use, recent infection, hemodialysis, immunosuppression
• Risk of vertebral compression fracture - advanced age, history of prolonged systemic glucocorticoid use, significant trauma, or mild trauma with history of osteoporosis

Question 17

Risk Assessment for Subacute back pain

Answer 17

For patients who have not improved after 4-6 weeks of conservative treatment

• If patients develop neurological deficits or symptoms of infection
• If patient has a cancer risk that didn’t meet red flag critieria
• Patients with signs and symptoms indicating ankylosing spondylitis should have plain radiograph to evlatuate SI joints
• Concern for osteoarthritis - lumbosacral, plevic, and/or hip radiographs may be considered for older patients with persisent back pain if there is concern for OA of the hip referred to the back or where mechanical adaptions to hip OA are causing back pain
• Patients without specific concerns should be continued on conversative management for another 8 weeks

Question 18

Treatment Acute Back Pain

Answer 18

• Nonpharmological
  
  • Heat - may reduce muscle spasm
  • Massage - no evidence of clinical benefits, but it is associated with increased patient satisfaction
  • Spinal manipulation - modest improvement in pain and function for low back
  • Exercises and physical therapy - generally don’t refer patients with acute low back pain. However, may refer patients with risk factors for developing chronic low back pain
• Pharmacotherapy
  
  • NSAIDs - short term trail of 2-4 weeks - first line therapy
  • Combination with muscle relaxants - muscle relaxants are a diverse group of drugs with analgesia and degree of skeletal muscle relaxation (i.e., cyclobenzaprine, baclofen, etc).
  • Evidence to use opioids and tramadol (opioid agonist) in acute low back pain is limited.

Question 19

Treatment Subacute and Chronic back pain

Answer 19

• Nonpharamological interventions
  
  • Mainting activity. Patients who require bedrest to relieve symptoms should be encouraged to return to normal activities. Bedrest does not improve function or pain compared with usual activity
  • Exercise therapy - motor control exercise, core strengthening, flexion/extension, movements, etc.
  • Spinal manipulation for low back pain
• Psychological interventions
  
  • CBT
  • Mind-body interventions - mindfulness and mediation
• Pharmacological therapies
  
  • Initial therapy - short course of NSAIDs
  • Second line therapy
    
    • Subacute - add a short course of nonbenzodiazepine muscle relaxant
    • Chronic - tramadol or duloxetine for patients who don’t resond to NSAIDs. Opioids may be appriopriate for short-term use in selected patients with acute exacerbations, but should not be used routinely. Opioids should be closely monitored
  • Other options - antidepressants, benzodiazepines (need to be careful about addicitive and sedating side effects), antiepileptic medications (despite common use evidence is limited)
  • *

Question 20

Axial Spondyloarthritis (axSpA)

Answer 20

A seronegative rheumatic disease that consists of two disorders

• Akylosing Spondylitis (AS) - A chronic inflammatory arthritis involving the sacroiliac joints and vertebra with enthesitis as major feature. Characterized by pathological deposition of new bone leading to spinal ankylosis. Demonstrate radiograph abnormalitis consistent with sacroilitis.
• Nonradiographic axSpA - Findings are not seen on plain radiography, but diagnosis is supported by evidence of active inflammation of the SI joints on MRI and/or other findings

Question 21

Etiology of Ankylosing Spondylitis

Answer 21

• Inflammation (begins at enthesis) → Osteopenia → Erosion → Ossification → Osteoproliferation (syndesmophytes)
• Inflammation starts due to interactions of several features including
  
  • Genes (HLA-B27)
  • Disturbed barrier function - Chron’s, psoriasis
  • Gut microbiome
  • Invasive pathogens
• These features result in the release of IL23, and subsequent enthesisitis. T-cells are also stimulated to release more IL, including IL22 and IL17.
  
  • IL22 - stimulates osteoproliferation and inflammation
  • IL17 - stimulates release of TNF which results in inflammation and bone loss
  • Eventually results in bone fusion

Question 22

Investigations Ankylosing Spondylitis

Answer 22

• HLA-B27 testing - present in 90-95% of AS patients vs. 8% of general popluation
• Acute phase reactants - ESR and CRP
• Imaging studies
  
  • Plain radiography
  • MRI of SI joints - indicated in those without evidence of scaroilitis on Xray but have other symptoms that are consistent
  • MRI of spine - if nr-asSpA is strongly suspected but MRI of SI joints is normal
  • Ultrasonography - may be sued to identify enthesitis

Question 23

Clinical Presentation of Ankylosing Spondylitis

Answer 23

• SI and spinal involvement
• Hip and shoulder involvement
• Peripheral arthritis in joints other than hip and shoulder
• Costovertebral, manubriosternal, and sternoclavicular, and costochondral inflammation
• Inflammation of extraspinal enthesis
• Dactylitis
• Low back and neck pain - almost all patients report back pain which is usually inflammatory in nature
  
  • Age of onset <40
  • Insidous onset
  • Improvement with exercise
  • No improvement with rest
  • Pain at night
• Impaired spinal mobility - fusion of the spone leads to extreme impairment of spinal mobility and chest expainsion
• Postural abnormalities - hyperkyphosis due to wedging of thoracic vertebrae, flexor deformity of neck, loss of normal lumbar lordosis, and flexion deformitis of the hip
• Buttock pain - especially alternating between 2 sides, may indicate SI involvement
• Enthesis - inflammation of enthesis is a classic feature of axSpA - pain, stiffness, and tenderness of insertion

Question 24

Extraarticular manifestations and comorbidities Ankylosing spondylitis

Answer 24

• Certain coexisting diseases (i.e., acute anterior uveitis, psoriasis and IBD) are so common that they are considered extraarticular manifestations rather than comorbidities
• Increase risk of cardiovascular disease including aortic regurgitation
• Pulmonary disease - due to restrictive changes caused by MSK changes and changes in the lungs themselves

Question 25

Complications of Ankylosing Spondylitis

Answer 25

• Osteopenia - low BMD is evident within first 10 years of disease
• Vertebral fragility factures from trauma are at least twice as common - due to combination of low BMD and spinal rigidity
• Neurologic manifestations - can occur by several mechanisms, inclduig cord and spinal nerve compression due to fracture
  
  • Spinal cord injury - more common in AS and affects the cervical spine most often
  • Atlantoaxial subluxation - clinically significant spontaneous subluxation of C1-C2 joint. Can result in spinal cord compression if not recognized.
  • Cauda equina syndrome - rare complication. Reprorted in those with longstanding disease who have marked ankylosis of the spine.
• Renal disease - uncommon in axSpA, but nonspecific glomerulopathy, immunoglobulin A (IgA) nephropathy, and renal amyloidosis may be seen in AS

Question 26

Diagnosis of Ankylosing Spondylitis

Answer 26

Question 27

Treatment Ankylosing Spondylitis

Answer 27

• Non-pharmacological therapy
  
  • Prevent fusion from poor posture and disability through exercise, postural and deep breathing exercises, PT, and smoking cessaation
• Pharmacological therapy
  
  • NSAIDs - first line treatment. Do a trial of NSAIDs before moving onto other treatments
  • DMARDs (sulfasalazine) - only helps with peripheral arthritis
  • Glcocorticoids - topical eye drops and local injections
  • anti-TNF - agents for axial and peripheral involvement - should only be used after a failure of at least NSAIDs
• Surgical Therapy
  
  • Hip replacement and vertebral osteotomy for marked deformity

Question 28

Mechanical vs. Inflammatory Back Pain

Answer 28

Question 29

Spina Bifida

Answer 29

• Spina bifida/Myelomeningocele is the most common type of neural tube defect (NTD). It is a NTD characterized by a celft in the vertebral column, with corresponding defect in skin so that meninges and spinal cord are exposed.
  
  • Neurologic defects - depend on level of the lesions and typically affects the trunk, legs, bowel, and bladder. Defects are severe and result in complete paralysis and absence of sensation.
  • Brain stem dysfunction - due to chiari malformation. Can result in issues such as difficulty swallowing, vocal cord paresis, and apneci episodes
  • Hydrocephalus - 90% have enlarged ventricles, indicating some degree of hydrocephalus. Due to chiari II malformation