Spinal Stenosis

I. Background

Spinal stenosis is a pathologic condition common in people over 50 years of age. It is caused by narrowing of the spinal canal and/or the neural foramina roots, which produces abnormal pres­sure on spinal nerve roots or the blood vessels supplying the nerve roots. The condition may be congenital (achondroplasia) or acquired. Acquired causes include degenerative changes of the spine, ie., disk degeneration, facet joint hypertrophy, ligamentous calcification and vertebral osteophytes; spondylolisthesis or other malalignment; progressive enlargement of the fusion mass after a posterior spinal fusion; Paget's disease or fluorosis. It may also occur after an unreduced burst fracture or fracture-dislocation of the lumbar spine. Patient population at risk varies from young adults (achondroplasia or spinal fractures), to middle aged pa­tients with a single nerve root trapped by lateral recess stenosis to elderly patients with multilevel central and lateral stenosis. Back pain may or may not be a presenting complaint. Sciatica or clau­dication in one or both legs are common presenting complaints. Pain, sensory disturbance, and motor weakness experienced by these patients are often aggravated by exercise and relieved by bending forward or flexing the low back by sitting. Bowel and/or bladder dysfunction and other neurologic symptoms may occur.

II. Diagnostic Criteria

A.    Pertinent Historical and Physical Findings

Patients may exhibit few objective findings such as reflex changes, motor weakness, sensory deficits, or inability to stoop. Hyperextension of the spine is usually limited and painful. A hallmark of this condition is that the severity of the clinical symptoms change with the position of the patient. Lower extremity reflexes often disappear, and pain, numbness, and weakness in the legs may appear after exercise. Sciatic tension tests are usually negative but weakness of the extensor hallucis longus muscle may be present. The condition may progress to the point of greatly impairing the patient's quality of life. At present, there are no studies that correlate the degree of spinal compression with the severity of symptoms.

B.    Appropriate Diagnostic Tests and Examinations (one or more)

1.   Routine x-rays of the low back will not confirm diagnosis but are needed to rule out other conditions.

2.   Myelography may confirm diagnosis

3.   CT scan may confirm diagnosis

4.   MRI may confirm diagnosis

5.   Bone scan

6.   Cystometrogram if symptoms warrant

7.   Evaluation of vascular system if symptoms warrant

C. Inappropriate Diagnostic Tests and Examinations

1.     Routine x-rays of the low back as sole diagnostic test

2.     EMG as sole diagnostic test

3.     Thermography

4.     Ultrasound

5.     Bone scan as sole diagnostic test

 

D. Exceptions to Above Criteria

1.     EMG in conjunction with neurologic consultation may be useful in preoperative planning for delineating involved nerve roots'.'

2.     Bone scans, laboratory tests, and other studies may be indicated in the evaluation of selected patients.

E. Evolving Diagnostic Tests and Examinations

1. Ambulatory performance of myelography is an evolving outpatient technique

F. Supporting Evidence

Studies have documented that myelography with water soluble contrast media and CT scans are the most accurate tests for con-firming the diagnosis of spinal stenosis. However, of these two studies, myelography is more accurate for documenting central stenosis and CT scans are more accurate for documenting nerve root canal stenosis. For this reason, most orthopaedists order both tests. EMG findings are abnormal in 80% of patients with this disorder, but the findings lack specificity, which make EMG an inappropriate test as the sole modality for confirming the diagnosis.

III. Treatment

A. Outpatient Treatment

1. Nonoperative Treatment

a. Indications: absence of severe or progressively abnormal neurologic signs

b. Treatment Options

1)     Restricted activity

2)     Ambulatory rest

3)     Physical modalities

4)     Nonsteroidal anti-inflammatory drugs

5)     Analgesics

6)     Periodic, epidural steroid injections

7)     Spinal orthotic supportive devices

c. Home Health Care: monitor compliance with treatment protocol and alter as indicated.

d. Rehabilitation

1)     Spinal muscle strengthening exercises

2)     Endurance and strength reactivation programs

e. Supporting Evidence: A few studies exist to show the value of short periods of bed rest followed by con-trolled activity in relieving low back pain and sciati­ca. These studies are mostly clinical series, not prospective controlled studies. No data currently exist to indicate the percent of patients who will need surgical intervention or the percent who may function satisfactorily without treatment.

2. Ambulatory Surgery, Indications: none 

B. Inpatient Treatment

1. Nonoperative Treatment

a. Indications for Admission

1)     Severe back and leg pain unresponsive to outpatient treatment

2)     Myelogram or combination myelogram

and CT scan

b. Treatment Options

1)     Monitored bed rest with sedation and

analgesics during acute phase

2)     Epidural steroid injection(s)

3)     Flexion body cast, bracing

4)     Endurance and strength reactivation

c. Indications for Discharge

1)     Relief of back and/or leg pain

2)     No response to nonoperative treatment options pending patient's consideration of surgical intervention

d. Home Health Care: Monitor compliance with treatment protocol and alter as indicated

e. Rehabilitation

1)     Spinal muscle strengthening exercises

2)     Endurance and strength reactivation programs

2. Operative Treatment

a. Indications for admission

1)     Quality of life significantly impaired

2)     Failure of nonoperative treatment to relieve symptoms

3)     Presence of severe or progressive abnormal

neurologic signs

4)     Diagnosis confirmed by myelography, CT scan,

or MRI

b. Procedure Options

1)     Decompression

2)     Decompression with fusion

3)     Decompression with fusion and instrumentation

c. Indications for Discharge

1) Uncomplicated

a)   Approximately 5 to 10 days following laminectomy

b)  Approximately 7 to 15 days if spinal fusion performed in conjunction with laminectomy

2) Complicated: stay may be extended for co-mor­bidity (e.g.,wound infection,thrombophlebitis, durotomy or spinal fluid leak).

d. Home Treatment

1)     Visiting nurse and/or physical therapist may be required to assist patient in returning to activities of daily living.

2)     Patient may need back brace.

e. Rehabilitation

1)     Assistance with spinal muscle strengthening program may be needed.

2)     Overall general physical conditioning  (e.g., cardiovascular and pulmonary fitness activities)

f. Supporting Evidence: Surgical intervention in spinal stenosis remains an elective decision based on the surgeon's clinical judgment and the patient's personal assessment of his/her quality of life impairment. The preferred surgical procedure for spinal stenosis remains undecided although most authorities favor decompressive laminectomy without fusion in central spinal stenosis. Lateral recess decompression may create instability or potential instability requiring fusion. Fusion may also be indicated in addition to the laminectomy in patients with symptomatic degenera­tive spondylolisthesis or other forms of spinal insta­bility. Satisfactory results from surgery can be expected in approximately 85% of patients. Long-standing nerve root compression may result in a less satisfactory surgical result.

 

C. Inappropriate Treatment

1.      Chemonucleolysis

2.      Percutaneous diskectomies

3.      Spinal fusion without decompressive laminectomy

D. Exceptions to Above Criteria: None

E. Estimated Duration of Care

1.      Nonoperative treatment indeterminant based on patient's symptoms

2.      Operative treatment 6 to 12 months

F. Anticipated Outcomes

1.      Complete or partial relief of back and leg pain

2.      Improved quality of life

G. Evolving Therapeutic Procedures

1. Laminoplasty or interlaminar decompression