Primary Care Evaluation and X-Ray Indications
Key Points:
- Fear, financial problems, anger, depression, job dissatisfaction, family problems or stress can contribute to prolonged disability.
- Generally anterior to posterior (AP) and lateral (LAT) views x-rays are not helpful in the acute setting
This includes a history and physical and consideration of psychosocial factors.
If a serious underlying disease such as cancer, Cauda Equina Syndrome, significant or progressive neurologic deficit, or other systemic illness is present, consult or refer.
Patient History Includes:
Cancer risk factors:
- 50 years old or older
- History of cancer
- Unexplained weight loss
- Failure to improve after four to six weeks of conservative LBP therapy
If all four of the above risk factors for cancer are absent, studies suggest that cancer can be ruled out with 100% sensitivity.
Risk factors for possible spinal infection:
- Intravenous (IV) drug use
- Immunosuppression
- Urinary infection
Signs and symptoms of Cauda Equina Syndrome:
- Urinary retention (if no urinary retention, the likelihood of Cauda Equina Syndrome is less than 1 in 10,000)
- Saddle anesthesia, unilateral or bilateral sciatica, sensory and motor deficits, and abnormal straight leg raising are all common.
Signs or symptoms of neurologic involvement:
- Complaint of numbness or weakness in the legs
- Sciatica with radiation past the knee (increases the likelihood of a true radiculopathy rather than pain radiating only to the posterior thigh)
- Sciatica has such a high sensitivity (95%) that its absence makes lumbar disc herniation unlikely
- The likelihood of disc herniation in a patient without sciatica would be 1 in 1,000
- Because more than 95% of lumbar disc herniations occur at the L4-5 or L5-S1 levels, the neurologic exam should focus on the L5 and S1 nerve roots; however, upper lumbar nerve root involvement may be suggested when pain conforms to L2, L3, or L4 dermatomal distribution and is accompanied by anatomically congruent motor weakness or reflex changes.
Psychosocial indications:
- Belief that pain and activity are harmful
- "Sickness behaviors" such as extended rest
- Depressed or negative moods, social withdrawal
- Treatment that does not fit best practice
- Problems with claim and compensation
- History of back pain, time off, or other claims
- Problems at work or low job satisfaction
- Heavy work, unsociable hours
- Overprotective family or lack of support
Psychosocial indications can be barriers to recovery. Consider factors such as fear, financial problems, anger, depression, job dissatisfaction, family problems, or stress which can contribute to prolonged disability. Refer to the National Guideline Clearinghouse (NGC) summary of the Institute for Clinical Systems Improvement (ICSI) guideline Major Depression in Adults in Primary Care for more information.
For more information on psychosocial indications, see the New Zealand Acute Low Back Pain Guide: Incorporating the Guide to Assessing Psychosocial Yellow Flags in Acute Low Back Pain, 2003.
(See Appendix C, "Psychosocial Screening and Assessment Tools" in the original guideline document.)
Physical Examination Should Document:
Palpation for spinal tenderness
Neuromuscular testing to include:
- Ankle dorsiflexion strength
- Great toe dorsiflexion strength
- Ankle reflexes
- Knee reflexes
- Sensory exam with pinprick sensation in the medial, dorsal, and lateral aspects of the foot
- Significant or progressive neuromotor deficit requires surgical consultation.
Straight leg raise (SLR) should be assessed bilaterally to evaluate for nerve root impingement, including but not limited to disc herniation.
- Positive SLR is defined as pain in the posterior leg that radiates below the knee with the patient lying supine and the hip flexed 60 degrees or less, is suggestive of disc herniation.
- Negative SLR rules out surgically significant disc herniation in 95% of cases.
Laboratory Evaluation
Consider a CBC (complete blood count) and erythrocyte sedimentation rate if suspicion of cancer or infection.
Referral
Early referral to physical therapy or another trained spine therapy professional could be considered. (See Annotations #13, "Re-evaluate and Consider Redirection," and Annotation #23, "Discuss Options and Consider Possible Surgical or Non-surgical Back Specialist" for details on specialties and treatments.)
- Referral could be considered when patient presents with severe incapacitating, disabling back or leg pain; or
- Patient has significant limitation of functional or job activities
Lumbar Spine X-ray (AP and LAT views) Red Flag Indications
Generally AP and LAT x-rays are not useful in the acute setting but may be warranted with:
- Unrelenting night pain or pain at rest (increased incidence of clinically significant pathology)
- History or suspicion of cancer (rule out metastatic disease)
- Fever above 38 degrees C (100.4 degrees F) for greater than 48 hours
- Osteoporosis
- Other systemic diseases
- Neuromotor or sensory deficit
- Chronic oral steroids
- Immunosuppression
- Serious accident or injury (fall from heights, blunt trauma, motor vehicle accident)--this does not include twisting or lifting injury unless other risk factors are present (e.g., history of osteoporosis) and
- Clinical suspicion of ankylosing spondylitis
Other conditions that may warrant AP or LAT x-rays:
- Over 50 years old (increased risk of malignancy, compression fracture)
- Failure to respond to four to six weeks of conservative therapy
- Drug or alcohol abuse (increased incidence of osteomyelitis, trauma, fracture)
Oblique view x-rays are not recommended; they add only minimal information in a small percentage of cases, and more than double the exposure to radiation.
Evidence supporting this recommendation is of classes: C, R