X-ray of the Spine for Subacute Back Pain
X-ray imaging of the spine is not recommended as the initial diagnostic test for patients with subacute back pain without clinical red flags, as it has low diagnostic yield and does not improve clinical outcomes. 1
When X-rays Are NOT Indicated
- For uncomplicated subacute back pain without red flags, imaging studies including x-rays are typically not indicated as they rarely change management and do not improve outcomes 2
- X-rays expose patients to unnecessary radiation without providing clinical benefit in cases of mechanical or nonspecific back pain 1
- Patient knowledge of imaging findings does not alter clinical outcomes and may actually be associated with a lesser sense of well-being 3
- Radiography of the lumbar spine in primary care patients with low back pain is associated with an increase in doctor workload without improving patient functioning or pain severity 2
When X-rays ARE Indicated (Clinical Red Flags)
X-rays of the spine may be helpful as an initial imaging study when the following red flags are present:
- Morning stiffness, gait abnormalities, night pain, or pain lasting >4 weeks despite conservative treatment 1, 4
- Neurologic deficits, radiating pain, fever, unintentional weight loss 1, 4
- Tachycardia, lymphadenopathy, or abnormal spinal curvature 1
- History of trauma, especially in patients with osteoporosis, advanced age, or chronic steroid use 1
- Suspected inflammatory conditions, infection, or neoplasm 1
Limitations of X-rays
- X-rays are insensitive during the early course of spine infection 1
- Radiographs alone may be inadequate in diagnosing severe pathologies, with studies showing only a 9% to 22% yield in accurate diagnosis even when performed with detailed history and physical examination 1
- Negative radiographs are not adequate to exclude pathology but can initiate further investigation with advanced imaging when needed 1
When to Consider Advanced Imaging Instead
- For suspected spinal infection with fever and elevated inflammatory markers, MRI is recommended as the initial imaging study 1, 4
- For suspected intraspinal neoplasm with neurologic deficits, MRI is recommended without preceding x-rays 1
- When there is concern for disc pathology, which has been found to be more common than previously thought due to increased usefulness of MRI in recent years 1
Follow-up After X-rays
- If initial radiographs identify a cause for back pain, specific treatment can be initiated without additional imaging 1
- If radiographs are negative or inconclusive but symptoms persist, further investigation with advanced imaging such as MRI or CT may be warranted 1
- For suspected spondylolysis or osseous neoplasms, a bone scan with SPECT or SPECT/CT through the region of interest may be a suitable next step after initial radiography 1
In summary, while x-rays are often ordered for reassurance or due to patient expectations, evidence shows they provide limited diagnostic value for uncomplicated subacute back pain and should be reserved for cases with specific clinical red flags.