MediNews

Table 2: Differential Diagnosis of Acute Low Back Pain
Disease or condition	Patient age (years)	Location of pain	Quality of pain	Aggravating or relieving factors	Signs
Back strain	20 to 40	Low back, buttock, posterior thigh	Ache, spasm	Increased with activity or bending	Local tenderness, limited spinal motion
Acute disc herniation	30 to 50	Low back to lower leg	Sharp, shooting or burning pain, paresthesia in leg	Decreased with standing; increased with bending or sitting	Positive straight leg raise test, weakness, asymmetric reflexes
Osteoarthritis or spinal stenosis	>50	Low back to lower leg; often bilateral	Ache, shooting pain, 'pins and needles' sensation	Increased with walking, especially up an incline; decreased with sitting	Mild decrease in extension of spine; may have weakness or asymmetric reflexes
Spondylolisthesis	Any age	Back, posterior thigh	Ache	Increased with activity or bending	Exaggeration of the lumbar curve, palpable 'step off' (defect between spinous processes), tight hamstrings
Ankylosing spondylitis	15 to 40	Sacroiliac joints, lumbar spine	Ache	Morning stiffness	Decreased back motion, tenderness over sacroiliac joints
Infection	Any age	Lumbar spine, sacrum	Sharp pain, ache	Varies	Fever, percussive tenderness; may have neurologic abnormalities or decreased motion
Malignancy	>50	Affected bone(s)	Dull ache, throbbing pain; slowly progressive	Increased with recumbency or cough	May have localized tenderness, neurologic signs or fever

INVESTIGATIONS

There are lot of investigations to diagnose the low back pain. They are as follows:

Plain Radiograph

The most widely practiced means to diagnose the cause of low back pain is a plain radiograph. Although it is of limited diagnostic value in PLID but helpful in ankylosing spondylitis, spondylolisthesis, sacroiliitis, Paget's disease, Pott's disease, lytic or sclerotic metastasis, osteoporotic crush fracture, etc. Disc degeneration can be associated with reduced or lost disc height and gas formation in the nucleus pulposus. Vertebral sclerosis with osteophyte formation is seen in lumbar spondylosis.

be practiced to diagnose disc protrusion, nerve root entrapment, etc but now a days it has been replaced by some modern non-invasive imaging techniques because of some unpleasant hazards, like headache, nausea, dizziness, etc.

Computerized Tomography (CT)
Now a days CT scan is the method of choice for detection of subtie abnormalities of the bony architecture of the spine and the sacroiliac joints.

Magnetic Resonance Imaging (MRI)
MRI is the unique imaging modality of choice for defining most difficult spinal pathology where surgery is being considered. But MRI is contraindicated in cases of metallic prosthetic implants other than titanium, cardiac pacemaker

Fig. 2: Plain radiographs of Spondylolisthesis (A) & Spinal fusion (B)

FFig. 3: MRI showing PLID (A & B)

Bone Scintigraphy
When a plain radiograph yields a negative result especially in cases of secondary deposits, Paget's, disease, Pott's disease, other bone infections, fractures, etc. bone scintigraphy with 99-m-Tc bisphosphorate is preferred.

Myelography
Myelography is an invasive procedure in which iopamidol can

ferromagnetic clips, etc. In such cases CT myelography may be of value.

Others

Besides these, hematological tests are done to aid the diagnosis of metastatic or primary malignancy, inflammation, Paget's disease, Pott's disease, etc.