Symptom Finder - Low Back Pain
LOW BACK PAIN
Nothing is more challenging to diagnose than a case of low back pain. That is why it is so important to have an extensive list of causes in mind before approaching the patient. Moving posteriorly from the skin inward, one encounters the muscle and fascial planes, the lumbosacral spine and its ligaments, the spinal cord and cauda equina, the abdominal aorta and its branches, the rectum, the prostate in the male, the uterus and pelvic organs in the female, and finally the bladder.
The skin may be involved by a pilonidal cyst, contusions and lacerations, or herpes zoster. The muscle and fascia are involved by fibromyositis, trichinosis, contusions, lacerations, strains, sprains, and herniation of fat through the subfascial plain. (The latter has been espoused as a common cause of lumbago.) A more important cause of muscle spasms and irritation is faulty posture. Slumping over a typewriter or computer, wearing the wrong shoes (e.g., very high heels), or having one leg shorter than the other may cause this.
The next layer is the lumbosacral spine. Vascular lesions are infrequent here, but inflammation caused by osteomyelitis and tuberculosis (Pott disease) is still seen in some countries. More common lesions of the spine inducing low back pain are metastatic carcinoma, herniated discs, rheumatoid spondylitis, or lumbar spondylosis (often erroneously labelled osteoarthritis). Osteoarthritis and other arthritides may involve the facets of the zygapophyseal joints, and produce back pain (“facet syndrome”).
Advanced osteoarthritis leads to spinal stenosis, especially in elderly persons. Multiple myeloma is not an uncommon cause and should be looked for in each case. Fractures are particularly frequent in association with this disease. Fractures are also seen with osteoporosis, osteitis fibrosa cystica, and osteomalacia. Paget disease, gout, and sprung back (in which the interspinous ligament is torn) are less common causes of low back pain originating in the spine. Congenital anomalies such as spondylolisthesis and scoliosis are important causes. In the spinal cord arteriovenous anomalies, myelitis, epidural abscesses, and primary tumors are important causes.
Moving deeper one encounters the aorta, and arteriosclerotic and dissecting aneurysms come to mind. Disease of the rectum may refer pain to the low back, particularly hemorrhoids, fissures, perirectal abscesses, and carcinomas. In the prostate, prostatitis and prostate carcinoma are frequent causes. Prostate carcinoma, however, produces low back pain most frequently by metastasis. The bladder and urethra are infrequent causes of low back pain, but a urinalysis and culture may be necessary to
rule out infections.
To diagnose low back pain in women, the uterus and other pelvic organs must be examined. Dysmenorrhea (functional) is often the cause, but tubo-ovarian abscess, ovarian cysts, endometriosis, fibroids, retroversion or flexion of the uterus, and uterine carcinomas must be looked for.
Approach to the Diagnosis
First, you must rule out malingering. This is done by the axial rotation test. With one hand on the hip and the other on the opposite shoulder rotate the patient’s body. If the patient experiences significant increase in their pain consider malingering. Our next priority in a patient who presents with low back pain is to rule out anything serious such as a herniated disc or cauda equina tumor. A pelvic and rectal examination must be performed to exclude a pelvic tumor or prostate carcinoma. A careful neurologic examination must be done. If one is too busy to do that, referral to an orthopedic surgeon or neurologist is indicated. The neurologic examination should include an SLR test, femoral stretch test, careful sensory examination, and an assessment for asymmetric reflexes. It is wise to carefully measure the thighs and calves to reveal muscular atrophy.
Also measure the leg length from the superior iliac spine to the medial malleolus. The author has found many cases of back pain are due to a short leg syndrome. Any findings to support a diagnosis of radiculopathy are a reasonable indication for a CT scan or MRI of the lumbar spine. However, it may be wise to have a neurologist or neurosurgeon examine the patient first because these tests are expensive.
If the patient has normal neurologic, pelvic, and rectal examinations, it is perfectly legitimate to manage the patient conservatively for a while without any testing other than clinical. Close follow-up is important in these cases, however. Should the pain persist despite rest and conservative treatment, a more thorough diagnostic workup is indicated regardless of the lack of objective findings. This will include plain films, MRI or CT scans, and an arthritis panel.
Other Useful Tests
1. CBC
2. Urinalysis (pyelonephritis)
3. Urine for Bence-Jones protein (multiple myeloma)
4. Protein electrophoresis (multiple myeloma)
5. Chemistry panel (metastatic carcinoma)
6. Prostate-specific antigen (prostatic carcinoma)
7. Urine culture and colony count (pyelonephritis)
8. Intravenous pyelogram (renal calculus, carcinoma)
9. Aortogram (abdominal aneurysm)
10. Nerve blocks (radiculopathy)
11. Lidocaine infiltration of trigger points
12. Bone scan (rheumatoid spondylitis)
13. Human leukocyte antigen-B27 antigen (rheumatoid spondylitis)
14. EMG and NCV (radiculopathy)
15. Myelogram (herniated disc, neoplasm)
16. Plain films of the lumbar spine
17. Sedimentation rate (polymyalgia rheumatica)
18. Bone densitometry (osteoporosis)
19. Plain films to measure leg length (short leg syndrome)
Nothing is more challenging to diagnose than a case of low back pain. That is why it is so important to have an extensive list of causes in mind before approaching the patient. Moving posteriorly from the skin inward, one encounters the muscle and fascial planes, the lumbosacral spine and its ligaments, the spinal cord and cauda equina, the abdominal aorta and its branches, the rectum, the prostate in the male, the uterus and pelvic organs in the female, and finally the bladder.
The skin may be involved by a pilonidal cyst, contusions and lacerations, or herpes zoster. The muscle and fascia are involved by fibromyositis, trichinosis, contusions, lacerations, strains, sprains, and herniation of fat through the subfascial plain. (The latter has been espoused as a common cause of lumbago.) A more important cause of muscle spasms and irritation is faulty posture. Slumping over a typewriter or computer, wearing the wrong shoes (e.g., very high heels), or having one leg shorter than the other may cause this.
The next layer is the lumbosacral spine. Vascular lesions are infrequent here, but inflammation caused by osteomyelitis and tuberculosis (Pott disease) is still seen in some countries. More common lesions of the spine inducing low back pain are metastatic carcinoma, herniated discs, rheumatoid spondylitis, or lumbar spondylosis (often erroneously labelled osteoarthritis). Osteoarthritis and other arthritides may involve the facets of the zygapophyseal joints, and produce back pain (“facet syndrome”).
Advanced osteoarthritis leads to spinal stenosis, especially in elderly persons. Multiple myeloma is not an uncommon cause and should be looked for in each case. Fractures are particularly frequent in association with this disease. Fractures are also seen with osteoporosis, osteitis fibrosa cystica, and osteomalacia. Paget disease, gout, and sprung back (in which the interspinous ligament is torn) are less common causes of low back pain originating in the spine. Congenital anomalies such as spondylolisthesis and scoliosis are important causes. In the spinal cord arteriovenous anomalies, myelitis, epidural abscesses, and primary tumors are important causes.
Moving deeper one encounters the aorta, and arteriosclerotic and dissecting aneurysms come to mind. Disease of the rectum may refer pain to the low back, particularly hemorrhoids, fissures, perirectal abscesses, and carcinomas. In the prostate, prostatitis and prostate carcinoma are frequent causes. Prostate carcinoma, however, produces low back pain most frequently by metastasis. The bladder and urethra are infrequent causes of low back pain, but a urinalysis and culture may be necessary to
rule out infections.
To diagnose low back pain in women, the uterus and other pelvic organs must be examined. Dysmenorrhea (functional) is often the cause, but tubo-ovarian abscess, ovarian cysts, endometriosis, fibroids, retroversion or flexion of the uterus, and uterine carcinomas must be looked for.
Approach to the Diagnosis
First, you must rule out malingering. This is done by the axial rotation test. With one hand on the hip and the other on the opposite shoulder rotate the patient’s body. If the patient experiences significant increase in their pain consider malingering. Our next priority in a patient who presents with low back pain is to rule out anything serious such as a herniated disc or cauda equina tumor. A pelvic and rectal examination must be performed to exclude a pelvic tumor or prostate carcinoma. A careful neurologic examination must be done. If one is too busy to do that, referral to an orthopedic surgeon or neurologist is indicated. The neurologic examination should include an SLR test, femoral stretch test, careful sensory examination, and an assessment for asymmetric reflexes. It is wise to carefully measure the thighs and calves to reveal muscular atrophy.
Also measure the leg length from the superior iliac spine to the medial malleolus. The author has found many cases of back pain are due to a short leg syndrome. Any findings to support a diagnosis of radiculopathy are a reasonable indication for a CT scan or MRI of the lumbar spine. However, it may be wise to have a neurologist or neurosurgeon examine the patient first because these tests are expensive.
If the patient has normal neurologic, pelvic, and rectal examinations, it is perfectly legitimate to manage the patient conservatively for a while without any testing other than clinical. Close follow-up is important in these cases, however. Should the pain persist despite rest and conservative treatment, a more thorough diagnostic workup is indicated regardless of the lack of objective findings. This will include plain films, MRI or CT scans, and an arthritis panel.
Other Useful Tests
1. CBC
2. Urinalysis (pyelonephritis)
3. Urine for Bence-Jones protein (multiple myeloma)
4. Protein electrophoresis (multiple myeloma)
5. Chemistry panel (metastatic carcinoma)
6. Prostate-specific antigen (prostatic carcinoma)
7. Urine culture and colony count (pyelonephritis)
8. Intravenous pyelogram (renal calculus, carcinoma)
9. Aortogram (abdominal aneurysm)
10. Nerve blocks (radiculopathy)
11. Lidocaine infiltration of trigger points
12. Bone scan (rheumatoid spondylitis)
13. Human leukocyte antigen-B27 antigen (rheumatoid spondylitis)
14. EMG and NCV (radiculopathy)
15. Myelogram (herniated disc, neoplasm)
16. Plain films of the lumbar spine
17. Sedimentation rate (polymyalgia rheumatica)
18. Bone densitometry (osteoporosis)
19. Plain films to measure leg length (short leg syndrome)