Case 10 45-year-old male presenting with low back pain - Mr. Payne Author: Shou Ling Leong, M.D., Penn State College of Medicine Learning Objectives: 1. 2. 3. 4. Understand the differential diagnosis for low back pain. Develop physical exam skills in evaluating low back pain. Develop the skills in the diagnosis and treatment of low back pain. Recognize the red flags or alarming symptoms for serious causes for low back pain. 5. Know when imaging studies are indicated. 6. Be able to prescribe treatment for back pain. 7. Know when to refer for consultation and surgical intervention Summary of Clinical Scenario: Mr. Payne, a 45-year-old white male truck driver presents with two weeks of back pain and a tingling sensation down his left leg after lifting a 10-pound box. After a thorough history rules out potentially serious causes of lower back pain and a physical exam reveals straight leg raising (SLR) is positive at 75 degrees on the left, Mr. Payne is given a provisionary diagnosis of back pain with radiculopathy and sent home for conservative treatment with physical therapy. At follow up three weeks later, Mr. Payne’s pain is now radiating down the lateral part of his left leg and side of his left foot. On physical exam, SLR is positive at 45 degrees on the left, and reflexes are absent at the left ankle and 1+ at the right ankle. An MRI is ordered, which depicts a large herniated disc at L5-S1. He is referred to the pain clinic for consultation and possible selective S1 nerve root injections. During a phone call two weeks later, Mr. Payne happily reports that the cortisone injection was a big success. His pain is much improved and he has gone back to work part-time. 1 of 11 7/20/10 11:45 AM After a few months of improvement, Mr. Payne’s pain flares up again and he develops weakness of his left foot. A repeat MRI shows progression of the disc herniation. He elects for surgery, which relieves his pain. Pain worse with movement and sitting, improves while lying down Pain radiates down the leg/numbness Key Findings from History No history of trauma No problem with bowel or bladder control No dysuria/frequency No fever or chills Tenderness on palpation on the left lumbar paraspinous muscle with increased tone Key Findings from Physical Exam Straight leg raising (SLR) is positive at 75 degrees on the left and negative on the right. Second exam: SLR is positive at 45 degrees on the left and reflexes are absent at the ankle. Lumbar strain, disc herniation, spinal Differential Diagnosis stenosis, spinal fracture, cauda equina syndrome, & pyelonephritis. MRI: herniated disc at L5-S1 with Key findings from Testing associated impingement on the S1 nerve roots. Final Diagnosis 2 of 11 Back strain with herniated disk. 7/20/10 11:45 AM Case Highlights: This case contains a detailed explanation of performing a complete neurological exam of lower extremities, illustrates the use of Evidence Based Medicine to determine when imaging studies are warranted in lower back pain, and discusses the use of conservative management for lower back pain while reserving surgery as the treatment of last resort. Key Teaching Points Knowledge: Low back pain (LBP) is the fifth most common reason for all doctor visits. In the US, lifetime prevalence of LBP is 60-80%. The direct and indirect costs for treatment of LBP are estimated to be $100 billion annually. Fortunately, most LBP resolves in two to four weeks. Major systems approach to LBP: A mnemonic such as CT MIND and V can serve as a reminder of the major systems to include when considering a broad differential for the etiologies of back pain. Congenital: Scoliosis/Kyphosis Toxic or traumatic: Lumbar strain, Compression fracture Metabolic: Osteoporosis, Hyperparathyroidism, Paget‘s disease, Osteomalacia Infectious: Pyelonephritis, Osteomyelitis, Discitis, Herpes zoster, Spinal or epidural abscess Inflammatory: Ankylosing Spondylitis, sacroiliitis, Rheumatoid Arthritis Neoplastic: Multiple Myeloma, Metastatic Disease, Lymphoma/Leukemia, Osteosarcoma Degenerative: Disc Herniation, Osteoarthritis , Facet arthropathy, spinal stenosis, sacroiliitis Vascular: Aortic Aneurysm, Diabetic Neuropathy Visceral: Prostatitis, PID, Ovarian cyst, Endometriosis, Kidney stones, Cholecystitis, Pancreatitis Common causes of LBP: 1. Mechanical: no primary inflammatory or neoplastic cause (97%). There are several common etiologies of mechanical LBP: 3 of 11 7/20/10 11:45 AM Lumbar strain/sprain (70%) Age related degenerative joint changes (10%) Herniated disc (4%) Osteoporotic fracture (4%) Spinal stenosis (3%) 2. 3. Visceral: no primary involvement of the spine (2%) Non-mechanical: others (1%) Risk factors for mechanical LBP: Prolonged sitting, with truck driving having the highest rate of LBP, followed by desk jobs. Deconditioning. Suboptimal lifting and carrying habits. Some radiologic findings are associated with LBP including spondylolysis, disc-space narrowing, spinal instability, and spina bifida occulta. Obesity is a possible risk factor, but the evidence is limited and inconsistent. Prognosis: Most cases of low back pain are acute in onset and resolution, with 90% resolving within one month and only 5% remain disabled longer than 3 months. For patients who are out of work greater than 6 months, there is only 50% chance of them returning to work; this drops to almost zero chance if greater than 2 years. Patients who are older (>45) and patients who have psychosocial stress take longer to recover. Recurrence rate for back pain is high at 35 to 75%. SKILLS History: 1. To get a good picture of the pain, determine: If the pain radiates Is the pain constant or remitting Exacerbating circumstances (active vs. passive motion, day vs. night) Palliative circumstances (medication, positioning-sitting, lying, standing) What has the patient tried to relieve the problem (what worked, what didn't) Intensity of the pain History of similar problem 2. Review of Systems: Neurologic problems (numbness, tingling, muscle weakness, incontinence) Urinary symptoms (frequency, dysuria) Fever, nausea, vomiting Unexplained weight loss Fatigue 4 of 11 7/20/10 11:45 AM 3. Pertinent history: Recent illness History of trauma Patient's occupation History of back injury, cancer, diabetes, etc. 4. Relevant Past Medical History 5. Current medications and allergies When disc herniation is suspected, a very important historical point is the position of comfort or worsening of symptoms. Classically, disc herniation is associated with exacerbation when sitting or bending, and relief while lying or standing Other symptoms of disc herniation include: increased pain with coughing and sneezing, pain radiating down the leg and sometimes the foot, parasthesias, and muscle weakness, such as foot drop. Physical Exam: Perform the back exam with the patient first standing, then sitting, and finally lying down. This should be done systematically, so as not to miss any step. Physical Exam: Standing 1. Inspection: Look at posture, contour and symmetry Check for lordosis Check for kyphosis Check for scoliosis* *Slight scoliosis may be more easily visualized during lumbar flexion. Have the patient stand with their feet and hands together, like they are about to dive off a diving board, bending forward toward their toes. Look out across the back to see if the shoulders are level. 2. Palpation: Check for any tenderness, tightness, rope-like tension, or inflammation in the paraspinous muscles or tenderness over bony prominences. This procedure checks for muscle spasm, vertebral fracture, or infection. 3. Range of Motion (ROM): Lumbar Flexion (normal is 90 degrees): This is the best measure of spine mobility. Restriction and pain during flexion are suggestive of herniation, osteoarthritis, or muscle spasm. Lumbar Extension (normal is 15 degrees): Pain with extension is suggestive of degenerative disease or spinal stenosis. Lateral motion (normal is 45 degrees): Most patients should be able to touch the proximal fibular head of the knee. Pain on the same side as 5 of 11 7/20/10 11:45 AM bending is suggestive of bone pathology, such as osteoarthritis or neural compression. Pain on the opposite side of bending is suggestive of a muscle strain. 4. Gait: Ask the patient to walk on heels and toes. Expect normal gait, even with disc herniation. Difficulty with heel walk is associated with L5 disc herniation. Difficulty with toe walk is associated with S1 disc herniation. 5. Stoop Test: Have the patient go from standing to squatting position. In patients with central spinal stenosis, squatting will reduce the pain. However, asking the patient to run is not part of a back exam and may cause discomfort to the patient who is already in pain. Physical Exam: Sitting 1. Check for costovertebral angle (CVA) tenderness, a sign suggesting pyelonephritis. 2. Straight leg raise (SLR) test: Raise each leg by extending the knee from 90 degrees to straight. If the pain is functional, the action is possible without difficulty. If the pain is due to structural disease, the patient will instinctively exhibit the "tripod sign" by leaning backward and supporting himself with his outstretched arms on the exam table. 3. Neurological exam: check reflexes, muscle strength, and sensation of the lower extremities. Most neuropathic back pain is due to impingement of L4, L5, and S1 nerve roots. Therefore, check the patellar and achilles reflexes. Check muscle strength for hip flexion, abduction, and adduction; knee extension and flexion; as well as ankle dorsiflexion and plantar flexion. Also, test for sharp and light touch along the dermatonal distribution of the great toe (L5), lateral malleolus and posteriolateral foot (S1). Nerve Root Impingement Associated Findings; Reflex; Pin-Prick Sensation; Motor Examination; Functional Test L3 - Patellar tendon, Lateral thigh and medial femoral condyle, Extend quadriceps, Squat down and rise L4 - Patellar tendon; Medial leg and medial ankle; Dorsiflex ankle; Walk on heels L5 - Medial hamstring; Lateral leg and dorsum of foot; Dorsiflex great toe; Walk on heels S1 - Achilles tendon; Posterior calf, sole of foot, and lateral ankle; Stand on toes; Walk on toes (plantarflex ankle) Physical Exam: Supine 1. Abdominal Exam Auscultation: Check for abdominal bruit, looking for abdominal aortic 6 of 11 7/20/10 11:45 AM aneurysm. Palpitation: Check for abdominal tenderness (on all patients, not just female patients), pelvic tenderness (PID), pulsatile mass, unequal femoral/brachial pulses (abdominal aortic aneurysm), or any general tenderness indicating visceral pathology. 2. Rectal Exam To be done only on patients with red flags or alarm symptoms. Check for masses, bleeding, or abnormal rectal tone. Bleeding or rectal mass can be signs of cancer with metastasis to the spine causing back pain. Decreased tone can indicate disc herniation and/or cauda equina syndrome. 3. Passive Straight Leg Raise (SLR or Lasegue’s sign) The normal leg can be raised 80 degrees. If a patient raises their leg <80 degrees, they have tight hamstrings or a sciatic nerve problem. To differentiate, raise the leg to the point of pain, lower slightly, then dorsiflex the foot. If there is no pain with dorsiflexion, the patient’s hamstrings are tight. The test is positive if pain radiates down the posterior/lateral thigh. This radiation indicates stretching of the nerve roots (specifically S1 or L5) over a herniated disc and will most likely occur between 40 and 70 degrees. Pain will not occur until the leg is lifted at least 30 degrees. Pain earlier than 30 degrees is suggestive of malingering. Pain in the opposite leg during a straight leg raise is suggestive of root compression due to complete disc herniation. The ipsilateral straight leg raise test has a sensitivity of 0.80 and a specificity of about 0.40. Thus, a negative test makes a herniated disc unlikely, but a positive test is nonspecific. 4. Crossed Leg Raise: Asymptomatic leg is raised. Test is positive if pain is increased in the contralateral leg; this correlates with the degree of disc herniation. Cross SLR test is much less sensitive (0.25) but is highly specific (about 0.90). Thus, a negative test is nonspecific, but a positive test is virtually diagnostic of disc herniation. 5. FABER Test: Flexion, ABduction, and External Rotation The Faber test looks for pathology of the hip joint or sacrum (sacroiliac pain from sacroiliitis). The test is performed by flexing the hip and placing the foot of the tested leg on the opposite knee. Pressure is then placed on the tested knee while stabilizing the opposite hip. The test is positive if there is pain at the hip or sacral joint or if the leg can not lower to the point of being parallel to the opposite leg. 7 of 11 7/20/10 11:45 AM The FABER test should done on all patients suspected of having sacroiliac pain, not just in the elderly patients. Sacroiliitis can occur in the young population as well. 6. Pelvic Compression Test Performed by forcibly pressing together the hips A positive test elicits pain in the sacroiliac joint. 7. Muscle Atrophy: of quadriceps and calf muscles. Lack of atrophy, despite patient's complaints of long-term weakness, suggests malingering. Differential Diagnosis: While most often back pain is benign and self-limited, a small number of cases are due to systemic diseases, such as cancer and infection. Furthermore, back pain with neurological symptoms can be treated surgically and should be followed carefully. Therefore, the major task in treating back pain is to distinguish the common causes for back pain (95% of cases) from the 5% with serious underlying diseases or neurologic impairments. Serious medical conditions: 1. Cauda equina syndrome: Spinal cord compression of the cauda equina, resulting from a large mass effect (such as an acute disc herniation or a tumor) causing pain radiating down the leg and numbness of the leg. Pain is usually worse with movement and sitting -- and improves with lying down. (As opposed to pain due to spinal stenosis, which is usually worse with walking and better with sitting and when the spine is flexed.) This is a true emergency and decompression should be performed within 72 hours to avoid permanent neurologic deficits. Red flags signaling cauda equina include: Progression of neurological deficit Difficulty urinating and fecal incontinence 2. Cancer: causes dull, throbbing back pain localized to the affected bones, that progresses slowly, and it increases with recumbency or cough. Red flags signaling cancer include: Unrelenting night pain, pain at rest, unexplained weight loss Patients over 50 or under 17 years old History of cancer 8 of 11 7/20/10 11:45 AM Failure to improve with therapy 3. Infection Red flags signaling infection include: Persistent fever (>100.4 F), fever/chills Risk factors for spinal infection such as recent bacterial infection (e.g., urinary tract infection), IV drug abuse, or immune suppression (steroids, transplant, or HIV). 4. Fractures: cause pain which may be aggravated with movement. Red flags signaling fractures include: Major trauma (such as vehicle accident or fall from height) Minor trauma (even strenuous lifting) in older patients who are potentially osteoporotic History of chronic oral steroid use or substance abuse. Studies: 1. In the absence of red flags or findings suggestive of systemic disease, diagnostic testing, especially imaging, is not indicated until after 4 to 6 weeks of conservative treatment. Ordering tests too early is not only cost ineffective, but can also cause harm to the patients. Spine film can expose a patient to radiation. This is especially concerning in young women because radiation to the gonads in a single plain radiograph of the lumbar spine is equal to getting daily CXR for more than a year. CT scans expose patients to contrast materials that have renal toxicity. Routine imaging with CT or MRI is not associated with improved outcomes, but can identify abnormalities that are unrelated to the patient's back pain. This can cause anxiety and could lead to more testing and possibly unnecessary intervention. After four to six weeks of conservative treatment, a plain radiograph is often the first imaging test in the evaluation of LBP because it is relatively inexpensive and easily accessible with a quick turnaround time for the results. 2. CBC and sedimentation rate should be ordered if tumor or infection is suspected. 3. Agency for Health Care Policy and Research (AHCPR) guidelines for x-ray: history of trauma, strenuous lifting in patient with osteoporosis, prolonged steroid use, osteoporosis, age <20 and >70, history of cancer, fever/chills/weight loss, pain worse when supine or severe at night (spinal fracture, tumor or infection). 4. Lumbar spine films are commonly used, but lack specificity and have a high 9 of 11 7/20/10 11:45 AM rate of false-positive. Deyo has suggested a series of high yield criteria for obtaining lumbar films: Age over 50 Significant trauma Neuromotor defect Weight loss of 10 pounds Ankylosing spondylitis Drug or alcohol abuse History of malignancy Fever of 100 degrees Fahrenheit Revisit without improvement or financial compensation 5. MRI testing is not associated with clinical benefit in randomized trials. Indications for MRI include: Neurological deficit Radiculopathy Progressive major motor weakness Cauda equina compression (sudden bowel/bladder disturbance) Suspected systemic disorder (metastatic or infectious disease) Failed 6 weeks of conservative care. (However, 75% of herniated discs improve with 6 weeks of conservative therapy.) Some recommend that in the absence of red flags, it is reasonable to obtain an imaging study after one month of symptoms if surgery is being considered. Management: 1. Conservative therapy for acute low back pain (0-3 months): Pharmacologic (aspirin/NSAID, muscle relaxants, combination drugs, some recommend corticosteroids) Activity level (avoid strenuous activities but to remain active) Local therapy (heat/cold) Maintain good posture and practice good lifting techniques at all time. Give patients instructions to call if there is no relief or if the pain increases, progression of neurologic deficits, development of problem with bowel or bladder control. Advanced imaging, such as MRI/CT scans, referral to a surgeon, or referral to the pain clinic should be entertained if back pain is not better in 4 to 6 weeks or if progression of neurologic deficits is demonstrated. 2. Physical Therapy: Tailored physical therapy is slightly more effective for acute back pain compared to patients who just stay active. Various interventions (exercises, traction, massage) and different modalities (heat, ice, ultrasound) may be used. 10 of 11 7/20/10 11:45 AM Back to Top Copyright © 2009 iInTIME. All Rights Reserved. 11 of 11 7/20/10 11:45 AM