March 1, 2007 • www.familypracticenews.com Musculoskeletal Disorders 43 MRI Findings for Low Back Pain Can Be Misleading BY BRUCE K. DIXON taken within 6-12 weeks of the start of a new low back er had some degenerative disease at the L4-5 level and, Chicago Bureau pain episode, were then compared with baseline (asymp- at follow-up scan, had a grade 1 spondylolisthesis with in- tomatic) images. creased stenosis,” Dr. Carragee said. S EATTLE — MRI findings within 12 weeks of serious Within the total cohort, 25% were evaluated with a Subjects involved in current compensation claims were low back pain inception are unlikely to represent new lumbar MRI for clinically serious low back pain episodes more likely to have an MRI scan to evaluate a low back structural change, according to a study at Stanford (Calif.) occurring during follow-up, and pain episode but were unlikely to University. 6% had a primary radicular com- have significant new findings. “We had hypothesized that serious low back pain plaint. Of those 51 patients, 43 ei- ‘Physicians “In usual practice, if a patient episodes would be commonly associated with new and ther had an unchanged MRI or directing has minor trauma from a fender specific findings on MRI, and we were really thinking showed regression of baseline treatment need to bender or a fall and you get an about such things as annular tears, fissures, disk hernia- changes. be careful before MRI, it shows a high-intensity tion, new disk protrusion, and end plate changes. But ... “There are relatively few new saying, “Aha! I zone, an annular fissure, or end the data didn’t support that hypothesis,” said Dr. Eugene findings compared to the burden of found the cause.” ’ plate changes, and the normal Carragee, professor of orthopedic surgery, at the annual disease at baseline. That is, when thing that we think is that these meeting of the North American Spine Society. you put the scan up and you see 5 DR. CARRAGEE findings are ... attributed to an The findings emerged from a 5-year, prospective, ob- or 10 things—an annular fissure or acute event and are related to the servational study with baseline and post–low back pain perhaps some facet arthrosis—the overwhelming amount symptoms, but that’s not what we found,” he said, adding monitoring of 200 subjects with lifetime histories free of of those things were there years before,” Dr. Carragee said. that fewer than 1 in 12 annular fissures and 1 in 15 disk significant low back pain problems but who were at high The most common progressive findings were disk sig- protrusions found on scans were new. risk for new low back pain episodes, Dr. Carragee said. nal loss (10%), progressive facet arthrosis (10%), or in- “In acute low back pain, MRI findings within 12 weeks At baseline, patients underwent physical examinations, creased end plate changes (4%). Only two patients, both of events were highly unlikely to represent new structural plain radiographs, and MRIs; they were then followed for with primary radicular complaints, had new findings of changes to the spine, and this means [physicians] direct- 5 years and participated in a detailed telephone interview probable clinical significance. ing treatment need to be careful before saying, ‘Aha! I every 6 months. Those with a new severe low back pain “Both had primary leg pain and one had a new disk ex- found the cause’ ” of a patient’s low back pain, Dr. Car- episode were assessed with diagnostic tests. New MRIs, trusion with root compression but no trauma. The oth- ragee concluded. ■ Back Problems Are Not Uncommon in Children, Adolescents BY DOUG BRUNK you should order a MRI of the cervi- weeks, it develops. .That’s because it takes “I’m generally not the biggest fan of San Diego Bureau cothoracic lumbar spine.” a while for the sternocleidomastoid muscle bracing for most things in orthopedics, He also recommends asking if the to fibrose or develop compartment but [using a brace for] this really seems L AS V EGAS — Not long ago, physi- child has ever had a lumbar puncture, sydrome after the trauma of birth,” he said. to work,” said Dr. Skaggs, who is also a cians were taught to believe that chron- because sometimes a little skin gets into If picked up early and physical thera- professor of orthopedics at the Universi- ic back pain does not occur in children. the spinal canal and can cause an epi- py is begun in a timely fashion, the con- ty of Southern California, Los Angeles. “But that just isn’t true,” Dr. David L. dermoid cyst. dition remits more than 95% of the Ǡ Late-onset torticollis. In this condi- Skaggs said at meeting sponsored by the Heavy backpacks also can be associ- time within the first year of life. How- tion, which is most commonly due to American Academy of Pediatrics’ Cali- ated with back pain. Dr. Skaggs and his ever, most case series report about a 5% C1-C2 rotatory subluxation, the sterno- fornia Chapters 1, 2, 3, and 4 and the associates studied the risk of back pain association with developmental dyspla- cleidomastoid muscle is tight on the op- AAP. in adolescents who carry backpacks. sia of the hip, “so I recommend getting posite side to where the ear is toward the “We did a study “We found that a screening ultrasound in an infant who chin. It’s in spasm from being stretched to of kids between the heavier the has congenital muscular torticollis. accommodate the head position. “Most of the ages of 11 and Kids don’t keep up backpack, the There are not enough studies to make the time, it resolves spontaneously in a few 14, and found that physical therapy. more likely you recommendations, but I think it makes days,” he said. “If it doesn’t resolve in a 37% of them had ‘It’s better to get are to have some common sense,” he said. week, that means an instant referral to a back pain at any them involved with back pain,” he Ǡ Plagiocephaly. This is secondary to con- specialist in pediatric spine disorders.” given time,” said something like said. “It’s a linear genital muscular torticollis most of the A CT scan of C1-C2 with the head Dr. Skaggs, associ- yoga and Pilates.’ relationship.” time. The best treatment for this is to treat turned to the right and left makes the di- ate director of the While some ex- the torticollis. “Encourage the child to sleep agnosis in most cases. If detected within Children’s Ortho- DR. SKAGGS perts advocate with the head tilted in the opposite position 1 week, treatment involves placement of pedic Center at physical therapy of normal, and eventually the plagiocephaly a soft cervical collar. If detected within 1 Children’s Hospital Los Angeles. “So for kids with generalized back pain, “I will resolve spontaneously,” he said. month, treatment involves traction for re- when a child comes in with back pain, don’t think that’s in the kid’s best inter- If the plagiocephaly doesn’t resolve in duction followed by placement of a cer- it can be difficult to decide what’s patho- est, because most kids don’t keep up 6-8 months, referral to a neurosurgeon vical collar. Detection after 1 month of on- logic and what’s not.” physical therapy,” Dr. Skaggs said. “I or an expert in bracing is warranted. set usually requires surgical fusion. ■ If a child presents with diffuse back think it’s better to get them involved pain that is triggered by physical activity, with something like yoga and Pilates, that comes and goes over time with peri- and go to the gym to get personal The 60-Second Exam for Back Pain ods of no pain, and that does not get strength training. If you get them in- worse at night, this is probably nothing to volved with something fun, it’s going to ere are tips to quickly assess normal. “But if it’s asymmetrical, worry about. “Ask the child where it strengthen their back and they’re likely Hchildren for back pain: there’s a great chance there’s syrinx.” hurts,” Dr. Skaggs advised. If they to keep it up.” Have the child jump up and down Test for ankle clonus. Push up on demonstrate region of interest distribu- Exercise that involves core strength- on one foot, then jump up and down the ball of the foot and forcibly dor- tion of pain across the back, “that’s ening with an emphasis on back exten- on the other. siflex the ankle. “If it beats once or when you say, ‘Welcome to adulthood.’ sor training is best. Dr. Skaggs also dis- Have the child walk on his or her twice that’s normal,” he said. “Three That’s chronic low back pain.” cussed the following spinal problems heels with the toes pointed upward. or four beats of clonus and I’d con- Worry when a child presents with that can occur in children: That covers L4 for ankle dorsiflexion. sider a neurological work-up and/or point tenderness back pain, or what he Ǡ Congenital muscular torticollis. In With these first two tests, almost all an MRI.” calls the “positive finger test” on physi- this condition, the child’s head tilts later- of the strength and balance of the Assess hamstring tightness. A cal exam. The culprit could be spondy- ally with the ear toward one shoulder lower extremities have been covered. popliteal angle up to 30-40 degrees is lolysis, diskitis, or a tumor.