1 Imaging in Lower Back PainShould we trust the guidelines? Imaging in Lower Back Pain Dr Leesa Huguenin MP Sports Physicians Winter Lecture Series 2014

2 What imaging options are available?Xray CT Nuclear Medicine MRI Discography

3 Xray Cost – low Availability – widespread Radiation doseThe average exposure from lumbar radiography is 75 x CXR Female gonadal irradiation from lumbar radiography is equivalent to having CXR daily for several years. Likely information disc space spondylolisthesis / pars defects tumour/ AVN/ OCD AND………Patients with LBP for 6/52having radiography report more pain and worse overall health status vs patients who do not receive routine radiography

4 CT Cost – moderate Availability – widespread Radiation dose – highLikely information disc space narrowing endplate changes obvious disc herniation facet arthropathy tumours osteophyte detail Risks contrast nephropathy/ hypersensitivity radiation exposure

5 MRI Cost High (government or patient pays) Availability LimitedRadiation dose NIL Likely outcomes excellent soft tissue detail poor correlation with symptoms in population studies Only method of identifying annular tears/ MODIC changes/ bone oedema in poorly responsive lower back pain Identify inflammatory changes in facet joints clear anatomy of disc/ nerve root interface

6 AND…… For work-related acute low back pain, MRI imaging is associated with an 8-fold increased risk for surgery and a 5-fold increased risk for high total subsequent medical costs Another study found that back pain sufferers who had an MRI in the first month after symptoms occurred consumed higher doses of pain-relief medicines and were off work, on average, almost 6 times longer than those who did not have an MRI. Severe symptoms were 8 times more likely to have surgery if they had had an MRI. Milder symptoms- MRI = 33 times more likely to have surgery than those who did not have an MRI scan, even though they had similar symptoms.

7 Discography Test to determine the anatomical source of lower back pain for the patient. TO determine if this is discogenic back pain. Discs pre-identified as degenerative on MRI Needles inserted to centre of disc under fluoroscopy. Contrast then injected. Positive – reproduce pts usual pain Negative – produce different pain

8 Discography Cost High (day procedure)Availability Specialist clinics only Radiation dose low/ moderate Likely outcomes identify focus of back pain with view to possible surgery

9 SUMMARY TABLE XRAY CT MRI Discography Cost Low Moderate High Very highAvailability Very low Radiation Nil Mod/High Outcomes Bony pathology Bony path/ large discs/ facet arthropathy Focal inflammatory change/ bone oedema/ disc detail Specific diagnosis discogenic pain

10 IMAGING FINDINGS IN PAIN FREE ADULT BACKS New England J Medicine July 1994MRI on 98 asymptomatic patients Read by 2 radiologists blinded. To ensure no bias, 27 MRI’s of symptomatic pts were also included randomly in pile. OF THE PAIN FREE SUBJECTS: 36% had NORMAL discs 52% had disc bulge at one level 27% had protrusion 1% had extrusion 38% had abnormality at more that one level 14% had annular tears 8% had facet arthropathy

11 Imaging guidelines in adult lower back painAustralia and America have very similar guidelines – adapted form those most recently put forward by the American College of Physicians in 2011. Developed because there is a weak correlation between most imaging findings and symptoms acute low back pain has a favourable prognosis with or without imaging Potential harms of unnecessary imaging (radiation, hypersensitivity reactions, contrast nephropathy, subsequent unnecessary tests required). In addition, knowledge of clinically irrelevant imaging findings might hinder recovery by causing patients to worry more, focus excessively on minor back symptoms, or avoid exercise or other recommended activities for fear of causing more structural damage.

12 A meta-analysis of 6 randomized studies consisting of 1804 patients with acute or subacute low back pain found no difference in outcomes for routine imaging vs usual care without imaging, including a lack of psychological benefits. Most patients with acute low back pain have substantial improvement within 4 weeks, and the yield of radiographic testing is thus low. Serious conditions such as vertebral infection, cancer, fracture, ankylosing spondylitis or cauda equina syndrome are rare causes of back pain (<1% of cases) in Australian primary care. Imaging and laboratory tests are only required when you suspect that the cause of the patient’s low back pain is a serious condition or the patient has radiculopathy or spinal stenosis AND is a candidate for surgery.

13 Early Imaging is recommended forIn the primary care setting, 0.7% of patients with low back pain have metastatic cancer, 0.01% have spinal infection, and 0.04% have the cauda equine syndrome Early Imaging is recommended for urinary retention saddle anesthesia faecal incontinence fever progressive neurological deficits high suspicion malignancy – (Phx cancer, LOW, no improvement over month, age >50)

15 Timing Imaging strategy Clinical Situation Immediate imaging Radiography plus erythrocyte sedimentation rate† Major risk factors for cancer (new onset of low back pain with history of cancer, multiple risk factors for cancer, or strong clinical suspicion for cancer) Magnetic resonance imaging Risk factors for spinal infection (new onset of low back pain with fever and history of intravenous drug use or recent infection) Risk factors for or signs of the cauda equina syndrome (new urine retention, faecal incontinence, or saddle anaesthesia) Severe neurologic deficits (progressive motor weakness or motor deficits at multiple neurologic levels) Defer imaging after a trial of therapy Radiography with or without erythrocyte sedimentation rate Weaker risk factors for cancer (unexplained weight loss or age >50 y) Risk factors for or signs of ankylosing spondylitis (morning stiffness that improves with exercise, alternating buttock pain, awakening because of back pain during the second part of the night, or younger age [20 to 40 y]) Risk factors for vertebral compression fracture (history of osteoporosis, use of corticosteroids, significant trauma, or older age [>65 y for women or >75 y for men]) Signs and symptoms of radiculopathy (back pain with leg pain in an L4, L5, or S1 nerve root distribution or positive result on straight leg raise or crossed straight leg raise test) in patients who are candidates for surgery or epidural steroid injection Risk factors for or symptoms of spinal stenosis (radiating leg pain, older age, or pseudoclaudication) in patients who are candidates for surgery No imaging No criteria for immediate imaging and back pain improved or resolved after a 1-month trial of therapy Previous spinal imaging with no change in clinical status

16 Paediatric lower back painTraditionally nervous of underlying sinister cause BUT lifetime prevalence is % by age 16 most cases no structural cause found (55- 75%) KEY QUESTIONS rest pain constitutional symptoms deformity (eg rapid scoliosis) response to aspirin/ NSAIds (osteoid osteoma) usual activities provocative movements family history

17 Paediatric imaging guidelinesBloods if suspect systemic issues XR not be recommended early if short duration symptoms and benign findings on physical and neurologic examination. XR is reasonable first Ix when required – need AP and lateral. Oblique views are not routinely obtained radiation risk subtle # unlikely to show 68% of children with specific diagnoses WILL be diagnosed on XR

18 Q: What next in kids after XRAY?A: MRI

19 Bone Scan and SPECT – exquisite pictures of active bone stressCT – high detail of bony injury BUT RADIATION RISK CANNOT BE JUSTIFIED  MRI BECOMES SECOND OR FIRST LINE FOR INVESTIGATION NB newer scanners/ techniques are reducing the risk and there are currently more studies underway to quantify risk. Currently – one extra case of cancer per CT scans in kids, but need to bear in mind cumulative risk as well.

21 Does she need imaging?

22 Imaging done and results

23 Outcomes Educated patient (again)Started exercise program with analgesic cover Finally developed compliance Significant improvement in all back pain, left gluteal pain over 3 months No LOW Right gluteal tendons still painful  progressed to ABI/ PWB 2/52 then back into rehab Currently continuing supervised exercise program

24 Case 2 12 yo moderate level dancer and netballer3 months mid lumbar back pain Poorly responsive to physio Pain features continues despite rest Requiring nightly analgesia mid lumbar no radiation Examination vitals normal neurologically intact large amounts muscle spasm paravertebrals no scoliosis Xrays done – reported as normal

25 Does she need imaging?

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28 Outcomes Review with paediatric spinal surgeon re possibility of bracing Elected not to brace due to high functional levels Monitored with 6/12 XR and MRI Good resolution of symptoms Some bony abnormality still evident Mild scoliosis to left at affected level Full return to pain free activity

29 Case 3 (Simon) 38 yo desk worker – commutes 1 hour to work dailyBack and right gluteal/ leg pain Occasional paraesthesia lateral calf Pain worse with sitting Has not responded to physio Stretching does help  about to commence pilates FHx disc issues PHx – cervical disc protrusion Examination restricted range of back motion, esp lat flex left SLR 50 vs 70 on left slump positive neuro NAD

30 Does he need imaging?

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32 Outcomes Pilates and postural changes in car over 1/12 awaiting MRI had positive impact on pain Ongoing postural rehab is now planned If symptoms had not settled, would have been a good candidate for TFE

33 Case 4 65 yo golfer/ walker Leg pain when walking only, also with prolongedstanding Pain pattern sounds claudicant, resolves with sitting Full vascular workup NAD  referred to SP Examination stiff back in lat flex bilat and extension slump – pos for pain both calves, worse with head up SLR NAD neuro NAD tender lower 2 facet joints bilaterally without referral

34 Does he need imaging?

35 Imaging done NIL Intervention trialled – facet joint CSI + LA with pain chart afterwards Complete resolution of pain 8 weeks Repeat injection  success till now What might we have seen on imaging?

36 Summary Back pain imaging guidelines are present to give cost effective management of lower back pain while avoiding false positives and helping people to focus on the rehabilitation required rather than the diagnosis seen on the pictures. Patients find it very hard to understand that disc protrusions may be painless or even resolve HOWEVER It is important that a clinician keeps their ears open for indications that all is not well and be prepared to venture outside the guidelines as required.