Acute Low Back Pain
Definition
- Main article: Low Back Pain Definitions
Starting with the wrong definition of low back pain can lead to the wrong diagnosis, and so it is important to be clear here. The IASP taxonomy categorises low back pain into lumbar spinal pain and sacral spinal pain. There is also an overlapping definition called lumbosacral pain. These three categories constitute the colloquial term "low back pain."
Lumbar spinal pain is pain in a region bounded superiorly by an imaginary transverse line through the tip T12, inferiorly by an imaginary transverse line through the tip of S1, and laterally by vertical lines tangential to the lateral borders of the lumbar erectores spinae.
Sacral Spinal Pain is pain in a region bounded superiorly by an imaginary transverse line through the tip of S1, inferiorly by an imaginary transverse line through the posterior sacrococcygeal joints, and laterally by imaginary lines passing through the posterior superior and posterior inferior iliac spines."
Lumbosacral Pain is pain perceived as arising from a region encompassing or centred over the lower third of the lumbar region as described above and the upper third of the sacral region as described above.
Prognosis
It is sometimes stated in guidelines that most patients with acute low back pain make an excellent recovery. The evidence is in fact quite conflicting, with markedly different findings across different studies. Overall the treating doctor can relay optimism, but be guarded about prognosis.
A systematic review of 11 studies performed in the US, Australia and Europe on patients with non-specific back pain found that recovery occurred in 33% of patients at 3 months, and by 1 year 65% still had pain. In studies that used total absence of pain as a criterion, 71% still had pain at 12 months. In studies that had a less stringent criteria, 57% still had pain at 12 months.[1]
Recurrences
Importantly, recurrences can occur after recovery. Again the literature has shown different rates for recurrence.
An old Dutch study of 443 people in General Practice found particularly poor rates with a relapse rate of 76% at 12 months, with a median number of two relapses (interquartile range 1-3), with a median time to relapse of 7 weeks (interquartile range: 5-12), and a median duration of 3 weeks for the first relapse, 2 weeks for the second and third, and 1 week for the fourth.[2]
A newer Australian study found lower rates of recurrence. They looked at 832 patients seen in General Practice with acute low back pain. Of these, 469 recovered (56%) within 6 weeks and were then followed to look for recurrences. The one year incidence of recurrence was 33%, and the one year incidence of recurrence with care seeking was 18%. Having two previous episodes tripled the odds of future recurrences.[3]
Another Australian study of 1334 patients found recurrences of 24% for "12-month recall" and 33% for "pain at follow-up" definitions of recurrence.[4]
Older Adults
A particular note should be made about older adults, where the prognosis tends to be worse. For example, in a US cohort study of 4,665 patients who had a new primary care visit for back pain, only 16% had complete resolution of their back pain and disability by two years. Average pain intensity reduced slightly from 5.0 to 3.7 at 3 months, and then stayed relatively static to 24 months, with around half having a clinically meaningful improvement in disability and pain. Baseline characteristics are more important predictors such as female gender, higher BMI, chronic back pain, higher disability, and negative expectations for recovery.[5]
Similar findings for older adults have been found in the Netherlands, [6] and the BACE study which took place in the Netherlands, Brazil, and Australia.[7][8]
Predictors for Persistent Disability and Back Pain
Predictors of recurrence are often variable across studies, but generally include [3]
- Sociodemographic: female gender, obesity, poor educational level
- Current History: previous episodes, duration of episode, days to seek care, pain and disability levels, leg pain
- General Health: Smoking, habitual physical activity, perceived health, use of medications
- Psychosocial: Perceived risk of recurrence, depression, anxiety
- Work-related: Involvement in heavy lifting or awkward positions, job satisfaction, compensable case
- Others: MRI findings, qualification of practitioner.
The predictors may be similar across age groups. In older adults they include female gender, race, worse baseline clinical characteristics of back pain, leg pain, back-related disability and duration of symptoms, smoking, anxiety symptoms, depressive symptoms, a history of falls, greater number of comorbidities, knee osteoarthritis, wide-spread pain syndromes, and an index diagnosis of lumbar spinal stenosis.[9]
It is difficult to predict who will have a recurrence after recovery. Number of previous episodes may be the only predictor.[4]
References
- ↑ Itz CJ, Geurts JW, van Kleef M, Nelemans P. Clinical Course of Non-Specific Low Back Pain: A Systematic Review of Prospective Cohort Studies Set in Primary Care. Eur J Pain. 2013;17(1):5-15. doi: 10.1002/j.1532-2149.2012.00170.x.
- ↑ van den Hoogen HJ, et al. On the course of low back pain in general practice: a one year follow up study. Ann Rheum Dis. 1998 Jan;57(1):13-9. doi: 10.1136/ard.57.1.13. PMID: 9536816; PMCID: PMC1752458.
- ↑ 3.0 3.1 Machado GC, et al. Can Recurrence After an Acute Episode of Low Back Pain Be Predicted? Phys Ther. 2017 Sep 1;97(9):889-895. doi: 10.1093/ptj/pzx067. PMID: 28969347
- ↑ 4.0 4.1 Stanton TR, Henschke N, Maher CG, Refshauge KM, Latimer J, McAuley JH. After an episode of acute low back pain, recurrence is unpredictable and not as common as previously thought. Spine (Phila Pa 1976). 2008 Dec 15;33(26):2923-8. doi: 10.1097/BRS.0b013e31818a3167. PMID: 19092626.
- ↑ Jarvik JG, et al. Long-term outcomes of a large, prospective observational cohort of older adults with back pain. Spine J. 2018 Sep;18(9):1540-1551. doi: 10.1016/j.spinee.2018.01.018. Epub 2018 Jan 31. PMID: 29391206.
- ↑ van der Gaag WH, Enthoven WTM, Luijsterburg PAJ, van Rijckevorsel-Scheele J, Bierma-Zeinstra SMA, Bohnen AM, van Tulder MW, Koes BW. Natural History of Back Pain in Older Adults over Five Years. J Am Board Fam Med. 2019 Nov-Dec;32(6):781-789. doi: 10.3122/jabfm.2019.06.190041. PMID: 31704746.
- ↑ Scheele J, et al. Back complaints in the elders (BACE); design of cohort studies in primary care: an international consortium. BMC Musculoskelet Disord. 2011 Aug 19;12:193. doi: 10.1186/1471-2474-12-193. PMID: 21854620; PMCID: PMC3182961.
- ↑ Enthoven WT, et al. Age Ageing. 2016 Nov;45(6):878-883. doi: 10.1093/ageing/afw127. Epub 2016 Aug 11. PMID: 27515678.
- ↑ Rundell SD, et al. Predictors of Persistent Disability and Back Pain in Older Adults with a New Episode of Care for Back Pain. Pain Med. 2017 Jun 1;18(6):1049-1062. doi: 10.1093/pm/pnw236. PMID: 27688311.
