​As the first touchpoint for many patients, general practitioners are in optimal position to identify when back pain is a sign of serious spinal pathology. This is of utmost importance as good patient outcomes hinge upon timely diagnosis and treatment. The SingHealth Duke-NUS Spine Centre shares about the symptoms, risk factors and red flags that GPs should look out for.

SPINE DISEASES: WHY RED FLAGS ARE IMPORTANT

Red flags are clinical symptoms and signs that aid in identifying patients with significant, time-critical disease.¹ The severity of such pathology necessitates timely diagnosis and intervention. Therefore, routine history taking and clinical examination must be able to elicit salient findings suggestive of significant red flag pathology.

In the primary care setting, the prevalence of serious spine pathology is less than 1%.² In degenerative spine diseases, common symptoms such as back pain have a lifetime prevalence of 90%³, with 95% of causes related to benign pathology⁴.

Nevertheless, it is critical for general practitioners (GPs) to be able to identify serious cases, as timely detection has a huge impact on patient outcomes. 

With over 46 different red flags identified in guidelines¹, a lack of awareness and omitted symptoms and signs are common reasons for missed pathology⁵.

In this article, we will therefore discuss important red flags in relation to spinal fractures, infections and metastasis. We will also review cauda equina syndrome (CES) as a possible presenting condition related to such pathology.

SPINAL FRACTURES, METASTASIS AND INFECTIONS: RISK FACTORS AND RED FLAGS

The majority of patients with spine disease present with a history of non-specific intermittent back or neck pain that is both non-radicular in nature and exacerbated by physical activity. This is usually self-limiting.

Lumbar or cervical spondylosis is an increasingly prevalent age-related progressive deterioration of the vertebral body, disc and/or facet joint that is commonly associated with a history of physical labour, previous injury and/or physical inactivity.

With routine imaging in patients with uncomplicated back pain showing no impact on outcome⁶, risk stratifying becomes crucial to identifying appropriate red flags⁷.

It is therefore important to elicit risk factors in history taking such as patients’ age, sex, general health, and physical and psychological stressors.⁸

Table 1 on page 19 summarises the common red flags for spinal vertebral fractures, spinal vertebral metastasis and spinal infections.

1. Older age

Whilst older age is a general risk factor for back pain, screening for other risk factors shared in Table 1 can aid in ruling out possible differentials of tumour and infection. For example, the presence of night pain and weight loss requires evaluation for malignancy.⁹

2. Osteoporosis

Patients with osteoporosis also have a higher risk of vertebral compression fractures with little or no trauma.10 Non-spinal pathology such as an abdominal aortic aneurysm or pancreatitis may also present similarly.¹¹ A thorough history taking and clinical examination to elicit a prior history of abdominal pain with fatty foods, significant alcohol consumption or a pulsatile abdominal mass are some examples of systemic symptoms and signs that can suggest non-spine-related pathology as a cause of back pain.

3. History of constitutional symptoms

Back pain with a history of constitutional symptoms such as fever or chills may be related to spinal infections, with fever having a reported incidence of up to 83% in patients with spinal epidural abscesses.¹¹ A triad of symptoms including fever, back pain and neurological deficits is only seen in 10% of such patients.¹²

4. History of intravenous drug use, endocarditis and haemodialysis

A history of intravenous drug use, endocarditis and haemodialysis with long-term catheters is associated with a higher risk of infections.^13,14

5. Poor general health

Poor general health related to alcohol abuse, malnutrition, poorly controlled diabetes or chronic corticosteroid use also increases susceptibility to both spinal infections and fractures.¹

Immunocompromised patients, in general, may not present in a typical fashion and should always warrant a heightened index of suspicion.

6. History of malignancy

Constitutional symptoms are also seen in patients with a malignancy. In patients with a history of known malignancy, prostate, breast and lung cancers are common causes of spinal metastases.¹⁵ Up to 20% of such patients can develop symptomatic spinal cord compression from epidural metastasis.¹⁵

Pin-point tenderness along the spine, which may often be worse at night or at rest, warrants further investigation.¹⁵ When accompanied by a history of unintentional weight loss, this is highly suspicious and worrisome for metastatic disease.^1,13

7. Recent spinal interventions

In the primary care setting, rarer presentations of back pain may be related to recent spinal interventions. Such interventions include surgery, epidural injections or a lumbar puncture.

In such patients, any change in pre-existing symptoms of back pain, such as severity or progression to involve new neurological deficits, should be reviewed for the possibility of haematoma or infection.¹

CAUDA EQUINA SYNDROME

Cauda equina refers to the collection of lumbosacral nerve roots in the spinal canal distal to the level of the conus medullaris, which typically terminates at the L1/2 level in adults.

Cauda equina syndrome (CES) refers to symptoms and signs related to the dysfunction of these nerve roots.

With an incidence of up to 8 in 100,000, common causes of CES include: ^16,17

• A degenerative disc disease (large herniated lumbar disc)

• Trauma

• Infection

• Tumours

Early identification and surgical intervention has been shown to improve neurological recovery.

Symptoms, risk factors and red flags

In patients with back pain associated with urinary retention or bowel incontinence, CES must be ruled out¹⁸.

Significant back or radicular pain associated with weakness or paraesthesia in the lower limbs, and bladder or bowel dysfunction are red flags of CES.¹⁹

Although not often elicited, such patients may also have a history of recent sexual dysfunction and saddle anaesthesia.¹⁸ Reduced anal sphincter tone, subjective urinary retention and bowel incontinence, however, have better predictive values for a clinical diagnosis of CES.²⁰

The red flags for CES are summarised in Table 1.

Treatment

Patients with CES require prompt surgical decompression.^21,22 Functional and neurological outcomes, including sphincter dysfunction, are better when done within 24 hours, although earlier studies have also shown adequate outcomes when done within 48 hours.^22,23

Various factors still confound outcome data, such as delays in presentation, diagnostic imaging and access to an emergency operating theatre for surgery.

CONCLUSION

Whilst most back pain remains non-specific, clinicians should be familiar with presentations indicating symptoms or signs suggestive of serious spinal pathology. Failure to recognise these can result in poor patient outcomes due to delay in diagnosis or treatment.

A detailed history taking of the symptoms and risk factors as outlined above, along with a thorough clinical examination, can guide GPs in recognising red flags.

REFERENCES

1. Verhagen AP, Downie A, Popal N, Maher C, Koes BW. Red flags presented in current low back pain guidelines: a review. Eur Spine J. Sep 2016;25(9):2788-802. doi:10.1007/s00586-016-4684-0

2. Henschke N, Maher CG, Refshauge KM, et al. Prevalence of and screening for serious spinal pathology in patients presenting to primary care settings with acute low back pain. Arthritis Rheum. Oct 2009;60(10):3072-80. doi:10.1002/art.24853

3. Palmer KT, Walsh K, Bendall H, Cooper C, Coggon D. Back pain in Britain: comparison of two prevalence surveys at an interval of 10 years. BMJ. Jun 10 2000;320(7249):1577-8. doi:10.1136/bmj.320.7249.1577

4. Jarvik JG, Deyo RA. Diagnostic evaluation of low back pain with emphasis on imaging. Ann Intern Med. Oct 1 2002;137(7):586-97. doi:10.7326/0003-4819-137-7-200210010-00010

5. Dubosh NM, Edlow JA, Goto T, Camargo CA, Jr., Hasegawa K. Missed Serious Neurologic Conditions in Emergency Department Patients Discharged With Nonspecific Diagnoses of Headache or Back Pain. Ann Emerg Med. Oct 2019;74(4):549-561. doi:10.1016/j.annemergmed.2019.01.020

6. Gilbert FJ, Grant AM, Gillan MG, et al. Low back pain: influence of early MR imaging or CT on treatment and outcome--multicenter randomized trial. Radiology. May 2004;231(2):343-51. doi:10.1148/radiol.2312030886

7. Arnau JM, Vallano A, Lopez A, Pellise F, Delgado MJ, Prat N. A critical review of guidelines for low back pain treatment. Eur Spine J. May 2006;15(5):543-53. doi:10.1007/s00586-005-1027-y

8. Parreira P, Maher CG, Steffens D, Hancock MJ, Ferreira ML. Risk factors for low back pain and sciatica: an umbrella review. Spine J. Sep 2018;18(9):1715-1721. doi:10.1016/j.spinee.2018.05.018

9. O'Sullivan P, Smith A, Beales D, Straker L. Understanding Adolescent Low Back Pain From a Multidimensional Perspective: Implications for Management. J Orthop Sports Phys Ther. Oct 2017;47(10):741-751. doi:10.2519/jospt.2017.7376

10. Watts NB, Manson JE. Osteoporosis and Fracture Risk Evaluation and Management: Shared Decision Making in Clinical Practice. JAMA. Jan 17 2017;317(3):253-254. doi:10.1001/jama.2016.19087

11. Della-Giustina D. Evaluation and treatment of acute back pain in the emergency department. Emerg Med Clin North Am. May 2015;33(2):311-26. doi:10.1016/j.emc.2014.12.005

12. Edlow JA. Managing Nontraumatic Acute Back Pain. Ann Emerg Med. Aug 2015;66(2):148-53. doi:10.1016/j.annemergmed.2014.11.011

13. Babic M, Simpfendorfer CS. Infections of the Spine. Infect Dis Clin North Am. Jun 2017;31(2):279-297. doi:10.1016/j.idc.2017.01.003

14. DePalma MG. Red flags of low back pain. JAAPA. Aug 2020;33(8):8-11. doi:10.1097/01.JAA.0000684112.91641.4c

15. Tsuzuki S, Park SH, Eber MR, Peters CM, Shiozawa Y. Skeletal complications in cancer patients with bone metastases. Int J Urol. Oct 2016;23(10):825-832. doi:10.1111/iju.13170

16. McKinley WO, Seel RT, Hardman JT. Nontraumatic spinal cord injury: incidence, epidemiology, and functional outcome. Arch Phys Med Rehabil. Jun 1999;80(6):619-23. doi:10.1016/s0003-9993(99)90162-4

17. Ma B, Wu H, Jia LS, Yuan W, Shi GD, Shi JG. Cauda equina syndrome: a review of clinical progress. Chin Med J (Engl). May 20 2009;122(10):1214-22.

18. Korse NS, Pijpers JA, van Zwet E, Elzevier HW, Vleggeert-Lankamp CLA. Cauda Equina Syndrome: presentation, outcome, and predictors with focus on micturition, defecation, and sexual dysfunction. Eur Spine J. Mar 2017;26(3):894-904. doi:10.1007/s00586-017-4943-8

19. van Tulder M, Becker A, Bekkering T, et al. Chapter 3. European guidelines for the management of acute nonspecific low back pain in primary care. Eur Spine J. Mar 2006;15 Suppl 2(Suppl 2):S169-91. doi:10.1007/s00586-006-1071-2

20. Fairbank J, Hashimoto R, Dailey A, Patel AA, Dettori JR. Does patient history and physical examination predict MRI proven cauda equina syndrome? Evid Based Spine Care J. Nov 2011;2(4):27-33. doi:10.1055/s-0031-1274754

21. Heyes G, Jones M, Verzin E, McLorinan G, Darwish N, Eames N. Influence of timing of surgery on Cauda equina syndrome: Outcomes at a national spinal centre. J Orthop. Mar 2018;15(1):210-215. doi:10.1016/j.jor.2018.01.020

22. Nater A, Fehlings MG. The timing of decompressive spinal surgery in cauda equina syndrome. World Neurosurg. Jan 2015;83(1):19-22. doi:10.1016/j.wneu.2014.03.017

23. Ahn UM, Ahn NU, Buchowski JM, Garrett ES, Sieber AN, Kostuik JP. Cauda equina syndrome secondary to lumbar disc herniation: a meta-analysis of surgical outcomes. Spine (Phila Pa 1976). Jun 15 2000;25(12):1515-22. doi:10.1097/00007632-200006150-00010

Dr Ling Ji Min

Campus Site Chief (NNI), SingHealth Duke-NUS Spine Centre; Head & Senior Consultant, Department of Neurosurgery, National Neuroscience Institute; Head & Senior Consultant, NNI@CGH; Senior Consultant, CGH-NNI Integrated Spine Centre, Changi General Hospital; Neurosurgery Service, Sengkang General Hospital

Dr Ling Ji Min is the Head and Senior Consultant at the Department of Neurosurgery, National Neuroscience Institute (NNI) and a spine surgeon. He is also the Head of Neurosurgical Service in CGH, a core clinician in the CGH-NNI integrated Spine Centre, and the Site Chief at NNI for the SingHealth Duke-NUS Spine Centre. 

GPs who would like more information about this procedure, please contact Dr Ling at [email protected].

GPs can call the SingHealth Duke-NUS Spine Centre for appointments at the following hotlines or click here to visit the website:
Singapore General Hospital: 6326 6060
Changi General Hospital: 6788 3003
Sengkang General Hospital: 6930 6000
KK Women's and Children's Hospital: 6692 2984
National Neuroscience Institute: 6330 6363