×

The RACGP is undergoing scheduled system maintenance: Wednesday, 17 April 2024 from 8:15PM – 10:15 PM AEST. During the maintenance window, some RACGP services will experience disruptions.
We apologise for any inconvenience caused.


Clinical guidance for MRI referral

MRI of the knee

MBS item description

MRI - scan of knee following acute knee trauma, after referral by a medical practitioner (other than a specialist or consultant physician), for a patient 16 to 49 years with:

  • inability to extend the knee suggesting the possibility of acute meniscal tear; or
  • clinical findings suggesting acute anterior cruciate ligament tear (R) (Contrast)

Key information

  • MRI of the knee joint can lead to improved health outcomes by reducing (or eliminating) the need for diagnostic arthroscopy.
  • In the majority of cases, clinical examination is as good as MRI for diagnosis.
  • If a diagnosis is clear on clinical exam, confirmation with MRI is not routinely warranted.
  • There is a role for MRI when the diagnosis is unclear and the level of patient disability/pain is such that surgery is being considered.
  • Not all meniscal and anterior cruciate ligament (ACL) tears require surgery – low-grade injuries respond well to conservative therapies.
Explanation
The recommendation is supported by fair evidence (consistent results from multiple studies, but with some risk of bias).

Recommendation
MRI is indicated in the assessment of ACL injuries, but is not always necessary if the clinical diagnosis is clear

Explanation
The recommendation is supported by fair evidence (consistent results from multiple studies, but with some risk of bias).

Recommendation
MRI is indicated for assessment of meniscal tears, but is not always necessary if a clear clinical diagnosis of meniscal tear has been made

Explanation
The recommendation is supported by fair evidence (consistent results from multiple studies, but with some risk of bias).

Recommendation
Use MRI particularly in situations where there is doubt about diagnosis or patient management

Explanation
The recommendation is supported by expert opinion only, based on level 4 evidence in the text, and the expertise within the multidisciplinary team.

Recommendation
Do not use MRI for the diagnosis of isolated medial collateral ligament injuries, except where there is concern about alternative pathology or if symptoms fail to settle after 6–8 weeks

Grade: None given

Recommendation
Further testing is not immediately needed in patients with knee injury who have negative physical examination findings, although close follow-up is required

Acute knee presentations are diagnosed by history, physical examination and plain X-ray (where indicated for suspected bony injury). Urgent further imaging is rarely indicated. Re-examination after a period of conservative management is recommended and at that time further imaging may be considered if it is likely to alter ongoing management.

ACL injury

History

Patients may report a popping sensation, or a sensation that the knee ‘came apart’, during sudden deceleration, stopping or change of direction (with a fixed foot, or hyperextension or posteroanterior force to the tibia). People engaged in sport at the time typically need to be helped from the field. There may be significant swelling within a few hours of the injury.52

Physical examination

The acute swelling that can accompany injuries may make the initial physical examination difficult. If a fracture is unlikely, a repeat examination in 1–2 weeks is recommended.53

Tests for ACL injury include the Lachman test, the pivot shift test and anterior drawer sign. The Lachman test, when correctly performed, is the most validated test for diagnosing ACL integrity and further imaging (with MRI) is unnecessary.53,54

Meniscal injury

History

Meniscal injuries typically occur during twisting or pivoting, and there may be no or minimal force required to cause a tear in middle-aged and older people. Patients may describe locking and/or catching of the knee, although these are not specific for meniscal injuries. Swelling is usually mild to moderate and takes hours (up to 36) to appear. The swelling may recur during the weeks following the injury.52

Physical examination

There may be an effusion, joint line tenderness and a block to full extension.52 Tests for meniscal injury include the Thessaly test (pain on twisting on the knee while standing with it bent at 5 and 20 degrees of flexion), the Apley test, joint line tenderness and McMurray test. The Thessaly test at 20 degrees of knee flexion can be used safely and effectively as a first-line screening test for the diagnosis of both medial and lateral meniscal tears.55 Combined findings from the history and physical examination are more clinically helpful than any one examination manoeuvre alone, and a thorough examination can be as accurate as MRI.53,56

X-ray

The Ottawa Knee Rules are highly sensitive for identifying knee fractures and should be used to determine which patients with acute knee injury require radiography.51,57 X-rays are not indicated for soft tissue injury assessment of the knee.

Table 2.11

Table 2.11

The Ottawa knee rules

Ultrasound

Ultrasound is not recommended for evaluation of menisci or cruciate ligament injuries.49

MRI

MRI is the imaging of choice for internal knee derangement.51 However, its use should be confined to more doubtful, difficult and complex knee injuries.56

Imaging issues, benefits and risks

Clinical examination, when combined with MRI, provides the most accurate non-invasive source of information currently available for pathological findings in the menisci and the ACL.58<

When comparing MRI and diagnostic arthroscopy for ACL and meniscal tears, MRI is superior and offers the health benefit of avoiding invasive surgery.50 In one study, almost half of patients presenting with an acutely locked knee had their management changed from surgical to conservative based on MRI findings.51

However, careful evaluation by an experienced examiner identifies patients with surgically treatable meniscus and ACL tears with equal (or better) reliability than MRI.50,53,54

The ACL can regain continuity after partial or complete rupture.59 Hence, the relative efficacy of surgical reconstruction and rehabilitation for the short-term and long-term outcomes after ACL rupture is debated. Results of a 2013 randomised controlled trial encourage doctors to consider rehabilitation as a primary treatment option following an acute ACL tear in young adults.60

MRI studies have higher false positive than false negative results.54,58 MRI shows lesions in the knee joint in most (almost 90%) middle-aged and elderly people in whom knee radiographs do not show any features of osteoarthritis, regardless of pain.61

MRI has been shown to have a false positive rate of 65% for identifying medial meniscal tears and 43% for lateral meniscus tears when compared with surgical findings.62

MRI of the knee is often performed in cases where a diagnosis is uncertain, and abnormal findings, such as meniscal tears, could be suspected to be the cause of the symptoms. However, incidental meniscal findings are common on MRI within the general population. For example in one study, 19% of women aged 50–59 years and 56% of men aged 70–90 years had asymptomatic meniscal injuries on MRI. Meniscal findings have been shown to increase with age.63 Additionally, no conclusion can be drawn about the natural course of meniscal injury seen at MRI imaging.59 A period of conservative management and re-evaluation is warranted in most cases.

MRI is not effective at detecting all forms of injury of the knee. For example:

  • radial meniscal injuries are difficult to visualise on MRI and account for a large number of tears missed by MRI58
  • MRI is not the most reliable tool for diagnosing recurrent meniscal tears, detecting only 66% compared with 88% with arthrography58
  • the accuracy of MRI decreases in patients with multiple injuries.64

MRI is the method of choice for the non-invasive diagnosis of meniscal and ACL tears. Despite the high performance of this method, some cases are challenging and the criteria described in the literature are not sufficient to reach a diagnosis.65

  1. Chou R, Qaseem A, Owens DK, Shekelle P. Clinical Guidelines Committee of the American College of Physicians. Diagnostic imaging for low back pain: advice for high-value health care from the American College of Physicians. Ann Intern Med 2011;154(3):181–89.
  2. Brito JP, Morris JC, Montori VM. Thyroid cancer: zealous imaging has increased detection and treatment of low risk tumours. BMJ 2013;347:f4706.
  3. Royal Australian and New Zealand College of Radiologists (RANZCR). Radiology written report guideline, (short) version 5 (final). Sydney: RANZCR, 2011.
  4. Lehnert BE, Bree RL. Analysis of appropriateness of outpatient CT and MRI referred from primary care clinics at an academic medical center: how critical is the need for improved decision support? J Am Coll Radiol 2010;7(3):192– 97.
  5. Moynihan R, Doust J, Henry D. Preventing overdiagnosis: how to stop harming the healthy. BMJ 2012;344:e3502.
  6. Royal Australian and New Zealand College of Radiologists (RANZCR). Guidance for GP referrals for MRI studies. Sydney: RANZCR, 2013.
  7. Krumholz A, Wiebe S, Gronseth G, et al. Practice parameter: Evaluating an apparent unprovoked first seizure in adults (an evidence-based review): report of the quality standards subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology 2007;69(21):1996–2007.
  8. Scottish Intercollegiate Guidelines Network (SIGN). Diagnosis and management of epilepsy in adults: a national clinical guideline. Edinburgh: SIGN, 2003.
  9. National Institute for Health and Clinical Excellence (NICE). The epilepsies: diagnosis and management of the epilepsies in adults in primary and secondary care. London: NICE, 2012.
  10. King MA, Newton MR, Jackson GD, et al. Epileptology of the first-seizure presentation: a clinical, electroencephalographic, and magnetic resonance imaging study of 300 consecutive patients. Lancet 1998;352(9133):1007–11.
  11. Wilden JA, Cohen-Gadol AA. Evaluation of first nonfebrile seizures. Am Fam Physician 2012;86(4):334.
  12. Berg AT. Risk of recurrence after a first unprovoked seizure. Epilepsia 2008;49:13–18.
  13. Pohlmann-Eden B, Beghi E, Camfield C, Camfield P. The first seizure and its management in adults and children. BMJ 2006;332(7537):339–42.
  14. Adams SM, Knowles PD. Evaluation of a first seizure. Am Fam Physician 2007;75:1342–47.
  15. Hamilton W, Kernick D. Clinical features of primary brain tumours: a case–control study using electronic primary care records. Br J Gen Pract 2007;57(542):695–9.
  16. Harden CL, Huff JS, Schwartz TH, et al. Reassessment: Neuroimaging in the emergency patient presenting with seizure (an evidence-based review): report of the therapeutics and technology assessment subcommittee of the American Academy of Neurology. Neurology 2007;69(18):1772–80.
  17. Smirniotopoulos JG, Wippold FJ, Cornelius RS, Angtuaco EJ, Broderick DF, Brown DC. Expert panel on neurologic imaging. ACR appropriateness criteria – seizures and epilepsy Reston, VA: American College of Radiology (ACR), 2011. [Online publication].
  18. Morris Z, Whiteley WN, Longstreth WT, et al. Incidental findings on brain magnetic resonance imaging: systematic review and meta-analysis. BMJ 2009;339:b3016.
  19. Vattipally VR, Bronen RA. MR imaging of epilepsy: strategies for successful interpretation. Neuroimaging Clin N Am 2004;14(3):349–72. Scottish Intercollegiate Guidelines Network (SIGN). Diagnosis and management of headache in adults. A national clinical guide. Edinburgh: NHS Scotland, 2008.
  20. Frishberg BM, Rosenberg JH, Matchar DB, et al. Evidence-based guidelines in the primary care setting: neuroimaging in patients with nonacute headache. The American Academy of Neurology, 2000.
  21. National Clinical Guideline Centre. Headaches: diagnosis and management of headaches in young people and adults. Methods, evidence and recommendations. London: NICE, 2012.
  22. Nunes VD, Sawyer L, Neilson J, Sarri G, Cross JH. Diagnosis and management of the epilepsies in adults and children: Summary of updated NICE guidance. BMJ 2012;344:e281.
  23. Steiner TJ, MacGregor EA, Davies PTG. Guidelines for all healthcare professionals in the diagnosis and management of migraine, tension-type, cluster and medication-overuse headache. British Association for the Study of Headache 2007;2007:1–52.
  24. Bogduk N. The anatomical basis for cervicogenic headache. Journal of Manipulative and Physiological Therapeutics 1992;15(1):67–70.
  25. Carville S, Padhi S, Reason T, Underwood M. Diagnosis and management of headaches in young people and adults: summary of NICE guidance. BMJ 2012;345:e5765 doi:10.1136/bmj.e5765.
  26. Davies MB. How do I diagnose headache? J R Coll Physicians Edinb 2006;36(4):336.
  27. Zagami AS, Goddard SL. Recurrent headaches with visual disturbance. Med J Aust 2012;196(3):178–83.
  28. North American Spine Society (NASS). Diagnosis and treatment of cervical radiculopathy from degenerative disorders. Burr Ridge, Ill: NASS, 2010.
  29. National Institute for Health and Clinical Excellence (NICE). Clinical knowledge summaries: neck pain – cervical radiculopathy. Revised January 2009
  30. Nordin M, Carragee EJ, Hogg-Johnson S, et al. Assessment of neck pain and its associated disorders. Eur Spine J 2008;17(1):101–22.
  31. Kuijper B, Beelen A, van der Kallen BF, et al. Interobserver agreement on MRI evaluation of patients with cervical radiculopathy. Clin Radiol 2011;66(1):25–29.
  32. Guzman J, Haldeman S, Carroll LJ, et al. Clinical practice implications of the bone and joint decade 2000-2010 task force on neck pain and its associated disorders: from concepts and findings to recommendations. J Manipulative Physiol Ther 2009;32(2 Suppl):S227–S43.
  33. Reneman L, de Win MM, Booij J, et al. Incidental head and neck findings on MRI in young healthy volunteers: prevalence and clinical implications. Am J Neuroradiol 2012;33(10):1971–74.
  34. Boden SD, Davis DO, Dina TS, Patronas NJ, Wiesel SW. Abnormal magnetic-resonance scans of the lumbar spine in asymptomatic subjects. A prospective investigation. J Bone Joint Surg Am 1990;72(3):403–8.
  35. Medical PA Criteria Proposal. MRI of cervical spine. ACS Heritage, 2005.
  36. Como JJ, Diaz JJ, Dunham CM, et al. Practice management guidelines for identification of cervical spine injuries following trauma: update from the Eastern Association for the Surgery of Trauma Practice Management Guidelines Committee. J Trauma 2009;67(3):651–59.
  37. Bussières AE, Taylor JA, Peterson C. Diagnostic imaging practice guidelines for musculoskeletal complaints in adults – an evidence-based approach. Part 3: Spinal disorders. J Manipulative Physiol Ther 2008;31(1):33–88.
  38. Daffner RH, Weissman BN, Angtuaco EJ, et al. ACR appropriateness criteria® – suspected spine trauma Reston, VA: American College of Radiology, 2012. [Online publication].
  39. Blackmore CC. Evidence-based imaging evaluation of the cervical spine in trauma. Neuroimaging Clinics of North America 2003;13(2):283–91.
  40. National Institute for Health and Care Excellence (NICE). Clinical knowledge summaries: neck pain – whiplash injury
  41. National Institute for Health and Care Excellence (NICE). Clinical knowledge summaries: neck pain – non-specific
  42. Greenbaum J, Walters N, Levy PD. An evidence-based approach to radiographic assessment of cervical spine injuries in the emergency department. J Emerg Med 2009;36(1):64–71.
  43. Blackham J, Benger J. Clearing the cervical spine in the unconscious trauma patient. Trauma 2011;13(1):65–79.
  44. Kongsted A, Sorensen JS, Andersen H, Keseler B, Jensen TS, Bendix T. Are early MRI findings correlated with long-lasting symptoms following whiplash injury? A prospective trial with 1-year follow-up. Eur Spine J 2008;17(8):996–1005.
  45. Horn EM, Lekovic GP, Feiz-Erfan I, Sonntag VK, Theodore N. Cervical magnetic resonance imaging abnormalities not predictive of cervical spine instability in traumatically injured patients: invited submission from the joint section meeting on disorders of the spine and peripheral nerves. J Neurosurg Spine 2004;1(1):39–42.
  46. Muchow RD, Resnick DK, Abdel MP, Munoz A, Anderson PA. Magnetic resonance imaging (MRI) in the clearance of the cervical spine in blunt trauma: a meta-analysis. J Trauma Acute Care Surg 2008;64(1):179–89.
  47. Schuster R, Waxman K, Sanchez B, et al. Magnetic resonance imaging is not needed to clear cervical spines in blunt trauma patients with normal computed tomographic results and no motor deficits. Arch Surg 2005;140(8):762.
  48. New Zealand Guidelines Group. MRI guidelines for the diagnosis of soft tissue knee injuries: internal derangements updated by ACC. Auckland: Accident Compensation Corporation; 2010.
  49. Ryzewicz M, Peterson B, Siparsky PN, Bartz RL. The diagnosis of meniscus tears: the role of MRI and clinical examination. Clin Orthop Relat Res 2007;455:123–33.
  50. Tuite MJ, Daffner RH, Weissman BN, et al. ACR appropriateness criteria® – acute trauma to the knee. J Am Coll Radiol 2012;9(2):96–103.
  51. National Institute for Health and Care Excellence (NICE). Clinical knowledge summaries: knee pain – assessment
  52. Grover M. Evaluating acutely injured patients for internal derangement of the knee. Am Fam Physician 2012;85(3):247–52.
  53. Benjaminse A, Gokeler A, van der Schans CP. Clinical diagnosis of an anterior cruciate ligament rupture: a metaanalysis. J Orthop Sports Phys Ther 2006;36(5):267–88.
  54. Karachalios T, Hantes M, Zibis AH, Zachos V, Karantanas AH, Malizos KN. Diagnostic accuracy of a new clinical test (the Thessaly test) for early detection of meniscal tears. J Bone Joint Surg 2005;87(5):955–62.
  55. Mohan BR, Gosal HS. Reliability of clinical diagnosis in meniscal tears. Int Orthop 2007;31(1):57–60.
  56. Yao K, Haque T. The Ottawa knee rules – a useful clinical decision tool. Aust Fam Physician 2012;41(4):223–24.
  57. Crawford R, Walley G, Bridgman S, Maffulli N. Magnetic resonance imaging versus arthroscopy in the diagnosis of knee pathology, concentrating on meniscal lesions and ACL tears: a systematic review. Br Med Bull 2007;84:5–23.
  58. Boks SS, Vroegindeweij D, Koes BW, Hunink MG, Bierma-Zeinstra SM. Follow-up of posttraumatic ligamentous and meniscal knee lesions detected at MR imaging: systematic review. Radiology 2006;238(3):863–71.
  59. Frobell RB, Roos HP, Roos EM, Roemer FW, Ranstam J, Lohmander LS. Republished research: Treatment for acute anterior cruciate ligament tear: five year outcome of randomised trial. Br J Sports Med 2013;47(6):373.
  60. Guermazi A, Niu J, Hayashi D, et al. Prevalence of abnormalities in knees detected by MRI in adults without knee osteoarthritis: population based observational study (Framingham Osteoarthritis Study). BMJ 2012;345:e5339.
  61. Ben-Galim P, Steinberg EL, Amir H, Ash N, Dekel S, Arbel R. Accuracy of magnetic resonance imaging of the knee and unjustified surgery. Clin Orthop Relat Res 2006;447:100–4.
  62. Englund M, Felson DT, Guermazi A, et al. Risk factors for medial meniscal pathology on knee MRI in older US adults: a multicentre prospective cohort study. Ann Rheum Dis 2011;70:1733–39.
  63. Behairy NH, Dorgham MA, Khaled SA. Accuracy of routine magnetic resonance imaging in meniscal and ligamentous injuries of the knee: comparison with arthroscopy. Int Orthop 2009;33(4):961–67.
  64. Oldrini G, Teixeira PG, Chanson A, et al. MRI appearance of the distal insertion of the anterior cruciate ligament of the knee: an additional criterion for ligament ruptures. Skeletal Radiol 2012;41(9):1111–20.
  65. Grant R. Overview: brain tumour diagnosis and management/Royal College of Physicians guidelines. J Neurol Neurosurg Psychiatry 2004;75(Suppl 2):ii18–23.
  66. Headache Classification Committee of the International Headache Society. The international classification of headache disorders, 3rd edition (beta version). Cephalalgia 2013;33(9):629–808.
This event attracts CPD points and can be self recorded

Did you know you can now log your CPD with a click of a button?

Create Quick log

Advertising