The Ottawa ankle and knee rules are validated clinical decision tools that guide clinicians in targeting radiology to those patients who are likely to have an ankle or knee fracture, thus minimizing x-ray exposure of patients and reducing costs

Fulde, G

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The University of Notre Dame Australia ResearchOnline@ND Medical Papers and Journal Articles School of Medicine 2015 Acute ankle and knee injuries: To x-ray or not? G Fulde The University of Notre Dame Australia, Gordian.Fulde@nd.edu.au Follow this and additional works at: https://researchonline.nd.edu.au/med_article  Part of the Medicine and Health Sciences Commons  This article was originally published as: Fulde, G. (2015). Acute ankle and knee injuries: To x-ray or not?. Medicine Today, 16 (11), 48-52. Original article available here: https://medicinetoday.com.au/mt/november-2015 This article is posted on ResearchOnline@ND at https://researchonline.nd.edu.au/med_article/836. For more information, please contact researchonline@nd.edu.au. This article originally published: - Fulde, G., (2015) Acute ankle and knee injuries: To x-ray or not? Medicine Today, 16(11): 48- 52. Permission granted by Medicine Today for use on ResearchOnline@ND. © Medicine Today 2015 (http://www.medicinetoday.com.au). Acute injuries to the ankle and knee joints are common and patients usually present to an emergency department or a general practice. Differ-entiating soft tissue injuries from fractures is important because the management of these two groups differ. Medical practi-tioners are becoming increasingly aware of the accumulative effects of x-rays and there is a move to minimise x-ray exposure, especially in younger patients. Clinical tools have been developed to help clinicians target x-rays to those patients who are likely to have a fracture and not those that almost certainly do not. Such clinical tools or rules must have a very high sensitivity and  reasonable specificity to be helpful. Acute knee injuries account for over one million emergency room visits in the USA annually.1 Ankle injuries are even more common, and have been shown to be one of the most common presentations to an emergency department.2 These inju-ries are rarely life- or limb-threatening but cause significant pain and disability for the patient. It has been shown that most patients presenting with knee and ankle injuries in the early 1990s under-went radiographic examination, and that more than 92% of this imaging for knees and 85% for ankles did not show a  fracture.2,3  The incidence of fracture in acute knee injury is less than 5%.4  The individual cost of a radiograph is not high but the high frequency at which they are requested results in significant cost and unnecessary irradiation for patients.  Furthermore, it has been suggested that radiography adds little information to a well  performed clinical history and examination.5  This article discusses the Ottawa rules used to guide clinicians in the investiga-tion of acute ankle and knee injuries. What are the Ottawa Rules and do they work?In 1992, a set of criteria was developed that used clinical signs to determine if an x-ray should be performed for an acute ankle injury – the Ottawa ankle rules (Box 1 and Figure 1).6 The criteria have been shown to have a sensitivity of 100% and a specificity of 40.1% for detecting malleolus fractures and result in a 36% reduction in radiography.6 The rules have also been shown to reduce the time patients spend in emergency departments, without reducing patient satisfaction.7 Pain in the midfoot region is covered by the Ottawa foot rules, which are often grouped with the ankle rules, as shown in Box 1. The Ottawa knee rules developed later, in 1995, showed similar success to the ankle rules, with a sensitivity of 98.5 to 100% and a specificity of 49% for detecting fractures (Box 2 and Figure 2).8,9 Furthermore, the Ottawa knee rules were shown to be superior when Acute ankle and knee injuriesTo x-ray or not?GORDIAN FULDE MB BS, FRACS, FRCS(Ed), FRCS/FRCP(A&E)Ed, FACEMThe Ottawa ankle and knee rules are validated clinical decision tools that guide clinicians in targeting radiology to those patients who are likely to have an ankle or knee fracture, thus minimising x-ray exposure of patients and reducing costs. EMERGENCY MEDICINE  PEER REVIEWEDMedicineToday 2015; 16(11): 48-51Professor Gordian Fulde is Director of Emergency Medicine at St Vincent’s Hospital, Sydney; Professor in Emergency Medicine at The University of Notre Dame, Sydney; and Associate Professor in Emergency Medicine at the University of New South Wales, Sydney, NSW. © PHOTO RESEARCHERS/GETTY IMAGES48   MedicineToday   ❙   NOVEMBER 2015, VOLUME 16, NUMBER 11Permission granted by Medicine Today for use on ResearchOnline@ND. © Medicine Today 2015 (www.medicinetoday.com.au)compared with other tools for assessing knee injuries, i.e. the Pittsburgh knee rules, the Weber and colleagues rule and the Fagan and Davies rule.10 Use of the Ottawa knee rules has been shown to lead to a relative reduction in radio-graphy of 37%.11 The Ottawa ankle rules are not used in patients who are younger than 18 years, pregnant or intoxicated, or if they have distracting painful injuries, diminished  s ensation in the legs or gross swelling  preventing palpation of malleolar tenderness.Uptake and utilisation of these rules has been variable.11-13 Case scenariosCase 1. A possible ankle fracture A 45-year-old woman limped into the emergency department one afternoon with the assistance of her husband and clearly in a lot of pain. She explained to the triage nurse that she was carrying out her usual daily activities when she tripped over her dog at home, rolling her ankle. The woman was unable to bear weight on her left leg. On closer physical examination, the left lower limb was neurologically intact with normal pulses, there was gross swelling around the lateral malleolus, marked tenderness over the lateral malleolar zone of the ankle and also tenderness on palpation over the posterior aspect of the lateral ankle, approximately 1 cm superior to the lateral malleolus.According to the Ottawa ankle rules, this woman should have a radiograph  performed. The Ottawa rules have a very high sensitivity but the specificity is fairly low at about 40%, meaning that although the criteria for an x-ray may be met there is still a reasonable chance a fracture may not be found. The patient was informed that a radio graph was indicated but she was convinced it was just a severe sprain and was eager to leave to pick her children up from school. She reluctantly agreed 1. THE OTTAWA ANKLE RULES6In patients with acute ankle injury, an ankle x-ray is necessary if there is: • Pain over the malleoli of the ankle and one or more of  – patient is aged 55 years or older – inability to bear weight both immediately and in emergency department – bone tenderness at the posterior tip of either the lateral or medial malleolus or the posterior 6 cm superior to either malleolus (Figure 1)In patients with acute ankle injury, a foot x-ray is necessary if there is:• Pain in the midfoot and either of  – bone tenderness at the navicular or the base of the fifth metatarsal (Figure 1) – inability to bear weight both immediately and in the emergency departmen2. THE OTTAWA KNEE RULES9In patients with acute knee injury,  a knee x-ray is necessary if any of the  following criteria are met:• Patient is aged 55 years or older• Isolated tenderness of the patella  (Figure 2)• Tenderness at the head of the fibula  (Figure 2)• Inability to flex the knee to 90°• Inability to bear weight both immediately  and in the emergency departmentFigure 1. Ottawa ankle rules – regions of bone tenderness. (Purple indicates malleolar zone; green indicates midfoot zone.) Adapted from Stiell et al., Ann Emerg Med 1992; 21: 384-390.6Figure 2. Ottawa knee rules – regions of bone tenderness. Adapted from Stiell et al., Ann Emerg Med 1995; 26: 405-413.9 © CHRIS WIKOFF, 2015© CHRIS WIKOFF, 2015PatellaHead of  fibulaMedial viewPosterior edge or tip of lateral malleolusBase of fifth metatarsal6 cm6 cmLateral viewPosterior edge  or tip of medial malleolusNavicularMedicineToday   ❙   NOVEMBER 2015, VOLUME 16, NUMBER 11    49Permission granted by Medicine Today for use on ResearchOnline@ND. © Medicine Today 2015 (www.medicinetoday.com.au)to the radiography. The x-ray showed an unstable Weber type B trimalleolar frac-ture of the fibula (Figure 3a; Table 1).14 The patient was admitted to hospital and her ankle was repaired surgically with plates and screws (Figure 3b).  Outpatient physio therapy helped her recovery.Case 2. A possible knee fractureA 22-year-old man, a semiprofessional soccer player, presented at the emergency department with right knee pain 24 hours after twisting his right knee while ‘turn-ing on the ball’. He reported pain and a ‘locking’ sensation in the right knee. On examination, the patient was able to bear weight on the affected leg and there was no deformity or obvious TABLE 1. MANAGEMENT OF ANKLE FRACTURES14 Injury Description ManagementLateral malleolar fractures – Weber ankle fracture classificationType A Fracture below the syndesmosis Avulsion fractures often associated with oblique or vertical medial malleolar fracturesIf stable fracture (undisplaced or minimally displaced), nonoperative:• walking cast ± crutches for 6 weeks • weight bear as tolerated in walking cast, cast can be taken off when not weightbearing • x-ray at 6 weeks – clinical union indicated by no pain at fracture siteIf unstable fracture, surgical repair (open reduction and internal fixation) Type B Fracture begins at the joint level and extends proximally in an oblique direction If accompanied by medial malleolus fracture or with deltoid ligament rupture, the ankle is considered unstableIf stable fracture (undisplaced and mortice intact), nonoperative:• full below knee plaster with crutches • repeat x-ray at 1 to 2 weeks• plaster for 6 weeks total• x-ray at 6 weeks out of plaster – clinical union indicated by no painIf unstable fracture, surgical repair (open reduction and internal fixation)Type C Fractures above the joint line, usually with syndesmotic injuryCan be associated with transverse avulsion medial malleolus fracture or deltoid ligament ruptureSurgical repair (open reduction and internal fixation)Other injuryLigamentous injuryDamage to any of the ligaments supporting the  ankle jointR – RestI – IceC – CompressionE – ElevationFigures 3a and b. Ankle fracture.  a (far left). X-ray at presentation.  b (left). X-ray after surgical repair.EMERGENCY MEDICINE continued 50   MedicineToday   ❙   NOVEMBER 2015, VOLUME 16, NUMBER 11Permission granted by Medicine Today for use on ResearchOnline@ND. © Medicine Today 2015 (www.medicinetoday.com.au)effusion. Both lower limbs were warm and neurovascularly intact. He had a  positive swipe test (a fluid wave bulge just below the medial distal portion or patellar  border on a particular pattern of stroking the leg in the knee area) on his right knee, consistent with a small effusion in the knee joint. There was joint line tenderness on the medial aspect of the knee but no isolated patellar or fibular head tenderness. The patient had a normal range of motion of both knees and the ligaments stabilising his knee joint (the anterior and posterior cruciate ligaments and the medial and lateral collateral ligaments) were intact. McMurray’s ligament test for injury to the meniscus was positive (pain felt by the patient or a click felt by patient or  examiner on particular  palpation of the knee). The combination of injury mechanism and clinical signs suggested medial meniscus tear. The patient was informed of this, and subsequently asked if he could have an x-ray to confirm the diagnosis. It was explained to the patient that, based on the Ottawa knee rules, his chance of having a fracture in the knee was extremely slim, with the rules having a negative predictive value of 1. He agreed that radiography was unnecessary and was then discharged, within an hour of his presentation, with a referral for outpatient orthopaedic management. As an outpa-tient he received advice to treat his knee with RICE (rest, ice, compression and elevation) and use NSAIDs for pain relief (Table 2).15,16 He subsequently received physiotherapy for the injury. In this situation, applying the Ottawa knee rules allowed a much faster discharge of the patient from the emergency depart-ment, without sacrificing patient care or outcome. This approach reduces unnec-essary x-ray  exposure, which is particu-larly important for a young person. Possible new directionNew imaging techniques are being developed to investigate acute injuries without exposing patients to x-rays. A recent study in the USA has shown that, with minimal training, orthopaedic registrars are able to use ultrasound imaging during the primary examina-tion in the emergency department to exclude significant ankle fractures.17 This could decrease the need for radio-graphic imaging, resulting in rapid diagnosis with no exposure to ionising radiation. ConclusionThe Ottawa ankle and knee rules have been proven to be highly sensitive and specific for detecting fractures and have been shown to significantly decrease the need for radiographic imaging of injured joints. If applied correctly, they have the potential to reduce unnecessary x-ray exposure and cost in an acute set-ting, as well as avoiding significant incon-venience to the patient.   MTAcknowledgementThe author acknowledges with thanks the major contribution to this article made by Jennifer Preddy, a research student in the medical faculty of the University of New South Wales, Sydney.ReferencesA list of references is included in the website version (www.medicinetoday.com.au) and the iPad app version of this article.COMPETING INTERESTS: None.TABLE 2. MANAGEMENT OF KNEE INJURIES15,16Injury Description ManagementExtra-articular fractureSupracondylar, in which the fracture does not extend to the knee joint lineUndisplaced: groin to toe plasterDisplaced: surgically with intramedullary nailsPartial articular fracturePartial articular or condylar, in which the fracture extends to the knee joint line but part of the condyles remain attached to the femur shaftUndisplaced: groin to toe plasterDisplaced: surgically with intramedullary nails Complete articular fractureComplete articular or intercondylar, in which the fracture extends to the knee joint line but the condyles are completely separated from the femur shaftUndisplaced: groin to toe plasterDisplaced: surgically with plate and screws Ligamentous injuryTear in the anterior cruciate, posterior cruciate, medial collateral or lateral collateral ligament of the kneeR – RestI – IceC – CompressionE – ElevationSurgical repair if major tear present Meniscal tear Tear in either the medial or lateral meniscus of the kneeR – RestI – IceC – CompressionE – ElevationNSAIDs PhysiotherapySurgical repair if tear present in the vascularised outer third of the meniscusMedicineToday   ❙   NOVEMBER 2015, VOLUME 16, NUMBER 11    51Permission granted by Medicine Today for use on ResearchOnline@ND. © Medicine Today 2015 (www.medicinetoday.com.au)MedicineToday 2015; 16(11): 48-51Acute ankle and knee injuriesTo x-ray or not?GORDIAN FULDE MB BS, FRACS, FRCS(Ed), FRCS/FRCP(A&E)Ed, FACEMReferences1. Kec RM, Richman PB, Szucs PA, Mandell M, Eskin B. Can emergency department triage nurses appropriately utilize the Ottawa knee rules to order radiographs? An implementation trial. Acad Emerg Med 2003; 10: 146-150.2. Stiell IG, McKnight RD, Greenberg GH, et al. Implementation of the Ottawa ankle rules. JAMA 1994; 271: 827-832.3. Stiell IG, Greenberg GH, Wells GA, et al. Prospective validation of a decision rule for the use of radiography in acute knee injuries. JAMA 1996; 275: 611-615.4. Stiell IG, Wells GA, McDowell I, et al. Use of radiography in acute knee injuries: need for clinical decision tools. Acad Emerg Med 1995; 2: 966-973.5. Stiell I, Wells G, Laupacis A, et al. Multicentre trial to introduce the Ottawa ankle rules for use of radiography in acute ankle injuries. BMJ 1995; 311: 594-597.6. Stiell IG, Greenberg GH, McKnight RD, Nair RC, McDowell I, Worthington JR. A study to develop clinical decision rules for the use of radiography in acute ankle injuries. Ann Emerg Med 1992; 21: 384-390.7. Stiell IG, Bennet C. Implementation of clinical decision rules in the emergency department. Acad Emerg Med 2007; 14: 955-959.8. Bachmann LM, Haberzeth S, Steurer J, ter Riet G. The accuracy of the Ottawa knee rule to rule out knee fractures: a systematic review. Ann Intern Med 2004; 140: 121-124.9. Stiell IG, Greenberg GH, Wells GA, et al. Derivation of a decision rule for the use of radiography in acute knee injuries. Ann Emerg Med 1995; 26: 405-413.10. Jackson JL, O’Malley PG, Kroenke K. Evaluation of acute knee pain in primary care. Ann Intern Med 2003; 139: 575-588.11. Beutal BG, Trehan SK, Shalvoy RM, Mello MJ. The Ottawa knee rule: examining use in an academic emergency department. West J Emerg Med 2012; 13: 366-373.12. Graham ID, Stiell IG, Laupacis A, O’Connor AM, Wells GA. Emergency physician’s attitudes toward and use of clinical decision rules for radiography. Acad Emerg Med 1998; 5: 134-140.13. Graham ID, Stiell IG, Laupacis A, et al. Awareness and use of the Ottawa ankle and knee rules in 5 countries: can publication alone be enough to change practice? Ann Emerg Med 2001; 37: 259-266.14. Wheeless III CR. Ankle fracture menu. In: Wheeless III CR, ed-in-chief. Wheeless’ textbook of orthopaedics. Durham, NC: Duke Orthopaedic; 2012.Available online at: http://www.wheelessonline.com/ortho/ankle_fracture_menu (accessed October 2015).15. Rajasekaran S, Kamath V, Dheenadhayalan J. (2012). Distal femoral fractures. In: Sivananthan S, Sherry E, Warnke P, Miller MD (eds). Mercer’s textbook of orthopaedics and trauma. 10th ed. Boca Raton: CRC Press; 2012. Ch 37; p. 358-362.16. Scotney B. Sports knee injuries: assessment and management. Aust Fam Physician 2010; 39: 30-34.17. Hedelin H, Goksor L, Karlsson J, Stjernstrom S. Ultrasound-assisted triage of ankle trauma can decrease the need for radiographic imaging. Am J Emerg Med 2013; 31: 1686-1689.Permission granted by Medicine Today for use on ResearchOnline@ND. © Medicine Today 2015 (www.medicinetoday.com.au)

Acute ankle and knee injuries: To x-ray or not?

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Acute ankle and knee injuries: To x-ray or not?

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