Archives of Academic Emergency Medicine. 2019; 7 (1): e57

LE T T E R TO ED I TO R

Screening of Trauma Patients in Need of Knee Radiogra-
phy by Triage Nurses and Using Ottawa Knee Rule; a Letter
to Editor
Samad Shams Vahdati1, Alireza Ala1, Zhila Samani2, Sasan Ghazanfar Ahari3, Mohammad
Mirza-Aghazadeh-Attari4,5∗

1. Emergency Medicine Research Team, Tabriz University of Medical Sciences, Tabriz, Iran.

2. Emergency Medicine Department, Tabriz University of Medical Sciences, Tabriz, Iran.

3. Student Research committee, Tabriz University of Medical Sciences, Tabriz, Iran.

4. Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran.

5. Medical Radiation Sciences Research Group, Department of Radiology, Imam Reza Hospital, Tabriz University of Medical Sciences, Tabriz,
Iran.

Received: August 2019; Accepted: September 2019; Published online: 6 October 2019

Cite this article as: Shams Vahdati S, Ala A, Samani Zh, Ghazanfar Ahari S, Mirza-Aghazadeh-Attari M. Screening of Trauma Patients in Need

of Knee Radiography by Triage Nurses and Using Ottawa Knee Rule; a Letter to Editor. Arch Acad Emerg Med. 2019; 7(1): e57.

In some clinical guidelines, emergency triage nurses request

radiographies according to the clinical decision-making pri-

orities. While some studies have suggested that nurses are

not as accurate as doctors in assessing major complications

of trauma to the knee, it is thought that they are as capable in

detecting minor traumas and inconsequential episodes (1).

Many studies have shown that the cost of treatment and the

waiting period for patients in the emergency department de-

crease without missing fractures when traumas are initially

assessed by a certified nurse. Routinely, a clinical criteria

termed Ottawa Knee Rule is utilized to determine if a pa-

tient is in need of a knee radiography or not (2, 3). Accord-

ing to this guideline, if a patient with suspected knee trauma

meets any of the following criteria, he or she should undergo

imaging modalities: Age above 55 years, tenderness at head

of fibula, isolated tenderness of patella, inability to flex the

knee more than 90◦, and inability to bear weight (4).
Investigating the ability of emergency nursing staff in triage

of patients in need of knee radiography, the authors of this

article selected 238 trauma patients who were admitted to

a tertiary referral trauma center from March 2018 to Octo-

ber 2018, using a random number generator. Triage nurses

evaluated the patients using Ottawa knee rule and recorded

their triage level. Then, all selected cases were assessed by an

∗Corresponding Author: Mohammad Mirza-Aghazadeh-Attari; Medical Radi-
ation Sciences Research Group, Department of Radiology, Imam Reza Hospi-
tal, Tabriz, Iran. Email: m.aghazadeh75@yahoo.com, Tel: 0413-3338397

emergency physician and the level of triage regarding knee

trauma was recorded, again. Finally, the patient’s knee radio-

graphs were taken, and the findings of nurses and physicians

were compared.

A five-hour course was conducted to train the theory and

practice of Ottawa knee rule to triage nurses. They were pro-

vided with a pocket flowchart that helped them be alert dur-

ing triage. The knee radiographs were obtained by a sin-

gle machine and interpreted by Radiology residents (years

2-4). Patients with decreased level of consciousness (Glas-

gow coma scale below 13) or multiple trauma, < 8 years old,

with unstable vital signs, and not willing to participate in the

study, were excluded. The Data were analyzed using SPSS

software version 15.00.

Finally, 18 patients were excluded due to lack of consent for

taking part in the study or being discharged against medical

advice, and 220 patients with the mean age of 43.94 ± 20.44
(8 – 95) years were triaged (74.5 % male). The most common

trauma mechanism was pedestrian accident with 21.8%, fol-

lowed by motorcycle accident 18.2%. Table 1 depicts the re-

sults of radiographies obtained from the patients. The results

of triage levels by emergency physicians and triage nurses are

presented in table 2. The records of the two groups were sig-

nificantly different regarding tenderness at the fibular head

and inability to bear weight (p <0.05).

It should be noted that, despite the 100% sensitivity of the

rule in identifying the patients in need of knee radiogra-

phy (both by physicians and emergency nurses), sensitivity

of the test was very low (21.4% by physicians and 8.9% by

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S. Shams Vahdati et al. 2

Table 1: Frequency of different radiographic findings

Radiographic finding Number (%)
Femoral shaft fracture 52 (23.6)
Fibula fracture 44 (20.0)
Tibia fracture 24 (10.9)
Tibia & fibula fracture 12 (5.5)
Pelvic fracture 12 (5.5)
Intertrochanteric fracture 4 (1.8)
Femoral fracture with pelvic fracture 4 (1.8)
Femoral fracture with tibia fracture 4 (1.8)
Patella fracture 4 (1.8)
Fracture of the leg with humerus fracture 4 (1.8)
No fracture 56 (25.5)

emergency nurses). This means that a considerable num-

bers of cases (20% to 23% of cases) underwent diagnostic

imaging and limb radiation without indication. In conclu-

sion, it seems that further training is needed before use of Ot-

tawa knee rule by emergency triage nurses in routine triage of

trauma patients.

1. Appendix

1.1. Acknowledgements

We would like to thank the emergency medicine research

team for their support, as the study was funded by this group.

This report contains data obtained from a thesis for recev-

ing a speciality degree in emergency medicine residency pro-

gram by Dr. Zhila Samani.

1.2. Author’s contribution

SSV: study conception, data collection, approval of the final

version

AA: data collection, data analysis

ZS: data collection, manuscript preparation, approval of the

final version of the manuscript

SGA: manuscript preparation, data collection, and final

approval

MMAA: Manuscript preparation, Data analysis and approval

of the final version

Authors ORCIDs
Samad Shams Vahdati: 0000-0002-4831-6691

Alireza Ala: 0000-0001-8231-2937

Zhila Samani: 0000-0002-3245-3234

Sasan Ghazanfar Ahari: 0000-0002-9808-4163

Mohammad Mirza-Aghazadeh-Attari: 0000-0001-7927-6912

1.3. Conflict of interest

No potential conflict of interest exists regarding this article.

1.4. Funding and support

Funding was done by the emergency medicine research team

and deputy of research of Tabriz University of Medical Sci-

ences.

References

1. Szucs PA, Richman PB, Mandell M. Triage nurse appli-

cation of the Ottawa knee rule. Academic Emergency

Medicine. 2001;8(2):112-6.

2. Bachmann LM, Haberzeth S, Steurer J, ter Riet G. The

accuracy of the Ottawa knee rule to rule out knee frac-

tures. Database of Abstracts of Reviews of Effects (DARE):

Quality-assessed Reviews [Internet]: Centre for Reviews

and Dissemination (UK); 2004.

3. Beutel BG, Trehan SK, Shalvoy RM, Mello MJ. The Ot-

tawa knee rule: examining use in an academic emergency

department. Western Journal of Emergency Medicine.

2012;13(4):366.

4. Stiell IG, Wells GA, Hoag RH, Sivilotti ML, Cacciotti TF, Ver-

beek PR, et al. Implementation of the Ottawa Knee Rule

for the use of radiography in acute knee injuries. Jama.

1997;278(23):2075-9.

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3 Archives of Academic Emergency Medicine. 2019; 7 (1): e57

Table 2: Comparison of Ottawa knee rule and triage levels by emergency nurses and physicians regarding the screening of patients in need of

knee radiography

Variables Physicians Nurses P
Ottawa knee variables
Age ≥55 68 (30.9) 68 (30.9) NA
Isolated patellar tenderness 104 (47.3) 104 (47.3) NA
Tenderness at the fibular head 76 (41.8) 94 (42.8) 0.048
Unable to flex knee to 90Âř 160 (72.7) 152 (69.1) 0.231
Unable to bear weight 208 (94.5) 216 (98.2) 0.036
Triage level
Level one 8 (3.6) 8 (3.6)
Level two 164 (74.6) 172 (78.2) 0.632
Level three 48 (21.8) 40(18.2)
Screening characteristics
True positive 164 164
True negative 12 5 NA
False positive 44 51
False negative 0 0
Sensitivity 100 (97.1 – 00.0) 100 (97.1 – 100) NA
Specificty 21.4 ( 12.0 – 34.7) 8.9 (3.3 – 20.3) 0.030
PPV 78.8 (72.5 – 84.0) 76.2 (69.9 – 81.6) 0.643
NPV 100 (69.9 – 100) 100 (46.3–100) NA
PLR 3.7 (2.7 – 4.8) 3.2 (2.5–4.1) 0.043
NLR 0.0 0.0 NA
Total accuracy 80.0 (74.1 – 58.1) 77.5 (71.5 – 82.8) 0.640
Data are presented as frequency (%). NA: not applicable. PPV: positive predictive value; NPV: negative predictive value;
PLR: positive likelihood ratio; NLR: negative likelihood ratio.

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	Appendix
	References