Ottawa ankle rules
Encyclopedia
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
, the Ottawa ankle rules are a set of guidelines for doctor
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...
s to aid them in deciding if a patient with foot or ankle
Ankle
The ankle joint is formed where the foot and the leg meet. The ankle, or talocrural joint, is a synovial hinge joint that connects the distal ends of the tibia and fibula in the lower limb with the proximal end of the talus bone in the foot...
pain should be offered X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
s to diagnose a possible bone fracture
Bone fracture
A bone fracture is a medical condition in which there is a break in the continuity of the bone...
. Before the introduction of the rules most patients with ankle injuries would have been X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
ed. However only about 15% of X-rays were positive for fracture, other patients had sprain
Sprain
A sprain is an injury in a joint, caused by the ligament being stretched beyond its capacity. A muscular tear caused in the same manner is referred to as a strain. In cases where either ligament or muscle tissue is torn, immobilization and surgical repair may be necessary...
s or other injuries. As a result many unnecessary X-rays were taken, which was costly, time consuming and a possible health risk.
The Ottawa ankle rules
X-rays are only required if there is any pain in the malleolar zone and any one of the following:- Bone tenderness along the distalAnatomical terms of locationStandard anatomical terms of location are designations employed in science that deal with the anatomy of animals to avoid ambiguities that might otherwise arise. They are not language-specific, and thus require no translation...
6 cm of the posteriorAnatomical terms of locationStandard anatomical terms of location are designations employed in science that deal with the anatomy of animals to avoid ambiguities that might otherwise arise. They are not language-specific, and thus require no translation...
edge of the tibiaTibiaThe tibia , shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones....
or tip of the medial malleolus, OR - Bone tenderness along the distal 6 cm of the posterior edge of the fibula or tip of the lateral malleolus, OR
- An inability to bear weight both immediately and in the emergency department for four steps.
The Ottawa foot rules are for assessing whether a foot X-ray series is indicated. It states that they are indicated if there is any pain in the midfoot zone and any one of the following:
- Bone tenderness at the base of the fifth metatarsal (for foot injuries), OR
- Bone tenderness at the navicular bone (for foot injuries), OR
- An inability to bear weight both immediately and in the emergency department for four steps.
Certain groups are excluded, in particular pregnant women, and those with diminished ability to follow the test (for example due to head injury
Head injury
Head injury refers to trauma of the head. This may or may not include injury to the brain. However, the terms traumatic brain injury and head injury are often used interchangeably in medical literature....
or intoxication). Several studies strongly support the use of the Ottawa Ankle Rules in children over 6 (98.5% sensitivity) . However, their usefulness in younger children has not yet been thoroughly examined.
Utility of the Ottawa rules
The rules have been found to have a very low rate of false negativeType I and type II errors
In statistical test theory the notion of statistical error is an integral part of hypothesis testing. The test requires an unambiguous statement of a null hypothesis, which usually corresponds to a default "state of nature", for example "this person is healthy", "this accused is not guilty" or...
s. Evidence in systematic review
Systematic review
A systematic review is a literature review focused on a research question that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question. Systematic reviews of high-quality randomized controlled trials are crucial to evidence-based medicine...
s supports the Ottawa ankle rules as an accurate instrument for excluding fractures of the ankle and mid-foot. The instrument has a sensitivity of almost 100% and a modest specificity, and its use should reduce the number of unnecessary radiographs by 30-40%.
Among the studies in the original review their research reported that the test was 100% sensitive and reduced the number of ankle X-rays by about 35%. A second trial with a larger number of patients confirmed these findings. Subsequently, a multi-centre study was done that explored the feasibility of implementing the rules on a wider scale. Unfortunately, teaching the rules to patients does not appear to help reduce presentation to hospital.
Generalization to other joints
The original rules were developed for ankle and foot injuries only, but similar guidelines have been developed for other injuries such as the Ottawa Knee Rule.History
The Ottawa ankle rules were developed by a team of doctors in the Urgent Care department of the Ottawa Hospital in OttawaOttawa
Ottawa is the capital of Canada, the second largest city in the Province of Ontario, and the fourth largest city in the country. The city is located on the south bank of the Ottawa River in the eastern portion of Southern Ontario...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
. Since the rules were formulated in Ottawa they were dubbed the Ottawa ankle rules by their creators a few years after their development, a title that has stuck. In this respect, the naming of the rules is similar to that of the Bristol stool scale
Bristol Stool Scale
The Bristol Stool Scale or Bristol Stool Chart is a medical aid designed to classify the form of human faeces into seven categories. Sometimes referred to in the UK as the "Meyers Scale", it was developed by Dr. Ken Heaton at the University of Bristol and was first published in the Scandinavian...
or the Glasgow Coma Scale
Glasgow Coma Scale
Glasgow Coma Scale or GCS is a neurological scale that aims to give a reliable, objective way of recording the conscious state of a person for initial as well as subsequent assessment...
(GCS), which also take their names from the cities in which they were formulated.
External links
- Ottawa Ankle Rules - Poster - ohri.ca.
- Ottawa Knee Rules - BandolierBandolier (journal)Bandolier is an independent online electronic journal about evidence-based healthcare, written by Oxford University scientists. It was started in 1994 and the National Health Service paid for its distribution to all doctors in the UK until 2002. Publication of the printed version ceased in 2007 and...
an independent journal about evidence-based medicineEvidence-based medicineEvidence-based medicine or evidence-based practice aims to apply the best available evidence gained from the scientific method to clinical decision making. It seeks to assess the strength of evidence of the risks and benefits of treatments and diagnostic tests...
. - Ottawa rules for x-ray of knee, ankle and foot (graphical explanation).