American College of Radiology
ACR Appropriateness Criteria®

Acute Trauma to the Knee

Variant 1: Adult or child >1 year old. Fall or twisting injury, no focal tenderness, no effusion; able to walk. First study.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
MRI knee without IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
X-ray knee Usually not appropriate ☢ <0.1 mSv ☢ <0.03 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
CT knee without IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
CT knee without and with IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
CT knee with IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRA knee without IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRA knee without and with IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRI knee without and with IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
Tc-99m bone scan with SPECT lower extremity Usually not appropriate ☢☢☢ 1-10 mSv 1 n/a 0 0 0 0 0 0 0 0 0
US knee Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
Variant 2: Adult or child >1 year old. Fall or twisting injury, with one or more of the following: focal tenderness, effusion, inability to bear weight. First study.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
X-ray knee Usually appropriate ☢ <0.1 mSv ☢ <0.03 mSv [ped] 9 n/a 0 0 0 0 0 0 0 0 0
MRI knee without IV contrast May be appropriate O 0 mSv O 0 mSv [ped] 5 n/a 0 0 0 0 0 0 0 0 0
CT knee without IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
Tc-99m bone scan with SPECT lower extremity Usually not appropriate ☢☢☢ 1-10 mSv 2 n/a 0 0 0 0 0 0 0 0 0
US knee Usually not appropriate O 0 mSv O 0 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
CT knee without and with IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRA knee without IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
CT knee with IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRA knee without and with IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRI knee without and with IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
Variant 3: Adult or child >1 year old. Fall or twisting injury with either no fracture or a Segond fracture seen on a radiograph, suspect internal derangement. Next study.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
MRI knee without IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 9 n/a 0 0 0 0 0 0 0 0 0
CT knee without IV contrast May be appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 5 n/a 0 0 0 0 0 0 0 0 0
CT knee with IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
CT knee without and with IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRA knee without IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRA knee without and with IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRI knee without and with IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
Tc-99m bone scan with SPECT lower extremity Usually not appropriate ☢☢☢ 1-10 mSv 1 n/a 0 0 0 0 0 0 0 0 0
US knee Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
Variant 4: Adult or child >1 year old. Fall or twisting injury with a tibial plateau fracture on a radiograph, with additional bone or soft-tissue injury suspected. Next study.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
CT knee without IV contrast Usually appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 9 n/a 0 0 0 0 0 0 0 0 0
MRI knee without IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
CT knee with IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
CT knee without and with IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRA knee without IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRA knee without and with IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRI knee without and with IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
Tc-99m bone scan with SPECT lower extremity Usually not appropriate ☢☢☢ 1-10 mSv 1 n/a 0 0 0 0 0 0 0 0 0
US knee Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
Variant 5: Adult or child >1 year old. Injury to knee, mechanism unknown. Focal patellar tenderness, effusion, able to walk.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
X-ray knee Usually appropriate ☢ <0.1 mSv ☢ <0.03 mSv [ped] 9 n/a 0 0 0 0 0 0 0 0 0
MRI knee without IV contrast May be appropriate O 0 mSv O 0 mSv [ped] 5 n/a 0 0 0 0 0 0 0 0 0
CT knee without IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
Tc-99m bone scan with SPECT lower extremity Usually not appropriate ☢☢☢ 1-10 mSv 2 n/a 0 0 0 0 0 0 0 0 0
US knee Usually not appropriate O 0 mSv O 0 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
CT knee without and with IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRA knee without IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRA knee without and with IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
CT knee with IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRI knee without and with IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
Variant 6: Adult or child >1 year old. Significant trauma to the knee from motor vehicle accident, suspect knee dislocation.
Procedure Appropriateness Category SOE Adult RRL Peds RRL Rating Median Final Tabulations
1 2 3 4 5 6 7 8 9
MRI knee without IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 9 n/a 0 0 0 0 0 0 0 0 0
X-ray knee Usually appropriate ☢ <0.1 mSv ☢ <0.03 mSv [ped] 9 n/a 0 0 0 0 0 0 0 0 0
CTA lower extremity with IV contrast Usually appropriate ☢☢☢ 1-10 mSv ☢☢☢☢ 3-10 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
Arteriography lower extremity Usually appropriate ☢☢ 0.1-1mSv ☢☢☢ 0.3-3 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
MRA knee without and with IV contrast Usually appropriate O 0 mSv O 0 mSv [ped] 7 n/a 0 0 0 0 0 0 0 0 0
MRA knee without IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 3 n/a 0 0 0 0 0 0 0 0 0
CT knee without IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
Tc-99m bone scan with SPECT lower extremity Usually not appropriate ☢☢☢ 1-10 mSv 2 n/a 0 0 0 0 0 0 0 0 0
US knee Usually not appropriate O 0 mSv O 0 mSv [ped] 2 n/a 0 0 0 0 0 0 0 0 0
CT knee without and with IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
CT knee with IV contrast Usually not appropriate ☢ <0.1 mSv ☢☢ 0.03-0.3 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
MRI knee without and with IV contrast Usually not appropriate O 0 mSv O 0 mSv [ped] 1 n/a 0 0 0 0 0 0 0 0 0
Please refer to the supporting documentation for a more complete discussion of the concepts and their definitions below.
Final Tabulations:
A histogram of the number of panel members who rated the recommendation as noted in the column heading (ie, 1, 2, 3, …etc.)
Disagree:
The variation of the individual ratings from the median rating indicates panel disagreement on the final recommendation.
References:
Lists the references associated with the recommendation
SQ:
Study Quality (1, 2, 3, 4, Good M or Inadequate M) of the references listed.
RRL:
Information on the Relative Radiation Level (RRL) designations can be found here.