For Canadian Healthcare Professionals
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Before diving into image scoring practice, walk through a patient case with this step-by-step tutorial. Learn which visual indicators to focus on, and how to calculate wrist, knee, and total RSS scores for your patients.
Only one wrist and one knee are used to calculate the overall RSS for a patient, so you will need to identify which wrist and which knee exhibit the most severe indications of XLH before assigning scores. While there are multiple ways to arrive at the same total RSS when scoring a wrist, knee, or patient, it is imperative that individual bone scores and multipliers are correctly selected. Correct selections will be highlighted in green when you hit the Check Answer button.
This tutorial requires audio. Please make sure your audio is enabled before proceeding.
Let's start with scoring the wrist.
Select the wrist with the most severe signs of XLH.
In this case, the left wrist shows more severe signs of XLH. There is a greater degree of lucency in both the radius and ulna of the left wrist.
In this case, the left wrist shows more severe signs of XLH. There is a greater degree of lucency in both the radius and ulna of the left wrist.
Now, we’ll score the radius and the ulna separately and add their scores together to calculate the total wrist score.
Now, we’ll score the radius and the ulna separately and add their scores together to calculate the total wrist score.
Radius + Ulna = Total Wrist Score
The radius shows lucency of the metaphyseal margin, but it has a smooth margin with no fraying or irregularity, so it’s scored as a 0.5. The ulna has a widened growth plate and irregularity of the metaphyseal margin, but does not show signs of concave cupping, so it’s scored as a 1. Adding these two scores together, we get a total score of 1.5 for the wrist.
Now that we have a total score for the wrist, let’s move on to the knee.
Choose the knee that exhibits the most severe signs of XLH.
In this case, both knees have a similar level of XLH severity. For the purposes of the tutorial, we’ll score the right knee.
In this case, both knees have a similar level of XLH severity. For the purposes of the tutorial, we’ll score the right knee.
First, score the femur and select the appropriate multiplier. Then, do the same for the tibia and add the scores for both bones together to get a total knee score.
First, score the femur and select the appropriate multiplier. Then, do the same for the tibia and add the scores for both bones together to get a total knee score.
(Femur x Multiplier) + (Tibia x Multiplier) = Total Knee Score
Both condyles of the femur are partially lucent, meaning that the score of 1 applies to both condyles. Therefore, our multiplier for the femur is 1. On the other hand, only one condyle of the tibia is partially lucent, so our score of 1 will be multiplied by 0.5. This will give us a tibia score of 0.5. By adding the scores for the femur and tibia together, we have a total knee score of 1.5.
The overall patient RSS is calculated by adding the total score for the wrist to the total score for the knee. In this example, a wrist score of 1.5 and a knee score of 1.5 are added to give us an overall patient RSS of 3.0.
Great job! You’ve completed the RSS Trainer tutorial! Continue to practice