Figure 3

Boxplot of preoperative HKA angle (a) and preoperative pain (b) for each Ahlbäck grade of knee OA (Median with quartiles). Any data observation which lays more than 1.5 IQR lower than the first quartile or higher than the third quartile is considered an outlier and marked as a dot. The horizontal line or "whisker" indicate where the smallest/highest value that is not an outlier by connecting it to the box).