Characterizing posterior calcaneal spur fractures in insertional Achilles tendinopathy: A case control study

Figure 1 Spur fracture in insertional Achilles tendinopathy. A: Sagittal computed tomography (CT) image showing a spur fracture (asterisk). Spur length was calculated by subtracting the fracture gap (asterisk) from the total distance between the base and the tip of the spur (arrow); B: Three-dimensional lateral CT image showing spur morphology (arrowhead); C: Three-dimensional posteroanterior CT image showing spur morphology (arrowhead).

Figure 2 Spur without fracture in insertional Achilles tendinopathy. A: Sagittal computed tomography (CT) image showing a spur without fracture. In these cases, the longest spur length observed on the sagittal plane was recorded (arrow); B: Three-dimensional lateral CT image showing spur morphology (arrowhead); C: Three-dimensional posteroanterior CT image showing spur morphology (arrowhead).

Figure 3 Spur with indeterminate fracture status. A: Sagittal computed tomography (CT) image in which the presence of a fracture was difficult to determine (arrowhead). Such cases were classified as not fractured; B: Three-dimensional lateral CT image showing spur morphology (arrowhead); C: Three-dimensional posteroanterior CT image showing spur morphology (arrowhead).

Figure 4  Histogram of patients with and without spur fractures.

Figure 5 Receiver operating characteristic curve showing the optimal cutoff value of spur length between the fracture and nonfracture groups. AUC: Area under the curve.