Objective: Abnormalities of the plantar aponeurosis are commonly encountered in patients with subcalcaneal heel pain. Understanding normal anatomy is required to accurately diagnose some disorders of the foot. The purpose of our study was to describe the normal anatomy of the plantar aponeurosis, using ultrasonography and MRI with close anatomic correlation in cadavers.
Materials and methods: After MRI and ultrasonography of 10 cadaveric foot specimens, the thickness of the central and lateral portions of the plantar aponeurosis displayed by imaging studies was measured by three radiologists. One specimen was sectioned in the transverse plane, one in the coronal plane, one in the sagittal plane, and two in a sagittal oblique plane. Normal anatomy was identified and similar measurements of the plantar aponeurosis were also made. An average value was determined and a statistical analysis was accomplished.
Results: The calcaneal insertions of the plantar aponeurosis were better visualized than its distal portions with both MRI and ultrasonography. The measurements of the plantar aponeurosis made by three different radiologists were different, but without statistical significance. The average measurements for the central and lateral portions of the plantar aponeurosis with both imaging methods were different from each other because of differences in the morphology of these structures. The values obtained with ultrasonography and MRI, were also different from each other for both the central and lateral portions of the plantar aponeurosis, but with no statistical significance.
Conclusions: We have described the detailed anatomy of the plantar aponeurosis with emphasis on the more distal structures that can be visualized with MRI. There was no statistically significant difference between the accuracy of ultrasonography and MRI regarding the measurements of the thickness of the central and lateral portions of the plantar aponeurosis. Knowledge of the normal anatomy of these structures enables the radiologist to identify early alterations, providing timely diagnosis and treatment.