chapter 4:imaging the patellofemoral joint
Evaluation of the patellofemoral joint with contrast material is rarely necessary if MRI is available. A small amount of contrast material may be injected, however, and radiographs are taken to evaluate congruence (Fig. 4.26). Tomographic imaging is most desirable. Imai et al (32) found arthrography helpful in evaluating the space between the medial facet and the trochlea, and graded patellofemoral alignment based on reduction of this space with increasing knee flexion.
Ficat et al (39) found single‑contrast arthrography very helpful in the evaluation of patients with patellofemoral pain, and Horns (40) noted an accuracy of 90% in localizing chondromalacia of the patella using arthrography.
Today, however, there are very few reasons to perform patellofemoral joint arthrography. When MRI is not available or contraindicated, and nonoperative evaluation of patellar or trochlear articular cartilage is indicated, patellofemoral joint arthrography may be an alternative. Computerized tomography with contrast may be particularly helpful in difficult cases.
Inside Chapter 4: