An experimental study of the redistribution of patellofemoral pressures by the anterior displacement of the anterior tuberosity of the tibia.

Using a series of miniature piezoelectric transducers constructed by the authors, a study was made of the effect of anterior displacement of the tuberosity of the tibia on the distribution of pressures in the patellofemoral joint. Proportionally, the most efficient displacements are those set at 1 cm; after this, and as advancement of the tuberosity is increased, the overall pressure continues to decrease progressively (although more slowly) because there are zones that, according to their situation, receive increased instead of decreased pressures. Consequently, values even higher than those of the original situation are reached. This is the case of the proximal part of the patella, particularly on its lateral facet. This situation can affect the results in cases where the lesion is preferentially located on the proximal part. In these cases it may be enough to advance 1 cm with which overall decompressions close to 50% of the pressure that initially affected the patellofemoral joint are obtained. In very evolved cases or when the lesions are located centrally or distally, it may be worthwhile to advance maximally in spite of the possible complications, seeking the greatest decompression effect that intense advancements can achieve.