Rupture of the anterior cruciate ligament leads to changes in normal knee pressure
patterns. Reports on in-situ repair of the ligament under preloading by using synthetic
augmentation devices have shown a high incidence of knee effusion and stiffness. However,
the reason for this adverse outcome was not explored completely. We hypothesise that
preloading is the main factor affecting outcome on in-situ anterior cruciate ligament
reconstruction. A pressure gauge was simultaneously applied into the medial and lateral
knee joint compartments of six cadaveric knees. The knees were mounted imitating the
intraoperative position. Three series of measurements were obtained. Joint pressures
were registered during a flexion-extension cycle to be used as control (I). The anterior
cruciate ligament was then resected and the measurements were repeated (II). A third
measurement was obtained after the repair of the ligament with an unloaded augmentation
device (III). The data on the reconstructed ligament under no preloading specimens
were similar to the data on the intact specimens. As more preloading was applied for
the reconstruction the more was the difference on pressure patterns when compared
to the intact specimens. Preloading deteriorates the capacity to restore normal joint
pressure patterns. By using a pressure gauge during in-situ reconstruction of the
anterior cruciate ligament, normal pressure patterns can be restored in a reliable
and consistent fashion.
anterior cruciate ligament - acute rupture - restoration of original pressure relation
- on-line data acquisition - effusion rate
