Biomechanical effects of different surgical procedures on the extensor mechanism of the patellofemoral joint.

Loadbearing stresses in the patellofemoral joint were studied at different degrees of flexion before and after various surgical techniques recommended to treat knee disorders. Surgical procedures intended to reduce the intensity of stress were analyzed experimentally. The study was done using different experimental methods on whole knee specimens from fresh human cadavers that were not treated with formaldehyde. The results indicate that the most predictable procedure for increasing surface area and decreasing patellar stress is a combined procedure of anterior displacement of the anterior tibial tubercle by 1 cm while displacing it 0.5 to 1 cm medially.