The effect of harvesting the central one-third of the patellar tendon on patellofemoral contact pressure.

Abstract

This study assessed whether removing the central one-third of the patellar tendon, with or without side-to-side repair of the patellar tendon defect, would alter patellofemoral pressure. Patellofemoral pressure was assessed by testing five stable knees from five different cadaveric donors on a specially designed hydraulic knee machine. Patellofemoral joint pressures were measured by placing pressure-sensitive film into the patellofemoral articulation. The joint was loaded in a static fashion, with quadriceps forces consistent with walking (647 N) and stair climbing (1923 N), at 30 degrees, 60 degrees, and 90 degrees of knee flexion. Using the same knees, the central one-third of the patellar tendon was then sectioned, and patellofemoral joint pressure measurements were repeated at identical knee flexion angles and quadriceps-forces. Side-to-side repair of the patellar tendon defect was performed and patellofemoral joint pressure measurements were repeated. There were no statistically significant differences between the control and sectioned values or between the control and repaired defect values. These results suggest that harvesting the central one-third of the patellar tendon--with or without side-to-side repair of the patellar tendon defect--does not alter patellofemoral pressures.