OCLC: 75956645
PROQUEST: 304969364
Recent injury statistics derived from the National Automotive Sampling System have shown that knee injuries represent about 10% of all injuries suffered during car crashes, of which 4.5% are posterior cruciate ligament (PCL) ruptures. Although not life threatening, there are several long term functional deficits associated with such injuries. The aims of the current study were to perform dynamic posterior drawer tests on cadaveric specimens to identify the PCL injury tolerance and to study the effects of PCL reconstruction procedures on knee kinematics (displacements and rotations) and articular contact pressures.
In the first part of the study, a total of 14 knees (eight intact specimens, three PCL-only knees and three PCL-only knees with tibial protection) were tested using a high-speed materials testing machine. The average displacement at failure for all PCL related injuries was 17.2±2.8 mm (n=6). This value is higher than the Injury Assessment Reference Value of 15 mm proposed by Mertz (1984), which is used in various regulations. This study also suggests that the existence of the soft tissues other than the PCL affect the injury outcome and that the intact knee would suffer predominantly tibial metaphyseal fractures possibly due to bending.
In the second part of the study, a total of 10 cadaveric knee specimens were tested under four different groups namely: normal, PCL deficient, and PCL reconstructed using single and double bundle procedures. The tests were performed on a force couple testing system (FCTS) with simulated quadriceps (400 N) and hamstrings (200 N) muscle loads along with a posterior shear load (150 N). Digital pressure sensors were placed in the medial and lateral tibial compartments to study the articular contact pressure distribution. Similar trends were observed between the normal knee kinematics obtained from this study and results obtained from previous studies, especially human volunteer data. No significant differences in the knee kinematics and contact pressure distributions were observed between the four groups. This study suggests that the posterolateral structures of the knee and the action of combined muscle loads may be important factors in stabilizing the knee joint with PCL deficiency