Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article


Master of Engineering Science


Mechanical and Materials Engineering


Willing, Ryan


Previous studies have shown that surgical treatments of PCL injuries are not successful in all cases and there is room for improvement. The effectiveness of an isolated PCL reconstruction, in the setting of what actually is a multi-ligament injury, may be inadequate, and therefore the biomechanical contribution of other ligaments in a PCL-deficient knee need to be better understood.

A new apparatus was used to analyze the effect of medial ligaments transection on the kinematics of the PCL-deficient knee during simulated clinical tests and activities of daily living. We observed that the anterior translation of the medial side of the joint increased after transection of the POL; however, this increase was small. Transection of neither the POL nor dMCL affected the posterior translation of the medial aspect of the joint; however, both contributed to resisting loads crossing the joint, which increase after the PCL transection.

Summary for Lay Audience

The posterior cruciate ligament (PCL) is one of the main ligaments in the knee joint which helps stabilize against the shearing motion. Injury to the PCL is common in knee injuries and it usually happens in sports or car accidents. There are several surgical techniques to treat PCL injury and regain pre-injury joint motion; however; studies show that these techniques have a high failure rate and need to be improved.

Since PCL injuries are combined with injuries to other structures of the knee; understanding the role of those structures in stabilizing of the PCL-deficient knee can be the key to PCL reconstruction improvement. Over the past few years, investigations on the effect that structures on the lateral side of the joint (the outward-facing side of the knee) have on the kinematics of the PCL-deficient knee have resulted in the reconstruction of lateral structures as an additional step in the PCL reconstruction. On the contrary, there is not enough data on the role of structures on the medial side of the knee (inward-facing side of the knee) when the PCL is injured.

In this study, a new joint motion simulator was used to analyze effects that ligaments on the medial side of the knee have on the kinematics of the knee. It was found that the PCL transection resulted in abnormal joint motion. During activities of daily living such as stair ascent and descent, PCL transection resulted in abnormal joint motion.

Medial structures of the knee had an effect on the kinematics of the joint when a torque was applied on the shinbone. Even though transection of medial ligaments did not affect the kinematics during other loading scenarios such as backward load or internal moment, our study discovered that they had a relatively large force contribution to resisting those motions. Thus, damage to these structures can lead to abnormal loading patterns on a reconstructed PCL and cause failure.